T-CELL MODULATORY CHIMERIC MOLECULES AND METHODS OF USE THEREOF CROSS-REFERENCE [0001] This application claims the benefit of U.S. Provisional Patent Application No.62/925,115, filed October 23, 2019, which application is incorporated herein by reference in its entirety. INTRODUCTION [0002] An adaptive immune response involves the engagement of the T cell receptor (TCR), present on the surface of a T cell, with a small peptide antigen non-covalently presented on the surface of an antigen presenting cell (APC) by a major histocompatibility complex (MHC; also referred to in humans as a human leukocyte antigen (HLA) complex). This engagement represents the immune system’s targeting mechanism and is a requisite molecular interaction for T cell modulation (activation or inhibition) and effector function. Following epitope-specific cell targeting, the targeted T cells are activated through engagement of costimulatory proteins found on the APC with counterpart costimulatory proteins the T cells. Both signals – epitope/TCR binding and engagement of APC costimulatory proteins with T cell costimulatory proteins – are required to drive T cell specificity and activation or inhibition. The TCR is specific for a given epitope; however, the costimulatory protein not epitope specific and instead is generally expressed on all T cells or on large T cell subsets. SUMMARY [0003] The present disclosure provides a chimeric molecule comprising: a) a T-cell modulatory multimeric polypeptide (TMMP); and b) a nucleic acid component, where the nucleic acid component comprises a nucleic acid comprising a nucleotide sequence encoding a chimeric antigen receptor (CAR) comprising an antibody that binds a cancer-associated antigen. The TMMP binds to and activates a target T cell; the nucleic acid component is taken up by the target T cell such that the target T cell expresses the CAR on its surface. The present disclosure provides methods of making the chimeric molecule. The present disclosure provides treatment methods comprising administering the chimeric molecule. BRIEF DESCRIPTION OF THE DRAWINGS [0004] FIG.1A-1B provide schematic depictions of exemplary embodiments of TMMPs. [0005] FIG.2A-2B provide schematic depictions of double disulfide-linked TMMPs. [0006] FIGs.3A-3G provide amino acid sequences (from top to bottom SEQ ID NOs: 376-387) of immunoglobulin Fc polypeptides. [0007] FIG.4 provides a multiple amino acid sequence alignment of beta-2 microglobulin (β2M) precursors (i.e., including the leader sequence) from Homo sapiens (NP_004039.1; SEQ ID NO:388), Pan troglodytes (NP_001009066.1; SEQ ID NO:388), Macaca mulatta (NP_001040602.1; SEQ ID NO:389), Bos taurus (NP_776318.1; SEQ ID NO:390) and Mus musculus (NP_033865.2; SEQ ID NO:391). Amino acids 1-20 are a signal peptide. [0008] FIGs.5A-5C provide amino acid sequences of full-length human HLA heavy chains of alleles A*0101 (SEQ ID NO:392), A*1101 (SEQ ID NO:393), A*2402 (SEQ ID NO:394), and A*3303 (SEQ ID NO:395) (FIG.5A); full-length human HLA heavy chain of allele B*0702 (FIG.5B; SEQ ID NO:396); and a full-length human HLA-C heavy chain (FIG.5C; SEQ ID NO:397). [0009] FIG.6 provides an alignment of eleven mature MHC class I heavy chain amino acid sequences without their leader sequences, transmembrane domains, and intracellular domains. [0010] FIGs.7A-7B provide an alignment of HLA-A heavy chain amino acid sequences (FIG.7A; from top to bottom SEQ ID NOs: 406, 185, 407-413) and a consensus sequence (FIG.7B; SEQ ID NO: 184). [0011] FIGs.8A-8B provide an alignment of HLA-B heavy chain amino acid sequences (FIG.8A; from top to bottom SEQ ID NOs: 195, 414-419) and a consensus sequence (FIG.8B; SEQ ID NO: 194). [0012] FIGs.9A-9B provide an alignment of HLA-C heavy chain amino acid sequences (FIG.9A; from top to bottom SEQ ID NOs: 420-424, 199, 425-427) and a consensus sequence (FIG.9B; SEQ ID NO: 198). [0013] FIG.10 provides a consensus amino acid sequence for each of HLA-E (SEQ ID NO:428), -F (SEQ ID NO:429), and -G (SEQ ID NO:430) heavy chains. Variable amino acid (aa) positions are indicated as “X” residues sequentially numbered; the locations of amino acids 84, 139, and 236 are double underlined. [0014] FIG.11 provides an alignment of consensus amino acid sequences for HLA-A (SEQ ID NO:184), -B (SEQ ID NO:194), -C (SEQ ID NO:198), -E (SEQ ID NO:431), -F (SEQ ID NO:432), and -G (SEQ ID NO:433). DEFINITIONS [0001] The terms “polynucleotide” and “nucleic acid,” used interchangeably herein, refer to a polymeric form of nucleotides of any length, either ribonucleotides or deoxyribonucleotides. Thus, this term includes, but is not limited to, single-, double-, or multi-stranded DNA or RNA, genomic DNA, cDNA, DNA-RNA hybrids, or a polymer comprising purine and pyrimidine bases or other natural, chemically or biochemically modified, non-natural, or derivatized nucleotide bases. [0002] The terms ''peptide," ''polypeptide," and "protein" are used interchangeably herein, and refer to a polymeric form of amino acids of any length, which can include coded and non-coded amino acids, chemically or biochemically modified or derivatized amino acids, and polypeptides having modified peptide backbones. [0003] A polynucleotide or polypeptide has a certain percent "sequence identity" to another polynucleotide or polypeptide, meaning that, when aligned, that percentage of bases or amino acids are the same, and in the same relative position, when comparing the two sequences. Sequence identity can be determined in a number of different ways. To determine sequence identity, sequences can be aligned using various convenient methods and computer programs (e.g., BLAST, T-COFFEE, MUSCLE, MAFFT, etc.), available over the world wide web at sites including ncbi.nlm.nili.gov/BLAST, ebi.ac.uk/Tools/msa/tcoffee/, ebi.ac.uk/Tools/msa/muscle/, mafft.cbrc.jp/alignment/software/. See, e.g., Altschul et al. (1990), J. Mol. Bioi.215:403-10. [0004] The term "conservative amino acid substitution" refers to the interchangeability in proteins of amino acid residues having similar side chains. For example, a group of amino acids having aliphatic side chains consists of glycine, alanine, valine, leucine, and isoleucine; a group of amino acids having aliphatic-hydroxyl side chains consists of serine and threonine; a group of amino acids having amide containing side chains consisting of asparagine and glutamine; a group of amino acids having aromatic side chains consists of phenylalanine, tyrosine, and tryptophan; a group of amino acids having basic side chains consists of lysine, arginine, and histidine; a group of amino acids having acidic side chains consists of glutamate and aspartate; and a group of amino acids having sulfur containing side chains consists of cysteine and methionine. Exemplary conservative amino acid substitution groups are: valine- leucine-isoleucine, phenylalanine-tyrosine, lysine-arginine, alanine-valine-glycine, and asparagine- glutamine. [0005] The term “immunological synapse” or “immune synapse” as used herein generally refers to the natural interface between two interacting immune cells of an adaptive immune response including, e.g., the interface between an antigen-presenting cell (APC) or target cell and an effector cell, e.g., a lymphocyte, an effector T cell, a natural killer cell, and the like. An immunological synapse between an APC and a T cell is generally initiated by the interaction of a T cell antigen receptor and major histocompatibility complex molecules, e.g., as described in Bromley et al., Annu Rev Immunol. 2001;19:375-96; the disclosure of which is incorporated herein by reference in its entirety. [0006] “T cell” includes all types of immune cells expressing CD3, including T-helper cells (CD4 ⁺ cells), cytotoxic T-cells (CD8 ⁺ cells), T-regulatory cells (Treg), and NK-T cells. [0007] The term “immunomodulatory polypeptide” (also referred to as a “co-stimulatory polypeptide”), as used herein, includes a polypeptide on an antigen presenting cell (APC) (e.g., a dendritic cell, a B cell, and the like) that specifically binds a cognate co-immunomodulatory polypeptide on a T cell, thereby providing a signal which, in addition to the primary signal provided by, for instance, binding of a TCR/CD3 complex with a major histocompatibility complex (MHC) polypeptide loaded with peptide, mediates a T cell response, including, but not limited to, proliferation, activation, differentiation, and the like. An immunomodulatory polypeptide can include, but is not limited to, CD7, B7-1 (CD80), B7-2 (CD86), PD-L1, PD-L2, 4-1BBL, OX40L, Fas ligand (FasL), inducible costimulatory ligand (ICOS-L), intercellular adhesion molecule (ICAM), CD30L, CD40, CD70, CD83, HLA-G, MICA, MICB, HVEM, lymphotoxin beta receptor, 3/TR6, ILT3, ILT4, HVEM, an agonist or antibody that binds Toll ligand receptor and a ligand that specifically binds with B7-H3. [0008] As noted above, an “immunomodulatory polypeptide” (also referred to herein as a “MOD”) specifically binds a cognate co-immunomodulatory polypeptide on a T cell. [0009] An “immunomodulatory domain” (“MOD”) of a TMMP binds a cognate co-immunomodulatory polypeptide, which may be present on a target T cell. [0010] In general, a T-cell modulatory polypeptide (TMP) comprises a polypeptide that preferentially binds to and activates target T cells bearing a T cell receptor (TCR) specific for an antigen of interest. Likewise, a T-cell modulatory multimeric polypeptide (TMMP) comprises a multimeric T-cell modulatory polypeptide that preferentially binds to and activates target T cells bearing a T cell receptor (TCR) specific for an antigen of interest. For example, a TMMP can comprise at least one heterodimer comprising 2 polypeptide chains: a) a first polypeptide comprising: i) a peptide epitope (e.g., a peptide that is at least 4 amino acids in length (e.g., from 4 amino acids to about 25 amino acids in length); and ii) first MHC polypeptide; b) a second polypeptide comprising a second MHC polypeptide, and c) at least one immunomodulatory polypeptide, where the first and/or the second polypeptide comprises the immunomodulatory polypeptide. A TMP or a TMMP also may be referred to as a “synTac” or an “Immuno-STAT™.” [0011] “Heterologous,” as used herein, means a nucleotide or polypeptide that is not found in the native nucleic acid or protein, respectively. [0012] The terms “expression construct,” or “DNA construct” are used interchangeably herein to refer to a DNA molecule comprising a vector and at least one insert. [0013] As used herein, the term "affinity" refers to the equilibrium constant for the reversible binding of two agents (e.g., an antibody and an antigen) and is expressed as a dissociation constant (KD). Affinity can be at least 1-fold greater, at least 2-fold greater, at least 3-fold greater, at least 4-fold greater, at least 5-fold greater, at least 6-fold greater, at least 7-fold greater, at least 8-fold greater, at least 9-fold greater, at least 10-fold greater, at least 20-fold greater, at least 30-fold greater, at least 40-fold greater, at least 50-fold greater, at least 60-fold greater, at least 70-fold greater, at least 80-fold greater, at least 90-fold greater, at least 100-fold greater, or at least 1,000-fold greater, or more, than the affinity of an antibody for unrelated amino acid sequences. Affinity of an antibody to a target protein can be, for example, from about 100 nanomolar (nM) to about 0.1 nM, from about 100 nM to about 1 picomolar (pM), or from about 100 nM to about 1 femtomolar (fM) or more. As used herein, the term “avidity” refers to the resistance of a complex of two or more agents to dissociation after dilution. The terms “immunoreactive” and “preferentially binds” are used interchangeably herein with respect to antibodies and/or antigen- binding fragments. [0014] The term “binding,” as used herein (e.g. with reference to binding of a TMMP to a polypeptide (e.g., a T-cell receptor) on a T cell; or with reference to binding of an antigen-binding polypeptide present in a CAR to an antigen such as a cancer-associated antigen), refers to a non-covalent interaction between two molecules. Non-covalent binding refers to a direct association between two molecules, due to, for example, electrostatic, hydrophobic, ionic, and/or hydrogen-bond interactions, including interactions such as salt bridges and water bridges. Non-covalent binding interactions are generally characterized by a dissociation constant (KD) of less than 10 ^-6 M, less than 10 ^-7 M, less than 10 ^-8 M, less than 10 ^-9 M, less than 10 ^-10 M, less than 10 ^-11 M, less than 10 ^-12 M, less than 10 ^-13 M, less than 10 ^-14 M, or less than 10 ^-15 M. "Affinity" refers to the strength of non-covalent binding, increased binding affinity being correlated with a lower KD. “Specific binding” generally refers to binding with an affinity of at least about 10 ^-7 M or greater, e.g., 5x 10 ^-7 M, 10 ^-8 M, 5 x 10 ^-8 M, 10 ^-9 M, and greater. “Non-specific binding” generally refers to binding (e.g., the binding of a ligand to a moiety other than its designated binding site or receptor) with an affinity of less than about 10 ^-7 M (e.g., binding with an affinity of 10- 6 M, 10 ^-5 M, 10 ^-4 M). However, in some contexts, e.g., binding between a TCR and a peptide/MHC complex, “specific binding” can be in the range of from 1 μM to 100 μM, or from 100 μM to 1 mM. “Covalent binding” or “covalent bond,” as used herein, refers to the formation of one or more covalent chemical binds between two different molecules. [0015] The terms "treatment", "treating" and the like are used herein to generally mean obtaining a desired pharmacologic and/or physiologic effect. The effect may be prophylactic in terms of completely or partially preventing a disease or symptom thereof and/or may be therapeutic in terms of a partial or complete cure for a disease and/or adverse effect attributable to the disease. "Treatment" as used herein covers any treatment of a disease or symptom in a mammal, and includes: (a) preventing the disease or symptom from occurring in a subject which may be predisposed to acquiring the disease or symptom but has not yet been diagnosed as having it; (b) inhibiting the disease or symptom, i.e., arresting its development; and/or (c) relieving the disease, i.e., causing regression of the disease. The therapeutic agent may be administered before, during or after the onset of disease or injury. The treatment of ongoing disease, where the treatment stabilizes or reduces the undesirable clinical symptoms of the patient, is of particular interest. Such treatment is desirably performed prior to complete loss of function in the affected tissues. The subject therapy will desirably be administered during the symptomatic stage of the disease, and in some cases after the symptomatic stage of the disease. [0016] The terms "individual," "subject," "host," and "patient," are used interchangeably herein and refer to any mammalian subject for whom diagnosis, treatment, or therapy is desired. Mammals include, e.g., humans, non-human primates, rodents (e.g., rats; mice), lagomorphs (e.g., rabbits), ungulates (e.g., cows, sheep, pigs, horses, goats, and the like), etc. [0017] The terms "antibodies" and “immunoglobulin” include antibodies or immunoglobulins of any isotype, fragments of antibodies that retain specific binding to antigen, including, but not limited to, Fab, Fv, scFv, and Fd fragments, chimeric antibodies, humanized antibodies, single-chain antibodies (scAb), single domain antibodies (dAb), single domain heavy chain antibodies, a single domain light chain antibodies, nanobodies, bi-specific antibodies, multi-specific antibodies, and fusion proteins comprising an antigen-binding (also referred to herein as antigen binding) portion of an antibody and a non-antibody protein. The antibodies can be detectably labeled, e.g., with a radioisotope, an enzyme that generates a detectable product, a fluorescent protein, and the like. The antibodies can be further conjugated to other moieties, such as members of specific binding pairs, e.g., biotin (member of biotin-avidin specific binding pair), and the like. Also encompassed by the term are Fab’, Fv, F(ab’)2, and or other antibody fragments that retain specific binding to antigen, and monoclonal antibodies. As used herein, a monoclonal antibody is an antibody produced by a group of identical cells, all of which were produced from a single cell by repetitive cellular replication. That is, the clone of cells only produces a single antibody species. While a monoclonal antibody can be produced using hybridoma production technology, other production methods known to those skilled in the art can also be used (e.g., antibodies derived from antibody phage display libraries). An antibody can be monovalent or bivalent. An antibody can be an Ig monomer, which is a “Y-shaped” molecule that consists of four polypeptide chains: two heavy chains and two light chains connected by disulfide bonds. [0018] The term "humanized immunoglobulin" as used herein refers to an immunoglobulin comprising portions of immunoglobulins of different origin, wherein at least one portion comprises amino acid sequences of human origin. For example, the humanized antibody can comprise portions derived from an immunoglobulin of nonhuman origin with the requisite specificity, such as a mouse, and from immunoglobulin sequences of human origin (e.g., chimeric immunoglobulin), joined together chemically by conventional techniques (e.g., synthetic) or prepared as a contiguous polypeptide using genetic engineering techniques (e.g., DNA encoding the protein portions of the chimeric antibody can be expressed to produce a contiguous polypeptide chain). Another example of a humanized immunoglobulin is an immunoglobulin containing one or more immunoglobulin chains comprising a complementarity-determining region (CDR) derived from an antibody of nonhuman origin and a framework region derived from a light and/or heavy chain of human origin (e.g., CDR-grafted antibodies with or without framework changes). Chimeric or CDR-grafted single chain antibodies are also encompassed by the term humanized immunoglobulin. See, e.g., U.S. Pat. No.4,816,567; European Patent No.0,125,023 B1; U.S. Pat. No.4,816,397; European Patent No.0,120,694 B1; WO 86/01533; European Patent No.0,194,276 B1; U.S. Pat. No.5,225,539; European Patent No.0,239,400 B1; and European Patent Application No.0,519,596 A1. See also, U.S. Pat. No.4,946,778; U.S. Pat. No. 5,476,786; and Bird et al. (1988) Science 242:423, regarding single chain antibodies. [0019] The term "nanobody" (Nb), as used herein, refers to the smallest antigen binding fragment or single variable domain (VHH) derived from naturally occurring heavy chain antibody and is known to the person skilled in the art. They are derived from heavy chain only antibodies, seen in camelids (Hamers- Casterman et al. (1993) Nature 363:446; Desmyter et al. (1996) Nature Structural Biol.3:803; and Desmyter et al. (2015) Curr. Opin. Struct. Biol.32:1). In the family of "camelids" immunoglobulins devoid of light polypeptide chains are found. "Camelids" comprise old world camelids (Camelus bactrianus and Camelus dromedarius) and new world camelids (for example, Llama paccos, Llama glama, Llama guanicoe and Llama vicugna). A single variable domain heavy chain antibody is referred to herein as a nanobody or a VHH antibody. [0020] "Antibody fragments" comprise a portion of an intact antibody, for example, the antigen binding or variable region of the intact antibody. Examples of antibody fragments include Fab, Fab', F(ab')2, and Fv fragments; diabodies; linear antibodies (Zapata et al., Protein Eng.8(10): 1057-1062 (1995)); domain antibodies (dAb; Holt et al. (2003) Trends Biotechnol.21:484); single-chain antibody molecules; and multi-specific antibodies formed from antibody fragments. Papain digestion of antibodies produces two identical antigen-binding fragments, called "Fab" fragments, each with a single antigen-binding site, and a residual "Fc" fragment, a designation reflecting the ability to crystallize readily. Pepsin treatment yields an F(ab') ₂ fragment that has two antigen combining sites and is still capable of cross-linking antigen. [0021] "Fv" is the minimum antibody fragment that contains a complete antigen-recognition and - binding site. This region consists of a dimer of one heavy- and one light-chain variable domain in tight, non-covalent association. It is in this configuration that the three CDRS of each variable domain interact to define an antigen-binding site on the surface of the VH-VL dimer. Collectively, the six CDRs confer antigen-binding specificity to the antibody. However, even a single variable domain (or half of an Fv comprising only three CDRs specific for an antigen) has the ability to recognize and bind antigen, although at a lower affinity than the entire binding site. [0022] The “Fab” fragment also contains the constant domain of the light chain and the first constant domain (CH1) of the heavy chain. Fab fragments differ from Fab' fragments by the addition of a few residues at the carboxyl terminus of the heavy chain CH1 domain including one or more cysteines from the antibody hinge region. Fab'-SH is the designation herein for Fab' in which the cysteine residue(s) of the constant domains bear a free thiol group. F(ab')2 antibody fragments originally were produced as pairs of Fab' fragments which have hinge cysteines between them. Other chemical couplings of antibody fragments are also known. [0023] The "light chains" of antibodies (immunoglobulins) from any vertebrate species can be assigned to one of two clearly distinct types, called kappa and lambda, based on the amino acid sequences of their constant domains. Depending on the amino acid sequence of the constant domain of their heavy chains, immunoglobulins can be assigned to different classes. There are five major classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and several of these classes can be further divided into subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA, and IgA2. The subclasses can be further divided into types, e.g., IgG2a and IgG2b. [0024] "Single-chain Fv" or "sFv" or “scFv” antibody fragments comprise the VH and VL domains of antibody, wherein these domains are present in a single polypeptide chain. In some embodiments, the Fv polypeptide further comprises a polypeptide linker between the VH and VL domains, which enables the sFv to form the desired structure for antigen binding. For a review of sFv, see Pluckthun in The Pharmacology of Monoclonal Antibodies, vol.113, Rosenburg and Moore eds., Springer-Verlag, New York, pp.269-315 (1994). [0025] The term "diabodies" refers to small antibody fragments with two antigen-binding sites, which fragments comprise a heavy-chain variable domain (VH) connected to a light-chain variable domain (VL) in the same polypeptide chain (V _H -V _L ). By using a linker that is too short to allow pairing between the two domains on the same chain, the domains are forced to pair with the complementary domains of another chain and create two antigen-binding sites. Diabodies are described more fully in, for example, EP 404,097; WO 93/11161; and Hollinger et al. (1993) Proc. Natl. Acad. Sci. USA 90:6444-6448. [0026] As used herein, the term “CDR” or “complementarity determining region” is intended to mean the non-contiguous antigen combining sites found within the variable region of both heavy and light chain polypeptides. CDRs have been described by Kabat et al (1977) J. Biol. Chem.252:6609; Kabat et al., U.S. Dept. of Health and Human Services, “Sequences of proteins of immunological interest” (1991) (also referred to herein as Kabat 1991); by Chothia et al. (1987) J. Mol. Biol.196:901 (also referred to herein as Chothia 1987); and MacCallum et al. (1996) J. Mol. Biol.262:732, where the definitions include overlapping or subsets of amino acid residues when compared against each other. Nevertheless, application of either definition to refer to a CDR of an antibody or grafted antibodies or variants thereof is intended to be within the scope of the term as defined and used herein. The amino acid residues, which encompass the CDRs, as defined by each of the above cited references are set forth below in Table 1 as a comparison. Table 1: CDR Definitions 1 Residue numbering follows the nomenclature of Kabat et al., 1991, supra 2 Residue numbering follows the nomenclature of Chothia et al., supra ³ Residue numbering follows the nomenclature of MacCallum et al., supra [0027] As used herein, the terms “CDR-L1”, “CDR-L2”, and “CDR-L3” refer, respectively, to the first, second, and third CDRs in a light chain variable region. As used herein, the terms “CDR-H1”, “CDR- H2”, and “CDR-H3” refer, respectively, to the first, second, and third CDRs in a heavy chain variable region. As used herein, the terms “CDR-1”, “CDR-2”, and “CDR-3” refer, respectively, to the first, second and third CDRs of either chain’s variable region. [0028] The terms “chimeric antigen receptor” and “CAR”, used interchangeably herein, refer to artificial multi-module molecules capable of triggering or inhibiting the activation of an immune cell which generally but not exclusively comprise an extracellular domain (e.g., a ligand/antigen binding domain), a transmembrane domain and one or more intracellular signaling domains. The term CAR is not limited specifically to CAR molecules but also includes CAR variants. CAR variants include split CARs wherein the extracellular portion (e.g., the ligand binding portion) and the intracellular portion (e.g., the intracellular signaling portion) of a CAR are present on two separate molecules. CAR variants also include ON-switch CARs which are conditionally activatable CARs, e.g., comprising a split CAR wherein conditional hetero-dimerization of the two portions of the split CAR is pharmacologically controlled. CAR variants also include bispecific CARs, which include a secondary CAR binding domain that can either amplify or inhibit the activity of a primary CAR. CAR variants also include inhibitory chimeric antigen receptors (iCARs) which may, e.g., be used as a component of a bispecific CAR system, where binding of a secondary CAR binding domain results in inhibition of primary CAR activation. CAR molecules and derivatives thereof (i.e., CAR variants) are described, e.g., in PCT Application No. US2014/016527; Fedorov et al. Sci Transl Med (2013) ;5(215):215ra172; Glienke et al. Front Pharmacol (2015) 6:21; Kakarla & Gottschalk 52 Cancer J (2014) 20(2):151-5; Riddell et al. Cancer J (2014) 20(2):141-4; Pegram et al. Cancer J (2014) 20(2):127-33; Cheadle et al. Immunol Rev (2014) 257(1):91-106; Barrett et al. Annu Rev Med (2014) 65:333-47; Sadelain et al. Cancer Discov (2013) 3(4):388-98; Cartellieri et al., J Biomed Biotechnol (2010) 956304; the disclosures of which are incorporated herein by reference in their entirety. [0029] Before the present invention is further described, it is to be understood that this invention is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims. [0030] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention. [0031] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. [0032] It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a T-cell modulatory multimeric polypeptide” includes a plurality of such polypeptides and reference to “the chimeric antigen receptor” includes reference to one or more chimeric antigen receptors and equivalents thereof known to those skilled in the art, and so forth. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. [0033] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. All combinations of the embodiments pertaining to the invention are specifically embraced by the present invention and are disclosed herein just as if each and every combination was individually and explicitly disclosed. In addition, all sub-combinations of the various embodiments and elements thereof are also specifically embraced by the present invention and are disclosed herein just as if each and every such sub- combination was individually and explicitly disclosed herein. [0034] The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. DETAILED DESCRIPTION [0035] The present disclosure provides a chimeric molecule comprising: a) a T-cell modulatory multimeric polypeptide (TMMP); and b) a nucleic acid component, where the nucleic acid component comprises a nucleic acid comprising a nucleotide sequence encoding a chimeric antigen receptor (CAR), where the CAR comprises an antibody that binds a cancer-associated antigen. The TMMP binds to and activates a target T cell; the nucleic acid component is taken up by the target T cell such that the target T cell expresses the CAR on its surface. The present disclosure provides methods of making the chimeric molecule. The present disclosure provides treatment methods comprising administering the chimeric molecule. [0036] The TMMP present in a chimeric molecule of the present disclosure comprises a heterodimer comprising: a) a first polypeptide comprising: i) a peptide epitope, wherein the peptide epitope is a peptide having a length of at least 4 amino acids (e.g., from 4 amino acids to about 25 amino acids); and ii) a first major histocompatibility complex (MHC) polypeptide; b) a second polypeptide comprising a second MHC polypeptide; and c) at least one immunomodulatory polypeptide, where the first and/or the second polypeptide comprises the at least one immunomodulatory polypeptide. The TMMP activates a target T-cell that comprises a T-cell receptor (TCR) that binds to the peptide epitope present in the TMMP. In some cases, the TMMP present in a chimeric molecule of the present disclosure comprises a peptide epitope that is not a cancer-associated antigen. For example, in some cases, the peptide epitope present in the TMMP is a viral peptide (a peptide of an antigen encoded by a virus) or a bacterial peptide. In some cases, a viral epitope is an epitope present in a viral antigen encoded by a virus that infects a majority of the human population, where such viruses include, e.g., cytomegalovirus (CMV), Epstein- Barr virus (EBV), human papilloma virus (HPV), adenovirus, and the like. The target T-cell is activated by the TMMP. The target T-cell also takes up the nucleic acid component of the chimeric molecule, and expresses the encoded CAR on its surface. The activated, CAR-expressing target T-cell (“activated CAR-T cell”) exhibits cytotoxic activity toward a cancer cell expressing a cancer-associated antigen recognized and bound by the CAR. CHIMERIC MOLECULES [0037] The present disclosure provides a chimeric molecule comprising: a) a T-cell modulatory multimeric polypeptide (TMMP); and b) a nucleic acid component covalently attached to the TMMP. The TMMP comprises: a) a first polypeptide comprising: i) a peptide epitope, wherein the peptide epitope is a peptide having a length of at least 4 amino acids (e.g., from 4 amino acids to about 25 amino acids); and ii) a first major histocompatibility complex (MHC) polypeptide; b) a second polypeptide comprising a second MHC polypeptide; and c) at least one immunomodulatory polypeptide, where the first and/or the second polypeptide comprises the at least one immunomodulatory polypeptide. The TMMP optionally also includes an immunoglobulin (Ig) Fc polypeptide or a non-Ig scaffold, where the first and/or the second polypeptide comprises the Ig Fc polypeptide or the non-Ig scaffold. The nucleic acid component covalently attached to the TMMP comprises one or more nucleic acids comprising nucleotide sequences encoding a chimeric antigen receptor (CAR). The CAR comprises an antigen- binding domain that binds to a cancer-associated antigen. [0038] When a chimeric molecule of the present disclosure contacts a T-cell comprising a TCR specific for the peptide epitope present in the TMMP, the chimeric molecule is taken up by the T-cell (e.g., by endocytosis), to produce a modified T-cell. The nucleic acid portion of the chimeric molecule is transcribed in the modified T-cell, and the encoded CAR is synthesized by the modified T-cell, such that the CAR is expressed on the surface of the modified T-cell. In addition, when a chimeric molecule of the present disclosure contacts a T-cell comprising a TCR specific for the peptide epitope present in the TMMP, the binding of the TMMP to the T-cell activates the T-cell. Thus, contacting a T-cell with a chimeric molecule of the present disclosure generates a modified, activated T-cell. The activated T-cell can, by virtue of the CAR expressed on its surface, bind to and kill a cancer cell that expresses on its surface the cancer-associated antigen to which the CAR binds. Thus, a chimeric molecule of the present disclosure can generate a CAR-T cell without the need to remove T cells from an individual and modify them in vitro to express a CAR. TMMP [0039] A chimeric molecule of the present disclosure comprises a TMMP comprising a heterodimer comprising: a) a first polypeptide comprising: i) a peptide epitope, wherein the peptide epitope is a peptide having a length of at least 4 amino acids (e.g., from 4 amino acids to about 25 amino acids); and ii) a first major histocompatibility complex (MHC) polypeptide; b) a second polypeptide comprising a second MHC polypeptide; and c) at least one immunomodulatory polypeptide, where the first and/or the second polypeptide comprises the at least one immunomodulatory polypeptide. The TMMP optionally also includes an immunoglobulin (Ig) Fc polypeptide or a non-Ig scaffold, where the first and/or the second polypeptide comprises the Ig Fc polypeptide or the non-Ig scaffold. [0040] As used herein, the term “peptide epitope” means a peptide that, when complexed with MHC polypeptides, presents an epitope to a TCR. A peptide epitope has a length of at least 4 amino acids, e.g., from 4 amino acids to about 25 amino acids (e.g., 4 amino acids (aa), 5 aa, 6 aa, 7 aa, 8 aa, 9 aa, 10 aa, 11 aa, 12 aa, 13 aa, 14 aa, 15 aa, 16 aa, 17 aa, 18 aa, 19 aa, 20 aa, 21 aa, 22 aa, 23 aa, 24 aa, or 25 aa, including within a range of from 4 to 20 aa., from 6 to 18 aa., from 8 to 15 aa. from 8 to 12 aa., from 5 to 10 aa., from 10 to 15 aa., from 15 to 20 aa., from 10 to 20 aa., or from 15 to 25 aa. in length). When complexed with MHC polypeptides, a peptide epitope can present one or more epitopes to one or more TCRs. In some cases, the peptide epitope present in a TMMP presents an infectious disease-associated epitope (e.g., a virus-encoded peptide). [0041] As noted above, a TMMP comprises a heterodimeric polypeptide comprising: a) a first polypeptide comprising: i) a peptide epitope; and ii) a first MHC polypeptide; b) a second polypeptide comprising a second MHC polypeptide; c) at least one immunomodulatory polypeptide, where the first and/or the second polypeptide comprises the at least one (i.e., one or more) immunomodulatory polypeptide; and, optionally, d) an Ig Fc polypeptide or a non-Ig scaffold, where the first and/or the second polypeptide comprises the Ig Fc polypeptide or the non-Ig scaffold. In some cases, the at least one immunomodulatory polypeptide is wild-type, i.e., comprises an amino acid sequence of a naturally- occurring immunomodulatory polypeptide. [0042] In some cases, at least one of the one or more immunomodulatory polypeptides is a variant immunomodulatory polypeptide that exhibits reduced affinity to a cognate co-immunomodulatory polypeptide compared to the affinity of a corresponding wild-type immunomodulatory polypeptide for the cognate co-immunomodulatory polypeptide. In some cases, the peptide epitope present in a TMMP of the present disclosure binds to a T-cell receptor (TCR) on a T cell with an affinity of at least 100 μM (e.g., at least 10 μM, at least 1 μM, at least 100 nM, at least 10 nM, or at least 1 nM). In some cases, a TMMP of the present disclosure binds to a first T cell with an affinity that is at least 25% higher than the affinity with which the TMMP binds a second T cell, where the first T cell expresses on its surface the cognate co-immunomodulatory polypeptide and a TCR that binds the epitope with an affinity of at least 100 μM, and where the second T cell expresses on its surface the cognate co-immunomodulatory polypeptide but does not express on its surface a TCR that binds the epitope with an affinity of at least 100 μM (e.g., at least 10 μM, at least 1 μM, at least 100 nM, at least 10 nM, or at least 1 nM). [0043] In some cases, a TMMP present in a chimeric molecule of the present disclosure is: [0044] A) a heterodimer comprising: a) a first polypeptide comprising a first MHC polypeptide; and b) a second polypeptide comprising a second MHC polypeptide, wherein the first polypeptide or the second polypeptide comprises a peptide epitope, wherein the first polypeptide and/or the second polypeptide comprises one or more immunomodulatory polypeptides that can be the same or different, and wherein at least one of the one or more immunomodulatory polypeptides may be a wild-type immunomodulatory polypeptide or a variant of a wild-type immunomodulatory polypeptide, wherein the variant immunomodulatory polypeptide comprises 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid substitutions compared to the amino acid sequence of the corresponding wild-type immunomodulatory polypeptide; wherein the first polypeptide and/or the second polypeptide comprises an Ig Fc polypeptide or a non-Ig scaffold; or [0045] B) a heterodimer comprising: a) a first polypeptide comprising a first MHC polypeptide; and b) a second polypeptide comprising a second MHC polypeptide, wherein the first polypeptide or the second polypeptide comprises an epitope; wherein the first polypeptide and/or the second polypeptide comprises one or more immunomodulatory polypeptides that can be the same or different, [0046] wherein at least one of the one or more immunomodulatory polypeptides is a variant of a wild- type immunomodulatory polypeptide, wherein the variant immunomodulatory polypeptide comprises 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid substitutions compared to the amino acid sequence of the corresponding wild-type immunomodulatory polypeptide, [0047] wherein at least one of the one or more immunomodulatory domains is a variant immunomodulatory polypeptide that exhibits reduced affinity to a cognate co-immunomodulatory polypeptide compared to the affinity of a corresponding wild-type immunomodulatory polypeptide for the cognate co-immunomodulatory polypeptide, and wherein the epitope binds to a TCR on a T cell with an affinity of at least 10 ^-7 M, such that: i) the TMMP polypeptide binds to a first T cell with an affinity that is at least 25% higher than the affinity with which the TMMP binds a second T cell, wherein the first T cell expresses on its surface the cognate co-immunomodulatory polypeptide and a TCR that binds the epitope with an affinity of at least 10 ^-7 M, and wherein the second T cell expresses on its surface the cognate co-immunomodulatory polypeptide but does not express on its surface a TCR that binds the epitope with an affinity of at least 10 ^-7 M; and/or ii) the ratio of the binding affinity of a control TMMP, wherein the control comprises a wild-type immunomodulatory polypeptide, to a cognate co- immunomodulatory polypeptide to the binding affinity of the TMMP comprising a variant of the wild- type immunomodulatory polypeptide to the cognate co-immunomodulatory polypeptide, when measured by bio-layer interferometry, is in a range of from 1.5:1 to 10 ⁶ :1; and wherein the variant immunomodulatory polypeptide comprises 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid substitutions compared to the amino acid sequence of the corresponding wild-type immunomodulatory polypeptide; and [0048] wherein the first polypeptide and/or the second polypeptide comprises an Ig Fc polypeptide or a non-Ig scaffold; or [0049] C) a heterodimer comprising: a) a first polypeptide comprising, in order from N-terminus to C- terminus: i) an epitope; ii) a first MHC polypeptide; and b) a second polypeptide comprising, in order from N-terminus to C-terminus: i) a second MHC polypeptide; and ii) optionally an immunoglobulin (Ig) Fc polypeptide or a non-Ig scaffold, wherein the TMMP comprises one or more immunomodulatory domains that can be the same or different, wherein at least one of the one or more immunomodulatory domain is: A) at the C-terminus of the first polypeptide; B) at the N-terminus of the second polypeptide; C) at the C-terminus of the second polypeptide; or D) at the C-terminus of the first polypeptide and at the N-terminus of the second polypeptide, and wherein at least one of the one or more immunomodulatory domains may be a wild-type immunomodulatory polypeptide or a variant of a wild-type immunomodulatory polypeptide, wherein the variant immunomodulatory polypeptide comprises 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid substitutions compared to the amino acid sequence of the corresponding wild-type immunomodulatory polypeptide; and [0050] optionally wherein at least one of the one or more immunomodulatory domains is a variant immunomodulatory polypeptide that exhibits reduced affinity to a cognate co-immunomodulatory polypeptide compared to the affinity of a corresponding wild-type immunomodulatory polypeptide for the cognate co-immunomodulatory polypeptide, and wherein the epitope binds to a TCR on a T cell with an affinity of at least 10 ^-7 M, such that: i) the TMMP binds to a first T cell with an affinity that is at least 25% higher than the affinity with which the TMMP binds a second T cell, wherein the first T cell expresses on its surface the cognate co-immunomodulatory polypeptide and a TCR that binds the epitope with an affinity of at least 10 ^-7 M, and wherein the second T cell expresses on its surface the cognate co- immunomodulatory polypeptide but does not express on its surface a TCR that binds the epitope with an affinity of at least 10 ^-7 M; and/or ii) the ratio of the binding affinity of a control TMMP, wherein the control comprises a wild-type immunomodulatory polypeptide, to a cognate co-immunomodulatory polypeptide to the binding affinity of the TMMP comprising a variant of the wild-type immunomodulatory polypeptide to the cognate co-immunomodulatory polypeptide, when measured by bio-layer interferometry, is in a range of from 1.5:1 to 10 ⁶ :1; and wherein the variant immunomodulatory polypeptide comprises 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid substitutions compared to the amino acid sequence of the corresponding wild-type immunomodulatory polypeptide. [0051] In some cases, the epitope present in a TMMP of a chimeric molecule of the present disclosure binds to a TCR on a T cell with an affinity of from about 10 ^-4 M to about 5 x 10 ^-4 M, from about 5 x 10 ^-4 M to about 10 ^-5 M, from about 10 ^-5 M to 5 x 10 ^-5 M, from about 5 x 10 ^-5 M to 10 ^-6 M, from about 10 ^-6 M to about 5 x 10 ^-6 M, from about 5 x 10 ^-6 M to about 10 ^-7 M, from about 10 ^-7 M to about 5 x 10 ^-7 M, from about 5 x 10 ^-7 M to about 10 ^-8 M, or from about 10 ^-8 M to about 10 ^-9 M. Expressed another way, in some cases, the epitope present in a TMMP of the present disclosure binds to a TCR on a T cell with an affinity of from about 1 nM to about 5 nM, from about 5 nM to about 10 nM, from about 10 nM to about 50 nM, from about 50 nM to about 100 nM, from about 0.1 μM to about 0.5 μM, from about 0.5 μM to about 1 μM, from about 1 μM to about 5 μM, from about 5 μM to about 10 μM, from about 10 μM to about 25 μM, from about 25 μM to about 50 μM, from about 50 μM to about 75 μM, from about 75 μM to about 100 μM. [0052] In some cases, an immunomodulatory polypeptide present in a TMMP of a chimeric molecule of the present disclosure comprises a wild-type (naturally-occurring) amino acid sequence. [0053] In some cases, an immunomodulatory polypeptide present in a TMMP of a chimeric molecule of the present disclosure binds to its cognate co-immunomodulatory polypeptide with an affinity that it at least 10% less, at least 15% less, at least 20% less, at least 25% less, at least 30% less, at least 35% less, at least 40% less, at least 45% less, at least 50% less, at least 55% less, at least 60% less, at least 65% less, at least 70% less, at least 75% less, at least 80% less, at least 85% less, at least 90% less, at least 95% less, or more than 95% less, than the affinity of a corresponding wild-type immunomodulatory polypeptide for the cognate co-immunomodulatory polypeptide. [0054] In some cases, a variant immunomodulatory polypeptide present in a TMMP of a chimeric molecule of the present disclosure has a binding affinity for a cognate co-immunomodulatory polypeptide that is from 1 nM to 100 nM, or from 100 nM to 100 μM. For example, in some cases, a variant immunomodulatory polypeptide present in a TMMP of a chimeric molecule of the present disclosure has a binding affinity for a cognate co-immunomodulatory polypeptide that is from about 100 nM to 150 nM, from about 150 nM to about 200 nM, from about 200 nM to about 250 nM, from about 250 nM to about 300 nM, from about 300 nM to about 350 nM, from about 350 nM to about 400 nM, from about 400 nM to about 500 nM, from about 500 nM to about 600 nM, from about 600 nM to about 700 nM, from about 700 nM to about 800 nM, from about 800 nM to about 900 nM, from about 900 nM to about 1 μM, to about 1 μM to about 5 μM, from about 5 μM to about 10 μM, from about 10 μM to about 15 μM, from about 15 μM to about 20 μM, from about 20 μM to about 25 μM, from about 25 μM to about 50 μM, from about 50 μM to about 75 μM, or from about 75 μM to about 100 μM. In some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure has a binding affinity for a cognate co-immunomodulatory polypeptide that is from about 1 nM to about 5 nM, from about 5 nM to about 10 nM, from about 10 nM to about 50 nM, from about 50 nM to about 100 nM [0055] The combination of the reduced affinity of the immunomodulatory polypeptide for its cognate co-immunomodulatory polypeptide, and the affinity of the epitope for a TCR, provides for enhanced selectivity of a TMMP. For example, a TMMP binds selectively to a first T cell that displays both: i) a TCR specific for the epitope present in the TMMP; and ii) a co-immunomodulatory polypeptide that binds to the immunomodulatory polypeptide present in the TMMP, compared to binding to a second T cell that displays: i) a TCR specific for an epitope other than the epitope present in the TMMP; and ii) a co-immunomodulatory polypeptide that binds to the immunomodulatory polypeptide present in the TMMP. For example, a TMMP of the present disclosure binds to the first T cell with an affinity that is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 2-fold, at least 2.5-fold, at least 5-fold, at least 10-fold, at least 15-fold, at least 20-fold, at least 25-fold, at least 50-fold, at least 100-fold, or more than 100-fold, higher than the affinity to which it binds the second T cell. [0056] In some cases, a chimeric molecule of the present disclosure, when administered to an individual in need thereof, induces both an epitope-specific T cell response and an epitope non-specific T cell response. In other words, in some cases, a chimeric molecule of the present disclosure, when administered to an individual in need thereof, induces an epitope-specific T cell response by modulating the activity of a first T cell that displays both: i) a TCR specific for the epitope present in the TMMP; ii) a co-immunomodulatory polypeptide that binds to the immunomodulatory polypeptide present in the TMMP; and induces an epitope non-specific T cell response by modulating the activity of a second T cell that displays: i) a TCR specific for an epitope other than the epitope present in the TMMP; and ii) a co-immunomodulatory polypeptide that binds to the immunomodulatory polypeptide present in the TMMP. The ratio of the epitope-specific T cell response to the epitope-non-specific T cell response is at least 2:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 50:1, or at least 100:1. The ratio of the epitope-specific T cell response to the epitope-non-specific T cell response is from about 2:1 to about 5:1, from about 5:1 to about 10:1, from about 10:1 to about 15:1, from about 15:1 to about 20:1, from about 20:1 to about 25:1, from about 25:1 to about 50:1, or from about 50:1 to about 100:1, or more than 100:1. “Modulating the activity” of a T cell can include one or more of: i) activating a cytotoxic (e.g., CD8 ⁺ ) T cell; ii) inducing cytotoxic activity of a cytotoxic (e.g., CD8 ⁺ ) T cell; iii) inducing production and release of a cytotoxin (e.g., a perforin; a granzyme; a granulysin) by a cytotoxic (e.g., CD8 ⁺ ) T cell; iv) inhibiting activity of an autoreactive T cell; and the like. [0057] The combination of the reduced affinity of the immunomodulatory polypeptide for its cognate co-immunomodulatory polypeptide, and the affinity of the epitope for a TCR, provides for enhanced selectivity of a TMMP. Thus, for example, a TMMP binds with higher avidity to a first T cell that displays both: i) a TCR specific for the epitope present in the TMMP; and ii) a co-immunomodulatory polypeptide that binds to the immunomodulatory polypeptide present in the TMMP, compared to the avidity to which it binds to a second T cell that displays: i) a TCR specific for an epitope other than the epitope present in the TMMP; and ii) a co-immunomodulatory polypeptide that binds to the immunomodulatory polypeptide present in the TMMP. [0058] Binding affinity between an immunomodulatory polypeptide and its cognate co- immunomodulatory polypeptide can be determined by bio-layer interferometry (BLI) using purified immunomodulatory polypeptide and purified cognate co-immunomodulatory polypeptide. Binding affinity between a TMMP and its cognate co-immunomodulatory polypeptide can be determined by BLI using purified TMMP and the cognate co-immunomodulatory polypeptide. BLI methods are well known to those skilled in the art. See, e.g., Lad et al. (2015) J. Biomol. Screen.20(4):498-507; and Shah and Duncan (2014) J. Vis. Exp.18:e51383. [0059] A BLI assay can be carried out using an Octet RED 96 (Pal FortéBio) instrument, or a similar instrument, as follows. A TMMP (e.g., a TMMP of the present disclosure; a control TMMP (where a control TMMP comprises a wild-type immunomodulatory polypeptide)) is immobilized onto an insoluble support (a “biosensor”). The immobilized TMMP is the “target.” Immobilization can be effected by immobilizing a capture antibody onto the insoluble support, where the capture antibody immobilizes the TMMP. For example, immobilization can be effected by immobilizing anti-Fc (e.g., anti-human IgG Fc) antibodies onto the insoluble support, where the immobilized anti-Fc antibodies bind to and immobilize the TMMP (where the TMMP comprises an IgFc polypeptide). A co- immunomodulatory polypeptide is applied, at several different concentrations, to the immobilized TMMP, and the instrument’s response recorded. Assays are conducted in a liquid medium comprising 25mM HEPES pH 6.8, 5% poly(ethylene glycol) 6000, 50 mM KCl, 0.1% bovine serum albumin, and 0.02% Tween 20 nonionic detergent. Binding of the co-immunomodulatory polypeptide to the immobilized TMMP is conducted at 30°C. As a positive control for binding affinity, an anti-MHC Class I monoclonal antibody can be used. For example, anti-HLA Class I monoclonal antibody W6/32 (American Type Culture Collection No. HB-95; Parham et al. (1979) J. Immunol.123:342), which has a K _D of 7 nM, can be used. A standard curve can be generated using serial dilutions of the anti-MHC Class I monoclonal antibody. The co-immunomodulatory polypeptide, or the anti-MHC Class I mAb, is the “analyte.” BLI analyzes the interference pattern of white light reflected from two surfaces: i) from the immobilized polypeptide (“target”); and ii) an internal reference layer. A change in the number of molecules (“analyte”; e.g., co-immunomodulatory polypeptide; anti-HLA antibody) bound to the biosensor tip causes a shift in the interference pattern; this shift in interference pattern can be measured in real time. The two kinetic terms that describe the affinity of the target/analyte interaction are the association constant (k _a ) and dissociation constant (k _d ). The ratio of these two terms (k _d / _a ) gives rise to the affinity constant K _D . [0060] The BLI assay is carried out in a multi-well plate. To run the assay, the plate layout is defined, the assay steps are defined, and biosensors are assigned in Octet Data Acquisition software. The biosensor assembly is hydrated. The hydrated biosensor assembly and the assay plate are equilibrated for 10 minutes on the Octet instrument. Once the data are acquired, the acquired data are loaded into the Octet Data Analysis software. The data are processed in the Processing window by specifying method for reference subtraction, y-axis alignment, inter-step correction, and Savitzky-Golay filtering. Data are analyzed in the Analysis window by specifying steps to analyze (Association and Dissociation), selecting curve fit model (1:1), fitting method (global), and window of interest (in seconds). The quality of fit is evaluated. KD values for each data trace (analyte concentration) can be averaged if within a 3-fold range. KD error values should be within one order of magnitude of the affinity constant values; R ² values should be above 0.95. See, e.g., Abdiche et al. (2008) J. Anal. Biochem.377:209. [0061] Unless otherwise stated herein, the affinity of a TMMP for a cognate co-immunomodulatory polypeptide, or the affinity of a control TMMP (where a control TMMP comprises a wild-type immunomodulatory polypeptide) for a cognate co-immunomodulatory polypeptide, is determined using BLI, as described above. [0062] In some cases, the ratio of: i) the binding affinity of a control TMMP (where the control comprises a wild-type immunomodulatory polypeptide) to a cognate co-immunomodulatory polypeptide to ii) the binding affinity of a TMMP of the present disclosure comprising a variant of the wild-type immunomodulatory polypeptide to the cognate co-immunomodulatory polypeptide, when measured by BLI (as described above), is at least 1.5:1, at least 2:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 50:1, at least 100:1, at least 500:1, at least 10 ² :1, at least 5 x 10 ² :1, at least 10 ³ :1, at least 5 x 10 ³ :1, at least 10 ⁴ :1, at least 10 ⁵ :1, or at least 10 ⁶ :1. In some cases, the ratio of: i) the binding affinity of a control TMMP (where the control comprises a wild-type immunomodulatory polypeptide) to a cognate co-immunomodulatory polypeptide to ii) the binding affinity of a TMMP comprising a variant of the wild-type immunomodulatory polypeptide to the cognate co- immunomodulatory polypeptide, when measured by BLI, is in a range of from 1.5:1 to 10 ⁶ :1, e.g., from 1.5:1 to 10:1, from 10:1 to 50:1, from 50:1 to 10 ² :1, from 10 ² :1 to 10 ³ :1, from10 ³ :1 to 10 ⁴ :1, from 10 ⁴ :1 to 10 ⁵ :1, or from 10 ⁵ :1 to 10 ⁶ :1. [0063] As an example, where a control TMMP comprises a wild-type IL-2 polypeptide, and where a TMMP of a chimeric molecule of the present disclosure comprises a variant IL-2 polypeptide (comprising from 1 to 10 amino acid substitutions relative to the amino acid sequence of the wild-type IL-2 polypeptide) as the immunomodulatory polypeptide, the ratio of: i) the binding affinity of the control TMMP to an IL-2 receptor (i.e., the cognate co-immunomodulatory polypeptide) to ii) the binding affinity of the TMMP of the present disclosure to the IL-2 receptor, when measured by BLI, is at least 1.5:1, at least 2:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 50:1, at least 100:1, at least 500:1, at least 10 ² :1, at least 5 x 10 ² :1, at least 10 ³ :1, at least 5 x 10 ³ :1, at least 10 ⁴ :1, at least 10 ⁵ :1, or at least 10 ⁶ :1. In some cases, where a control TMMP comprises a wild-type IL-2 polypeptide, and where a TMMP of a chimeric molecule of the present disclosure comprises a variant IL-2 polypeptide (comprising from 1 to 10 amino acid substitutions relative to the amino acid sequence of the wild-type IL-2 polypeptide) as the immunomodulatory polypeptide, the ratio of: i) the binding affinity of the control TMMP to an IL-2 receptor (i.e., the cognate co-immunomodulatory polypeptide) to ii) the binding affinity of the TMMP of a chimeric molecule the present disclosure to the IL-2 receptor, when measured by BLI, is in a range of from 1.5:1 to 10 ⁶ :1, e.g., from 1.5:1 to 10:1, from 10:1 to 50:1, from 50:1 to 10 ² :1, from 10 ² :1 to 10 ³ :1, from10 ³ :1 to 10 ⁴ :1, from 10 ⁴ :1 to 10 ⁵ :1, or from 10 ⁵ :1 to 10 ⁶ :1. [0064] As another example, where a control TMMP comprises a wild-type CD80 polypeptide, and where a TMMP of the present disclosure comprises a variant CD80 polypeptide (comprising from 1 to 10 amino acid substitutions relative to the amino acid sequence of the wild-type CD80 polypeptide) as the immunomodulatory polypeptide, the ratio of: i) the binding affinity of the control TMMP to a CTLA4 polypeptide (i.e., the cognate co-immunomodulatory polypeptide) to ii) the binding affinity of the TMMP of the present disclosure to the CTLA4 polypeptide, when measured by BLI, is at least 1.5:1, at least 2:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 50:1, at least 100:1, at least 500:1, at least 10 ² :1, at least 5 x 10 ² :1, at least 10 ³ :1, at least 5 x 10 ³ :1, at least 10 ⁴ :1, at least 10 ⁵ :1, or at least 10 ⁶ :1. [0065] As another example, where a control TMMP comprises a wild-type CD80 polypeptide, and where a TMMP of the present disclosure comprises a variant CD80 polypeptide (comprising from 1 to 10 amino acid substitutions relative to the amino acid sequence of the wild-type CD80 polypeptide) as the immunomodulatory polypeptide, the ratio of: i) the binding affinity of the control TMMP to a CD28 polypeptide (i.e., the cognate co-immunomodulatory polypeptide) to ii) the binding affinity of the TMMP of the present disclosure to the CD28 polypeptide, when measured by BLI, is at least 1.5:1, at least 2:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 50:1, at least 100:1, at least 500:1, at least 10 ² :1, at least 5 x 10 ² :1, at least 10 ³ :1, at least 5 x 10 ³ :1, at least 10 ⁴ :1, at least 10 ⁵ :1, or at least 10 ⁶ :1. [0066] As another example, where a control TMMP comprises a wild-type 4-1BBL polypeptide, and where a TMMP of the present disclosure comprises a variant 4-1BBL polypeptide (comprising from 1 to 10 amino acid substitutions relative to the amino acid sequence of the wild-type 4-1BBL polypeptide) as the immunomodulatory polypeptide, the ratio of: i) the binding affinity of the control TMMP to a 4-1BB polypeptide (i.e., the cognate co-immunomodulatory polypeptide) to ii) the binding affinity of the TMMP of the present disclosure to the 4-1BB polypeptide, when measured by BLI, is at least 1.5:1, at least 2:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 50:1, at least 100:1, at least 500:1, at least 10 ² :1, at least 5 x 10 ² :1, at least 10 ³ :1, at least 5 x 10 ³ :1, at least 10 ⁴ :1, at least 10 ⁵ :1, or at least 10 ⁶ :1. [0067] As another example, where a control TMMP comprises a wild-type CD86 polypeptide, and where a TMMP of the present disclosure comprises a variant CD86 polypeptide (comprising from 1 to 10 amino acid substitutions relative to the amino acid sequence of the wild-type CD86 polypeptide) as the immunomodulatory polypeptide, the ratio of: i) the binding affinity of the control TMMP to a CD28 polypeptide (i.e., the cognate co-immunomodulatory polypeptide) to ii) the binding affinity of the TMMP of the present disclosure to the CD28 polypeptide, when measured by BLI, is at least 1.5:1, at least 2:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 50:1, at least 100:1, at least 500:1, at least 10 ² :1, at least 5 x 10 ² :1, at least 10 ³ :1, at least 5 x 10 ³ :1, at least 10 ⁴ :1, at least 10 ⁵ :1, or at least 10 ⁶ :1. [0068] Binding affinity of a TMMP of the present disclosure to a target T cell can be measured in the following manner: A) contacting a TMMP of the present disclosure with a target T-cell expressing on its surface: i) a cognate co-immunomodulatory polypeptide that binds the parental wild-type immunomodulatory polypeptide; and ii) a T-cell receptor that binds to the epitope, where the TMMP comprises an epitope tag, such that the TMMP binds to the target T-cell; B) contacting the target T-cell- bound TMMP with a fluorescently labeled binding agent (e.g., a fluorescently labeled antibody) that binds to the epitope tag, generating a TMMP/target T-cell/binding agent complex; C) measuring the mean fluorescence intensity (MFI) of the TMMP/target T-cell/binding agent complex using flow cytometry. The epitope tag can be, e.g., a FLAG tag, a hemagglutinin tag, a c-myc tag, a poly(histidine) tag, etc. The MFI measured over a range of concentrations of the TMMP library member provides a measure of the affinity. The MFI measured over a range of concentrations of the TMMP library member provides a half maximal effective concentration (EC ₅₀ ) of the TMMP. In some cases, the EC ₅₀ of a TMMP of the present disclosure for a target T cell is in the nM range; and the EC50 of the TMMP for a control T cell (where a control T cell expresses on its surface: i) a cognate co-immunomodulatory polypeptide that binds the parental wild-type immunomodulatory polypeptide; and ii) a T-cell receptor that does not bind to the epitope present in the TMMP) is in the μM range. In some cases, the ratio of the EC ₅₀ of a TMMP of the present disclosure for a control T cell to the EC ₅₀ of the TMMP for a target T cell is at least 1.5:1, at least 2:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 50:1, at least 100:1, at least 500:1, at least 10 ² :1, at least 5 x 10 ² :1, at least 10 ³ :1, at least 5 x 10 ³ :1, at least 10 ⁴ :1, at lease 10 ⁵ :1, or at least 10 ⁶ :1. The ratio of the EC ₅₀ of a TMMP of the present disclosure for a control T cell to the EC ₅₀ of the TMMP for a target T cell is an expression of the selectivity of the TMMP. [0069] In some cases, when measured as described in the preceding paragraph, a TMMP of the present disclosure exhibits selective binding to target T-cell, compared to binding of the TMMP library member to a control T cell that comprises: i) the cognate co-immunomodulatory polypeptide that binds the parental wild-type immunomodulatory polypeptide; and ii) a T-cell receptor that binds to an epitope other than the epitope present in the TMMP library member. Epitopes [0070] A peptide epitope present in a TMMP of a chimeric molecule of the present disclosure can have a length of at least 4 amino acids, e.g., from 4 amino acids to about 25 amino acids in length (e.g., 4 amino acids (aa), 5 aa, 6 aa, 7 aa, 8 aa, 9 aa, 10 aa, 11 aa, 12 aa, 13 aa, 14 aa, 15 aa, 16 aa, 17 aa, 18 aa, 19 aa, 20 aa, 21 aa, 22 aa, 23 aa, 24 aa, or 25 aa, including within a range of from 4 to 20 amino acids, from 6 to 18 amino acids, from 8 to 15 amino acids, from 8 to 12 amino acids, from 5 to 10 amino acids, from 10 to 20 amino acids, and from 15 to 25 amino acids in length). [0071] A TMMP of a chimeric molecule of the present disclosure comprises any of a variety of peptide epitopes. As discussed above, a peptide epitope present in a TMMP of the present disclosure is a peptide that, when complexed with MHC polypeptides, presents an epitope to a T-cell receptor (TCR). An epitope-specific T cell binds an epitope having a given amino acid sequence, i.e., a “reference” amino acid sequence, but does not substantially bind an epitope that differs from the reference amino acid sequence. For example, an epitope-specific T cell binds an epitope that differs from the reference amino acid sequence, if at all, with an affinity that is less than 10 ^-6 M, less than 10 ^-5 M, or less than 10 ^-4 M. An epitope-specific T cell can bind an epitope having a reference amino acid sequence, i.e., for which it is specific, with an affinity of at least 10 ^-7 M, at least 10 ^-8 M, at least 10 ^-9 M, or at least 10 ^-10 M. [0072] In some cases, the epitope peptide present in a TMMP of a chimeric molecule of the present disclosure presents an epitope specific to an HLA-A, -B, -C, -E, -F, or -G allele. In an embodiment, the epitope peptide present in a TMMP presents an epitope restricted to HLA-A*0101, A*0201, A*0301, A*1101, A*2301, A*2402, A*2407, A*3303, and/or A*3401. In an embodiment, the epitope peptide present in a TMMP presents an epitope restricted to HLA- B*0702, B*0801, B*1502, B*3802, B*4001, B*4601, and/or B*5301. In an embodiment, the epitope peptide present in a TMMP presents an epitope restricted to C*0102, C*0303, C*0304, C*0401, C*0602, C*0701, C*702, C*0801, and/or C*1502. [0073] In some cases, the peptide epitope is a viral epitope. In some cases, a viral epitope is an epitope present in a viral antigen encoded by a virus that infects a majority of the human population, where such viruses include, e.g., cytomegalovirus (CMV), Epstein-Barr virus (EBV), human papilloma virus, influenza virus, adenovirus, and the like. In some cases, the peptide epitope is a bacterial epitope, e.g., a bacterial epitope that is included in a vaccine and to which a majority of the human population has immunity. 1) CMV peptide epitopes [0074] In some cases, a TMMP present in a chimeric molecule of the present disclosure comprises a CMV peptide epitope, i.e., a peptide that when in an MHC/peptide complex (e.g., an HLA/peptide complex), presents a CMV epitope (i.e., an epitope present in a CMV antigen) to a T cell. As with other peptide epitopes of this disclosure, a CMV peptide epitope has a length of at least 4 amino acids, e.g., from 4 amino acids to about 25 amino acids (e.g., 4 amino acids (aa), 5 aa, 6 aa, 7 aa, 8 aa, 9 aa, 10 aa, 11 aa, 12 aa, 13 aa, 14 aa, 15 aa, 16 aa, 17 aa, 18 aa, 19 aa, 20 aa, 21 aa, 22 aa, 23 aa, 24 aa, or 25 aa, including within a range of from 4 to 20 aa., from 6 to 18 aa., from 8 to 15 aa. from 8 to 12 aa., from 5 to 10 aa., from 10 to 15 aa., from 15 to 20 aa., from 10 to 20 aa., or from 15 to 25 aa. in length). [0075] A given CMV epitope-specific T cell binds an epitope having a reference amino acid sequence of a given CMV epitope, but does not substantially bind an epitope that differs from the reference amino acid sequence. For example, a given CMV epitope-specific T cell binds a CMV epitope having a reference amino acid sequence, and binds an epitope that differs from the reference amino acid sequence, if at all, with an affinity that is less than 10 ^-6 M, less than 10 ^-5 M, or less than 10 ^-4 M. A given CMV epitope-specific T cell can bind an epitope for which it is specific with an affinity of at least 10 ^-7 M, at least 10 ^-8 M, at least 10 ^-9 M, or at least 10 ^-10 M. [0076] In some cases, a CMV peptide epitope present in a TMMP of a chimeric molecule of the present disclosure is a peptide from CMV pp65. In some cases, a CMV peptide epitope present in a TMMP of a chimeric molecule of the present disclosure is a peptide from CMV gB (glycoprotein B). [0077] For example, in some cases, a CMV peptide epitope present in a TMMP of a chimeric molecule of the present disclosure is a peptide of a CMV polypeptide having a length of at least 4 amino acids, e.g., from 4 amino acids to about 25 amino acids (e.g., 4 amino acids (aa), 5 aa, 6 aa, 7 aa, 8 aa, 9 aa, 10 aa, 11 aa, 12 aa, 13 aa, 14 aa, 15 aa, 16 aa, 17 aa, 18 aa, 19 aa, 20 aa, 21 aa, 22 aa, 23 aa, 24 aa, or 25 aa, including within a range of from 4 to 20 aa., from 6 to 18 aa., from 8 to 15 aa. from 8 to 12 aa., from 5 to 10 aa., from 10 to 15 aa., from 15 to 20 aa., from 10 to 20 aa., or from 15 to 25 aa. in length), and comprising an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following CMV pp65 amino acid sequence: [0078] Q [0079] As one non-limiting example, a CMV peptide epitope present in a TMMP of a chimeric molecule of the present disclosure has the amino acid sequence NLVPMVATV (SEQ ID NO:172) and has a length of 9 amino acids. [0080] In some cases, a CMV peptide epitope present in a TMMP of a chimeric molecule of the present disclosure is a peptide having a length of at least 4 amino acids, e.g., from 4 amino acids to about 25 amino acids (e.g., 4 amino acids (aa), 5 aa, 6 aa, 7 aa, 8 aa, 9 aa, 10 aa, 11 aa, 12 aa, 13 aa, 14 aa, 15 aa, 16 aa, 17 aa, 18 aa, 19 aa, 20 aa, 21 aa, 22 aa, 23 aa, 24 aa, or 25 aa, including within a range of from 4 to 20 aa., from 6 to 18 aa., from 8 to 15 aa. from 8 to 12 aa., from 5 to 10 aa., from 10 to 15 aa., from 15 to 20 aa., from 10 to 20 aa., or from 15 to 25 aa. in length) of a CMV polypeptide comprising an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following CMV gB amino acid sequence: [0082] In some cases, the CMV epitope present in a TMMP of a chimeric molecule of the present disclosure presents an epitope specific to an HLA-A, -B, -C, -E, -F, or -G allele. In some cases, the epitope peptide present in a TMMP presents an epitope restricted to HLA-A*0101, A*0201, A*0301, A*1101, A*2301, A*2402, A*2407, A*3303, and/or A*3401. In some cases, the CMV epitope present in a TMMP of the present disclosure presents an epitope restricted to HLA- B*0702, B*0801, B*1502, B*3802, B*4001, B*4601, and/or B*5301. In some cases, the CMV epitope present in a TMMP of a chimeric molecule of the present disclosure presents an epitope restricted to C*0102, C*0303, C*0304, C*0401, C*0602, C*0701, C*702, C*0801, and/or C*1502. As one example, in some cases, a TMMP of the present disclosure comprises: a) a CMV peptide epitope having amino acid sequence NLVPMVATV (SEQ ID NO:172) and having a length of 9 amino acids; b) an HLA-A*0201 class I heavy chain polypeptide; and c) a β2M polypeptide. 2) HPV epitopes [0083] An HPV peptide suitable for inclusion in a TMMP of a chimeric molecule of the present disclosure can be a peptide of an HPV E6 polypeptide or an HPV E7 polypeptide. The HPV epitope can be an epitope of HPV of any of a variety of genotypes, including, e.g., HPV16, HPV18, HPV31, HPV33, HPV35, HPV39, HPV45, HPV51, HPV52, HPV56, HPV58, HPV59, HPV68, HPV73, or HPV82. In some cases, the epitope is an HPV E6 epitope. In some cases, the epitope is an HPV E7 epitope. [0084] An HPV epitope present in a TMMP of a chimeric molecule of the present disclosure is a peptide specifically bound by a T-cell, i.e., the epitope is specifically bound by an HPV epitope-specific T cell. An epitope-specific T cell binds an epitope having a reference amino acid sequence, but does not substantially bind an epitope that differs from the reference amino acid sequence. For example, an epitope-specific T cell binds an epitope having a reference amino acid sequence, and binds an epitope that differs from the reference amino acid sequence, if at all, with an affinity that is less than 10 ^-6 M, less than 10 ^-5 M, or less than 10 ^-4 M. An epitope-specific T cell can bind an epitope for which it is specific with an affinity of at least 10 ^-7 M, at least 10 ^-8 M, at least 10 ^-9 M, or at least 10 ^-10 M. [0085] Examples of HPV E6 peptides suitable for inclusion in a TMMP of a chimeric molecule of the present disclosure include, but are not limited to, E618-26 (KLPQLCTEL; SEQ ID NO:124); E6 26-34 (LQTTIHDII; SEQ ID NO:125); E649-57 (VYDFAFRDL; SEQ ID NO:126); E652-60 (FAFRDLCIV; SEQ ID NO:127); E675-83 (KFYSKISEY; SEQ ID NO:128); and E680-88 (ISEYRHYCY; SEQ ID NO:129). [0086] Examples of HPV E7 peptides suitable for inclusion in a TMMP of a chimeric molecule of the present disclosure include, but are not limited to, E77-15 (TLHEYMLDL; SEQ ID NO:130); E7 [0087] In some cases, a suitable HPV peptide is an HPV E6 peptide that binds HLA-A24 (e.g., is an HLA-A2401-restricted epitope). Non-limiting examples include: VYDFAFRDL (SEQ ID NO:126); [0088] In some cases, a suitable HPV peptide is selected from the group consisting of: [0089] In some cases, a suitable HPV peptide presents an HLA-A*2401-restricted epitope. Non-limiting examples of HPV peptides presenting an HLA-A*2401-restricted epitope are: VYDFAFRDL (SEQ ID NO:126); RAHYNIVTF (SEQ ID NO:133); CDSTLRLCV (SEQ ID NO:134); and LCVQSTHVDI (SEQ ID NO:135). In some cases, an HPV peptide suitable for inclusion in a TMMP of a chimeric molecule of the present disclosure is VYDFAFRDL (SEQ ID NO:126). In some cases, an HPV peptide suitable for inclusion in a TMMP of a chimeric molecule of the present disclosure is RAHYNIVTF (SEQ ID NO:132). In some cases, an HPV peptide suitable for inclusion in a TMMP of the present disclosure is CDSTLRLCV (SEQ ID NO:134). In some cases, an HPV peptide suitable for inclusion in a TMMP of a chimeric molecule of the present disclosure is LCVQSTHVDI (SEQ ID NO:135). 3) Influenza virus epitopes [0090] Influenza virus peptides that are suitable for inclusion as a peptide epitope of a TMMP of a chimeric molecule of the present disclosure include peptides of from 4 amino acids to 25 amino acids in length of an influenza polypeptide, e.g., an influenza polypeptide that is included in a vaccine, or that is present in an influenza virus that infects a human. As one example, an influenza virus peptide that is suitable for inclusion as a peptide epitope of a TMMP of a chimeric molecule of the present disclosure can be a peptide of from 4 amino acids to 25 amino acids in length of an influenza virus nucleoprotein. As another example, an influenza virus peptide that is suitable for inclusion as a peptide epitope of a TMMP of a chimeric molecule of the present disclosure can be a peptide of from 4 amino acids to 25 amino acids in length of an influenza virus hemagglutinin polypeptide. As another example, an influenza virus peptide that is suitable for inclusion as a peptide epitope of a TMMP of a chimeric molecule of the present disclosure can be a peptide of from 4 amino acids to 25 amino acids in length of an influenza A virus Matrix protein 1. As another example, an influenza virus peptide that is suitable for inclusion as a peptide epitope of a TMMP of a chimeric molecule of the present disclosure can be a peptide of from 4 amino acids to 25 amino acids in length of an influenza virus neuraminidase polypeptide. In some cases, the peptide is a peptide that presents an immunodominant influenza virus protein epitope. One non- limiting example of a suitable influenza peptide is a peptide having the sequence GILGFVFTL (SEQ ID NO:160) and having a length of 9 amino acids. 4) Tetanus epitopes [0091] Tetanus peptides that are suitable for inclusion as a peptide epitope of a TMMP of a chimeric molecule of the present disclosure include peptides of from 4 amino acids to 25 amino acids in length of a tetanus toxin. Examples of suitable tetanus peptides include, but are not limited to, MHC polypeptides [0092] As noted above, a TMMP of a chimeric molecule of the present disclosure includes MHC polypeptides. For the purposes of the instant disclosure, the term “major histocompatibility complex (MHC) polypeptides” is meant to include MHC polypeptides of various species, including human MHC (also referred to as human leukocyte antigen (HLA)) polypeptides, rodent (e.g., mouse, rat, etc.) MHC polypeptides, and MHC polypeptides of other mammalian species (e.g., lagomorphs, non-human primates, canines, felines, ungulates (e.g., equines, bovines, ovines, caprines, etc.), and the like. The term “MHC polypeptide” is meant to include Class I MHC polypeptides (e.g., β-2 microglobulin and MHC class I heavy chain). [0093] In some cases, the first MHC polypeptide is an MHC Class I β2M (β2M) polypeptide, and the second MHC polypeptide is an MHC Class I heavy chain (H chain) (“MHC-H”)). In other instances, the first MHC polypeptide is an MHC Class I heavy chain polypeptide; and the second MHC polypeptide is a β2M polypeptide. In some cases, both the β2M and MHC-H chain are of human origin; i.e., the MHC- H chain is an HLA heavy chain, or a variant thereof. Unless expressly stated otherwise, a TMMP of the present disclosure does not include membrane anchoring domains (transmembrane regions) of an MHC Class I heavy chain, or a part of MHC Class I heavy chain sufficient to anchor the resulting TMMP to a cell (e.g., eukaryotic cell such as a mammalian cell) in which it is expressed. In some cases, the MHC Class I heavy chain present in a TMMP of the present disclosure does not include a signal peptide, a transmembrane domain, or an intracellular domain (cytoplasmic tail) associated with a native MHC Class I heavy chain. Thus, e.g., in some cases, the MHC Class I heavy chain present in a TMMP of the present disclosure includes only the α1, α2, and α3 domains of an MHC Class I heavy chain. In some cases, the MHC Class I heavy chain present in a TMMP of the present disclosure has a length of from about 270 amino acids (aa) to about 290 aa. In some cases, the MHC Class I heavy chain present in a TMMP of the present disclosure has a length of 270 aa, 271 aa, 272 aa, 273 aa, 274 aa, 275 aa, 276 aa, 277 aa, 278 aa, 279 aa, 280 aa, 281 aa, 282 aa, 283 aa, 284 aa, 285 aa, 286 aa, 287 aa, 288 aa, 289 aa, or 290 aa. [0094] In some cases, an MHC polypeptide of a TMMP is a human MHC polypeptide, where human MHC polypeptides are also referred to as “human leukocyte antigen” (“HLA”) polypeptides. In some cases, an MHC polypeptide of a TMMP is a Class I HLA polypeptide, e.g., a β2-microglobulin polypeptide, or a Class I HLA heavy chain polypeptide. Class I HLA heavy chain polypeptides include HLA-A heavy chain polypeptides, HLA-B heavy chain polypeptides, HLA-C heavy chain polypeptides, HLA-E heavy chain polypeptides, HLA-F heavy chain polypeptides, and HLA-G heavy chain polypeptides. MHC Class I heavy chains [0095] In some cases, an MHC Class I heavy chain polypeptide present in a TMMP of the present disclosure comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to all or part (e.g., 50, 75, 100, 150, 200, or 250 contiguous amino acids) of the amino acid sequence of any of the human HLA heavy chain polypeptides depicted in FIGs.5-11. In some cases, the MHC Class I heavy chain has a length of 270 aa, 271 aa, 272 aa, 273 aa, 274 aa, 275 aa, 276 aa, 277 aa, 278 aa, 279 aa, 280 aa, 281 aa, 282 aa, 283 aa, 284 aa, 285 aa, 286 aa, 287 aa, 288 aa, 289 aa, or 290 aa. In some cases, an MHC Class I heavy chain polypeptide present in a TMMP of the present disclosure comprises 1-30, 1-5, 5-10, 10-15, 15-20, 20-25 or 25-30 amino acid insertions, deletions, and/or substitutions (in addition to those locations indicated as being variable in the heavy chain consensus sequences) of any one of the amino acid sequences depicted in FIGs 5-11. In some cases, the MHC Class I heavy chain does not include transmembrane or cytoplasmic domains. As an example, a MHC Class I heavy chain polypeptide of a TMMP of the present disclosure can comprise an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to amino acids 25-300 (lacking all, or substantially all, of the leader, transmembrane and cytoplasmic sequence) or amino acids 25-365 (lacking the leader) of a human HLA-A heavy chain polypeptides depicted in any one of FIG.5A, 5B, and 5C. [0096] FIGs.5A, 5B and 5C provide amino acid sequences of human leukocyte antigen (HLA) Class I heavy chain polypeptides. Signal sequences, amino acids 1-24, are bolded and underlined. FIG.5A entry: 3A.1 is the HLA-A heavy chain (HLA-A*01:01:01:01 or A*0101) (NCBI accession NP_001229687.1), SEQ ID NO:392; entry 3A.2 is from HLA-A*1101 SEQ ID NO:393; entry 3A.3 is from HLA-A*2402 SEQ ID NO:394 and entry 3A.4 is from HLA-A*3303 SEQ ID NO:395. FIG.5B provides the sequence HLA-B*07:02:01 (HLA-B*0702) NCBI GenBank Accession NP_005505.2 (see also GenBank Accession AUV50118.1.). FIG.5C provides the sequence HLA- C*0701 (GenBank Accession NP_001229971.1) (HLA-C*07:01:01:01 or HLA-Cw*070101, HLA-Cw*07 see GenBank Accession CAO78194.1). [0097] FIG.6 provides an alignment of eleven mature MHC class I heavy chain amino acid sequences without their leader sequences or transmembrane domains or intracellular domains. The aligned sequences are human HLA-A, HLA-B, and HLA-C, a mouse H2K protein sequence, three variants of HLA-A (var.1, var.2C, and var.2CP), and 3 human HLA-A variants (HLA-A*1101; HLA-A*2402; and HLA-A*3303). Indicated in the alignment are the locations (84 and 139 of the mature proteins) where cysteine residues may be introduced (e.g., by substitution) for the formation of a disulfide bond to stabilize the MHC H chain – β2M complex. Also shown in the alignment is position 236 (of the mature polypeptide), which may be substituted by a cysteine residue that can form an inter-chain disulfide bond with β2M (e.g., at aa 12). An arrow appears above each of those locations and the residues are bolded. The seventh HLA-A sequence shown in the alignment (var.2c), shows the sequence of variant 2 substituted with C residues at positions 84, 139 and 236. The boxes flanking residues 84, 139 and 236 show the groups of five amino acids on either sides of those six sets of five residues, denoted aac1 (for “amino acid cluster 1”), aac2 (for “amino acid cluster 2”), aac3 (for “amino acid cluster 3”), aac4 (for “amino acid cluster 4”), aac5 (for “amino acid cluster 5”), and aac6 (for “amino acid cluster 6”), that may be replaced by 1 to 5 amino acids selected independently from (i) any naturally occurring amino acid or (ii) any naturally occurring amino acid except proline or glycine. [0098] With regard to FIG.6, in some cases: i) aac1 (amino acid cluster 1) may be the amino acid sequence GTLRG (SEQ ID NO:174) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., L replaced by I, V, A or F); ii) aac2 (amino acid cluster 2) may be the amino acid sequence YNQSE (SEQ ID NO:175) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., N replaced by Q, Q replaced by N, and/or E replaced by D); iii) aac3 (amino acid cluster 3) may be the amino acid sequence TAADM (SEQ ID NO:176) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., T replaced by S, A replaced by G, D replaced by E, and/or M replaced by L, V, or I); iv) aac4 (amino acid cluster 4) may be the amino acid sequence AQTTK (SEQ ID NO:177) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., A replaced by G, Q replaced by N, or T replaced by S, and/or K replaced by R or Q); v) aac5 (amino acid cluster 5) may be the amino acid sequence VETRP (SEQ ID NO:178) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., V replaced by I or L, E replaced by D, T replaced by S, and/or R replaced by K); and/or vi) aac6 (amino acid cluster 6) may be the amino acid sequence GDGTF (SEQ ID NO:179) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., D replaced by E, T replaced by S, or F replaced by L, W, or Y). [0099] FIGs.7-9 provide alignments of mature HLA class I heavy chain amino acid sequences (without leader sequences or transmembrane domains or intracellular domains). The aligned amino acid sequences in FIG.7A are HLA-A class I heavy chains of the following alleles: A*0101, A*0201, A*0301, A*1101, A*2301, A*2402, A*2407, A*3303, and A*3401. The aligned amino acid sequences in FIG.8A are HLA-B class I heavy chains of the following alleles: B*0702, B*0801, B*1502, B*3802, B*4001, B*4601, and B*5301. The aligned amino acid sequences in FIG.9A are HLA-C class I heavy chains of the following alleles: C*0102, C*0303, C*0304, C*0401, C*0602, C*0701, C*0801, and C*1502. Indicated in the alignments are the locations (84 and 139 of the mature proteins) where cysteine residues may be introduced (e.g., by substitution) for the formation of a disulfide bond to stabilize the HLA H chain – β2M complex. Also shown in the alignment is position 236 (of the mature polypeptide), which may be substituted by a cysteine residue that can form an inter-chain disulfide bond with β2M (e.g., at aa 12). The boxes flanking residues 84, 139 and 236 show the groups of five amino acids on either sides of those six sets of five residues, denoted aac1 (for “amino acid cluster 1”), aac2 (for “amino acid cluster 2”), aac3 (for “amino acid cluster 3”), aac4 (for “amino acid cluster 4”), aac5 (for “amino acid cluster 5”), and aac6 (for “amino acid cluster 6”), that may be replaced by 1 to 5 amino acids selected independently from (i) any naturally occurring amino acid or (ii) any naturally occurring amino acid except proline or glycine. [00100] FIGs.7A, 8A, and 9A provide alignments of the amino acid sequences of mature HLA- A, -B, and -C class I heavy chains, respectively. The sequences are provided for the extracellular portion of the mature protein (without leader sequences or transmembrane domains or intracellular domains). As described in FIG.6, the positions of aa residues 84, 139, and 236 and their flanking residues (aac1 to aac6) that may be replaced by 1 to 5 amino acids selected independently from (i) any naturally occurring amino acid or (ii) any naturally occurring amino acid except proline or glycine ae also shown. FIG.7B, 8B, and 9B provide consensus amino acid sequences for the HLA-A, -B, and -C sequences, respectively, provide in FIG.7A, 8A, and 9A. The consensus sequences show the variable amino acid positions as “X” residues sequentially numbered and the locations of amino acids 84, 139 and 236 double underlined. [00101] With regard to FIG.7A, in some cases: i) aac1 (amino acid cluster 1) may be the amino acid sequence GTLRG (SEQ ID NO:174) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., L replaced by I, V, A or F); ii) aac2 (amino acid cluster 2) may be the amino acid sequence YNQSE (SEQ ID NO:175) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., N replaced by Q, Q replaced by N, and/or E replaced by D); iii) aac3 (amino acid cluster 3) may be the amino acid sequence TAADM (SEQ ID NO:176) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., T replaced by S, A replaced by G, D replaced by E, and/or M replaced by L, V, or I); iv) aac4 (amino acid cluster 4) may be the amino acid sequence AQTTK (SEQ ID NO:177) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., A replaced by G, Q replaced by N, or T replaced by S, and or K replaced by R or Q); v) aac5 (amino acid cluster 5) may be the amino acid sequence VETRP (SEQ ID NO:178) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., V replaced by I or L, E replaced by D, T replaced by S, and/or R replaced by K); and/or vi) aac6 (amino acid cluster 6) may be the amino acid sequence GDGTF (SEQ ID NO:179) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., D replaced by E, T replaced by S, or F replaced by L, W, or Y). [00102] With regard to FIG.8A, in some cases: i) aac1 (amino acid cluster 1) may be the amino acid sequence RNLRG (SEQ ID NO:180) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., N replaced by T or I; and/or L replaced by A; and/or the second R replaced by L; and/or the G replaced by R); ii) aac2 (amino acid cluster 2) may be the amino acid sequence YNQSE (SEQ ID NO:175) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., N replaced by Q, Q replaced by N, and/or E replaced by D); iii) aac3 (amino acid cluster 3) may be the amino acid sequence TAADT (SEQ ID NO:181) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., the first T replaced by S; and/or A replaced by G; and/or D replaced by E; and/or the second T replaced by S); iv) aac4 (amino acid cluster 4) may be the amino acid sequence AQITQ (SEQ ID NO:182) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., A replaced by G; and/or the first Q replaced by N; and/or I replaced by L or V; and/or the T replaced by S; and/or the second Q replaced by N); v) aac5 (amino acid cluster 5) may be the amino acid sequence VETRP (SEQ ID NO:178) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., V replaced by I or L, E replaced by D, T replaced by S, and/or R replaced by K); and/or vi) aac6 (amino acid cluster 6) may be the amino acid sequence GDRTF (SEQ ID NO:183) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., D replaced by E; and/or T replaced by S; and/or R replaced by K or H; and/or F replaced by L, W, or Y). [00103] With regard to FIG.9A, in some cases: i) aac1 (amino acid cluster 1) may be the amino acid sequence RNLRG (SEQ ID NO:180) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., N replaced by K; and/or L replaced by A or I; and/or the second R replaced by H; and/or the G replaced by T or S); ii) aac2 (amino acid cluster 2) may be the amino acid sequence YNQSE (SEQ ID NO:175) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., N replaced by Q, Q replaced by N, and/or E replaced by D); iii) aac3 (amino acid cluster 3) may be the amino acid sequence TAADT (SEQ ID NO:181) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., the first T replaced by S; and/or A replaced by G; and/or D replaced by E; and/or the second T replaced by S); iv) aac4 (amino acid cluster 4) may be the amino acid sequence AQITQ (SEQ ID NO:182) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., A replaced by G; and/or the first Q replaced by N; and/or I replaced by L; and/or the second Q replaced by N or K); v) aac5 (amino acid cluster 5) may be the amino acid sequence VETRP (SEQ ID NO:178) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., V replaced by I or L, E replaced by D, T replaced by S, and/or R replaced by K or H); and/or vi) aac6 (amino acid cluster 6) may be the amino acid sequence GDGTF (SEQ ID NO:179) or that sequence with one or two amino acids deleted or substituted with other naturally occurring amino acids (e.g., D replaced by E; and/or T replaced by S; and/or F replaced by L, W, or Y). 1) HLA-A [00104] In some cases, a TMMP of the present disclosure comprises an HLA-A heavy chain polypeptide. The HLA-A heavy chain peptide sequences, or portions thereof, that may be that may be incorporated into a TMMP of the present disclosure include, but are not limited to, the alleles: A*0101, A*0201, A*0301, A*1101, A*2301, A*2402, A*2407, A*3303, and A*3401, which are aligned without all, or substantially all, of the leader, transmembrane and cytoplasmic sequences in FIG.7A. Any of those alleles may comprise a mutation at one or more of positions 84, 139 and/or 236 (as shown in FIG. 7A) selected from: a tyrosine to alanine at position 84 (Y84A); a tyrosine to cysteine at position 84 (Y84C); an alanine to cysteine at position 139 (A139C); and an alanine to cysteine substitution at position 236 (A236C). In addition, HLA-A sequence having at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%) or 100% amino acid sequence identity to all or part (e.g., 50, 75, 100, 150, 200, or 250 contiguous amino acids) of the sequence of those HLA-A alleles may also be employed (e.g., it may comprise 1-25, 1-5, 5-10, 10-15, 15-20, 20-25, or 25-30 amino acid insertions, deletions, and/or substitutions). [00105] In some cases, a TMMP of the present disclosure comprises an HLA-A heavy chain polypeptide comprising the following HLA-A consensus amino acid sequence: [00107] As one example, an MHC Class I heavy chain polypeptide of a TMMP can comprise an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-A heavy chain amino acid sequence: [00108] In some cases, an HLA-A heavy chain polypeptide suitable for inclusion in a TMMP of the present disclosure comprises the following amino acid sequence: is also referred to as “HLA-A*0201” or simply “HLA-A02.” In some cases, the C-terminal Pro is not included in a TMMP of the present disclosure. For example, in some cases, an HLA-A02 polypeptide suitable for inclusion in a TMMP of the present disclosure comprises the following amino acid sequence: 2) HLA-A (Y84A; A236C) [00109] In some cases, the MHC Class I heavy chain polypeptide comprises Y84A and A236C substitutions. For example, in some cases, the MHC Class I heavy chain polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-A heavy chain (Y84A; A236C) amino acid sequence: acid 236 is Cys. In some cases, the Cys-236 forms an interchain disulfide bond with Cys-12 of a variant β2M polypeptide that comprises an R12C substitution. [00110] In some cases, an HLA-A heavy chain polypeptide suitable for inclusion in a TMMP of the present disclosure is an HLA-A02 (Y84A; A236C) polypeptide comprising the following amino acid sequence: [00111] In some cases, an HLA-A heavy chain polypeptide suitable for inclusion in a TMMP of the present disclosure is an HLA-A02 (Y84A; A236C) polypeptide comprising the following amino acid sequence: 3) HLA-A (Y84C; A139C) [00112] In some cases, the MHC Class I heavy chain polypeptide comprises Y84C and A139C substitutions. For example, in some cases, the MHC Class I heavy chain polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-A heavy chain (Y84C; A139C) amino acid sequence: acid 139 is Cys. In some cases, Cys-84 forms an intrachain disulfide bond with Cys-139. 4) HLA-A11 (HLA-A*1101) [00113] As one non-limiting example, an MHC Class I heavy chain polypeptide of a TMMP can comprise an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA- A11 heavy chain amino acid sequence: Such an MHC Class I heavy chain may be prominent in Asian populations, including populations of individuals of Asian descent. 5) HLA-A11 (Y84A; A236C) [00114] As one non-limiting example, in some cases, the MHC Class I heavy chain polypeptide is an HLA-A11 allele that comprises Y84A and A236C substitutions. For example, in some cases, the MHC Class I heavy chain polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-A A11 heavy chain (Y84A; A236C) amino acid sequence: where amino acid 84 is Ala and amino acid 236 is Cys. In some cases, the Cys-236 forms an interchain disulfide bond with Cys-12 of a variant β2M polypeptide that comprises an R12C substitution. 6) HLA-A24 (HLA-A*2402) [00115] As one non-limiting example, an MHC Class I heavy chain polypeptide of a TMMP of the present disclosure can comprise an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-A24 heavy chain amino acid sequence: ( ) Such an MHC Class I heavy chain may be prominent in Asian populations, including populations of individuals of Asian descent. In some cases, amino acid 84 is an Ala. In some cases, amino acid 84 is a Cys. In some cases, amino acid 236 is a Cys. In some cases, amino acid 84 is an Ala and amino acid 236 is a Cys. In some cases, amino acid 84 is an Cys and amino acid 236 is a Cys. 7) HLA-A33 (HLA-A*3303) [00116] As one non-limiting example, an MHC Class I heavy chain polypeptide of a TMMP of the present disclosure can comprise an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-A33 heavy chain amino acid sequence: ( ) Such an MHC Class I heavy chain may be prominent in Asian populations, including populations of individuals of Asian descent. In some cases, amino acid 84 is an Ala. In some cases, amino acid 84 is a Cys. In some cases, amino acid 236 is a Cys. In some cases, amino acid 84 is an Ala and amino acid 236 is a Cys. In some cases, amino acid 84 is an Cys and amino acid 236 is a Cys. 8) HLA-B [00117] In some cases, a TMMP of the present disclosure comprises an HLA-B heavy chain polypeptide. The HLA-B heavy chain peptide sequences, or portions thereof, that may be that may be incorporated into a TMMP of the present disclosure include, but are not limited to, the alleles: B*0702, B*0801, B*1502, B*3802, B*4001, B*4601, and B*5301, which are aligned without all, or substantially all, of the leader, transmembrane and cytoplasmic sequences in FIG.8A. Any of those alleles may comprise a mutation at one or more of positions 84, 139 and/or 236 (as shown in FIG.8A) selected from: a tyrosine to alanine at position 84 (Y84A); a tyrosine to cysteine at position 84 (Y84C); an alanine to cysteine at position 139 (A139C); and an alanine to cysteine substitution at position 236 (A236C). In addition, a HLA-B polypeptide comprising an amino acid sequence having at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%) or 100% amino acid sequence identity to all or part (e.g., 50, 75, 100, 150, 200, or 250 contiguous amino acids) of the sequence of those HLA-B alleles may also be employed (e.g., it may comprise 1-25, 1-5, 5-10, 10-15, 15-20, 20-25, or 25-30 amino acid insertions, deletions, and/or substitutions). [00118] In some cases, a TMMP of the present disclosure comprises an HLA-B heavy chain polypeptide comprising the following HLA-B consensus amino acid sequence: S; X24 is R or S; X25 is S or T; X26 is L or W; X27 is E OR V; X28 is R, D, L or W; X29 is A or T; X30 is L, E or T; X31 is E or D; X32 is K or T; X33 is E or Q; and X34 is I or V. [00120] As an example, an MHC Class I heavy chain polypeptide of a TMMP of the present disclosure can comprise an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-B heavy chain amino acid sequence: [00121] As one non-limiting example, in some cases, the MHC Class I heavy chain polypeptide is an HLA-B polypeptide that comprises Y84A and A236C substitutions. For example, in some cases, the MHC Class I heavy chain polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-B heavy chain (Y84A; A236C) amino acid sequence: 236 is Cys. In some cases, the Cys-236 forms an interchain disulfide bond with Cys-12 of a variant β2M polypeptide that comprises an R12C substitution. 10) HLA-B (Y84C; A139C) [00122] In some cases, the MHC Class I heavy chain polypeptide comprises Y84C and A139C substitutions. For example, in some cases, the MHC Class I heavy chain polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-B heavy chain (Y84C; A139C) amino acid sequence: GEEQRYTCHVQHEGLPKPLTLRWEP (SEQ ID NO:197), where amino acid 84 is Cys and amino acid 139 is Cys. In some cases, Cys-84 forms an intrachain disulfide bond with Cys-139. 11) HLA-B*0702 [00123] As an example, in some cases, a MHC Class I heavy chain polypeptide present in a TMMP of the present disclosure comprises an amino acid sequence of HLA-B*0702 (SEQ ID NO:195) in FIG.8A, or a sequence having at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%) or 100%, amino acid sequence identity to all or part (e.g., 50, 75, 100, 150, 200, or 250 contiguous amino acids) of that sequence (e.g., it may comprise 1-25, 1-5, 5-10, 10-15, 15-20, 20-25, or 25-30 amino acid insertions, deletions, and/or substitutions). In some cases, where the HLA-B heavy chain polypeptide of TMMP of the present disclosure has less than 100% identity to the sequence labeled HLA-B in FIG.6, or labeled “B*0702 in FIG.8A, it may comprise a mutation at one or more of positions 84, 139 and/or 236 selected from: a tyrosine to alanine substitution at position 84 (Y84A); a tyrosine to cysteine substitution at position 84 (Y84C); an alanine to cysteine at position 139 (A139C); and an alanine to cysteine substitution at position 236 (A236C). In some cases, the HLA-B heavy chain polypeptide of TMMP of the present disclosure comprises Y84A and A236C substitutions. In some cases, the HLA-B*0702 heavy chain polypeptide of TMMP of the present disclosure comprises Y84C and A139C substitutions. In some cases, the HLA-B heavy chain polypeptide of TMMP of the present disclosure comprises Y84C, A139C, and A236C substitutions. 12) HLA-C [00124] In some cases, a TMMP of the present disclosure comprises an HLA-C heavy chain polypeptide. The HLA-C heavy chain polypeptide, or portions thereof, that may be that may be incorporated into a TMMP of the present disclosure include, but are not limited to, the alleles: C*0102, C*0303, C*0304, C*0401, C*0602, C*0701, C*0801, and C*1502, which are aligned without all, or substantially all, of the leader, transmembrane and cytoplasmic sequences in FIG.9A. Any of those alleles may comprise a mutation at one or more of positions 84, 139 and/or 236 (as shown in FIG.9A) selected from: a tyrosine to alanine substitution at position 84 (Y84A); a tyrosine to cysteine substitution at position 84 (Y84C); an alanine to cysteine substitution at position 139 (A139C); and an alanine to cysteine substitution at position 236 (A236C). In addition, an HLA-C polypeptide comprising an amino acid sequence having at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%) or 100% amino acid sequence identity to all or part (e.g., 50, 75, 100, 150, 200, or 250 contiguous amino acids) of the sequence of those HLA-C alleles may also be employed (e.g., it may comprise 1-25, 1-5, 5-10, 10-15, 15-20, 20-25, or 25-30 amino acid insertions, deletions, and/or substitutions). [00125] In some cases, a TMMP of the present disclosure comprises an HLA-C heavy chain polypeptide comprising the following HLA-C consensus amino acid sequence: [00127] As an example, an MHC Class I heavy chain polypeptide of a TMMP of the present disclosure can comprise an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-C heavy chain amino acid sequence: [00128] As one non-limiting example, in some cases, the MHC Class I heavy chain polypeptide is an HLA-C polypeptide that comprises Y84A and A236C substitutions. For example, in some cases, the MHC Class I heavy chain polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-C heavy chain (Y84A; A236C) amino acid sequence: acid 236 is Cys. In some cases, the Cys-236 forms an interchain disulfide bond with Cys-12 of a variant β2M polypeptide that comprises an R12C substitution. 14) HLA-C (Y84C; A139C) [00129] In some cases, the MHC Class I heavy chain polypeptide comprises Y84C and A139C substitutions. For example, in some cases, the MHC Class I heavy chain polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following human HLA-C heavy chain (Y84C; A139C) amino acid sequence: [00130] In some cases, a MHC Class I heavy chain polypeptide of a TMMP of the present disclosure comprises an amino acid sequence of HLA-C*0701 of FIG.9A (labeled HLA-C in FIG.6), or an amino acid sequence having at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%) or 100% amino acid sequence identity to all or part (e.g., 50, 75, 100, 150, 200, or 250 contiguous amino acids) of that sequence (e.g., it may comprise 1-25, 1-5, 5-10, 10-15, 15-20, 20-25, or 25-30 amino acid insertions, deletions, and/or substitutions). In some cases, where the HLA-C heavy chain polypeptide of a TMMP of the present disclosure has less than 100% identity to the sequence labeled HLA-C*0701 in FIG.9A, it may comprise a mutation at one or more of positions 84, 139 and/or 236 selected from: a tyrosine to alanine substitution at position 84 (Y84A); a tyrosine to cysteine substitution at position 84 (Y84C); an alanine to cysteine at position 139 (A139C); and an alanine to cysteine substitution at position 236 (A236C). In some cases, the HLA-C heavy chain polypeptide of a TMMP of the present disclosure comprises Y84A and A236C substitutions. In some cases, the HLA-C*0701 heavy chain polypeptide of a TMMP or its epitope conjugate comprises Y84C and A139C substitutions. In some cases, the HLA-C heavy chain polypeptide of a TMMP of the present disclosure comprises Y84C, A139C, and A236C substitutions. Non-classical HLA-E, -F, and -G MHC Class I heavy chains [00131] In some cases, a TMMP of the present disclosure comprises a non-classical MHC Class I heavy chain polypeptide. Among the non-classical HLA heavy chain polypeptides, or portions thereof, that may be that may be incorporated into a TMMP of the present disclosure include, but are not limited to, those of HLA-E, -F, and -G alleles. Amino acid sequences for HLA-E, -F, and -G heavy chain polypeptides, (and the HLA-A, B and C alleles) may be found on the world wide web hla.alleles.org/ nomenclature/index.html, the European Bioinformatics Institute (www(dot)ebi(dot)ac(dot)uk), which is part of the European Molecular Biology Laboratory(EMBL), and at the National Center for Biotechnology Information (www(dot)ncbi(dot)nlm(dot)nih(dot)gov). [00132] Non-limiting examples of suitable HLA-E alleles include, but are not limited to, HLA- E*0101 (HLA-E*01:01:01:01), HLA-E*01:03(HLA-E*01:03:01:01), HLA-E*01:04, HLA-E*01:05, HLA-E*01:06, HLA-E*01:07, HLA-E*01:09, and HLA-E*01:10. Non-limiting examples of suitable HLA-F alleles include, but are not limited to, HLA-F*0101 (HLA-F*01:01:01:01), HLA-F*01:02, HLA- F*01:03(HLA-F*01:03:01:01), HLA-F*01:04, HLA-F*01:05, and HLA-F*01:06. Non-limiting examples of suitable HLA-G alleles include, but are not limited to, HLA-G*0101 (HLA-G*01:01:01:01), HLA-G*01:02, HLA-G*01:03(HLA-G*01:03:01:01), HLA-G*01:04 (HLA-G*01:04:01:01), HLA- G*01:06, HLA-G*01:07, HLA-G*01:08, HLA-G*01:09: HLA-G*01:10, HLA-G*01:10, HLA-G*01:11, HLA-G*01:12, HLA-G*01:14, HLA-G*01:15, HLA-G*01:16, HLA-G*01:17, HLA-G*01:18: HLA- G*01:19, HLA-G*01:20, and HLA-G*01:22. Consensus sequences for those HLA E, -F and -G alleles without all, or substantially all, of the leader, transmembrane and cytoplasmic sequences are provided in FIG.10, and aligned with consensus sequences of the above-mentioned HLA-A, -B and -C alleles in FIG.11. [00133] FIG.11 provides a consensus sequence for each of HLA-E, -F, and -G with the variable aa positions indicated as “X” residues sequentially numbered and the locations of aas 84, 139 and 236 double underlined. [00134] FIG.11 provides an alignment of the consensus amino acid sequences for HLA-A, -B, - C, -E, -F, and -G, which are given in FIGs.7-11. Variable residues in each sequence are listed as “X” with the sequential numbering removed. As indicated in FIG.6, the locations of aas 84, 139 and 236 are indicated with their flanking five-amino acid clusters that may be replaced by 1 to 5 amino acids selected independently from (i) any naturally occurring amino acid or (ii) any naturally occurring amino acid except proline or glycine are also shown. [00135] Any of the above-mentioned HLA-E, -F, and/or -G alleles may comprise a substitution at one or more of positions 84, 139 and/or 236 as shown in FIG.11 for the consensus sequences. In some cases, the substitutions may be selected from a: position 84 tyrosine to alanine (Y84A) or cysteine (Y84C), or, in the case of HLA-F, an R84A or R84C substitution; a position 139 alanine to cysteine (A139C), or, in the case of HLA-F, a V139C; and an alanine to cysteine substitution at position 236 (A236C). In addition, an HLA-E, -F and /or -G sequence having at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%) or 100% amino acid sequence identity to all or part (e.g., 50, 75, 100, 150, 200, or 250 contiguous amino acids) of any of the consensus sequences of set forth in FIG.11 may also be employed (e.g., the sequences may comprise 1-25, 1-5, 5-10, 10-15, 15- 20, 20-25, or 25-30 amino acid insertions, deletions, and/or substitutions in addition to changes at variable residues listed therein). Mouse H2K [00136] In some cases, a MHC Class I heavy chain polypeptide present in a TMMP of the present disclosure comprises an amino acid sequence of MOUSE H2K (SEQ ID NO:401) (MOUSE H2K in FIG.6), or a sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100% amino acid sequence identity to all or part (e.g., 50, 75, 100, 150, 200, or 250 contiguous amino acids) of that sequence (e.g., it may comprise 1-25, 1-5, 5-10, 10-15, 15-20, 20- 25, or 25-30 amino acid insertions, deletions, and/or substitutions). In some cases, where the MOUSE H2K heavy chain polypeptide of a TMMP of the present disclosure has less than 100% identity to the sequence labeled MOUSE H2K in FIG.6, it may comprise a mutation at one or more of positions 84, 139 and/or 236 selected from: a tyrosine to alanine at position 84 (Y84A); a tyrosine to cysteine at position 84 (Y84C); an alanine to cysteine at position 139 (A139C); and an alanine to cysteine substitution at position 236 (A236C). In some cases, the MOUSE H2K heavy chain polypeptide of a TMMP of the present disclosure comprises Y84A and A236C substitutions. In some cases, the MOUSE H2K heavy chain polypeptide of a TMMP of the present disclosure comprises Y84C and A139C substitutions. In some cases, the MOUSE H2K heavy chain polypeptide of a TMMP of the present disclosure comprises Y84C, A139C and A236C substitutions. Exemplary combinations [00137] Table 2, below, presents various combinations of MHC Class I heavy chain sequence modifications that can be incorporated in a TMMP of the present disclosure. TABLE 2

^ The Sequence Identity Range is the permissible range in sequence identity of an MHC-H polypeptide sequence incorporated into a TMMP relative to the corresponding portion of the sequences listed in FIG. 6-11 not counting the variable residues in the consensus sequences. Beta-2 microglobulin [00138] A β2-microglobulin (β2M) polypeptide of a TMMP of the present disclosure can be a human β2M polypeptide, a non-human primate β2M polypeptide, a murine β2M polypeptide, and the like. In some instances, a β2M polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to a β2M amino acid sequence depicted in FIG.4. In some instances, a β2M polypeptide comprises an amino acid sequence having at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to amino acids 21 to 119 of a β2M amino acid sequence depicted in FIG.4. [00139] In some cases, a suitable β2M polypeptide comprises the following amino acid sequence: and the HLA Class I heavy chain polypeptide comprises the following amino acid sequence: indicated as {C} form an disulfide bond between the α1 and α2-1 helices and tII residue forms a disulfide bond with the β2M polypeptide cysteine at position 12. In the sequence above, “aa1” is “amino acid cluster 1”; “aa2” is “amino acid cluster 2”; “aa3” is “amino acid cluster 3”; “aa4” is “amino acid cluster 4”; “aa5” is “amino acid cluster 5”; and “aa6” is “amino acid cluster 6”; see, e.g., FIG.6. Each occurrence of aa1, aa2, aa3, aa4, aa5, and aa6 is and independently selected to be 1-5 amino acid residues, wherein the amino acid residues are i) selected independently from any naturally occurring (e.g., encoded) amino acid or ii) any naturally occurring amino acid except proline or glycine. [00142] In some cases, an MHC polypeptide comprises a single amino acid substitution relative to a reference MHC polypeptide (where a reference MHC polypeptide can be a wild-type MHC polypeptide), where the single amino acid substitution substitutes an amino acid with a cysteine (Cys) residue. Such cysteine residues, when present in an MHC polypeptide of a first polypeptide of a TMMP of the present disclosure, can form a disulfide bond with a cysteine residue present in a second polypeptide chain of a TMMP of the present disclosure. [00143] In some cases, a first MHC polypeptide in a first polypeptide of a TMMP of the present disclosure, and/or the second MHC polypeptide in the second polypeptide of a TMMP of the present disclosure, includes an amino acid substitution to substitute an amino acid with a cysteine, where the substituted cysteine in the first MHC polypeptide forms a disulfide bond with a cysteine in the second MHC polypeptide, where a cysteine in the first MHC polypeptide forms a disulfide bond with the substituted cysteine in the second MHC polypeptide, or where the substituted cysteine in the first MHC polypeptide forms a disulfide bond with the substituted cysteine in the second MHC polypeptide. [00144] For example, in some cases, one of following pairs of residues in an HLA β2- microglobulin and an HLA Class I heavy chain is substituted with cysteines (where residue numbers are those of the mature polypeptide): 1) β2M residue 12, HLA Class I heavy chain residue 236; 2) β2M residue 12, HLA Class I heavy chain residue 237; 3) β2M residue 8, HLA Class I heavy chain residue 234; 4) β2M residue 10, HLA Class I heavy chain residue 235; 5) β2M residue 24, HLA Class I heavy chain residue 236; 6) β2M residue 28, HLA Class I heavy chain residue 232; 7) β2M residue 98, HLA Class I heavy chain residue 192; 8) β2M residue 99, HLA Class I heavy chain residue 234; 9) β2M residue 3, HLA Class I heavy chain residue 120; 10) β2M residue 31, HLA Class I heavy chain residue 96; 11) β2M residue 53, HLA Class I heavy chain residue 35; 12) β2M residue 60, HLA Class I heavy chain residue 96; 13) β2M residue 60, HLA Class I heavy chain residue 122; 14) β2M residue 63, HLA Class I heavy chain residue 27; 15) β2M residue Arg3, HLA Class I heavy chain residue Gly120; 16) β2M residue His31, HLA Class I heavy chain residue Gln96; 17) β2M residue Asp53, HLA Class I heavy chain residue Arg35; 18) β2M residue Trp60, HLA Class I heavy chain residue Gln96; 19) β2M residue Trp60, HLA Class I heavy chain residue Asp122; 20) β2M residue Tyr63, HLA Class I heavy chain residue Tyr27; 21) β2M residue Lys6, HLA Class I heavy chain residue Glu232; 22) β2M residue Gln8, HLA Class I heavy chain residue Arg234; 23) β2M residue Tyr10, HLA Class I heavy chain residue Pro235; 24) β2M residue Ser11, HLA Class I heavy chain residue Gln242; 25) β2M residue Asn24, HLA Class I heavy chain residue Ala236; 26) β2M residue Ser28, HLA Class I heavy chain residue Glu232; 27) β2M residue Asp98, HLA Class I heavy chain residue His192; and 28) β2M residue Met99, HLA Class I heavy chain residue Arg234. The amino acid numbering of the MHC/HLA Class I heavy chain is in reference to the mature MHC/HLA Class I heavy chain, without a signal peptide. For example, in some cases, residue 236 of the mature HLA-A amino acid sequence is substituted with a Cys. In some cases, residue 236 of the mature HLA-B amino acid sequence is substituted with a Cys. In some cases, residue 236 of the mature HLA-C amino acid sequence is substituted with a Cys. In some cases, residue 32 (corresponding to Arg-12 of mature β2M) of an amino acid sequence depicted in FIG.4 is substituted with a Cys. [00145] In some cases, a β2M polypeptide comprises the amino acid sequence: IQRTPKIQVY . In some cases, a β2M polypeptide comprises the amino acid sequence: IQRTPKIQVY SCHPAENGKS NFLNCYVSGF [00146] In some cases, an HLA Class I heavy chain polypeptide comprises the amino acid sequence: [00147] In some cases, an HLA Class I heavy chain polypeptide comprises the amino acid sequence: [00148] In some cases, an HLA Class I heavy chain polypeptide comprises the amino acid sequence: [00149] In some cases, the β2M polypeptide comprises the following amino acid sequence: [00150] IQRTPKIQVY SCHPAENGKS NFLNCYVSGF HPSDIEVDLLKNGERIEKVE HSDLSFSKDW SFYLLYYTEF TPTEKDEYAC RVNHVTLSQP KIVKWDRDM (SEQ ID NO:202); and the HLA Class I heavy chain polypeptide of a TMMP of the present disclosure comprises the following amino acid sequence: residues that are underlined and in bold form a disulfide bond with one another in the TMMP. [00152] In some cases, the β2M polypeptide comprises the amino acid sequence: IQRTPKIQVYSCHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDW SFYLL YYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM (SEQ ID NO:202). [00153] In some cases, the first polypeptide and the second polypeptide of a TMMP of the present disclosure are disulfide linked to one another through: i) a Cys residue present in a linker connecting the peptide epitope and a β2M polypeptide in the first polypeptide chain; and ii) a Cys residue present in an MHC Class I heavy chain in the second polypeptide chain. In some cases, the Cys residue present in the MHC Class I heavy chain is a Cys introduce as a Y84C substitution. In some cases, the linker connecting the peptide epitope and the β2M polypeptide in the first polypeptide chain is GCGGS(G4S)n (SEQ ID NO:206), where n is 1, 2, 3, 4, 5, 6, 7, 8, or 9. For example, in some cases, the linker comprises the amino acid sequence GCGGSGGGGSGGGGSGGGGS (SEQ ID NO:207). As another example, the linker comprises the amino acid sequence GCGGSGGGGSGGGGS (SEQ ID NO:208). Examples of disulfide-linked first and second polypeptides of a TMMP of the present disclosure are depicted schematically in FIG.1A-1B. Immunomodulatory polypeptides [00154] In some cases, an immunomodulatory polypeptide present in a TMMP of a chimeric molecule of the present disclosure is a wild-type immunomodulatory polypeptide. In other cases, an immunomodulatory polypeptide present in a TMMP of the present disclosure is a variant immunomodulatory polypeptide that has reduced affinity for a co-immunomodulatory polypeptide, compared to the affinity of a corresponding wild-type immunomodulatory polypeptide for the co- immunomodulatory polypeptide. Suitable immunomodulatory domains that exhibit reduced affinity for a co-immunomodulatory domain can have from 1 amino acid (aa) to 20 aa differences from a wild-type immunomodulatory domain. For example, in some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure differs in amino acid sequence by 1 aa, 2 aa, 3 aa, 4 aa, 5 aa, 6 aa, 7 aa, 8 aa, 9 aa, or 10 aa, from a corresponding wild-type immunomodulatory polypeptide. As another example, in some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure differs in amino acid sequence by 11 aa, 12 aa, 13 aa, 14 aa, 15 aa, 16 aa, 17 aa, 18 aa, 19 aa, or 20 aa, from a corresponding wild-type immunomodulatory polypeptide. As an example, in some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes a single amino acid substitution compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 2 amino acid substitutions (e.g., no more than 2 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 3 amino acid substitutions (e.g., no more than 3 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 4 amino acid substitutions (e.g., no more than 4 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 5 amino acid substitutions (e.g., no more than 5 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 6 amino acid substitutions (e.g., no more than 6 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 7 amino acid substitutions (e.g., no more than 7 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 8 amino acid substitutions (e.g., no more than 8 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 9 amino acid substitutions (e.g., no more than 9 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 10 amino acid substitutions (e.g., no more than 10 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00155] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 11 amino acid substitutions (e.g., no more than 11 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00156] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 12 amino acid substitutions (e.g., no more than 12 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00157] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 13 amino acid substitutions (e.g., no more than 13 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00158] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 14 amino acid substitutions (e.g., no more than 14 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00159] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 15 amino acid substitutions (e.g., no more than 15 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00160] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 16 amino acid substitutions (e.g., no more than 16 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00161] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 17 amino acid substitutions (e.g., no more than 17 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00162] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 18 amino acid substitutions (e.g., no more than 18 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00163] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 19 amino acid substitutions (e.g., no more than 19 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00164] In some cases, variant immunomodulatory polypeptide present in a TMMP of the present disclosure includes 20 amino acid substitutions (e.g., no more than 20 amino acid substitutions) compared to a corresponding reference (e.g., wild-type) immunomodulatory polypeptide. [00165] As discussed above, a variant immunomodulatory polypeptide suitable for inclusion in a TMMP of the present disclosure exhibits reduced affinity for a cognate co-immunomodulatory polypeptide, compared to the affinity of a corresponding wild-type immunomodulatory polypeptide for the cognate co-immunomodulatory polypeptide. [00166] Exemplary pairs of immunomodulatory polypeptide and cognate co-immunomodulatory polypeptide include, but are not limited to: [00167] a) 4-1BBL (immunomodulatory polypeptide) and 4-1BB (cognate co- immunomodulatory polypeptide); [00168] b) PD-L1 (immunomodulatory polypeptide) and PD1 (cognate co-immunomodulatory polypeptide); [00169] c) IL-2 (immunomodulatory polypeptide) and IL-2 receptor (cognate co- immunomodulatory polypeptide); [00170] d) CD80 (immunomodulatory polypeptide) and CD86 (cognate co-immunomodulatory polypeptide); [00171] e) CD86 (immunomodulatory polypeptide) and CD28 (cognate co-immunomodulatory polypeptide); [00172] f) OX40L (CD252) (immunomodulatory polypeptide) and OX40 (CD134) (cognate co- immunomodulatory polypeptide); [00173] g) Fas ligand (immunomodulatory polypeptide) and Fas (cognate co-immunomodulatory polypeptide); [00174] h) ICOS-L (immunomodulatory polypeptide) and ICOS (cognate co-immunomodulatory polypeptide); [00175] i) ICAM (immunomodulatory polypeptide) and LFA-1 (cognate co-immunomodulatory polypeptide); [00176] j) CD30L (immunomodulatory polypeptide) and CD30 (cognate co-immunomodulatory polypeptide); [00177] k) CD40 (immunomodulatory polypeptide) and CD40L (cognate co-immunomodulatory polypeptide); [00178] l) CD83 (immunomodulatory polypeptide) and CD83L (cognate co-immunomodulatory polypeptide); [00179] m) HVEM (CD270) (immunomodulatory polypeptide) and CD160 (cognate co- immunomodulatory polypeptide); [00180] n) JAG1 (CD339) (immunomodulatory polypeptide) and Notch (cognate co- immunomodulatory polypeptide); [00181] o) JAG1 (immunomodulatory polypeptide) and CD46 (cognate co-immunomodulatory polypeptide); [00182] p) CD80 (immunomodulatory polypeptide) and CTLA4 (cognate co-immunomodulatory polypeptide); [00183] q) CD86 (immunomodulatory polypeptide) and CTLA4 (cognate co-immunomodulatory polypeptide); and [00184] r) CD70 (immunomodulatory polypeptide) and CD27 (cognate co-immunomodulatory polypeptide). [00185] In some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure has a binding affinity for a cognate co-immunomodulatory polypeptide that is from 100 nM to 100 μM. For example, in some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure has a binding affinity for a cognate co-immunomodulatory polypeptide that is from about 100 nM to 150 nM, from about 150 nM to about 200 nM, from about 200 nM to about 250 nM, from about 250 nM to about 300 nM, from about 300 nM to about 350 nM, from about 350 nM to about 400 nM, from about 400 nM to about 500 nM, from about 500 nM to about 600 nM, from about 600 nM to about 700 nM, from about 700 nM to about 800 nM, from about 800 nM to about 900 nM, from about 900 nM to about 1 μM, to about 1 μM to about 5 μM, from about 5 μM to about 10 μM, from about 10 μM to about 15 μM, from about 15 μM to about 20 μM, from about 20 μM to about 25 μM, from about 25 μM to about 50 μM, from about 50 μM to about 75 μM, or from about 75 μM to about 100 μM. [00186] A variant immunomodulatory polypeptide present in a TMMP of the present disclosure exhibits reduced affinity for a cognate co-immunomodulatory polypeptide. Similarly, a TMMP of the present disclosure that comprises a variant immunomodulatory polypeptide exhibits reduced affinity for a cognate co-immunomodulatory polypeptide. Thus, for example, a TMMP of the present disclosure that comprises a variant immunomodulatory polypeptide has a binding affinity for a cognate co- immunomodulatory polypeptide that is from 100 nM to 100 μM. For example, in some cases, a TMMP of the present disclosure that comprises a variant immunomodulatory polypeptide has a binding affinity for a cognate co-immunomodulatory polypeptide that is from about 100 nM to 150 nM, from about 150 nM to about 200 nM, from about 200 nM to about 250 nM, from about 250 nM to about 300 nM, from about 300 nM to about 350 nM, from about 350 nM to about 400 nM, from about 400 nM to about 500 nM, from about 500 nM to about 600 nM, from about 600 nM to about 700 nM, from about 700 nM to about 800 nM, from about 800 nM to about 900 nM, from about 900 nM to about 1 μM, to about 1 μM to about 5 μM, from about 5 μM to about 10 μM, from about 10 μM to about 15 μM, from about 15 μM to about 20 μM, from about 20 μM to about 25 μM, from about 25 μM to about 50 μM, from about 50 μM to about 75 μM, or from about 75 μM to about 100 μM. CD80 variants [00187] In some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure is a variant CD80 polypeptide. Wild-type CD80 binds to CD28. Wild-type CD80 also binds to CD86. [00188] A wild-type amino acid sequence of the ectodomain of human CD80 can be as follows: disclosure comprises a variant CD80 polypeptide, a “cognate co-immunomodulatory polypeptide” is a CD28 polypeptide comprising the amino acid sequence of SEQ ID NO:436. [00191] A wild-type CD28 amino acid sequence can be as follows: MLRLLLALNL [00192] A wild-type CD28 amino acid sequence can be as follows: MLRLLLALNL [00193] In some cases, a variant CD80 polypeptide exhibits reduced binding affinity to CD28, compared to the binding affinity of a CD80 polypeptide comprising the amino acid sequence set forth in SEQ ID NO:4 for CD28. For example, in some cases, a variant CD80 polypeptide binds CD28 with a binding affinity that is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50% less, at least 55% less, at least 60% less, at least 65% less, at least 70% less, at least 75% less, at least 80% less, at least 85% less, at least 90% less, at least 95% less, or more than 95% less, than the binding affinity of a CD80 polypeptide comprising the amino acid sequence set forth in SEQ ID NO:4 for CD28 (e.g., a CD28 polypeptide comprising the amino acid sequence set forth in one of SEQ ID NO:436, 437, or 438). [00194] In some cases, a variant CD80 polypeptide has a binding affinity to CD28 that is from 100 nM to 100 μM. As another example, in some cases, a variant CD80 polypeptide of the present disclosure has a binding affinity for CD28 (e.g., a CD28 polypeptide comprising the amino acid sequence set forth in SEQ ID NO:5, SEQ ID NO:6, or SEQ ID NO:7) that is from about 100 nM to 150 nM, from about 150 nM to about 200 nM, from about 200 nM to about 250 nM, from about 250 nM to about 300 nM, from about 300 nM to about 350 nM, from about 350 nM to about 400 nM, from about 400 nM to about 500 nM, from about 500 nM to about 600 nM, from about 600 nM to about 700 nM, from about 700 nM to about 800 nM, from about 800 nM to about 900 nM, from about 900 nM to about 1 μM, to about 1 μM to about 5 μM, from about 5 μM to about 10 μM, from about 10 μM to about 15 μM, from about 15 μM to about 20 μM, from about 20 μM to about 25 μM, from about 25 μM to about 50 μM, from about 50 μM to about 75 μM, or from about 75 μM to about 100 μM. [00195] In some cases, a variant CD80 polypeptide has a single amino acid substitution compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has from 2 to 10 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 2 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 3 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 4 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 5 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 6 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 7 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 8 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 9 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. In some cases, a variant CD80 polypeptide has 10 amino acid substitutions compared to the CD80 amino acid sequence set forth in SEQ ID NO:435. [00196] Suitable CD80 variants include a polypeptide that comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to any one of the following amino acid sequences: any amino acid other than Asn. In some cases, X is Ala; any amino acid other than Asn. In some cases, X is Ala; any amino acid other than Ile. In some cases, X is Ala; CD86 variants [00214] In some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure is a variant CD86 polypeptide. Wild-type CD86 binds to CD28. In some cases, where a TMMP of the present disclosure comprises a variant CD86 polypeptide, a “cognate co- immunomodulatory polypeptide” is a CD28 polypeptide comprising the amino acid sequence of SEQ ID NO:5. [00215] The amino acid sequence of the full ectodomain of a wild-type human CD86 can be as [00217] In some cases, a variant CD86 polypeptide exhibits reduced binding affinity to CD28, compared to the binding affinity of a CD86 polypeptide comprising the amino acid sequence set forth in SEQ ID NO:226 or SEQ ID NO:227 for CD28. For example, in some cases, a variant CD86 polypeptide binds CD28 with a binding affinity that is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50% less, at least 55% less, at least 60% less, at least 65% less, at least 70% less, at least 75% less, at least 80% less, at least 85% less, at least 90% less, at least 95% less, or more than 95% less, than the binding affinity of a CD86 polypeptide comprising the amino acid sequence set forth in SEQ ID NO:226 or SEQ ID NO:227 for CD28 (e.g., a CD28 polypeptide comprising the amino acid sequence set forth in one of SEQ ID NO:436, 437, or 438). [00218] In some cases, a variant CD86 polypeptide has a binding affinity to CD28 that is from 100 nM to 100 μM. As another example, in some cases, a variant CD86 polypeptide of the present disclosure has a binding affinity for CD28 (e.g., a CD28 polypeptide comprising the amino acid sequence set forth in one of SEQ ID NOs:5, 6, or 7) that is from about 100 nM to 150 nM, from about 150 nM to about 200 nM, from about 200 nM to about 250 nM, from about 250 nM to about 300 nM, from about 300 nM to about 350 nM, from about 350 nM to about 400 nM, from about 400 nM to about 500 nM, from about 500 nM to about 600 nM, from about 600 nM to about 700 nM, from about 700 nM to about 800 nM, from about 800 nM to about 900 nM, from about 900 nM to about 1 μM, to about 1 μM to about 5 μM, from about 5 μM to about 10 μM, from about 10 μM to about 15 μM, from about 15 μM to about 20 μM, from about 20 μM to about 25 μM, from about 25 μM to about 50 μM, from about 50 μM to about 75 μM, or from about 75 μM to about 100 μM. [00219] In some cases, a variant CD86 polypeptide has a single amino acid substitution compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has from 2 to 10 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 2 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 3 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 4 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 5 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 6 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 7 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 8 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 9 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. In some cases, a variant CD86 polypeptide has 10 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:226. [00220] In some cases, a variant CD86 polypeptide has a single amino acid substitution compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has from 2 to 10 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 2 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 3 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 4 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 5 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 6 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 7 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 8 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 9 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. In some cases, a variant CD86 polypeptide has 10 amino acid substitutions compared to the CD86 amino acid sequence set forth in SEQ ID NO:227. [00221] Suitable CD86 variants include a polypeptide that comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to any one of the following amino acid sequences: X2 is any amino acid other than Asp, and X3 is any amino acid other than His . In some cases, X1 is Ala, X2 is Ala, and X3 is Ala; and where X1 is any amino acid other than Asn, X2 is any amino acid other than Asp, and X3 is any amino acid other than His . In some cases, X1 is Ala, X2 is Ala, and X3 is Ala. 4-1BBL variants [00246] In some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure is a variant 4-1BBL polypeptide. Wild-type 4-1BBL binds to 4-1BB (CD137). [00247] A wild-type 4-1BBL amino acid sequence can be as follows: MEYASDASLD [00248] In some cases, a variant 4-1BBL polypeptide is a variant of the tumor necrosis factor (TNF) homology domain (THD) of human 4-1BBL. [00249] A wild-type amino acid sequence of the THD of human 4-1BBL can be, e.g., one of GGCEL (SEQ ID NO:434). In some cases, where a TMMP of the present disclosure comprises a variant 4-1BBL polypeptide, a “cognate co-immunomodulatory polypeptide” is a 4-1BB polypeptide comprising the amino acid sequence of SEQ ID NO:434. [00254] In some cases, a variant 4-1BBL polypeptide exhibits reduced binding affinity to 4-1BB, compared to the binding affinity of a 4-1BBL polypeptide comprising the amino acid sequence set forth in one of SEQ ID NOs:252-255. For example, in some cases, a variant 4-1BBL polypeptide of the present disclosure binds 4-1BB with a binding affinity that is at least 10% less, at least 15% less, at least 20% less, at least 25%, at least 30% less, at least 35% less, at least 40% less, at least 45% less, at least 50% less, at least 55% less, at least 60% less, at least 65% less, at least 70% less, at least 75% less, at least 80% less, at least 85% less, at least 90% less, at least 95% less, or more than 95% less, than the binding affinity of a 4-1BBL polypeptide comprising the amino acid sequence set forth in one of SEQ ID NOs:252-255 for a 4-1BB polypeptide (e.g., a 4-1BB polypeptide comprising the amino acid sequence set forth in SEQ ID NO:434), when assayed under the same conditions. [00255] In some cases, a variant 4-1BBL polypeptide has a binding affinity to 4-1BB that is from 100 nM to 100 μM. As another example, in some cases, a variant 4-1BBL polypeptide has a binding affinity for 4-1BB (e.g., a 4-1BB polypeptide comprising the amino acid sequence set forth in SEQ ID NO:14) that is from about 100 nM to 150 nM, from about 150 nM to about 200 nM, from about 200 nM to about 250 nM, from about 250 nM to about 300 nM, from about 300 nM to about 350 nM, from about 350 nM to about 400 nM, from about 400 nM to about 500 nM, from about 500 nM to about 600 nM, from about 600 nM to about 700 nM, from about 700 nM to about 800 nM, from about 800 nM to about 900 nM, from about 900 nM to about 1 μM, to about 1 μM to about 5 μM, from about 5 μM to about 10 μM, from about 10 μM to about 15 μM, from about 15 μM to about 20 μM, from about 20 μM to about 25 μM, from about 25 μM to about 50 μM, from about 50 μM to about 75 μM, or from about 75 μM to about 100 μM. [00256] In some cases, a variant 4-1BBL polypeptide has a single amino acid substitution compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4-1BBL polypeptide has from 2 to 10 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4-1BBL polypeptide has 2 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:10-13. In some cases, a variant 4-1BBL polypeptide has 3 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4-1BBL polypeptide has 4 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4-1BBL polypeptide has 5 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4-1BBL polypeptide has 6 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4-1BBL polypeptide has 7 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4-1BBL polypeptide has 8 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4- 1BBL polypeptide has 9 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. In some cases, a variant 4-1BBL polypeptide has 10 amino acid substitutions compared to the 4-1BBL amino acid sequence set forth in one of SEQ ID NOs:252-255. [00257] Suitable 4-1BBL variants include a polypeptide that comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to any one of the following amino acid sequences:

IL-2 variants [00342] In some cases, a variant immunomodulatory polypeptide present in a TMMP of the present disclosure is a variant IL-2 polypeptide. Wild-type IL-2 binds to IL-2 receptor (IL-2R), i.e., a heterotrimeric polypeptide comprising IL-2Rα, IL-2Rβ, and IL-2Rγ. [00344] Wild-type IL2 binds to an IL2 receptor (IL2R) on the surface of a cell. An IL2 receptor is in some cases a heterotrimeric polypeptide comprising an alpha chain (IL-2Rα; also referred to as CD25), a beta chain (IL-2Rβ; also referred to as CD122: and a gamma chain (IL-2Rγ; also referred to as CD132). Amino acid sequences of human IL-2Rα, IL2Rβ, and IL-2Rγ can be as follows.

[00348] In some cases, where a TMMP of the present disclosure comprises a variant IL-2 polypeptide, a “cognate co-immunomodulatory polypeptide” is an IL-2R comprising polypeptides comprising the amino acid sequences of SEQ ID NO:16, 17, and 18. [00349] In some cases, a variant IL-2 polypeptide exhibits reduced binding affinity to IL-2R, compared to the binding affinity of a IL-2 polypeptide comprising the amino acid sequence set forth in SEQ ID NO:15. For example, in some cases, a variant IL-2 polypeptide binds IL-2R with a binding affinity that is at least 10% less, at least 15% less, at least 20% less, at least 25%, at least 30% less, at least 35% less, at least 40% less, at least 45% less, at least 50% less, at least 55% less, at least 60% less, at least 65% less, at least 70% less, at least 75% less, at least 80% less, at least 85% less, at least 90% less, at least 95% less, or more than 95% less, than the binding affinity of an IL-2 polypeptide comprising the amino acid sequence set forth in SEQ ID NO:340 for an IL-2R (e.g., an IL-2R comprising polypeptides comprising the amino acid sequence set forth in SEQ ID NOs:341-343), when assayed under the same conditions. [00350] In some cases, a variant IL-2 polypeptide has a binding affinity to IL-2R that is from 100 nM to 100 μM. As another example, in some cases, a variant IL-2 polypeptide has a binding affinity for IL-2R (e.g., an IL-2R comprising polypeptides comprising the amino acid sequence set forth in SEQ ID NOs:16-18) that is from about 100 nM to 150 nM, from about 150 nM to about 200 nM, from about 200 nM to about 250 nM, from about 250 nM to about 300 nM, from about 300 nM to about 350 nM, from about 350 nM to about 400 nM, from about 400 nM to about 500 nM, from about 500 nM to about 600 nM, from about 600 nM to about 700 nM, from about 700 nM to about 800 nM, from about 800 nM to about 900 nM, from about 900 nM to about 1 μM, to about 1 μM to about 5 μM, from about 5 μM to about 10 μM, from about 10 μM to about 15 μM, from about 15 μM to about 20 μM, from about 20 μM to about 25 μM, from about 25 μM to about 50 μM, from about 50 μM to about 75 μM, or from about 75 μM to about 100 μM. [00351] In some cases, a variant IL-2 polypeptide has a single amino acid substitution compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has from 2 to 10 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 2 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 3 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 4 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 5 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 6 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 7 amino acid substitutions compared to the IL- 2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 8 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 9 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. In some cases, a variant IL-2 polypeptide has 10 amino acid substitutions compared to the IL-2 amino acid sequence set forth in SEQ ID NO:340. [00352] Suitable IL-2 variants include a polypeptide that comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to any one of the following amino acid sequences: some cases, X is Ala. In some cases, X is Thr. In some cases, X is Asn. In some cases, X is Cys. In some cases, X is Gln. In some cases, X is Met. In some cases, X is Val. In some cases, X is Trp; some cases, X is Ala. In some cases, X is Arg. In some cases, X is Asn. In some cases, X is Asp. In some cases, X is Cys. In some cases, X is Glu. In some cases, X is Gln. In some cases, X is Gly. In some cases, X is Ile. I n some cases, X is Lys. In some cases, X is Leu. In some cases, X is Met. In some cases, X is Phe. In some cases, X is Pro. In some cases, X is Ser. In some cases, X is Thr. In some cases, X is Tyr. In some cases, X is Trp. In some cases, X is Val; where X2 is any amino acid other than Asp; and where X3 is any amino acid other than Phe. In some cases, X1 is Ala. In some cases, X2 is Ala. In some cases, X3 is Ala. In some cases, X1 is Ala; X2 is Ala; and X3 is Ala; where X ₂ is any amino acid other than Asp; and where X ₃ is any amino acid other than Phe. In some cases, X ₁ is Ala. In some cases, X ₂ is Ala. In some cases, X ₃ is Ala. In some cases, X ₁ is Ala; X ₂ is Ala; and X ₃ is Ala; where X ₂ is any amino acid other than Phe; and where X ₃ is any amino acid other than Gln. In some cases, X1 is Ala. In some cases, X2 is Ala. In some cases, X3 is Ala. In some cases, X1 is Ala; X2 is Ala; and X ₃ is Ala; TATIVEFLNRWITFCQSIIS TLT (SEQ ID NO:356), where X1 is any amino acid other than Asp; where X2 is any amino acid other than Phe; and where X3 is any amino acid other than Tyr. In some cases, X1 is Ala. In some cases, X2 is Ala. In some cases, X3 is Ala. In some cases, X1 is Ala; X2 is Ala; and X3 is Ala; TATIVEFLNRWITFCQSIIS TLT (SEQ ID NO:357), where X ₁ is any amino acid other than His; where X2 is any amino acid other than Asp; where X3 is any amino acid other than Phe; and where X4 is any amino acid other than Tyr. In some cases, X1 is Ala. In some cases, X2 is Ala. In some cases, X3 is Ala. In some cases, X4 is Ala. In some cases, X1 is Ala; X2 is Ala; X3 is Ala; and X4 is Ala; TATIVEFLNRWITFCX ₄ SIIS TLT (SEQ ID NO:358), where X ₁ is any amino acid other than Asp; where X ₂ is any amino acid other than Phe; where X ₃ is any amino acid other than Tyr; and where X ₄ is any amino acid other than Gln. In some cases, X ₁ is Ala. In some cases, X ₂ is Ala. In some cases, X ₃ is Ala. In some cases, X ₄ is Ala. In some cases, X ₁ is Ala; X ₂ is Ala; X ₃ is Ala; and X ₄ is Ala; where X ₂ is any amino acid other than Asp; where X ₃ is any amino acid other than Phe; where X ₄ is any amino acid other than Tyr; and where X ₅ is any amino acid other than Gln. In some cases, X ₁ is Ala. In some cases, X ₂ is Ala. In some cases, X ₃ is Ala. In some cases, X ₄ is Ala. In some cases, X ₅ is Ala. In some cases, X ₁ is Ala; X ₂ is Ala; X ₃ is Ala; X ₄ is Ala; X ₅ is Ala; and ( Q ), y ; where X2 is any amino acid other than Phe; and where X3 is any amino acid other than Gln. In some cases, X ₁ is Ala. In some cases, X ₂ is Ala. In some cases, X ₃ is Ala. In some cases, X ₁ is Ala; X ₂ is Ala; and X ₃ is Ala. Scaffold polypeptides [00370] A TMMP of the present disclosure can comprise an Fc polypeptide, or can comprise another suitable scaffold polypeptide. [00371] Suitable scaffold polypeptides include antibody-based scaffold polypeptides and non- antibody-based scaffolds. Non-antibody-based scaffolds include, e.g., albumin, an XTEN (extended recombinant) polypeptide, transferrin, an Fc receptor polypeptide, an elastin-like polypeptide (see, e.g., Hassouneh et al. (2012) Methods Enzymol.502:215; e.g., a polypeptide comprising a pentapeptide repeat unit of (Val-Pro-Gly-X-Gly; SEQ ID NO:361), where X is any amino acid other than proline), an albumin-binding polypeptide, a silk-like polypeptide (see, e.g., Valluzzi et al. (2002) Philos Trans R Soc Lond B Biol Sci.357:165), a silk-elastin-like polypeptide (SELP; see, e.g., Megeed et al. (2002) Adv Drug Deliv Rev.54:1075), and the like. Suitable XTEN polypeptides include, e.g., those disclosed in WO 2009/023270, WO 2010/091122, WO 2007/103515, US 2010/0189682, and US 2009/0092582; see also Schellenberger et al. (2009) Nat Biotechnol.27:1186). Suitable albumin polypeptides include, e.g., human serum albumin. [00372] Suitable scaffold polypeptides will in some cases be a half-life extending polypeptides. Thus, in some cases, a suitable scaffold polypeptide increases the in vivo half-life (e.g., the serum half- life) of the TMMP, compared to a control TMMP lacking the scaffold polypeptide. For example, in some cases, a scaffold polypeptide increases the in vivo half-life (e.g., the serum half-life) of the TMMP, compared to a control TMMP lacking the scaffold polypeptide, by at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 50%, at least about 2-fold, at least about 2.5- fold, at least about 5-fold, at least about 10-fold, at least about 25-fold, at least about 50-fold, at least about 100-fold, or more than 100-fold. As an example, in some cases, an Fc polypeptide increases the in vivo half-life (e.g., the serum half-life) of the TMMP, compared to a control TMMP lacking the Fc polypeptide, by at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 50%, at least about 2-fold, at least about 2.5-fold, at least about 5-fold, at least about 10-fold, at least about 25-fold, at least about 50-fold, at least about 100-fold, or more than 100-fold. Fc polypeptides [00373] In some cases, the first and/or the second polypeptide chain of a TMMP of the present disclosure comprises an Fc polypeptide. The Fc polypeptide of a TMMP of the present disclosure can be a human IgG1 Fc, a human IgG2 Fc, a human IgG3 Fc, a human IgG4 Fc, etc. In some cases, the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to an amino acid sequence of an Fc region depicted in FIG. 3A-3G. In some cases, the Fc region comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to the human IgG1 Fc polypeptide depicted in FIG.3A. In some cases, the Fc region comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to the human IgG1 Fc polypeptide depicted in FIG.3A; and comprises a substitution of N77; e.g., the Fc polypeptide comprises an N77A substitution. In some cases, the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to the human IgG2 Fc polypeptide depicted in FIG.3A; e.g., the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to amino acids 99-325 of the human IgG2 Fc polypeptide depicted in FIG.3A. In some cases, the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to the human IgG3 Fc polypeptide depicted in FIG. 3A; e.g., the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to amino acids 19-246 of the human IgG3 Fc polypeptide depicted in FIG.3A. In some cases, the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to the human IgM Fc polypeptide depicted in FIG.3B; e.g., the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to amino acids 1-276 to the human IgM Fc polypeptide depicted in FIG.3B. In some cases, the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to the human IgA Fc polypeptide depicted in FIG.3C; e.g., the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to amino acids 1-234 to the human IgA Fc polypeptide depicted in FIG.3C. [00374] In some cases, the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to the human IgG4 Fc polypeptide depicted in FIG.3C. In some cases, the Fc polypeptide comprises an amino acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99%, or 100%, amino acid sequence identity to amino acids 100 to 327 of the human IgG4 Fc polypeptide depicted in FIG.3C. [00375] In some cases, the IgG4 Fc polypeptide comprises the following amino acid sequence: [00376] In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3A (human IgG1 Fc). In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3A (human IgG1 Fc), except for a substitution of N297 (N77 of the amino acid sequence depicted in FIG.3A) with an amino acid other than asparagine. In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3C (human IgG1 Fc comprising an N297A substitution, which is N77 of the amino acid sequence depicted in FIG.3A). In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3A (human IgG1 Fc), except for a substitution of L234 (L14 of the amino acid sequence depicted in FIG.3A) with an amino acid other than leucine. In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3A (human IgG1 Fc), except for a substitution of L235 (L15 of the amino acid sequence depicted in FIG.3A) with an amino acid other than leucine. [00377] In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3E. In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3F. In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.5G (human IgG1 Fc comprising an L234A substitution and an L235A substitution, corresponding to positions 14 and 15 of the amino acid sequence depicted in FIG.3G). In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3A (human IgG1 Fc), except for a substitution of P331 (P111 of the amino acid sequence depicted in FIG.3A) with an amino acid other than proline; in some cases, the substitution is a P331S substitution. In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3A (human IgG1 Fc), except for substitutions at L234 and L235 (L14 and L15 of the amino acid sequence depicted in FIG.3A) with amino acids other than leucine. In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3A (human IgG1 Fc), except for substitutions at L234 and L235 (L14 and L15 of the amino acid sequence depicted in FIG.3A) with amino acids other than leucine, and a substitution of P331 (P111 of the amino acid sequence depicted in FIG.3A) with an amino acid other than proline. In some cases, the Fc polypeptide present in a TMMP comprises the amino acid sequence depicted in FIG.3E (human IgG1 Fc comprising L234F, L235E, and P331S substitutions (corresponding to amino acid positions 14, 15, and 111 of the amino acid sequence depicted in FIG.3E). In some cases, the Fc polypeptide present in a TMMP is an IgG1 Fc polypeptide that comprises L234A and L235A substitutions (substitutions of L14 and L15 of the amino acid sequence depicted in FIG.3A with Ala), as depicted in FIG.3G. Linkers [00378] A TMMP of the present disclosure can include one or more linkers, where the one or more linkers are between one or more of: i) an MHC Class I polypeptide and an Ig Fc polypeptide, where such a linker is referred to herein as “L1”; ii) an immunomodulatory polypeptide and an MHC Class I polypeptide, where such a linker is referred to herein as “L2”; iii) a first immunomodulatory polypeptide and a second immunomodulatory polypeptide, where such a linker is referred to herein as “L3”; iv) a peptide antigen (“epitope”) and an MHC Class I polypeptide; v) an MHC Class I polypeptide and a dimerization polypeptide (e.g., a first or a second member of a dimerizing pair); and vi) a dimerization polypeptide (e.g., a first or a second member of a dimerizing pair) and an IgFc polypeptide. [00379] Suitable linkers (also referred to as “spacers”) can be readily selected and can be of any of a number of suitable lengths, such as from 1 amino acid to 25 amino acids, from 3 amino acids to 20 amino acids, from 2 amino acids to 15 amino acids, from 3 amino acids to 12 amino acids, including 4 amino acids to 10 amino acids, 5 amino acids to 9 amino acids, 6 amino acids to 8 amino acids, or 7 amino acids to 8 amino acids. A suitable linker can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 amino acids in length. In some cases, a linker has a length of from 25 amino acids to 50 amino acids, e.g., from 25 to 30, from 30 to 35, from 35 to 40, from 40 to 45, or from 45 to 50 amino acids in length. [00380] Exemplary linkers include glycine polymers (G)n, glycine-serine polymers (including, for example, (GS)n, (GSGGS)n (SEQ ID NO:363) and (GGGS)n (SEQ ID NO:364), where n is an integer of at least one), glycine-alanine polymers, alanine-serine polymers, and other flexible linkers known in the art. Glycine and glycine-serine polymers can be used; both Gly and Ser are relatively unstructured, and therefore can serve as a neutral tether between components. Glycine polymers can be used; glycine accesses significantly more phi-psi space than even alanine, and is much less restricted than residues with longer side chains (see Scheraga, Rev. Computational Chem.11173-142 (1992)). Exemplary linkers can comprise amino acid sequences including, but not limited to, GGSG (SEQ ID NO:365), GGSGG (SEQ ID NO:366), GSGSG (SEQ ID NO:367), GSGGG (SEQ ID NO:368), GGGSG (SEQ ID NO:369), GSSSG (SEQ ID NO:370), and the like. Exemplary linkers can include, e.g., Gly(Ser4)n (SEQ ID NO:371), where n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some cases, a linker comprises the amino acid sequence (GSSSS)n (SEQ ID NO:371), where n is 4. In some cases, a linker comprises the amino acid sequence (GSSSS)n (SEQ ID NO:371), where n is 5. In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 1. In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 2. In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 3. In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 4. In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 5. In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 6. In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 7, In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 8, In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 9, In some cases, a linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is 10. In some cases, a linker comprises the amino acid sequence AAAGG (SEQ ID NO:372). [00381] In some cases, a linker polypeptide, present in a first polypeptide of a TMMP of the present disclosure, includes a cysteine residue that can form a disulfide bond with a cysteine residue present in a second polypeptide of a TMMP of the present disclosure. In some cases, for example, a suitable linker comprises the amino acid sequence GCGGSGGGGSGGGGS (SEQ ID NO:208). As another example, a suitable linker can comprise the amino acid sequence GCGGS(G4S)n (SEQ ID NO:206), where n is 1, 2, 3, 4, 5, 6, 7, 8, or 9. For example, in some cases, the linker comprises the amino acid sequence GCGGSGGGGSGGGGSGGGGS (SEQ ID NO:207). As another example, the linker comprises the amino acid sequence GCGGSGGGGSGGGGS (SEQ ID NO:208). Multiple disulfide bonded TMMPs [00382] In some cases, the first polypeptide and the second polypeptide of a TMMP of the present disclosure are linked to one another by at least two disulfide bonds (i.e., two interchain disulfide bonds). Examples of such multiple disulfide-linked TMMP are depicted schematically in FIG.2A and 2B. In addition, where a TMMP of the present disclosure comprises an IgFc polypeptide, a heterodimeric TMMP can be dimerized, such that disulfide bonds link the IgFc polypeptides in the two heterodimeric TMMPs. Such an arrangement is depicted schematically in FIG.2A and 2B, where disulfide bonds are represented by dashed lines. Unless otherwise stated, the at least two disulfide bonds described in the multiple disulfide-linked TMMPPs in this section are not referring to disulfide bonds linking IgFc polypeptides in dimerized TMMPs. [00383] As noted above, in some cases, the first polypeptide and the second polypeptide of a TMMP of the present disclosure are linked to one another by at least two disulfide bonds (i.e., two interchain disulfide bonds). For example, in some instances, the first polypeptide and the second polypeptide of a TMMP of the present disclosure are linked to one another by 2 interchain disulfide bonds. As another example, in some instances, the first polypeptide and the second polypeptide of a TMMP of the present disclosure are linked to one another by 3 interchain disulfide bonds. As another example, in some instances, the first polypeptide and the second polypeptide of a TMMP of the present disclosure are linked to one another by 4 interchain disulfide bonds. [00384] In some cases where a peptide epitope in a first polypeptide of a TMMP of the present disclosure is linked to a β2M polypeptide by a linker comprising a Cys, at least one of the at least two disulfide bonds links a Cys in the linker to a Cys in an MHC Class I heavy chain in the second polypeptide. In some cases, where a peptide epitope in a first polypeptide of a TMMP of the present disclosure is linked to an MHC Class I heavy chain polypeptide by a linker, at least one of the at least two disulfide bonds links a Cys in the linker to a Cys in a β2M polypeptide present in the second polypeptide. [00385] A multiple disulfide-linked TMMP of the present disclosure (e.g., a double disulfide- linked TMMP) can comprise, for example: a) a first polypeptide comprising: i) a peptide epitope (e.g., a peptide of from 4 amino acids to about 25 amino acids in length, that is bound by a TCR when the peptide is complexed with MHC polypeptides); and ii) a first MHC polypeptide, where the first polypeptide comprises a peptide linker between the KRAS peptide and the first MHC polypeptide, where the peptide linker comprises a Cys residue, and where the first MHC polypeptide is a β2M polypeptide that comprises an amino acid substitution that introduces a Cys residue; b) and a second polypeptide comprising a second MHC polypeptide, where the second MHC polypeptide is a Class I heavy chain comprising a Y84C substitution and an A236C substitution, based on the amino acid numbering of HLA- A*0201 (depicted in FIG.7A), or at corresponding positions in another Class I heavy chain allele, where the TMMP comprises a disulfide bond between the Cys residue in the peptide linker and the Cys residue at amino acid position 84 of the Class I heavy chain or corresponding position of another Class I heavy chain allele, and where the TMMP comprises a disulfide bond between the introduced Cys residue in the β2M polypeptide and the Cys at amino acid position 236 of the Class I heavy chain or corresponding position of another Class I heavy chain allele; and c) at least one immunomodulatory polypeptide, where the first and/or the second polypeptide comprises the at least one immunomodulatory polypeptide.. [00386] In some cases, the peptide linker comprises the amino acid sequence GCGGS (SEQ ID NO:373). In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is an integer from 1 to 10. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 1. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 2. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 3. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 4. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 5. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 6. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 7. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 8. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 9. In some cases, the peptide linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is 10. [00387] In some cases, the peptide linker comprises the amino acid sequence CGGGS (SEQ ID NO:374). In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is an integer from 1 to 10. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 1. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 2. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 3. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 4. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 5. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 6. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 7. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 8. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 9. In some cases, the peptide linker comprises the amino acid sequence CGGGS(GGGGS)n (SEQ ID NO:375), where n is 10. Dimerized chimeric molecules [00388] A chimeric molecule of the present disclosure can be dimerized; i.e., the present disclosure provides a chimeric molecule comprising a dimer of a TMMP. Thus, the present disclosure provides a chimeric molecule comprising a TMMP comprising: A) a first heterodimer comprising: a) a first polypeptide comprising: i) a peptide epitope; and ii) a first major histocompatibility complex (MHC) polypeptide; and b) a second polypeptide comprising: i) a second MHC polypeptide, wherein the first heterodimer comprises one or more immunomodulatory polypeptides; and B) a second heterodimer comprising: a) a first polypeptide comprising: i) a peptide epitope; and ii) a first MHC polypeptide; and b) a second polypeptide comprising: i) a second MHC polypeptide, wherein the second heterodimer comprises one or more immunomodulatory polypeptides, and wherein the first heterodimer and the second heterodimer are covalently linked to one another. The nucleic acid component is attached to the first heterodimer and the second heterodimer. [00389] In some cases, the two TMMPs are identical to one another in amino acid sequence. In some cases, the first heterodimer and the second heterodimer are covalently linked to one another via a C-terminal region of the second polypeptide of the first heterodimer and a C-terminal region of the second polypeptide of the second heterodimer. In some cases, first heterodimer and the second heterodimer are covalently linked to one another via the C-terminal amino acid of the second polypeptide of the first heterodimer and the C-terminal region of the second polypeptide of the second heterodimer; for example, in some cases, the C-terminal amino acid of the second polypeptide of the first heterodimer and the C-terminal region of the second polypeptide of the second heterodimer are linked to one another, either directly or via a linker. The linker can be a peptide linker. The peptide linker can have a length of from 1 amino acid to 200 amino acids (e.g., from 1 amino acid (aa) to 5 aa, from 5 aa to 10 aa, from 10 aa to 25 aa, from 25 aa to 50 aa, from 50 aa to 100 aa, from 100 aa to 150 aa, or from 150 aa to 200 aa). In some cases, the peptide epitope of the first heterodimer and the peptide epitope of the second heterodimer comprise the same amino acid sequence. In some cases, the first MHC polypeptide of the first and the second heterodimer is an MHC Class I β2-microglobulin, and wherein the second MHC polypeptide of the first and the second heterodimer is an MHC Class I heavy chain. In some cases, the immunomodulatory polypeptide of the first heterodimer and the immunomodulatory polypeptide of the second heterodimer comprise the same amino acid sequence. In some cases, the immunomodulatory polypeptide of the first heterodimer and the immunomodulatory polypeptide of the second heterodimer are variant immunomodulatory polypeptides that comprise from 1 to 10 amino acid substitutions compared to a corresponding parental wild-type immunomodulatory polypeptide, and wherein the from 1 to 10 amino acid substitutions result in reduced affinity binding of the variant immunomodulatory polypeptide to a cognate co-immunomodulatory polypeptide. In some cases, the immunomodulatory polypeptide of the first heterodimer and the immunomodulatory polypeptide of the second heterodimer are each independently selected from the group consisting of IL-2, 4-1BBL, PD-L1, CD80, CD86, ICOS-L, OX-40L, FasL, JAG1 (CD339), TGFβ, CD70, and ICAM. Examples, of suitable MHC polypeptides, immunomodulatory polypeptides, and peptide epitopes are described below. The first and/or the second polypeptide comprises: i) an Ig Fc polypeptide or a non-Ig scaffold; and ii) a tumor- targeting polypeptide. Chimeric Antigen Receptor [00390] A CAR generally comprises: a) an extracellular domain comprising an antigen-binding domain (antigen-binding polypeptide); b) a transmembrane region; and c) a cytoplasmic domain comprising an intracellular signaling domain (intracellular signaling polypeptide). In some cases, a CAR comprises: a) an extracellular domain comprising the antigen-binding domain; b) a transmembrane region; and c) a cytoplasmic domain comprising: i) a co-stimulatory polypeptide; and ii) an intracellular signaling domain. In some cases, a CAR comprises hinge region between the extracellular antigen- binding domain and the transmembrane domain. Thus, in some cases, a CAR comprises: a) an extracellular domain comprising the antigen-binding domain; b) a hinge region; c) a transmembrane region; and d) a cytoplasmic domain comprising an intracellular signaling domain. In some cases, a CAR comprises: a) an extracellular domain comprising the antigen-binding domain; b) a hinge region; c) a transmembrane region; and d) a cytoplasmic domain comprising: i) a co-stimulatory polypeptide; and ii) an intracellular signaling domain. [00391] Exemplary CAR structures are known in the art (See e.g., WO 2009/091826; US 20130287748; WO 2015/142675; WO 2014/055657; WO 2015/090229; and U.S. Patent No.9,587,020. [00392] In some cases, a CAR is a single polypeptide chain. In some cases, a CAR comprises two polypeptide chains. [00393] CARs specific for a variety of tumor antigens are known in the art; for example CD171- specific CARs (Park et al., Mol Ther (2007) 15(4):825-833), EGFRvIII-specific CARs (Morgan et al., Hum Gene Ther (2012) 23(10):1043-1053), EGF-R-specific CARs (Kobold et al., J. Natl Cancer Inst (2014) 107(1):364), carbonic anhydrase IX-specific CARs (Lamers et al., Biochem Soc Trans (2016) 44(3):951-959), folate receptor-α (FR-α)-specific CARs (Kershaw et al., Clin Cancer Res (2006) 12(20):6106-6015), HER2-specific CARs (Ahmed et al., J Clin Oncol (2015) 33(15)1688-1696; Nakazawa et al., Mol Ther (2011) 19(12):2133-2143; Ahmed et al., Mol Ther (2009) 17(10):1779-1787; Luo et al., Cell Res (2016) 26(7):850-853; Morgan et al., Mol Ther (2010) 18(4):843-851; Grada et al., Mol Ther Nucleic Acids (2013) 9(2):32), CEA-specific CARs (Katz et al., Clin Cancer Res (2015) 21(14):3149-3159), IL-13Rα2-specific CARs (Brown et al., Clin Cancer Res (2015) 21(18):4062-4072), ganglioside GD2-specific CARs (Louis et al., Blood (2011) 118(23):6050-6056; Caruana et al., Nat Med (2015) 21(5):524-529; Yu et al. (2018) J. Hematol. Oncol.11:1), ErbB2-specific CARs (Wilkie et al., J Clin Immunol (2012) 32(5):1059-1070), VEGF-R-specific CARs (Chinnasamy et al., Cancer Res (2016) 22(2):436-447), FAP-specific CARs (Wang et al., Cancer Immunol Res (2014) 2(2): 154-166), mesothelin (MSLN)-specific CARs (Moon et al, Clin Cancer Res (2011) 17(14):4719-30), NKG2D- specific CARs (VanSeggelen et al., Mol Ther (2015) 23(10):1600-1610), CD19-specific CARs (Axicabtagene ciloleucel (Yescarta™) and Tisagenlecleucel (Kymriah™). See also, Li et al., J Hematol and Oncol (2018) 11:22, reviewing clinical trials of tumor-specific CARs; Heyman and Yan (2019) Cancers 11:pii:E191; Baybutt et al. (2019) Clin. Pharmacol. Ther.105:71. Antigen-binding domain [00394] As noted above, a CAR comprises an extracellular domain comprising an antigen-binding domain. The antigen-binding domain present in a CAR can be any antigen-binding polypeptide, a wide variety of which are known in the art. In some instances, the antigen-binding domain is a single chain Fv (scFv). Other antibody-based recognition domains (cAb VHH (camelid antibody variable domains) and humanized versions, IgNAR VH (shark antibody variable domains) and humanized versions, sdAb VH (single domain antibody variable domains) and “camelized” antibody variable domains are suitable. In some cases, the antigen-binding domain is a nanobody. [00395] In some cases, the antigen bound by the antigen-binding domain of a CAR is selected from: a MUC1 polypeptide, an LMP2 polypeptide, an epidermal growth factor receptor (EGFR) vIII polypeptide, a HER-2/neu polypeptide, a melanoma antigen family A, 3 (MAGE A3) polypeptide, a p53 polypeptide, a mutant p53 polypeptide, an NY-ESO-1 polypeptide, a folate hydrolase (prostate-specific membrane antigen; PSMA) polypeptide, a carcinoembryonic antigen (CEA) polypeptide, a melanoma antigen recognized by T-cells (melanA/MART1) polypeptide, a Ras polypeptide, a gp100 polypeptide, a proteinase3 (PR1) polypeptide, a bcr-abl polypeptide, a tyrosinase polypeptide, a survivin polypeptide, a prostate specific antigen (PSA) polypeptide, an hTERT polypeptide, a sarcoma translocation breakpoints polypeptide, a synovial sarcoma X (SSX) breakpoint polypeptide, an EphA2 polypeptide, an acid phosphatase, prostate (PAP) polypeptide, a melanoma inhibitor of apoptosis (ML-IAP) polypeptide, an epithelial cell adhesion molecule (EpCAM) polypeptide, an ERG (TMPRSS2 ETS fusion) polypeptide, a NA17 polypeptide, a paired-box-3 (PAX3) polypeptide, an anaplastic lymphoma kinase (ALK) polypeptide, an androgen receptor polypeptide, a cyclin B1 polypeptide, an N-myc proto-oncogene (MYCN) polypeptide, a Ras homolog gene family member C (RhoC) polypeptide, a tyrosinase-related protein-2 (TRP-2) polypeptide, a mesothelin polypeptide, a prostate stem cell antigen (PSCA) polypeptide, a melanoma associated antigen-1 (MAGE A1) polypeptide, a cytochrome P4501B1 (CYP1B1) polypeptide, a placenta-specific protein 1 (PLAC1) polypeptide, a BORIS polypeptide (also known as CCCTC-binding factor or CTCF), an ETV6-AML polypeptide, a breast cancer antigen NY- BR-1 polypeptide (also referred to as ankyrin repeat domain-containing protein 30A), a regulator of G- protein signaling (RGS5) polypeptide, a squamous cell carcinoma antigen recognized by T-cells (SART3) polypeptide, a carbonic anhydrase IX polypeptide, a paired box-5 (PAX5) polypeptide, an OY- TES1 (testis antigen; also known as acrosin binding protein) polypeptide, a sperm protein 17 polypeptide, a lymphocyte cell-specific protein-tyrosine kinase (LCK) polypeptide, a high molecular weight melanoma associated antigen (HMW-MAA), an A-kinase anchoring protein-4 (AKAP-4), a synovial sarcoma X breakpoint 2 (SSX2) polypeptide, an X antigen family member 1 (XAGE1) polypeptide, a B7 homolog 3 (B7H3; also known as CD276) polypeptide, a legumain polypeptide (LGMN1; also known as asparaginyl endopeptidase), a tyrosine kinase with Ig and EGF homology domains-2 (Tie-2; also known as angiopoietin-1 receptor) polypeptide, a P antigen family member 4 (PAGE4) polypeptide, a vascular endothelial growth factor receptor 2 (VEGF2) polypeptide, a MAD- CT-1 polypeptide, a fibroblast activation protein (FAP) polypeptide, a platelet derived growth factor receptor beta (PDGFβ) polypeptide, a MAD-CT-2 polypeptide, or a Fos-related antigen-1 (FOSL) polypeptide. In some cases, the antigen is a human papilloma virus (HPV) antigen. In some cases, the antigen is an alpha-feto protein (AFP) antigen. In some cases, the antigen is a Wilms tumor-1 (WT1) antigen. [00396] The antigen-binding polypeptide of a CAR can bind any of a variety of cancer- associated antigens, including, e.g., antigens of the immunoglobulin superfamily (see, e.g., Barclay (2003) Seminars in Immunology 15:215); antigens of the tumor necrosis factor (TNF) superfamily (see, e.g., Aggarwal et al. (2012) Blood 119:651; Locksley et al. (2001) Cell 104:487; and Hehlgan and Pfeffer (2005) Immunol.115:1); antigens of the TNF receptor (TNFR) superfamily (see, e.g., Locksley et al. (2001) Cell 104:487; and Hehlgan and Pfeffer (2005) Immunol.115:1); antigens of the B7 superfamily (see, e.g., Greenwald et al. (2005) Ann. Rev. Immunol.23:515; and Sharpe and Freeman (2002) Nat. Rev. Immunol.2:116); and antigens of the lectin superfamily (see, e.g., Zelensky and Gready (2005) FEBS J.272:6179). [00397] The antigen-binding polypeptide of a CAR can bind any of a variety of cancer- associated antigens, including, e.g., CD19, CD20, CD38, CD30, Her2/neu, ERBB2, CA125, MUC-1, prostate-specific membrane antigen (PSMA), CD44 surface adhesion molecule, mesothelin, carcinoembryonic antigen (CEA), epidermal growth factor receptor (EGFR), EGFRvIII, vascular endothelial growth factor receptor-2 (VEGFR2), B-cell maturation antigen (BCMA), high molecular weight-melanoma associated antigen (HMW-MAA), MAGE-A1, IL-13R-a2, GD2, and the like. Cancer- associated antigens also include, e.g., 4-1BB, 5T4, adenocarcinoma antigen, alpha-fetoprotein (AFP), BAFF, B-lymphoma cell, C242 antigen, CA-125, carbonic anhydrase 9 (CA-IX), C-MET, CCR4, CD152, CD19, CD20, CD200, CD22, CD221, CD23 (IgE receptor), CD28, CD30 (TNFRSF8), CD33, CD4, CD40, CD44 v6, CD51, CD52, CD56, CD74, CD80, CEA, CNTO888, CTLA-4, DRS, EGFR, EpCAM, CD3, FAP, fibronectin extra domain-B, folate receptor 1, GD2, GD3 ganglioside, glycoprotein 75, GPNMB, HER2/neu, HGF, human scatter factor receptor kinase, IGF-1 receptor, IGF-I, IgG1, L1- CAM, IL-13, IL-6, insulin-like growth factor I receptor, integrin α5β1, integrin αvβ3, MORAb-009, MS4A1, MUC1, mucin CanAg, N-glycolylneuraminic acid, NPC-1C, PDGF-R α, PDL192, phosphatidylserine, prostatic carcinoma cells, RANKL, RON, ROR1, SCH 900105, SDC1, SLAMF7, TAG-72, tenascin C, TGF beta 2, TGF-β, TRAIL-R1, TRAIL-R2, tumor antigen CTAA16.88, VEGF-A, VEGFR-1, VEGFR2, and vimentin. [00398] In some cases, the cancer-associated antigen bound by the antigen-binding polypeptide of a CAR is selected from AFP, BCMA, CD10, CD117, CD123, CD133, CD128, CD171, CD19, CD20, CD22, CD30, CD33, CD34, CD38, CD5, CD56, CD7, CD70, CD80, CD86, CEA, CLD18, CLL-1, cMet, EGFR, EGFRvIII, EpCAM, EphA2, GD-2, glypican-3, GPC3, HER-2, kappa immunoglobulin, LeY, LMP1, mesothlin, MG7, MUC1, NKG2D ligand, PD-L1, PSCA, PSMA, ROR1, ROR1R, TACI, and VEGFR2. In some cases, the cancer-associated antigen is BCMA. In some cases, the cancer- associated antigen is MUC1. In some cases, the cancer-associated antigen is CD19. In some cases, the cancer-associated antigen is AFP. [00399] VH and VL amino acid sequences of various cancer-associated antigen-binding antibodies are known in the art, as are the light chain and heavy chain CDRs of such antibodies. See, e.g., Ling et al. (2018) Frontiers Immunol.9:469; WO 2005/012493; US 2019/0119375; US 2013/0066055. The following are non-limiting examples of antibodies that bind cancer-associated antigens. 1) Anti-Her2 [00400] In some cases, an anti-Her2 antibody comprises: a) a light chain comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00403] In some cases, an anti-Her2 antibody comprises a light chain variable region (VL) present in the light chain amino acid sequence provided above; and a heavy chain variable region (VH) present in the heavy chain amino acid sequence provided above. For example, an anti-Her2 antibody can comprise: a) a VL comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: ID NO:4). In some cases, an anti-Her2 antibody comprises, in order from N-terminus to C-terminus: a) a VH comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: ID NO:4); b) a linker; and c) a VL comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: described elsewhere herein and include, e.g., (GGGGS)n (SEQ ID NO:5), where n is an integer from 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10). [00404] In some cases, an anti-Her2 antibody comprises VL CDR1, VL CDR2, and VL CDR3 present in the light chain amino acid sequence provided above; and VH CDR1, CDR2, and CDR3 present in the heavy chain amino acid sequence provided above. In some cases, the V _H and V _L CDRs are as defined by Kabat (see, e.g., Table 1, above; and Kabat 1991). In some cases, the V _H and V _L CDRs are as defined by Chothia (see, e.g., Table 1, above; and Chothia 1987). [00405] For example, an anti-Her2 antibody can comprise a VL CDR1 having the amino acid sequence RASQDVNTAVA (SEQ ID NO:6); a VL CDR2 having the amino acid sequence SASFLY (SEQ ID NO:7); a VL CDR3 having the amino acid sequence QQHYTTPP (SEQ ID NO:8); a VH CDR1 having the amino acid sequence GFNIKDTY (SEQ ID NO:9); a VH CDR2 having the amino acid sequence IYPTNGYT (SEQ ID NO:10); and a VH CDR3 having the amino acid sequence SRWGGDGFYAMDY (SEQ ID NO:11). [00406] In some cases, an anti-Her2 antibody is a scFv antibody. For example, an anti-Her2 scFv can comprise an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00407] As another example, in some cases, an anti-Her2 antibody comprises: a) a light chain variable region (VL) comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: (VH) comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00410] In some cases, an anti-Her2 antibody comprises a VL present in the light chain amino acid sequence provided above; and a VH present in the heavy chain amino acid sequence provided above. For example, an anti-Her2 antibody can comprise: a) a VL comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: ) [00411] In some cases, an anti-Her2 antibody comprises VL CDR1, VL CDR2, and VL CDR3 present in the light chain amino acid sequence provided above; and VH CDR1, CDR2, and CDR3 present in the heavy chain amino acid sequence provided above. In some cases, the VH and VL CDRs are as defined by Kabat (see, e.g., Table 1, above; and Kabat 1991). In some cases, the VH and VL CDRs are as defined by Chothia (see, e.g., Table 1, above; and Chothia 1987). [00412] For example, an anti-HER2 antibody can comprise a VL CDR1 having the amino acid [00413] In some cases, an anti-Her2 antibody is a scFv. For example, in some cases, an anti-Her2 scFv comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: 2) Anti-CD19 [00415] Anti-CD19 antibodies are known in the art; and the VH and VL, or the VH and VL CDRs, of any anti-CD19 antibody can be included in a CAR. See e.g., WO 2005/012493. [00416] In some cases, an anti-CD19 antibody includes a VL CDR1 comprising the amino acid ( ) i i h i id the amino acid sequence DASNLVS (SEQ ID NO:24); a VL CDR3 comprising the amino acid sequence QQSTEDPWT (SEQ ID NO:25); a VH CDR1 comprising the amino acid sequence SYWMN (SEQ ID NO:26); a VH CDR2 comprising the amino acid sequence QIWPGDGDTNYNGKFKG (SEQ ID NO:27); and a VH CDR3 comprising the amino acid sequence RETTTVGRYYYAMDY (SEQ ID NO:28). [00417] In some cases, an anti-CD19 antibody is a scFv. For example, in some cases, an anti- CD19 scFv comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: ) 3) Anti-mesothelin [00418] Anti-mesothelin antibodies are known in the art; and the VH and VL, or the VH and VL CDRs, of any anti-mesothelin antibody can be included in a CAR. See, e.g., U.S.2019/0000944; WO 2009/045957; WO 2014/031476; USPN 8,460,660; US 2013/0066055; and WO 2009/068204. [00419] In some cases, an anti-mesothelin antibody comprises: a) a light chain comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: Q Q ( Q ); [00421] b) a heavy chain comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00423] In some cases, an anti-mesothelin antibody comprises a VL present in the light chain amino acid sequence provided above; and a VH present in the heavy chain amino acid sequence provided above. For example, an anti-mesothelin antibody can comprise: a) a VL comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: Q ( Q ); ) comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: ) [00424] In some cases, an anti-mesothelin antibody comprises VL CDR1, VL CDR2, and VL CDR3 present in the light chain amino acid sequence provided above; and VH CDR1, CDR2, and CDR3 present in the heavy chain amino acid sequence provided above. In some cases, the V _H and V _L CDRs are as defined by Kabat (see, e.g., Table 1, above; and Kabat 1991). In some cases, the V _H and V _L CDRs are as defined by Chothia (see, e.g., Table 1, above; and Chothia 1987). [00425] For example, an anti-mesothelin antibody can comprise a VL CDR1 having the amino acid sequence TGTSSDIGGYNSVS (SEQ ID NO:34); a VL CDR2 having the amino acid sequence ID NO:36); a VH CDR1 having the amino acid sequence GYSFTSYWIG (SEQ ID NO:37); a VH CDR2 having the amino acid sequence WMGIIDPGDSRTRYSP (SEQ ID NO:38); and a VH CDR3 having the amino acid sequence GQLYGGTYMDG (SEQ ID NO:39). [00426] An anti-mesothelin antibody can be a scFv. As one non-limiting example, an anti- mesothelin scFv can comprise the following amino acid sequence: NO:40), where VH CDR1, CDR2, and CDR3 are underlined; and VL CDR1, CDR2, and CDR3 are bolded and underlined. [00427] As one non-limiting example, an anti-mesothelin scFv can comprise the following amino acid sequence: CDR3 are underlined; and VL CDR1, CDR2, and CDR3 are bolded and underlined. 4) Anti-BCMA [00428] Anti-BCMA (B-cell maturation antigen) antibodies are known in the art; and the VH and VL, or the VH and VL CDRs, of any anti-BCMA antibody can be included in a CAR. See, e.g., WO 2014/089335; US 2019/0153061; and WO 2017/093942. [00429] In some cases, an anti-BCMA antibody comprises: a) a light chain comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00431] b) a heavy chain comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: ( Q ) [00432] In some cases, an anti-BCMA antibody comprises a VL present in the light chain amino acid sequence provided above; and a VH present in the heavy chain amino acid sequence provided above. For example, an anti-BCMA antibody can comprise: a) a VL comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: NO:44); and b) a VH comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the amino acid sequence: [00435] In some cases, an anti-BCMA antibody comprises VL CDR1, VL CDR2, and VL CDR3 present in the light chain amino acid sequence provided above; and VH CDR1, CDR2, and CDR3 present in the heavy chain amino acid sequence provided above. In some cases, the VH and VL CDRs are as defined by Kabat (see, e.g., Table 1, above; and Kabat 1991). In some cases, the VH and VL CDRs are as defined by Chothia (see, e.g., Table 1, above; and Chothia 1987). [00436] For example, an anti-BCMA antibody can comprise a VL CDR1 having the amino acid sequence SSNIGSNT (SEQ ID NO:46), a VL CDR2 having the amino acid sequence NYH, a VL CDR3 having the amino acid sequence AAWDDSLNGWV (SEQ ID NO:47)), a VH CDR1 having the amino acid sequence GFTFGDYA (SEQ ID NO:48), a VH CDR2 having the amino acid sequence SRSKAYGGTT (SEQ ID NO:49), and a VH CDR3 having the amino acid sequence ASSGYSSGWTPFDY (SEQ ID NO:50). [00437] An anti-BCMA antibody can be a scFv. As one non-limiting example, an anti-BCMA scFv can comprise the following amino acid sequence: [00438] As another example, an anti-BCMA scFv can comprise the following amino acid sequence: [00439] In some cases, an anti-BCMA antibody can comprise a VL CDR1 having the amino acid sequence SASQDISNYLN (SEQ ID NO:53); a VL CDR2 having the amino acid sequence YTSNLHS (SEQ ID NO:54); a VL CDR3 having the amino acid sequence QQYRKLPWT (SEQ ID NO:55); a VH CDR1 having the amino acid sequence NYWMH (SEQ ID NO:56); a VH CDR2 having the amino acid sequence ATYRGHSDTYYNQKFKG (SEQ ID NO:57); and a VH CDR3 having the amino acid sequence GAIYNGYDVLDN (SEQ ID NO:58). [00440] In some cases, an anti-BCMA antibody comprises: a) a light chain comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00441] In some cases, an anti-BCMA antibody comprises: a) a heavy chain comprising an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00442] In some cases, an anti-BCMA antibody (e.g., an antibody referred to in the literature as belantamab) comprises a light chain comprising the amino acid sequence: DIQMTQSPSSLSASVGDRVTITCSASQDISNYLNWYQQKPGKAPKLLIYYTSNLHSGVPS RFSGS GSGTDFTLTISSLQPEDFATYYCQQYRKLPWTFGQGTKLEIKR (SEQ ID NO:61); and a heavy chain comprising the amino acid sequence: ( Q ) [00443] In some cases, the anti-BCMA antibody has a cancer chemotherapeutic agent linked to the antibody. For example, in some cases, the anti-BCMA antibody is GSK2857916 (belantamab- mafodotin), where monomethyl auristatin F (MMAF) is linked via a maleimidocaproyl linker to the anti- BCMA antibody belantamab. 5) Anti-MUC1 [00444] In some cases, an antigen-binding polypeptide present in a CAR is a single-chain Fv specific for MUC1. See, e.g., Singh et al. (2007) Mol. Cancer Ther.6:562; Thie et al. (2011) PLoSOne 6:e15921; Imai et al. (2004) Leukemia 18:676; Posey et al. (2016) Immunity 44:1444; EP3130607; EP3164418; WO 2002/044217; and US 2018/0112007. In some cases, an antigen-binding polypeptide present in a CAR is a scFv specific for the MUC1 peptide VTSAPDTRPAPGSTAPPAHG (SEQ ID NO:61). In some cases, a TTP is a scFv specific for the MUC1 peptide SNIKFRPGSVVVQLTLAFREGTINVHDVETQFNQYKTEAASRY (SEQ ID NO:62). In some cases, an antigen-binding polypeptide present in a CAR is a scFv specific for the MUC1 peptide SVVVQLTLAFREGTINVHDVETQFNQYKTEAASRY (SEQ ID NO:63). In some cases, a TTP is a scFv specific for the MUC1 peptide LAFREGTINVHDVETQFNQY (SEQ ID NO:64). In some cases, an antigen-binding polypeptide present in a CAR is a scFv specific for the MUC1 peptide SNIKFRPGSVVVQLTLAAFREGTIN (SEQ ID NO:65). [00445] As an example, an anti-MUC1 antibody can comprise: a VH CDR1 having the amino acid sequence RYGMS (SEQ ID NO:66); a VH CDR2 having the amino acid sequence TISGGGTYIYYPDSVKG (SEQ ID NO:67); a VH CDR3 having the amino acid sequence DNYGRNYDYGMDY (SEQ ID NO:68); a VL CDR1 having the amino acid sequence SATSSVSYIH (SEQ ID NO:69); a VL CDR2 having the amino acid sequence STSNLAS (SEQ ID NO:70); and a VL CDR3 having the amino acid sequence QQRSSSPFT (SEQ ID NO:71). See, e.g., US 2018/0112007. [00446] As another example, an anti-MUC1 antibody can comprise a VH CDR1 having the amino acid sequence GYAMS (SEQ ID NO:72); a VH CDR2 having the amino acid sequence TISSGGTYIYYPDSVKG (SEQ ID NO:73); a VH CDR3 having the amino acid sequence LGGDNYYEYFDV (SEQ ID NO:74); a VL CDR1 having the amino acid sequence RASKSVSTSGYSYMH (SEQ ID NO:75); a VL CDR2 having the amino acid sequence LASNLES (SEQ ID NO:76); and a VL CDR3 having the amino acid sequence QHSRELPFT (SEQ ID NO:77). See, e.g., US 2018/0112007. [00447] As another example, an anti-MUC1 antibody can comprise a VH CDR1 having the amino acid sequence DYAMN (SEQ ID NO:78); a VH CDR2 having the amino acid sequence VISTFSGNINFNQKFKG (SEQ ID NO:79); a VH CDR3 having the amino acid sequence SDYYGPYFDY (SEQ ID NO:80); a VL CDR1 having the amino acid sequence RSSQTIVHSNGNTYLE (SEQ ID NO:81); a VL CDR2 having the amino acid sequence KVSNRFS (SEQ ID NO:82); and a VL CDR3 having the amino acid sequence (FQGSHVPFT (SEQ ID NO:83). See, e.g., US 2018/0112007. [00448] As another example, an anti-MUC1 antibody can comprise a VH CDR1 having the amino acid sequence GYAMS (SEQ ID NO:72); a VH CDR2 having the amino acid sequence TISSGGTYIYYPDSVKG (SEQ ID NO:73); a VH CDR3 having the amino acid sequence LGGDNYYEY (SEQ ID NO:84); a VL CDR1 having the amino acid sequence TASKSVSTSGYSYMH (SEQ ID NO:85); a VL CDR2 having the amino acid sequence LVSNLES (SEQ ID NO:86); and a VL CDR3 having the amino acid sequence QHIRELTRSE (SEQ ID NO:87). See, e.g., US 2018/0112007. 6) Anti-MUC16 [00449] In some cases, an antigen-binding polypeptide present in a CAR is specific for a MUC16 polypeptide present on a cancer cell. See, e.g., US 2018/0118848; and US 2018/0112008. In some cases, a MUC16-specific antigen-binding polypeptide is a scFv. In some cases, a MUC16-specific antigen- binding polypeptide is a nanobody. [00450] As one example, an anti-MUC16 antibody can comprise a VH CDR1 having the amino acid sequence GFTFSNYY (SEQ ID NO:88); a VH CDR2 having the amino acid sequence ISGRGSTI (SEQ ID NO:89); a VH CDR3 having the amino acid sequence VKDRGGYSPY (SEQ ID NO:90); a VL CDR1 having the amino acid sequence QSISTY (SEQ ID NO:91); a VL CDR2 having the amino acid sequence TAS; and a VL CDR3 having the amino acid sequence QQSYSTPPIT (SEQ ID NO:92). See, e.g., US 2018/0118848. 7) Examples of antigen-binding domains [00451] In some cases, a suitable CAR comprises a scFv specific for CD19. For example, in some cases, an anti-CD19 scFv comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00452] In some cases, a suitable CAR comprises a scFv specific for mesothelin. For example, in some cases, an anti-mesothelin scFv comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00453] In some cases, an anti-mesothelin scFv comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00454] In some cases, a suitable CAR comprises a scFv specific for B-cell maturation antigen (BCMA). For example, in some cases, an anti-BCMA scFv comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00455] In some cases, an anti-BCMA scFv comprises an amino acid sequence having at least 90%, at least 95%, at least 98%, at least 99%, or 100%, amino acid sequence identity to the following amino acid sequence: [00456] As noted above, a CAR can include a hinge region between the extracellular domain and the transmembrane domain. As used herein, the term “hinge region” refers to a flexible polypeptide connector region (also referred to herein as “hinge” or “spacer”) providing structural flexibility and spacing to flanking polypeptide regions and can consist of natural or synthetic polypeptides. The hinge region can include complete hinge region derived from an antibody of a different class or subclass from that of the CH1 domain. The term “hinge region” can also include regions derived from CD8 and other receptors that provide a similar function in providing flexibility and spacing to flanking regions. [00457] The hinge region can have a length of from about 4 amino acids to about 50 amino acids, e.g., from about 4 aa to about 10 aa, from about 10 aa to about 15 aa, from about 15 aa to about 20 aa, from about 20 aa to about 25 aa, from about 25 aa to about 30 aa, from about 30 aa to about 40 aa, or from about 40 aa to about 50 aa. [00458] As non-limiting examples, an immunoglobulin hinge region can include one of the following amino acid sequences: DKTHT (SEQ ID NO:93); CPPC (SEQ ID NO:94); ELKTPLGDTTHTCPRCP (SEQ ID NO:102) (human IgG3 hinge); SPNMVPHAHHAQ (SEQ ID NO:103) (human IgG4 hinge); and the like. The hinge region can comprise an amino acid sequence derived from human CD8; e.g., the hinge region can comprise the amino acid sequence: TTTPAPRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFACD (SEQ ID NO:104), or a variant thereof. Transmembrane domain [00459] Any transmembrane (TM) domain that provides for insertion of a polypeptide into the cell membrane of a eukaryotic (e.g., mammalian) cell is suitable for use. The transmembrane region of a CAR can be derived from (i.e. comprise at least the transmembrane region(s) of) the alpha, beta or zeta chain of the T-cell receptor, CD28, CD3 epsilon, CD45, CD4, CD5, CD8 (e.g., CD8 alpha, CD8 beta), CD9, CD16, CD22, CD33, CD37, CD64, CD80, CD86, CD134, CD137, or CD154, KIRDS2, OX40, CD2, CD27, LFA-1 (CD11a, CD18), ICOS (CD278), 4-1BB (CD137), GITR, CD40, BAFFR, HVEM (LIGHTR), SLAMF7, NKp80 (KLRF1), CD160, CD19, IL2R beta, IL2R gamma, IL7R .alpha., ITGA1, VLA1, CD49a, ITGA4, IA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CD11d, ITGAE, CD103, ITGAL, CD11a, LFA-1, ITGAM, CD11b, ITGAX, CD11c, ITGB1, CD29, ITGB2, CD18, LFA-1, ITGB7, TNFR2, DNAM1 (CD226), SLAMF4 (CD244, 2B4), CD84, CD96 (Tactile), CEACAM1, CRTAM, Ly9 (CD229), CD160 (BY55), PSGL1, CD100 (SEMA4D), SLAMF6 (NTB-A, Ly108), SLAM (SLAMF1, CD150, IPO-3), BLAME (SLAMF8), SELPLG (CD162), LTBR, and PAG/Cbp. The transmembrane domain can be synthetic, in which case it can comprise predominantly hydrophobic residues such as leucine and valine. In some cases, a triplet of phenylalanine, tryptophan and valine will be found at each end of a synthetic transmembrane domain. [00460] As one non-limiting example, the TM sequence IYIWAPLAGTCGVLLLSLVITLYC (SEQ ID NO:105) can be used. Additional non-limiting examples of suitable TM sequences include: a) CD8 beta derived TM: LGLLVAGVLVLLVSLGVAIHLCC (SEQ ID NO:106); b) CD4 derived TM: ALIVLGGVAGLLLFIGLGIFFCVRC (SEQ ID NO:107); c) CD3 zeta derived TM: LCYLLDGILFIYGVILTALFLRV (SEQ ID NO:108); d) CD28 derived TM: WVLVVVGGVLACYSLLVTVAFIIFWV (SEQ ID NO:109); e) CD134 (OX40) derived TM: VAAILGLGLVLGLLGPLAILLALYLL (SEQ ID NO:110); and f) CD7 derived TM: ALPAALAVISFLLGLGLGVACVLA (SEQ ID NO:111). Intracellular domain – co-stimulatory polypeptide [00461] The intracellular portion (cytoplasmic domain) of a CAR can comprise one or more co- stimulatory polypeptides. Non-limiting examples of suitable co-stimulatory polypeptides include, but are not limited to, 4-1BB (CD137), CD28, ICOS, OX-40, BTLA, CD27, CD30, GITR, and HVEM. Suitable co-stimulatory polypeptides include, e.g.: 1) a 4-1BB polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL (SEQ ID NO:112); 2) a CD28 polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: FWVRSKRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAYRS (SEQ ID NO:113); 3) an ICOS polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: TKKKYSSSVHDPNGEYMFMRAVNTAKKSRLTDVTL (SEQ ID NO:114); 4) an OX40 polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: RRDQRLPPDAHKPPGGGSFRTPIQEEQADAHSTLAKI (SEQ ID NO:115); 5) a BTLA polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: CCLRRHQGKQNELSDTAGREINLVDAHLKSEQTEASTRQNSQVLLSETGIYDNDPDLCFR MQEG SEVYSNPCLEENKPGIVYASLNHSVIGPNSRLARNVKEAPTEYASICVRS (SEQ ID NO:116); 6) a CD27 polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: HQRRKYRSNKGESPVEPAEPCRYSCPREEEGSTIPIQEDYRKPEPACSP (SEQ ID NO:117); 7) a CD30 polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: RRACRKRIRQKLHLCYPVQTSQPKLELVDSRPRRSSTQLRSGASVTEPVAEERGLMSQPL METC HSVGAAYLESLPLQDASPAGGPSSPRDLPEPRVSTEHTNNKIEKIYIMKADTVIVGTVKA ELPEG RGLAGPAEPELEEELEADHTPHYPEQETEPPLGSCSDVMLSVEEEGKEDPLPTAASGK (SEQ ID NO:118); 8) a GITR polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: HIWQLRSQCMWPRETQLLLEVPPSTEDARSCQFPEEERGERSAEEKGRLGDLWV (SEQ ID NO:119); and 9) an HVEM polypeptide having at least 90%, at least 95%, at least 98%, or 100%, amino acid sequence identity to the following amino acid sequence: CVKRRKPRGDVVKVIVSVQRKRQEAEGEATVIEALQAPPDVTTVAVEETIPSFTGRSPNH (SEQ ID NO:120). The co-stimulatory polypeptide can have a length of from about 30 aa to about 35 aa, from about 35 aa to about 40 aa, from about 40 aa to about 45 aa, from about 45 aa to about 50 aa, from about 50 aa to about 55 aa, from about 55 aa to about 60 aa, from about 60 aa to about 65 aa, or from about 65 aa to about 70 aa. Intracellular domain – signaling polypeptide [00462] The intracellular portion of a CAR can comprise a signaling polypeptide. Suitable signaling polypeptides include, e.g., an immunoreceptor tyrosine-based activation motif (ITAM)- containing intracellular signaling polypeptide. An ITAM motif is YX ₁ X ₂ L/I (SEQ ID NO:121), where X ₁ and X2 are independently any amino acid. In some cases, the intracellular signaling domain of a subject CAR comprises 1, 2, 3, 4, or 5 ITAM motifs. In some cases, an ITAM motif is repeated twice in an intracellular signaling domain, where the first and second instances of the ITAM motif are separated from one another by 6 to 8 amino acids, e.g., (YX1X2L/I)(X3)n(YX1X2L/I) (SEQ ID NO:122), where n is an integer from 6 to 8, and each of the 6-8 X3 can be any amino acid. In some cases, the intracellular signaling domain of a CAR comprises 3 ITAM motifs. [00463] A suitable intracellular signaling domain can be an ITAM motif-containing portion that is derived from a polypeptide that contains an ITAM motif. For example, a suitable intracellular signaling domain can be an ITAM motif-containing domain from any ITAM motif-containing protein. Thus, a suitable intracellular signaling domain need not contain the entire sequence of the entire protein from which it is derived. Examples of suitable ITAM motif-containing polypeptides include, but are not limited to: DAP12; FCER1G (Fc epsilon receptor I gamma chain); CD3D (CD3 delta); CD3E (CD3 epsilon); CD3G (CD3 gamma); CD3Z (CD3 zeta); and CD79A (antigen receptor complex-associated protein alpha chain). Nucleic acids [00464] As indicated above, a chimeric molecule of the present disclosure comprises a nucleic acid covalently linked to a TMMP, where the nucleic acid comprises a nucleotide sequence encoding a CAR. [00465] In some cases, the nucleic acid is DNA. In some cases, the nucleic acid is an expression vector (e.g., a recombinant expression vector). In some cases, the recombinant expression vector is a viral construct, e.g., a recombinant adeno-associated virus (AAV) construct, a recombinant adenoviral construct, and the like. [00466] In some cases, the nucleic acid is an RNA. In some cases, the nucleic acid is a viral RNA construct. For example, in some cases, the RNA is a retroviral construct comprising a nucleotide sequence encoding a CAR. As an example, in some cases, the RNA is a lentiviral construct comprising a nucleotide sequence encoding a CAR. In some cases, the nucleic acid is an mRNA. mRNAs [00467] In some cases, the nucleic acid component of a chimeric molecule of the present disclosure is an mRNA. In some cases, the mRNA is covalently linked to the C-terminus of the first polypeptide of the heterodimer of the TMMP. In some cases, the mRNA is covalently linked to the C- terminus of second polypeptide of the heterodimer of the TMMP. In some cases, the mRNA is covalently linked to the C-terminus of an Fc polypeptide present in the TMMP. [00468] The mRNA can include one or more of the following features: i) a 5’cap structure; ii) a poly(adenosine) (polyA) tail (i.e., a polyA tract at the 3’ end of the mRNA; iii) a 5’ untranslated region (5’ UTR); and iv) a 3’ untranslated region (3’ UTR). An mRNA can be produced using any known method, including, e.g., in vitro transcription. See, e.g., Van Hoecke and Roose (2019) J. Transl. Med. 17:54. [00469] In some cases, the mRNA comprises one or more modifications. For example, the mRNA component of a chimeric molecule of the present disclosure can comprise one or more of: i) a modified base; ii) a modified sugar; and iii) a modified backbone. An mRNA comprises nucleosides. In some cases, the base of one or more nucleosides of the mRNA is modified. In some cases, the sugar of one or more nucleosides of the mRNA is modified. In some cases, both the base and the sugar of one or more nucleosides of the mRNA is modified. [00470] Examples of suitable mRNA modifications include modified nucleic acid backbones and non-natural internucleoside linkages. Nucleic acids having modified backbones include those that retain a phosphorus atom in the backbone and those that do not have a phosphorus atom in the backbone. [00471] Suitable modified backbones containing a phosphorus atom therein include, for example, phosphorothioates, chiral phosphorothioates, phosphorodithioates, phosphotriesters, aminoalkylphosphotriesters, methyl and other alkyl phosphonates including 3'-alkylene phosphonates, 5'- alkylene phosphonates and chiral phosphonates, phosphinates, phosphoramidates including 3'-amino phosphoramidate and aminoalkylphosphoramidates, phosphorodiamidates, thionophosphoramidates, thionoalkylphosphonates, thionoalkylphosphotriesters, selenophosphates and boranophosphates having normal 3'-5' linkages, 2'-5' linked analogs of these, and those having inverted polarity wherein one or more internucleotide linkages is a 3' to 3', 5' to 5' or 2' to 2' linkage. Suitable mRNAs having inverted polarity comprise a single 3' to 3' linkage at the 3'-most internucleotide linkage i.e. a single inverted nucleoside residue which may be a basic (the nucleobase is missing or has a hydroxyl group in place thereof). Various salts (such as, for example, potassium or sodium salts), mixed salts, and free acid forms can also be included. [00472] In some cases, an mRNA comprises one or more phosphorothioate and/or heteroatom internucleoside linkages, in particular -CH ₂ -NH-O-CH ₂ -, -CH ₂ -N(CH ₃ )-O-CH ₂ - (known as a methylene (methylimino) or MMI backbone), -CH2-O-N(CH3)-CH2-, -CH2-N(CH3)-N(CH3)-CH2- and -O-N(CH3)- CH2-CH2- (wherein the native phosphodiester internucleotide linkage is represented as -O-P(=O)(OH)- O-CH2-). MMI type internucleoside linkages are disclosed in the above referenced U.S. Pat. No. 5,489,677. Suitable amide internucleoside linkages are disclosed in t U.S. Pat. No.5,602,240. [00473] Also suitable are mRNAs having morpholino backbone structures as described in, e.g., U.S. Pat. No.5,034,506. For example, in some cases, an mRNA comprises a 6-membered morpholino ring in place of a ribose ring. In some cases, a phosphorodiamidate or other non-phosphodiester internucleoside linkage replaces a phosphodiester linkage. [00474] Suitable modified polynucleotide backbones that do not include a phosphorus atom therein have backbones that are formed by short chain alkyl or cycloalkyl internucleoside linkages, mixed heteroatom and alkyl or cycloalkyl internucleoside linkages, or one or more short chain heteroatomic or heterocyclic internucleoside linkages. These include those having morpholino linkages (formed in part from the sugar portion of a nucleoside); siloxane backbones; sulfide, sulfoxide and sulfone backbones; formacetyl and thioformacetyl backbones; methylene formacetyl and thioformacetyl backbones; riboacetyl backbones; alkene containing backbones; sulfamate backbones; methyleneimino and methylenehydrazino backbones; sulfonate and sulfonamide backbones; amide backbones; and others having mixed N, O, S and CH2 component parts. [00475] The mRNA component of a chimeric molecule of the present disclosure can include one or more substituted sugar moieties. Suitable polynucleotides comprise a sugar substituent group selected from: OH; F; O-, S-, or N-alkyl; O-, S-, or N-alkenyl; O-, S- or N-alkynyl; or O-alkyl-O-alkyl, wherein the alkyl, alkenyl and alkynyl may be substituted or unsubstituted C.sub.1 to C10 alkyl or C2 to C10 alkenyl and alkynyl. Particularly suitable are O((CH2)nO) mCH3, O(CH2)nOCH3, O(CH2)nNH2, O(CH ₂ ) _n CH ₃ , O(CH ₂ ) _n ONH ₂ , and O(CH ₂ ) _n ON((CH ₂ ) _n CH ₃ ) ₂ , where n and m are from 1 to about 10. Other suitable polynucleotides (e.g., mRNA) comprise a sugar substituent group selected from: C ₁ to C ₁₀ lower alkyl, substituted lower alkyl, alkenyl, alkynyl, alkaryl, aralkyl, O-alkaryl or O-aralkyl, SH, SCH ₃ , OCN, Cl, Br, CN, CF ₃ , OCF ₃ , SOCH ₃ , SO ₂ CH ₃ , ONO ₂ , NO ₂ , N ₃ , NH ₂ , heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, polyalkylamino, substituted silyl, an RNA cleaving group, a reporter group, an intercalator, a group for improving the pharmacokinetic properties of an mRNA, or a group for improving the pharmacodynamic properties of an mRNA, and other substituents having similar properties. A suitable modification includes 2'-methoxyethoxy (2'-O-CH ₂ CH ₂ OCH ₃ , also known as 2'- O-(2-methoxyethyl) or 2'-MOE) i.e., an alkoxyalkoxy group. A further suitable modification includes 2'- dimethylaminooxyethoxy, i.e., a O(CH ₂ ) ₂ ON(CH ₃ ) ₂ group, also known as 2'-DMAOE, and 2'- dimethylaminoethoxyethoxy (also known in the art as 2'-O-dimethyl-amino-ethoxy-ethyl or 2'- DMAEOE), i.e., 2'-O-CH ₂ -O-CH ₂ -N(CH ₃ ) ₂ . [00476] Other suitable sugar substituent groups include methoxy (-O-CH3), aminopropoxy (--O CH2 CH2 CH2NH2), allyl (-CH2-CH=CH2), -O-allyl (-O-CH2—CH=CH2) and fluoro (F).2'-sugar substituent groups may be in the arabino (up) position or ribo (down) position. A suitable 2'-arabino modification is 2'-F. Similar modifications may also be made at other positions on the mRNA, particularly the 3' position of the sugar on the 3' terminal nucleoside or in 2'-5' linked mRNA and the 5' position of 5' terminal nucleotide. An mRNA may also have sugar mimetics such as cyclobutyl moieties in place of the pentofuranosyl sugar. [00477] A guide RNA may also include nucleobase (often referred to in the art simply as "base") modifications or substitutions. As used herein, "unmodified" or "natural" nucleobases include the purine bases adenine (A) and guanine (G), and the pyrimidine bases thymine (T), cytosine (C) and uracil (U). Modified nucleobases include other synthetic and natural nucleobases such as 5-methylcytosine (5-me- C), 5-hydroxymethyl cytosine, xanthine, hypoxanthine, 2-aminoadenine, 6-methyl and other alkyl derivatives of adenine and guanine, 2-propyl and other alkyl derivatives of adenine and guanine, 2- thiouracil, 2-thiothymine and 2-thiocytosine, 5-halouracil and cytosine, 5-propynyl (-C=C-CH3) uracil and cytosine and other alkynyl derivatives of pyrimidine bases, 6-azo uracil, cytosine and thymine, 5- uracil (pseudouracil), 4-thiouracil, 8-halo, 8-amino, 8-thiol, 8-thioalkyl, 8-hydroxyl and other 8- substituted adenines and guanines, 5-halo particularly 5-bromo, 5-trifluoromethyl and other 5-substituted uracils and cytosines, 7-methylguanine and 7-methyladenine, 2-F-adenine, 2-amino-adenine, 8- azaguanine and 8-azaadenine, 7-deazaguanine and 7-deazaadenine and 3-deazaguanine and 3- deazaadenine. Further modified nucleobases include tricyclic pyrimidines such as phenoxazine cytidine(1H-pyrimido(5,4-b)(1,4)benzoxazin-2(3H)-one), phenothiazine cytidine (1H-pyrimido(5,4- b)(1,4)benzothiazin-2(3H)-one), G-clamps such as a substituted phenoxazine cytidine (e.g.9-(2- aminoethoxy)-H-pyrimido(5,4-(b) (1,4)benzoxazin-2(3H)-one), carbazole cytidine (2H-pyrimido(4,5- b)indol-2-one), pyridoindole cytidine (H-pyrido(3',2':4,5)pyrrolo(2,3-d)pyrimidin-2-one). [00478] Heterocyclic base moieties may also include those in which the purine or pyrimidine base is replaced with other heterocycles, for example 7-deaza-adenine, 7-deazaguanosine, 2- aminopyridine and 2-pyridone. Additional suitable modified bases include 5-substituted pyrimidines, 6- azapyrimidines and N-2, N-6 and O-6 substituted purines, including 2-aminopropyladenine, 5- propynyluracil and 5-propynylcytosine.5-methylcytosine substitutions are suitable base substitutions, e.g., when combined with 2'-O-methoxyethyl sugar modifications. Suitable modified nucleosides that can be incorporated in an mRNA include pseudouridine, 2-thiouridine, 5-methylpyridine, N ¹ - methylpseudouridine, and 5-methylcytidine. Cleavable linkers [00479] A chimeric molecule of the present disclosure comprises a nucleic acid covalently linked to a TMMP. In some cases, the nucleic acid is linked to the TMMP via a non-cleavable linker. In some cases, the nucleic acid is linked to the TMMP via a cleavable linker. Suitable cleavable linkers include acid-labile linkers, peptidase-sensitive linkers (proteolytically cleavable linkers), photolabile linkers, dimethyl linkers, and disulfide-containing linkers. In some cases, the cleavable linker is cleaved by intracellular conditions. In some cases, the cleavable linker is cleaved by lysosomal conditions. In some cases, the cleavable linker is acid labile, e.g., is cleaved by low pH conditions (e.g., in low pH environment of the lysosome or endosome). An example of an acid-labile linker is one comprising a bis- sialyl ether. A cleavable linker can comprise a cathepsin-labile substrate. Examples of a cleavable linker include a linker having an -S-S- (disulfide) bond, where the disulfide bond can be cleaved under intracellular reducing environment, where such linkers include a SS linker and a DMSS linker); a linker having a hydrazone bond, where the hydrazone bond can be cleaved by low pH in an endosome; a linker having an ortho ester bond in the structure; and a linker having a peptide bond being cleaved by cathepsin B in the structure (for example, a linker having a valine-citrulline dipeptide (a Val-Cit linker)). In some cases, the linker comprises a valine-citrulline dipeptide (a “Val-Cit” linker). In some cases, the linker comprises a disulfide (S-S) group. In some cases, the linker comprises a dimethyl SS (DMSS) group. [00480] In some cases, the linker is a proteolytically cleavable linker. For example, the proteolytically cleavable linker can comprise a matrix metalloproteinase (MMP) cleavage site, e.g., a cleavage site for a MMP selected from collagenase-1, -2, and -3 (MMP-1, -8, and -13), gelatinase A and B (MMP-2 and -9), stromelysin 1, 2, and 3 (MMP-3, -10, and -11), matrilysin (MMP-7), and membrane metalloproteinases (MT1-MMP and MT2-MMP). For example, the cleavage sequence of MMP-9 is Pro- X-X-Hy (SEQ ID NO:439; wherein, X represents an arbitrary residue; Hy, a hydrophobic residue), e.g., Pro-X-X-Hy-(Ser/Thr) (SEQ ID NO:440), e.g., Pro-Leu/Gln-Gly-Met-Thr-Ser (SEQ ID NO:441) or Pro- Leu/Gln-Gly-Met-Thr (SEQ ID NO:442). Another example of a protease cleavage site is a plasminogen activator cleavage site, e.g., a uPA or a tissue plasminogen activator (tPA) cleavage site. In some cases, the cleavage site is a furin cleavage site. Specific examples of cleavage sequences of uPA and tPA include sequences comprising Val-Gly-Arg. Another example of a protease cleavage site that can be included in a proteolytically cleavable linker is a tobacco etch virus (TEV) protease cleavage site, e.g., ENLYTQS (SEQ ID NO:443), where the protease cleaves between the glutamine and the serine. Another example of a protease cleavage site that can be included in a proteolytically cleavable linker is an enterokinase cleavage site, e.g., DDDDK (SEQ ID NO:444), where cleavage occurs after the lysine residue. Another example of a protease cleavage site that can be included in a proteolytically cleavable linker is a thrombin cleavage site, e.g., LVPR (SEQ ID NO:445). Additional suitable linkers comprising protease cleavage sites include linkers comprising one or more of the following amino acid sequences: LEVLFQGP (SEQ ID NO:446), cleaved by PreScission protease (a fusion protein comprising human rhinovirus 3C protease and glutathione-S-transferase; Walker et al. (1994) Biotechnol.12:601); a thrombin cleavage site, e.g., CGLVPAGSGP (SEQ ID NO:447); SLLKSRMVPNFN (SEQ ID NO:448) or SLLIARRMPNFN (SEQ ID NO:449), cleaved by cathepsin B; SKLVQASASGVN (SEQ ID NO:450) or SSYLKASDAPDN (SEQ ID NO:451), cleaved by an Epstein-Barr virus protease; RPKPQQFFGLMN (SEQ ID NO:452) cleaved by MMP-3 (stromelysin); SLRPLALWRSFN (SEQ ID NO:453) cleaved by MMP-7 (matrilysin); SPQGIAGQRNFN (SEQ ID NO:454) cleaved by MMP-9; DVDERDVRGFASFL SEQ ID NO:455) cleaved by a thermolysin-like MMP; SLPLGLWAPNFN (SEQ ID NO:456) cleaved by matrix metalloproteinase 2(MMP-2); SLLIFRSWANFN (SEQ ID NO:457) cleaved by cathespin L; SGVVIATVIVIT (SEQ ID NO:458) cleaved by cathepsin D; SLGPQGIWGQFN (SEQ ID NO:459) cleaved by matrix metalloproteinase 1(MMP-1); KKSPGRVVGGSV (SEQ ID NO:460) cleaved by urokinase-type plasminogen activator; PQGLLGAPGILG (SEQ ID NO:461) cleaved by membrane type 1 matrixmetalloproteinase (MT- MMP); HGPEGLRVGFYESDVMGRGHARLVHVEEPHT (SEQ ID NO:462) cleaved by stromelysin 3 (or MMP-11), thermolysin, fibroblast collagenase and stromelysin-1; GPQGLAGQRGIV (SEQ ID NO:463) cleaved by matrix metalloproteinase 13 (collagenase-3); GGSGQRGRKALE (SEQ ID NO:464) cleaved by tissue-type plasminogen activator(tPA); SLSALLSSDIFN (SEQ ID NO:465) cleaved by human prostate-specific antigen; SLPRFKIIGGFN (SEQ ID NO:466) cleaved by kallikrein (hK3); SLLGIAVPGNFN (SEQ ID NO:467) cleaved by neutrophil elastase; and FFKNIVTPRTPP (SEQ ID NO:468) cleaved by calpain (calcium activated neutral protease). Transcriptional control elements [00481] As indicated above, a chimeric molecule of the present disclosure comprises a nucleic acid covalently linked to a TMMP, where the nucleic acid comprises a nucleotide sequence encoding a CAR. Where the nucleic acid is DNA, the nucleotide sequences encoding the CAR can be operably linked to a transcriptional control element such as a promoter. The transcriptional control element (e.g., a promoter) is one that is functional in a T cell. Suitable promoters include constitutive promoters and regulatable (e.g., inducible) promoters. [00482] One example of a suitable promoter is the immediate early cytomegalovirus (CMV) promoter sequence. This promoter sequence is a strong constitutive promoter sequence capable of driving high levels of expression of an operably linked nucleotide sequence. Another example of a suitable promoter is Elongation Growth Factor-1α (EF-1α). However, other constitutive promoter sequences may also be used, including, but not limited to, the simian virus 40 (SV40) early promoter, MND (myeloproliferative sarcoma virus) promoter, mouse mammary tumor virus (MMTV), human immunodeficiency virus (HIV) long terminal repeat (LTR) promoter, Moloney Murine Leukemia Virus (MoMuLV) promoter, an avian leukemia virus promoter, an Epstein-Barr virus immediate early promoter, a Rous sarcoma virus promoter, as well as human gene promoters such as, but not limited to, the actin promoter, the myosin promoter, the hemoglobin promoter, and the creatine kinase promoter. Examples of inducible promoters include, but are not limited to, a metallothionine promoter, a glucocorticoid-inducible promoter, a progesterone-inducible promoter, and a tetracycline-inducible promoter. [00483] In some cases, the promoter is a CD8 cell-specific promoter, a CD4 cell-specific promoter, a neutrophil-specific promoter, or an NK-specific promoter. For example, a CD4 gene promoter can be used; see, e.g., Salmon et al. (1993) Proc. Natl. Acad. Sci. USA 90: 7739; and Marodon et al. (2003) Blood 101:3416. As another example, a CD8 gene promoter can be used. NK cell-specific expression can be achieved by use of an Ncr1 (p46) promoter; see, e.g., Eckelhart et al. (2011) Blood 117:1565. METHOD OF MAKING A CHIMERIC MOLECULE [00484] The present disclosure provides a method of making a chimeric molecule of the present disclosure. [00485] The nucleic acid component of a chimeric molecule of the present disclosure can be covalently linked to one or both polypeptide chains of the TMMP component of the chimeric molecule using any of a variety of attachment chemistries. A variety of chemistries for attaching a nucleic acid to a polypeptide are known in the art; any such chemistry can be used. [00486] Suitable attachment chemistries include: 1) reaction of acrylamides, alkyl halides, alkyl sulfonates, aziridines, haloacetamides, or maleimides with thiols to form thioether bonds; 2) reaction of acyl halides, acyl nitriles, anhydrides, or carboxylic acids with alcohols or phenols to form an ester bond; 3) reaction of an aldehyde with an amine or aniline to form an imine bond; 4) reaction of an aldehyde or ketone with a hydrazine to form a hydrazone bond; 5) reaction of an aldehyde or ketone with a hydroxylamine to form an oxime bond; 6) reaction of an alkyl halide with an amine or aniline to form an alkyl amine bond; 7) reaction of alkyl halides, alkyl sulfonates, diazoalkanes, or epoxides with carboxylic acids to form an ester bond; 8) reaction of an alkyl halide or alkyl sulfonate with an alcohol or phenol to form an ether bond; 9) reaction of an anhydride with an amine or aniline to form a carboxamide or imide bond; 10) reaction of an aryl halide with a thiol to form a thiophenol bond; 11) reaction of an aryl halide with an amine to form an aryl amine bond; 12) reaction of a boronate with a glycol to form a boronate ester bond; 13) reaction of a carboxylic acid with a hydrazine to form a hydrazide bond; 14) of a carbodiimide with a carboxylic acid to form an N-acylurea or anhydride bond; 15) reaction of an epoxide with a thiol to form a thioether bond; 16) reaction of a haloplatinate with an amino or heterocyclic group to form a platinum complex; 16) reaction of a halotriazine with an amine or aniline to form an aminotriazine bond; 17) reaction of a halotriazines with an alcohol or phenol to form a triazinyl ether bond; 18) reaction of an imido ester with an amine or aniline to form an amidine bond; 19) reaction of an isocyanate with an amine or aniline to form a urea; 20) reaction of an isocyanate with an alcohol or phenol to form a urethane bond; 21) reaction of an isothiocyanate with an amine or aniline to form a thiourea bond; 22) reaction of a phosphoramidate with an alcohol to form a phosphite ester bond; 23) reaction of a silyl halide with an alcohol to form a silyl ether bond; 24) reaction of a sulfonate ester with an amine or aniline to form an alkyl amine bond; 25) reaction of a sulfonyl halide with an amine or aniline to form a sulfonamide bond; 26) reaction of a thioester with the thiol group of a cysteine followed by rearrangement to form an amide bond; 27) reaction of an azide with an alkyne to form a 1,2,3- triazole; and 28) of an aldehyde with an N-terminal cysteine to form a 5-membered thiazolidine ring. [00487] The nucleic acid can comprise, or can be modified to comprise, a first reactive coupling group; and one or both polypeptide chains of the TMMP can comprise, or can be modified to comprise, a second reactive coupling group. The first reactive coupling group is capable of reacting with the second reactive coupling group to form a covalent bond. In some cases, a coupling reagent is used to link the first reactive coupling group with the second reactive coupling group. For example, a cross-linking reagent can be used to link the two components (the nucleic acid component and the TMMP component), where one of the two components comprises a first reactive coupling group, and the other component (the other of the two components) comprises a second reactive coupling group. [00488] One of either the first reactive coupling group or the second reactive coupling group can be a primary amine, where the other reactive coupling group can be an amine-reactive linking group such as isothiocyanates, isocyanates, acyl azides, N-hydroxysuccinimide (NHS) esters, sulfonyl chlorides, aldehydes, glyoxals, epoxides, oxiranes, carbonates, aryl halides, imidoesters, carbodiimides, anhydrides, and fluorophenyl esters. As an example, the first reactive coupling group can comprise an amine; the second reactive coupling group can comprise a complimentary reactive group, such an NHS ester; and a coupling reagent such as dicyclohexylcarbodiimide (DCC) or 1-ethyl-3-(3-dimethyl-aminopropyl) carbodiimide (EDC) can be used to covalently link the amine group with the NHS ester. [00489] One of either the first reactive coupling group or the second reactive coupling group can be an aldehyde, where the other reactive coupling group can be an aldehyde reactive linking group such as hydrazides, alkoxyamines, and primary amines. [00490] One of either the first reactive coupling group or the second reactive coupling group can be a thiol, where the other reactive coupling group can be a sulfhydryl reactive group such as maleimides, haloacetyls, and pyridyl disulfides. As one example, the heterobifunctional cross-linking reagent succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC) can be used to link the two components, where one of the two components comprises a carboxyl group as the first reactive coupling group, and the other component comprises a thiol group (e.g., an SH group) as the second reactive coupling group. [00491] As one example, the cross-linking reagent EDC can be used to link the two components, where one of the two components comprises a free carboxyl (COOH) group as the first reactive coupling group, and the other component comprises an amine group as the second reactive coupling group. [00492] As another example, the cross-linking reagent tris(hydroxymethyl)phosphine (TMP) or β-[tris(hydroxymethyl)phosphino] propionic acid (THPP) can be used to link the two components, where one of the two components comprises a primary amine group as the first reactive coupling group, and the other component comprises a primary amine group as the second reactive coupling group. [00493] The two components can be linked to one another using a “click” chemistry. See, e.g., Kolb et al. (2001) Angewandte Chemie, International Edition 40:2004; Tornoe et al. (2002) J. Org. Chem.67:3057-3064; Rostovtsev et al. (2002) Angew. Chem., Int. Ed.41:2596-2599; Agard et al. (2004) J. Am. Chem. Soc.126:15046-15047; and Jewett et al. (2010) J. Am. Chem. Soc.132:3688-3690. For example, one of the two components comprises an alkyne as the first reactive coupling group, and the other of the two component comprises an azide as the second reactive coupling group. The alkyne and azide can undergo a "click" reaction to form a covalent bond. COMPOSITIONS [00494] The present disclosure provides compositions, including pharmaceutical compositions, comprising a chimeric molecule of the present disclosure. [00495] A composition of the present disclosure can comprise, in addition to a chimeric molecule of the present disclosure, one or more of: a salt, e.g., NaCl, MgCl2, KCl, MgSO4, etc.; a buffering agent, e.g., a Tris buffer, N-(2-Hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) (HEPES), 2-(N- Morpholino)ethanesulfonic acid (MES), 2-(N-Morpholino)ethanesulfonic acid sodium salt (MES), 3-(N- Morpholino)propanesulfonic acid (MOPS), N-tris[Hydroxymethyl]methyl-3-aminopropanesulfonic acid (TAPS), etc.; a solubilizing agent; a detergent, e.g., a non-ionic detergent such as Tween-20, etc.; a protease inhibitor; glycerol; and the like. [00496] The composition may comprise a pharmaceutically acceptable excipient, a variety of which are known in the art and need not be discussed in detail herein. Pharmaceutically acceptable excipients have been amply described in a variety of publications, including, for example, “Remington: The Science and Practice of Pharmacy”, 19 ^th Ed. (1995), or latest edition, Mack Publishing Co; A. Gennaro (2000) "Remington: The Science and Practice of Pharmacy", 20th edition, Lippincott, Williams, & Wilkins; Pharmaceutical Dosage Forms and Drug Delivery Systems (1999) H.C. Ansel et al., eds 7 ^th ed., Lippincott, Williams, & Wilkins; and Handbook of Pharmaceutical Excipients (2000) A.H. Kibbe et al., eds., 3 ^rd ed. Amer. Pharmaceutical Assoc. [00497] A pharmaceutical composition can comprise a chimeric molecule of the present disclosure, and a pharmaceutically acceptable excipient. In some cases, a subject pharmaceutical composition will be suitable for administration to a subject, e.g., will be sterile. For example, in some cases, a subject pharmaceutical composition will be suitable for administration to a human subject, e.g., where the composition is sterile and is free of detectable pyrogens and/or other toxins. [00498] The protein compositions may comprise other components, such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium, carbonate, and the like. The compositions may contain pharmaceutically acceptable auxiliary substances as required to approximate physiological conditions such as pH adjusting and buffering agents, toxicity adjusting agents and the like, for example, sodium acetate, sodium chloride, potassium chloride, calcium chloride, sodium lactate, hydrochloride, sulfate salts, solvates (e.g., mixed ionic salts, water, organics), hydrates (e.g., water), and the like. [00499] For example, compositions may include aqueous solution, powder form, granules, tablets, pills, suppositories, capsules, suspensions, sprays, and the like. The composition may be formulated according to the various routes of administration described below. [00500] Where a chimeric molecule of the present disclosure is administered as an injectable (e.g. subcutaneously, intraperitoneally, intramuscularly, and/or intravenously) directly into a tissue, a formulation can be provided as a ready-to-use dosage form, or as non-aqueous form (e.g. a reconstitutable storage-stable powder) or aqueous form, such as liquid composed of pharmaceutically acceptable carriers and excipients. The protein-containing formulations may also be provided so as to enhance serum half-life of the chimeric molecule following administration. For example, the chimeric molecule may be provided in a liposome formulation, prepared as a colloid, or other conventional techniques for extending serum half-life. A variety of methods are available for preparing liposomes, as described in, e.g., Szoka et al.1980 Ann. Rev. Biophys. Bioeng.9:467, U.S. Pat. Nos.4,235,871, 4,501,728 and 4,837,028. The preparations may also be provided in controlled release or slow-release forms. [00501] Other examples of formulations suitable for parenteral administration include isotonic sterile injection solutions, anti-oxidants, bacteriostats, and solutes that render the formulation isotonic with the blood of the intended recipient, suspending agents, solubilizers, thickening agents, stabilizers, and preservatives. For example, a subject pharmaceutical composition can be present in a container, e.g., a sterile container, such as a syringe. The formulations can be presented in unit-dose or multi-dose sealed containers, such as ampules and vials, and can be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid excipient, for example, water, for injections, immediately prior to use. Extemporaneous injection solutions and suspensions can be prepared from sterile powders, granules, and tablets. [00502] The concentration of a chimeric molecule of the present disclosure in a formulation can vary widely (e.g., from less than about 0.1%, usually at or at least about 2% to as much as 20% to 50% or more by weight) and will usually be selected primarily based on fluid volumes, viscosities, and patient-based factors in accordance with the particular mode of administration selected and the patient's needs. [00503] The present disclosure provides a container comprising a composition of the present disclosure, e.g., a liquid composition. The container can be, e.g., a syringe, an ampoule, and the like. In some cases, the container is sterile. In some cases, both the container and the composition are sterile. [00504] The present disclosure provides compositions, including pharmaceutical compositions, comprising a chimeric molecule of the present disclosure. A composition can comprise: a) a TMMP of the present disclosure; and b) an excipient, as described above. In some cases, the excipient is a pharmaceutically acceptable excipient. [00505] In some cases, a chimeric molecule of the present disclosure is present in a liquid composition. Thus, the present disclosure provides compositions (e.g., liquid compositions, including pharmaceutical compositions) comprising a chimeric molecule of the present disclosure. In some cases, a composition of the present disclosure comprises: a) a chimeric molecule of the present disclosure; and b) saline (e.g., 0.9% NaCl). In some cases, the composition is sterile. In some cases, the composition is suitable for administration to a human subject, e.g., where the composition is sterile and is free of detectable pyrogens and/or other toxins. Thus, the present disclosure provides a composition comprising: a) a chimeric molecule of the present disclosure; and b) saline (e.g., 0.9% NaCl), where the composition is sterile and is free of detectable pyrogens and/or other toxins. M ^{ETHODS OF} M ^ODULATING T C ^ELL A ^CTIVITY [00506] The present disclosure provides a method of selectively modulating the activity of T cell specific for an epitope (e.g., a T cell specific for a viral antigen or a bacterial antigen). The method comprises contacting the T cell with a chimeric molecule of the present disclosure. The contacting selectively modulates the activity of the epitope-specific T cell. In some cases, the contacting step is carried out in vitro. In some cases, the contacting step is carried out in vivo. [00507] In some cases, e.g., where the target T cell is a CD8 ⁺ T cell, the TMMP comprises Class I MHC polypeptides (e.g., β2-microglobulin and Class I MHC heavy chain). [00508] Where a TMMP in a chimeric molecule of the present disclosure includes an immunomodulatory polypeptide that is an activating polypeptide, contacting the T cell with the chimeric activates the epitope-specific T cell and/or increases the number of the epitope-specific T cells. In some instances, the epitope-specific T cell is a T cell that is specific for viral epitope, the CAR encoded by the nucleic acid component of the chimeric molecule is specific for a cancer-associated epitope present on a cancer cell, and contacting the viral epitope-specific T cell with the chimeric molecule increases cytotoxic activity of the T cell toward the cancer cell. In some instances, the epitope-specific T cell is a T cell that is specific for viral epitope, the CAR encoded by the nucleic acid component of the chimeric molecule is specific for a cancer-associated epitope present on a cancer cell, and contacting the viral epitope-specific T cell with the chimeric molecule increases the number of the viral epitope-specific T cells that have cytotoxic activity toward cancer cells that express a cancer-associated antigen recognized by the CAR. TREATMENT METHODS [00509] The present disclosure provides a method of treating a cancer in an individual. The method comprises administering to an individual having a cancer an effective amount of a chimeric molecule of the present disclosure. Alternatively, or in addition, the patient’s blood can be removed and treated in vitro with chimeric molecules of the present disclosure in order to prepare genetically modified target T cells as described herein that are then introduced into the patient. As used herein, the term “in vitro” is intended to connote any process, system, container, apparatus, equipment, etc. that is outside of the patient, i.e., ex vivo, for making, holding and/or delivering the genetically modified target T cells as described herein. In Vivo Treatment Methods [00510] As noted above, the chimeric molecules can be administered to the cancer patient to generate the genetically modified target T cells in vivo in the patient. The method comprises administering to an individual having a cancer a composition comprising an effective amount of a chimeric molecule of the present disclosure. [00511] In some cases, prior to administration of the composition comprising the chimeric molecule, the patient is given a pre-treatment regimen comprising the administration of one or more pharmaceutical doses of a T-cell modulatory polypeptide (e.g., a TMMP, as described herein) that binds to and activates substantially only the target T cells in order to increase the population of target T cells in the patient prior to administering the chimeric molecules. In some cases, the dose comprising a TMMP is administered to the individual at a period of time of from 1 day to 1 month (e.g., from 1 day to 4 days, from 4 days to 7 days, from 1 week to 2 weeks, from 2 weeks to 3 weeks, or from 3 weeks to 1 month) before the composition comprising the chimeric molecules is administered. In some cases, multiple doses of the TMMP are administered to the individual before the composition comprising the chimeric molecules is administered to the individual. Such a pre-treatment regimen thus can increase the number of target T cells that may be contacted and genetically modified by the chimeric molecules. [00512] Additionally, or alternatively, following administration of the composition comprising the chimeric molecule, the patient is given a post-treatment regimen comprising the administration of one or more pharmaceutical doses of the T-cell modulatory polypeptide (e.g., a TMMP, as described herein) that binds to and activates substantially only the target T cells in order to increase the population of target T cells and genetically modified target T cells in the patient. In some cases, the dose comprising a TMMP is administered to the individual at a period of time of from 1 day to 1 month (e.g., from 1 day to 4 days, from 4 days to 7 days, from 1 week to 2 weeks, from 2 weeks to 3 weeks, or from 3 weeks to 1 month) after administration of the composition comprising the chimeric molecules. In some cases, multiple doses of the TMMP are administered to the individual after the composition comprising the chimeric molecules is administered to the individual. Such a post-treatment regimen thus can increase the number of target T cells and genetically modified target T cells. [00513] In some cases, the patient will receive both a pre-treatment regimen and a post-treatment regimen described above. Moreover, the patient may receive multiple doses of the chimeric molecules. Additional doses of the chimeric molecules can be given during administration of the post-treatment regimen of TMMPs. In Vitro Treatment Methods [00514] As noted above, the chimeric molecules alternatively or additionally can be used to generate genetically modified target T cells in vitro. The method comprises a contacting step in which target T cells that have been removed from a patient are contacted in vitro by a chimeric molecule of the present disclosure to generate genetically modified target T cells that can then be introduced to the patient. As used herein, the term “in vitro” is intended to connote any process, system, container, apparatus, equipment, etc. that is outside of the patient, i.e., ex vivo, for making, holding and/or delivering to the patient the genetically modified target T cells. In this method, blood is drawn from the patient, and a composition comprising target T cells are then contacted with the chimeric molecules to generate the genetically modified target T cells. In such cases, the blood optionally can be treated to at least partially separate target T cells from non-target T cells, i.e., T cells comprising a TCR that is not specific for the peptide epitope, thereby generating an enriched target T cell population. In some cases, the separation step yields a composition that comprises T cells, the majority of which are target T cells. Thereafter, the composition comprising target T cells (optionally enriched) is contacted with the chimeric molecules to generate a composition comprising genetically modified target T cells. The composition comprising the genetically modified target T cells optionally can be further treated by a separation step to further enrich the population of genetically modified target T cells before an effective amount of the genetically modified target T cells are then administered into the patient. [00515] In some cases, prior to contacting step, the patient undergoes a pre-treatment regimen as described above comprising the administration of one or more pharmaceutical doses of a T-cell modulatory polypeptide (e.g., a TMMP, as described herein) that binds to and activates substantially only the target T cells in order to increase the population of target T cells. In some cases, the dose comprising a TMMP is administered to the individual at a period of time of from 1 day to 1 month (e.g., from 1 day to 4 days, from 4 days to 7 days, from 1 week to 2 weeks, from 2 weeks to 3 weeks, or from 3 weeks to 1 month) before the composition comprising the chimeric molecules is administered. In some cases, multiple doses of the TMMP are administered to the individual before the composition comprising the chimeric molecules is administered to the individual. Such a pre-treatment regimen thus can increase the number of target T cells that may be contacted and genetically modified by the chimeric molecules. Thereafter, blood is drawn from the patient, and a composition comprising target T cells are contacted with the chimeric molecules to generate the genetically modified target T cells. As discussed above, the blood can be treated to at least partially separate target T cells from non-target T cells., i.e., T cells comprising a TCR that is not specific for the peptide epitope, thereby generating an enriched target T cell population, and thereafter contacting the composition comprising an enriched population of target T cells with the chimeric molecules to generate the genetically modified target T cells. [00516] Optionally, after the contacting step and prior to administering an effective amount of the genetically modified target T cells to the patient, the composition comprising genetically modified target T cells may be further treated by contacting the composition with one or more pharmaceutical doses of a T-cell modulatory polypeptide (e.g., a TMMP, as described herein) that binds to and activates the genetically modified target T cells in order to increase the population of genetically modified target T cells. [00517] In some cases, after administration of an effective amount of the genetically modified target T cells, the patient undergoes a post-treatment regimen as described above comprising the administration of one or more pharmaceutical doses of a T-cell modulatory polypeptide (e.g., a TMMP, as described herein) that binds to and activates target T cells, including the genetically modified target T cells, in order to increase the population of target T cells and genetically modified target T cells. In some cases, the dose comprising a TMMP is administered to the individual at a period of time of from 1 day to 1 month (e.g., from 1 day to 4 days, from 4 days to 7 days, from 1 week to 2 weeks, from 2 weeks to 3 weeks, or from 3 weeks to 1 month) after the composition comprising the chimeric molecules is administered. In some cases, multiple doses of the TMMP are administered to the individual after the composition comprising the genetically modified target T cells is administered to the individual. Such a post-treatment regimen thus can increase the number of target T cells and modified target T cells. [00518] In some cases, the patient will receive both a pre-treatment regimen and a post-treatment regimen described above. Moreover, the patient may receive multiple doses of the genetically modified target T cells. Additional doses of the genetically modified target T cells can be given during administration of the post-treatment regimen of TMMPs. [00519] While the in vitro methods and compositions described above involve the removal of T cells from a patient and the introduction of genetically modified target T cells back into the same patient, it also is expressly contemplated that allogeneic T cells can be used instead of (or in addition to) T cells removed from the patient. If a heterogenous population of allogeneic T cells is employed as a starting material, then an enriched population optionally can be prepared as described above. The genetically modified target T cells made from allogeneic T cells thus can contain both a TCR specific for a preselected antigen (including such TCRs expressed as a result of gene-editing), as well as one or more nucleic acids comprising nucleotide sequences encoding a CAR, where the CAR comprises an antigen-binding domain specific for a cancer-associated antigen. The genetically modified target T cells prepared from allogeneic T cells then would be employed for treatment in the same manner as described herein for patient-derived, genetically modified target T cells. Effective Amounts [00520] In some cases, an “effective amount” of a chimeric molecule, or of the genetically modified target T cells in the case of in vitro generation, is an amount that, when administered in one or more doses to an individual in need thereof, leads to a reduction in the number of cancer cells in the individual. The amount that is an effective amount may depend on whether the patient is receiving additional treatments in combination with the chimeric molecule or genetically modified target T cells, including a post-treatment regimen with TMMPs as discussed above. [00521] For example, in some cases, an “effective amount” of a chimeric molecule or genetically modified target T cell of the present disclosure is an amount that, when administered in one or more doses to an individual in need thereof, leads to a reductions in the number of cancer cells in the individual by at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%, compared to the number of cancer cells in the individual before administration of the chimeric molecule or genetically modified target T cells, or in the absence of administration with the chimeric molecule or genetically modified target T cell. In some cases, an “effective amount” of the chimeric molecule or genetically modified target T cells is an amount that, when administered in one or more doses to an individual in need thereof, leads to a reduction in the number of cancer cells in the individual to undetectable levels. [00522] In some cases, an “effective amount” of a chimeric molecule or of the genetically modified target T cells of the present disclosure is an amount that, when administered in one or more doses to an individual in need thereof, leads to a reduction in the tumor mass in the individual. For example, in some cases, an “effective amount” of a chimeric molecule or of the genetically modified target T cells of the present disclosure is an amount that, when administered in one or more doses to an individual in need thereof (an individual having a tumor), leads to a reduction in the tumor mass in the individual by at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%, compared to the tumor mass in the individual before administration of the chimeric molecule or genetically modified target T cells, or in the absence of administration with the chimeric molecule or genetically modified target T cells. In some cases, an “effective amount” of a chimeric molecule or of the genetically modified target T cells of the present disclosure is an amount that, when administered in one or more doses to an individual in need thereof (an individual having a tumor), leads to a reduction in the tumor volume in the individual. For example, in some cases, an “effective amount” of a chimeric molecule or genetically modified target T cells of the present disclosure is an amount that, when administered in one or more doses to an individual in need thereof (an individual having a tumor), leads to a reduction in the tumor volume in the individual by at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%, compared to the tumor volume in the individual before administration of the chimeric molecule or genetically modified target T cell, or in the absence of administration with the chimeric molecule or genetically modified target T cell. In some cases, an “effective amount” of a chimeric molecule or genetically modified target T cells of the present disclosure is an amount that, when administered in one or more doses to an individual in need thereof, leads to an increase in survival time of the individual. For example, in some cases, an “effective amount” of a chimeric molecule or the genetically modified target T cells of the present disclosure is an amount that, when administered in one or more doses to an individual in need thereof, increases survival time of the individual by at least 1 month, at least 2 months, at least 3 months, from 3 months to 6 months, from 6 months to 1 year, from 1 year to 2 years, from 2 years to 5 years, from 5 years to 10 years, or more than 10 years, compared to the expected survival time of the individual in the absence of administration with the chimeric molecule or genetically modified target T cells. [00523] Cancers that can be treated with a method of the present disclosure include any cancer that can be targeted with a CAR. Cancers that can be treated with a method of the present disclosure include carcinomas, sarcomas, melanoma, leukemias, and lymphomas. Cancers that can be treated with a method of the present disclosure include solid tumors. Cancers that can be treated with a method of the present disclosure include metastatic cancers. [00524] Carcinomas that can treated by a method disclosed herein include, but are not limited to, esophageal carcinoma, hepatocellular carcinoma, basal cell carcinoma (a form of skin cancer), squamous cell carcinoma (various tissues), bladder carcinoma, including transitional cell carcinoma (a malignant neoplasm of the bladder), bronchogenic carcinoma, colon carcinoma, colorectal carcinoma, gastric carcinoma, lung carcinoma, including small cell carcinoma and non-small cell carcinoma of the lung, adrenocortical carcinoma, thyroid carcinoma, pancreatic carcinoma, breast carcinoma, ovarian carcinoma, prostate carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinoma, cystadenocarcinoma, medullary carcinoma, renal cell carcinoma, ductal carcinoma in situ or bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilm's tumor, cervical carcinoma, uterine carcinoma, testicular carcinoma, osteogenic carcinoma, epithelial carcinoma, and nasopharyngeal carcinoma. [00525] Sarcomas that can be treated by a method disclosed herein include, but are not limited to, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, chordoma, osteogenic sarcoma, osteosarcoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing's sarcoma, leiomyosarcoma, rhabdomyosarcoma, and other soft tissue sarcomas. [00526] Other solid tumors that can be treated by a method disclosed herein include, but are not limited to, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, menangioma, melanoma, neuroblastoma, and retinoblastoma. [00527] Leukemias that can be amenable to therapy by a method disclosed herein include, but are not limited to, a) chronic myeloproliferative syndromes (neoplastic disorders of multipotential hematopoietic stem cells); b) acute myelogenous leukemias (neoplastic transformation of a multipotential hematopoietic stem cell or a hematopoietic cell of restricted lineage potential; c) chronic lymphocytic leukemias (CLL; clonal proliferation of immunologically immature and functionally incompetent small lymphocytes), including B-cell CLL, T-cell CLL prolymphocytic leukemia, and hairy cell leukemia; and d) acute lymphoblastic leukemias (characterized by accumulation of lymphoblasts). Lymphomas that can be treated using a subject method include, but are not limited to, B-cell lymphomas (e.g., Burkitt's lymphoma); Hodgkin's lymphoma; non-Hodgkin's lymphoma, and the like. [00528] Other cancers that can be treated according to the methods disclosed herein include atypical meningioma, islet cell carcinoma, medullary carcinoma of the thyroid, mesenchymoma, hepatocellular carcinoma, hepatoblastoma, clear cell carcinoma of the kidney, and neurofibroma mediastinum. Formulations [00529] Suitable formulations are described above, where suitable formulations include a pharmaceutically acceptable excipient. In some cases, a suitable formulation comprises: a) a chimeric molecule of the present disclosure; and b) a pharmaceutically acceptable excipient. Suitable pharmaceutically acceptable excipients are described above. Dosages [00530] A suitable dosage (e.g., of a TMMP, a chimeric molecule, a genetically modified target T cell) can be determined by an attending physician or other qualified medical personnel, based on various clinical factors. As is well known in the medical arts, dosages for any one patient depend upon many factors, including the patient's size; the patient's body surface area; the patient's age; the particular polypeptide (e.g., TMMP) or chimeric molecule or genetically modified T cell to be administered; sex of the patient; time and route of administration; the patient's general health; and other drugs being administered concurrently. [00531] A chimeric molecule of the present disclosure may be administered in amounts between 1 ng/kg body weight and 20 mg/kg body weight per dose, e.g. between 0.1 mg/kg body weight and 10 mg/kg body weight, e.g. between 0.5 mg/kg body weight and 5 mg/kg body weight; however, doses below or above this exemplary range are envisioned, especially considering the aforementioned factors. If the regimen is a continuous infusion, it can also be in the range of 1 μg to 10 mg per kilogram of body weight per minute. A chimeric molecule of the present disclosure can be administered in an amount of from about 1 mg/kg body weight to 50 mg/kg body weight, e.g., from about 1 mg/kg body weight to about 5 mg/kg body weight, from about 5 mg/kg body weight to about 10 mg/kg body weight, from about 10 mg/kg body weight to about 15 mg/kg body weight, from about 15 mg/kg body weight to about 20 mg/kg body weight, from about 20 mg/kg body weight to about 25 mg/kg body weight, from about 25 mg/kg body weight to about 30 mg/kg body weight, from about 30 mg/kg body weight to about 35 mg/kg body weight, from about 35 mg/kg body weight to about 40 mg/kg body weight, or from about 40 mg/kg body weight to about 50 mg/kg body weight. [00532] In some cases, a suitable dose of a chimeric molecule of the present disclosure is from 0.01 μg to 100 g per kg of body weight, from 0.1 μg to 10 g per kg of body weight, from 1 μg to 1 g per kg of body weight, from 10 μg to 100 mg per kg of body weight, from 100 μg to 10 mg per kg of body weight, or from 100 μg to 1 mg per kg of body weight. Persons of ordinary skill in the art can easily estimate repetition rates for dosing based on measured residence times and concentrations of the administered agent in bodily fluids or tissues. Following successful treatment, it may be desirable to have the patient undergo maintenance therapy to prevent the recurrence of the disease state, wherein a chimeric molecule of the present disclosure is administered in maintenance doses, ranging from 0.01 μg to 100 g per kg of body weight, from 0.1 μg to 10 g per kg of body weight, from 1 μg to 1 g per kg of body weight, from 10 μg to 100 mg per kg of body weight, from 100 μg to 10 mg per kg of body weight, or from 100 μg to 1 mg per kg of body weight. [00533] Those of skill will readily appreciate that dose levels can vary as a function of the specific chimeric molecule, the severity of the symptoms, and the susceptibility of the subject to side effects. Preferred dosages for a given chimeric molecule are readily determinable by those of skill in the art by a variety of means. [00534] A TMMP may be administered in amounts between 1 ng/kg body weight and 20 mg/kg body weight per dose, e.g. between 0.1 mg/kg body weight to 10 mg/kg body weight, e.g. between 0.1 mg/kg body weight and 4 mg/kg body weight, between 0.5 mg/kg body weight and 2 mg/kg body weight, or between 0.5 mg/kg body weight and 5 mg/kg body weight; however, doses below or above this exemplary range are envisioned, especially considering the aforementioned factors. If the regimen is a continuous infusion, it can also be in the range of 1 μg to 10 mg per kilogram of body weight per minute. A TMMP can be administered in an amount of from about 1 mg/kg body weight to 50 mg/kg body weight, e.g., from about 1 mg/kg body weight to about 5 mg/kg body weight, from about 5 mg/kg body weight to about 10 mg/kg body weight, from about 10 mg/kg body weight to about 15 mg/kg body weight, from about 15 mg/kg body weight to about 20 mg/kg body weight, from about 20 mg/kg body weight to about 25 mg/kg body weight, from about 25 mg/kg body weight to about 30 mg/kg body weight, from about 30 mg/kg body weight to about 35 mg/kg body weight, from about 35 mg/kg body weight to about 40 mg/kg body weight, or from about 40 mg/kg body weight to about 50 mg/kg body weight. [00535] In some cases, a suitable dose of a TMMP is from 0.01 μg to 100 g per kg of body weight, from 0.1 μg to 10 g per kg of body weight, from 1 μg to 1 g per kg of body weight, from 10 μg to 100 mg per kg of body weight, from 100 μg to 10 mg per kg of body weight, or from 100 μg to 1 mg per kg of body weight. Persons of ordinary skill in the art can easily estimate repetition rates for dosing based on measured residence times and concentrations of the administered agent in bodily fluids or tissues. Following successful treatment, it may be desirable to have the patient undergo maintenance therapy to prevent the recurrence of the disease state, wherein a TMMP is administered in maintenance doses, ranging from 0.01 μg to 100 g per kg of body weight, from 0.1 μg to 10 g per kg of body weight, from 1 μg to 1 g per kg of body weight, from 10 μg to 100 mg per kg of body weight, from 100 μg to 10 mg per kg of body weight, or from 100 μg to 1 mg per kg of body weight. [00536] Those of skill will readily appreciate that dose levels can vary as a function of the specific TMMP, the severity of the symptoms, and the susceptibility of the subject to side effects. Preferred dosages for a given TMMP are readily determinable by those of skill in the art by a variety of means. [00537] In some cases, a suitable dose of genetically modified target T cells is equal to or less than a number selected from the group consisting of 10 cells/kg body weight, 10 ² cells/kg body weight, 10 ³ cells/kg body weight, 10 ⁴ cells/kg body weight, 10 ⁵ cells/kg body weight, 10 ⁶ cells/kg body weight, 10 ⁷ cells/kg body weight, 10 ⁸ cells/kg body weight, and 10 ⁹ cells/kg body weight. In some cases, a suitable dose of genetically modified target T cells is from about 10 cells/kg body weight to about 10 ² cells/kg body weight, from about 10 ² cells/kg body weight to about 10 ³ cells/kg body weight, from about 10 ³ cells/kg body weight to about 10 ⁴ cells/kg body weight, from about 10 ⁴ cells/kg body weight to about 10 ⁵ cells/kg body weight, from about 10 ⁵ cells/kg body weight to about 10 ⁶ cells/kg body weight, from about 10 ⁶ cells/kg body weight to about 10 ⁷ cells/kg body weight, from about 10 ⁷ cells/kg body weight to about 10 ⁸ cells/kg body weight, or from about 10 ⁸ cells/kg body weight to about 10 ⁹ cells/kg body weight. In some cases, lower doses of genetically modified target T cells can be employed, e.g., less than about 10 ⁷ cells/kg body weight, less than about 10 ⁶ cells/kg body weight, less than about 10 ⁵ cells/kg body weight, less than about 10 ⁴ cells/kg body weight or less than about 10 ³ cells/kg body weight, where a TMMP post-treatment regimen as described above is employed in order to increase the number of genetically modified target T cells in the patient after administration of the genetically modified target T cells to the patient. [00538] Those of skill will readily appreciate that dose levels can vary as a function of the specific genetically modified target T cells, the severity of the symptoms, and the susceptibility of the subject to side effects. Preferred dosages for a given genetically modified target T cell are readily determinable by those of skill in the art by a variety of means. Routes of administration [00539] An active agent (a chimeric molecule or genetically modified target T cells of the present disclosure; and/or a second therapeutic agent) is administered to an individual using any available method and route suitable for drug delivery, including in vivo and ex vivo methods, as well as systemic and localized routes of administration. [00540] Conventional and pharmaceutically acceptable routes of administration include intratumoral, peritumoral, intramuscular, intralymphatic, intratracheal, intracranial, subcutaneous, intradermal, topical application, intravenous, intraarterial, rectal, nasal, oral, and other enteral and parenteral routes of administration. Routes of administration may be combined, if desired, or adjusted depending upon the chimeric molecule and/or the desired effect. A chimeric molecule or genetically modified target T cell of the present disclosure can be administered in a single dose or in multiple doses. [00541] In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered intravenously. In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered intramuscularly. In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered intralymphatically. In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered locally. In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered intratumorally. In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered peritumorally. In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered intracranially. In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered subcutaneously. [00542] Parenteral routes of administration other than inhalation administration include, but are not necessarily limited to, topical, transdermal, subcutaneous, intramuscular, intraorbital, intracapsular, intraspinal, intrasternal, intratumoral, intralymphatic, peritumoral, and intravenous routes, i.e., any route of administration other than through the alimentary canal. Parenteral administration can be carried to effect systemic or local delivery of a chimeric molecule of the present disclosure. Where systemic delivery is desired, administration typically involves invasive or systemically absorbed topical or mucosal administration of pharmaceutical preparations. Combination therapies [00543] In some cases, a method of the present disclosure for treating cancer in an individual comprises: a) administering a chimeric molecule or genetically modified target T cell of the present disclosure; and b) administering at least one additional therapeutic agent or therapeutic treatment. Suitable additional therapeutic agents include, but are not limited to, a small molecule cancer chemotherapeutic agent, a TMMP as described herein (where the TMMP is not conjugated to a nucleic acid component), and an immune checkpoint inhibitor. Suitable additional therapeutic treatments include, e.g., radiation, surgery (e.g., surgical resection of a tumor), and the like. [00544] A treatment method of the present disclosure can comprise co-administration of a chimeric molecule or genetically modified target T cell of the present disclosure and at least one additional therapeutic agent. By “co-administration” is meant that both a chimeric molecule or genetically modified target T cell of the present disclosure and at least one additional therapeutic agent are administered to an individual, although not necessarily at the same time, in order to achieve a therapeutic effect that is the result of having administered both the chimeric molecule or genetically modified target T cell and the at least one additional therapeutic agent. The administration of the chimeric molecule or genetically modified target T cell and the at least one additional therapeutic agent can be substantially simultaneous, e.g., the chimeric molecule or genetically modified target T cell can be administered to an individual within about 1 minute to about 24 hours (e.g., within about 1 minute, within about 5 minutes, within about 15 minutes, within about 30 minutes, within about 1 hour, within about 4 hours, within about 8 hours, within about 12 hours, or within about 24 hours) of administration of the at least one additional therapeutic agent. In some cases, a chimeric molecule or genetically modified target T cell of the present disclosure is administered to an individual who is undergoing treatment with, or who has undergone treatment with, the at least one additional therapeutic agent. The administration of the chimeric molecule and the at least one additional therapeutic agent can occur at different times and/or at different frequencies. [00545] In some cases, a method of the present disclosure for treating cancer in an individual comprises: a) administering a chimeric molecule or genetically modified target T cell of the present disclosure; and b) administering a TMMP as described herein (where the TMMP is not conjugated to a nucleic acid component; i.e., an unconjugated TMMP). In some cases, the unconjugated TMMP comprises the same peptide epitope as the TMMP present in the chimeric molecule. In some cases, the chimeric molecule or genetically modified target T cell and the unconjugated TMMP are administered at the same time. In some cases, the chimeric molecule or genetically modified target T cell and the TMMP are administered to an individual within about 1 minute to about 24 hours (e.g., within about 1 minute, within about 5 minutes, within about 15 minutes, within about 30 minutes, within about 1 hour, within about 4 hours, within about 8 hours, within about 12 hours, or within about 24 hours) of one another. In some cases, the individual is treated with a TMMP (a TMMP not conjugated to a nucleic acid) before the individual is treated with a chimeric molecule or genetically modified target T cell of the present disclosure. For example, in some cases, a method of the present disclosure comprises: a) administering a TMMP; and b) after a period of time, administering a chimeric molecule of the present disclosure. For example, in some cases, a TMMP is administered from 1 week to 4 weeks (e.g., 1 week, 2 weeks, 3 weeks, or 4 weeks) before the chimeric molecule or genetically modified target T cell of the present disclosure is administered. [00546] As another example, a treatment method of the present disclosure can comprise co- administration of a chimeric molecule or genetically modified target T cell of the present disclosure and an immune checkpoint inhibitor such as an antibody specific for an immune checkpoint. By “co- administration” is meant that both a chimeric molecule or genetically modified target T cell of the present disclosure and an antibody specific for an immune checkpoint are administered to an individual, although not necessarily at the same time, in order to achieve a therapeutic effect that is the result of having administered both the chimeric molecule or genetically modified target T cell and the immune checkpoint inhibitor. The administration of the chimeric molecule and the antibody specific for an immune checkpoint can be substantially simultaneous, e.g., the chimeric molecule or genetically modified target T cell can be administered to an individual within about 1 minute to about 24 hours (e.g., within about 1 minute, within about 5 minutes, within about 15 minutes, within about 30 minutes, within about 1 hour, within about 4 hours, within about 8 hours, within about 12 hours, or within about 24 hours) of administration of the antibody specific for an immune checkpoint. In some cases, a chimeric molecule of the present disclosure is administered to an individual who is undergoing treatment with, or who has undergone treatment with, an antibody specific for an immune checkpoint. The administration of the chimeric molecule or genetically modified target T cell and the antibody specific for an immune checkpoint can occur at different times and/or at different frequencies. [00547] Exemplary immune checkpoint inhibitors include inhibitors that target immune checkpoint polypeptide such as CD27, CD28, CD40, CD122, CD96, CD73, CD47, OX40, GITR, CSF1R, JAK, PI3K delta, PI3K gamma, TAM, arginase, CD137 (also known as 4-1BB), ICOS, A2AR, B7-H3, B7-H4, BTLA, CTLA-4, LAG3, TIM3, VISTA, CD96, TIGIT, CD122, PD-1, PD-L1 and PD- L2. In some cases, the immune checkpoint polypeptide is a stimulatory checkpoint molecule selected from CD27, CD28, CD40, ICOS, OX40, GITR, CD122 and CD137. In some cases, the immune checkpoint polypeptide is an inhibitory checkpoint molecule selected from A2AR, B7-H3, B7-H4, BTLA, CTLA-4, IDO, KIR, LAG3, PD-1, TIM3, CD96, TIGIT and VISTA. [00548] In some cases, the immune checkpoint inhibitor is an antibody specific for an immune checkpoint. In some cases, the anti-immune checkpoint antibody is a monoclonal antibody. In some cases, the anti-immune checkpoint antibody is humanized, or de-immunized such that the antibody does not substantially elicit an immune response in a human. In some cases, the anti-immune checkpoint antibody is a humanized monoclonal antibody. In some cases, the anti-immune checkpoint antibody is a de-immunized monoclonal antibody. In some cases, the anti-immune checkpoint antibody is a fully human monoclonal antibody. In some cases, the anti-immune checkpoint antibody inhibits binding of the immune checkpoint polypeptide to a ligand for the immune checkpoint polypeptide. In some cases, the anti-immune checkpoint antibody inhibits binding of the immune checkpoint polypeptide to a receptor for the immune checkpoint polypeptide. [00549] Suitable anti-immune checkpoint antibodies include, but are not limited to, nivolumab (Bristol-Myers Squibb), pembrolizumab (Merck), pidilizumab (Curetech), AMP-224 (GlaxoSmithKline/Amplimmune), MPDL3280A (Roche), MDX-1105 (Medarex, Inc./Bristol Myer Squibb), MEDI-4736 (Medimmune/AstraZeneca), arelumab (Merck Serono), ipilimumab (YERVOY, (Bristol-Myers Squibb), tremelimumab (Pfizer), pidilizumab (CureTech, Ltd.), IMP321 (Immutep S.A.), MGA271 (Macrogenics), BMS-986016 (Bristol-Meyers Squibb), lirilumab (Bristol-Myers Squibb), urelumab (Bristol-Meyers Squibb), PF-05082566 (Pfizer), IPH2101 (Innate Pharma/Bristol-Myers Squibb), MEDI-6469 (MedImmune/AZ), CP-870,893 (Genentech), Mogamulizumab (Kyowa Hakko Kirin), Varlilumab (CelIDex Therapeutics), Avelumab (EMD Serono), Galiximab (Biogen Idec), AMP- 514 (Amplimmune/AZ), AUNP 12 (Aurigene and Pierre Fabre), Indoximod (NewLink Genetics), NLG- 919 (NewLink Genetics), INCB024360 (Incyte); KN035; and combinations thereof. For example, in some cases, the immune checkpoint inhibitor is an anti-PD-1 antibody. Suitable anti-PD-1 antibodies include, e.g., nivolumab, pembrolizumab (also known as MK-3475), pidilizumab, SHR-1210, PDR001, and AMP-224. In some cases, the anti-PD-1 monoclonal antibody is nivolumab, pembrolizumab or PDR001. Suitable anti-PD1 antibodies are described in U.S. Patent Publication No.2017/0044259. For pidilizumab, see, e.g., Rosenblatt et al. (2011) J. Immunother.34:409-18. In some cases, the immune checkpoint inhibitor is an anti-CTLA-4 antibody. In some cases, the anti-CTLA-4 antibody is ipilimumab or tremelimumab. For tremelimumab, see, e.g., Ribas et al. (2013) J. Clin. Oncol.31:616-22. In some cases, the immune checkpoint inhibitor is an anti-PD-L1 antibody. In some cases, the anti-PD- L1 monoclonal antibody is BMS-935559, MEDI4736, MPDL3280A (also known as RG7446), KN035, or MSB0010718C. In some embodiments, the anti-PD-L1 monoclonal antibody is MPDL3280A (atezolizumab) or MEDI4736 (durvalumab). For durvalumab, see, e.g., WO 2011/066389. For atezolizumab, see, e.g., U.S. Patent No.8,217,149. Subjects suitable for treatment [00550] Subjects suitable for treatment with a method of the present disclosure include individuals who have cancer, including individuals who have been diagnosed as having cancer, individuals who have been treated for cancer but who failed to respond to the treatment, and individuals who have been treated for cancer and who initially responded but subsequently became refractory to the treatment. [00551] In some cases, the individual being treated according to a method of the present disclosure has not undergone a lymphodepleting regimen prior to administration of a chimeric molecule or genetically modified target T cell of the present disclosure. In some cases, the individual being treated according to a method of the present disclosure has undergone a lymphodepleting regimen prior to administration of a chimeric molecule or genetically modified target T cell of the present disclosure. In some cases, the lymphodepletion regimen is a non-myeloablative lymphodepletion regimen. Lymphodepletion can be accomplished by administering to the individual: i) cyclophosphamide/fludarabine combination; or ii) cyclophosphamide alone. Examples of Non-Limiting Aspects of the Disclosure [00552] Aspects, including embodiments, of the present subject matter described above may be beneficial alone or in combination, with one or more other aspects or embodiments. Without limiting the foregoing description, certain non-limiting aspects of the disclosure numbered 1-70 are provided below. As will be apparent to those of skill in the art upon reading this disclosure, each of the individually numbered aspects may be used or combined with any of the preceding or following individually numbered aspects. This is intended to provide support for all such combinations of aspects and is not limited to combinations of aspects explicitly provided below: [00553] Aspect 1. A chimeric molecule comprising: [00554] A) a T-cell modulatory multimeric polypeptide (TMMP) comprising at least one heterodimer comprising: [00555] a) a first polypeptide comprising: [00556] i) a peptide epitope, wherein the peptide epitope is a peptide having a length of at least 4 amino acids; and [00557] ii) a first major histocompatibility complex (MHC) polypeptide; [00558] b) a second polypeptide comprising a second MHC polypeptide; [00559] c) at least one immunomodulatory polypeptide, wherein the first and/or the second polypeptide comprises the at least one immunomodulatory polypeptide; and, optionally, [00560] d) an immunoglobulin (Ig) Fc polypeptide or a non-Ig scaffold, wherein the first and/or the second polypeptide comprises the Ig Fc polypeptide or the non-Ig scaffold. [00561] and [00562] (B) a nucleic acid component covalently attached to the TMMP, wherein the nucleic acid component comprises one or more nucleic acids comprising nucleotide sequences encoding a chimeric antigen receptor (CAR), wherein the CAR comprises an antigen-binding domain specific for a cancer-associated antigen. [00563] Aspect 2. A chimeric molecule of aspect 1, wherein the second polypeptide comprises the Ig Fc polypeptide. [00564] Aspect 3. A chimeric molecule of aspect 1 or aspect 2, wherein the Ig Fc polypeptide is an IgG1 Fc polypeptide. [00565] Aspect 4. A chimeric molecule of aspect 3, wherein IgG1 Fc polypeptide comprises one or more amino acid substitutions selected from N297A, L234A, L235A, L234F, L235E, and P331S. [00566] Aspect 5. A chimeric molecule of any one of aspects 1-4, wherein [00567] a1) the first polypeptide comprises, in order from N-terminus to C-terminus: [00568] i) the peptide epitope; [00569] ii) the first MHC polypeptide; and [00570] iii) the at least one immunomodulatory polypeptide; and [00571] b1) the second polypeptide comprises, in order from N-terminus to C-terminus: [00572] i) the second MHC polypeptide; [00573] ii) the Ig Fc polypeptide; and [00574] iii) the tumor-targeting polypeptide; or [00575] a2) the first polypeptide comprises, in order from N-terminus to C-terminus: [00576] i) the peptide epitope; and [00577] ii) the first MHC polypeptide; and [00578] b2) the second polypeptide comprises, in order from N-terminus to C-terminus: [00579] i) the at least one immunomodulatory polypeptide; [00580] ii) the second MHC polypeptide; [00581] iii) the Ig Fc polypeptide; and [00582] iv) the tumor-targeting polypeptide; or [00583] a3) the first polypeptide comprises, in order from N-terminus to C-terminus: [00584] i) the peptide epitope; and [00585] ii) the first MHC polypeptide; [00586] iii) the at least one immunomodulatory polypeptide and [00587] b3) the second polypeptide comprises, in order from N-terminus to C-terminus: [00588] i) the second MHC polypeptide; [00589] ii) the at least one immunomodulatory polypeptide; [00590] iii) the Ig Fc polypeptide; and [00591] iv) the tumor-targeting polypeptide; or [00592] a4) the first polypeptide comprises, in order from N-terminus to C-terminus: [00593] i) the peptide epitope; [00594] ii) the first MHC polypeptide; [00595] iii) the at least one immunomodulatory polypeptide; and [00596] b4) the second polypeptide comprises, in order from N-terminus to C-terminus: [00597] i) the at least one immunomodulatory polypeptide; [00598] ii) the second MHC polypeptide; [00599] iii) the Ig Fc polypeptide; and [00600] iv) the tumor-targeting polypeptide; or [00601] a5) the first polypeptide comprises, in order from N-terminus to C-terminus: [00602] i) the at least one immunomodulatory polypeptide; [00603] ii) the peptide epitope; and [00604] ii) the first MHC polypeptide; and [00605] b5) a second polypeptide comprises, in order from N-terminus to C-terminus: [00606] i) the second MHC polypeptide; [00607] ii) the Ig Fc polypeptide; and [00608] iii) the tumor-targeting polypeptide; or [00609] a6) the first polypeptide comprises, in order from N-terminus to C-terminus: [00610] i) the peptide epitope; and [00611] ii) the first MHC polypeptide; and [00612] b6) the second polypeptide comprises, in order from N-terminus to C-terminus: [00613] i) the second MHC polypeptide; [00614] ii) the at least one immunomodulatory polypeptide; [00615] iii) the Ig Fc polypeptide; and [00616] iv) the tumor-targeting polypeptide; or [00617] a7) the first polypeptide comprises, in order from N-terminus to C-terminus: [00618] i) the peptide epitope; [00619] ii) the first MHC polypeptide; and [00620] iii) the at least one immunomodulatory polypeptide; and [00621] b7) the second polypeptide comprises, in order from N-terminus to C-terminus: [00622] i) the at least one immunomodulatory polypeptide; [00623] ii) the second MHC polypeptide; [00624] iii) the Ig Fc polypeptide; and [00625] iv) the tumor-targeting polypeptide; or [00626] a8) the first polypeptide comprises, in order from N-terminus to C-terminus: [00627] i) the peptide epitope; [00628] ii) the first MHC polypeptide; and [00629] iii) the at least one immunomodulatory polypeptide; and [00630] b8) the second polypeptide comprises, in order from N-terminus to C-terminus: [00631] i) the second MHC polypeptide; [00632] ii) the at least one immunomodulatory polypeptide; [00633] iii) the Ig Fc polypeptide; and [00634] iv) the tumor-targeting polypeptide; or [00635] a9) the first polypeptide comprises, in order from N-terminus to C-terminus: [00636] i) the peptide epitope; and [00637] ii) the first MHC polypeptide; and [00638] b9) the second polypeptide comprises, in order from N-terminus to C-terminus: [00639] i) the tumor-targeting polypeptide; [00640] ii) the second MHC polypeptide; [00641] iii) the Ig Fc polypeptide; and [00642] iv) the at least one immunomodulatory polypeptide; or [00643] [00644] a10) the first polypeptide comprises, in order from N-terminus to C-terminus: [00645] i) the peptide epitope; and [00646] ii) the first MHC polypeptide; and [00647] b10) the second polypeptide comprises, in order from N-terminus to C-terminus: [00648] i) the tumor-targeting polypeptide; [00649] ii) the second MHC polypeptide; [00650] iii) the at least one immunomodulatory polypeptide; and [00651] iv) the Ig Fc polypeptide; or [00652] [00653] a11) the first polypeptide comprises, in order from N-terminus to C-terminus: [00654] i) the peptide epitope; [00655] ii) the first MHC polypeptide; and [00656] iii) the tumor-targeting polypeptide; and [00657] b11) the second polypeptide comprises, in order from N-terminus to C-terminus: [00658] i) the at least one immunomodulatory polypeptide; [00659] ii) the second MHC polypeptide; and [00660] iii) the Ig Fc polypeptide; or [00661] a12) the first polypeptide comprises, in order from N-terminus to C-terminus: [00662] i) the peptide epitope; [00663] ii) the first MHC polypeptide; and [00664] iii) the tumor-targeting polypeptide; and [00665] b12) the second polypeptide comprises, in order from N-terminus to C-terminus: [00666] i) the second MHC polypeptide; [00667] ii) the at least one immunomodulatory polypeptide; and [00668] iii) the Ig Fc polypeptide. [00669] Aspect 6. A chimeric molecule of any one of aspects 1-5, wherein the first polypeptide comprises a peptide linker between the epitope and the first MHC polypeptide and/or wherein the second polypeptide comprises a peptide linker between the immunomodulatory polypeptide and the second MHC polypeptide. [00670] Aspect 7. A chimeric molecule of aspect 6, wherein the peptide linker comprises the amino acid sequence (GGGGS)n (SEQ ID NO:5), where n is an integer from 1 to 10. [00671] Aspect 8. A chimeric molecule of any one of aspects 1-7, wherein the first MHC polypeptide is a β2-microglobulin polypeptide; and wherein the second MHC polypeptide is an MHC class I heavy chain polypeptide. [00672] Aspect 9. A chimeric molecule of any one of aspects 1-8, wherein the at least one immunomodulatory polypeptide is selected from the group consisting of a wild type polypeptide, a variant of a wild type polypeptide, or a fragment of a wild type or variant polypeptide selected from the group consisting of a cytokine, a 4-1BBL polypeptide, a B7-1 polypeptide; a B7-2 polypeptide, an ICOS- L polypeptide, an OX-40L polypeptide, a CD80 polypeptide, a CD86 polypeptide, a PD-L1 polypeptide, a FasL polypeptide, a PD-L2 polypeptide, and combinations thereof. [00673] Aspect 10. A chimeric molecule of aspect 9, wherein the at least one immunomodulatory polypeptide is an IL-2 polypeptide. [00674] Aspect 11. A chimeric molecule of any one of aspects 1-10, wherein the multimeric polypeptide comprises at least two immunomodulatory polypeptides, and wherein at least two of the immunomodulatory polypeptides are the same. [00675] Aspect 12. A chimeric molecule of aspect 11, wherein the 2 or more immunomodulatory polypeptides are in tandem. [00676] Aspect 13. A chimeric molecule of any one of aspects 1-12, wherein the first polypeptide and the second polypeptide are covalently linked to one another. [00677] Aspect 14. A chimeric molecule of aspect 13, wherein the covalent linkage is via a disulfide bond. [00678] Aspect 15. A chimeric molecule of aspect 14, wherein the β2M polypeptide and the MHC heavy chain polypeptide are joined by a disulfide bond that joins a Cys residue in the β2M polypeptide and a Cys residue in the MHC heavy chain polypeptide. [00679] Aspect 16. A chimeric molecule of aspect 15, wherein a Cys at amino acid residue 12 of the β2M polypeptide is disulfide bonded to a Cys at amino acid residue 236 of the MHC heavy chain polypeptide. [00680] Aspect 17. A chimeric molecule of any one of aspects 13-16, wherein the first polypeptide chain comprises a linker between the peptide epitope and the β2M polypeptide, and wherein the disulfide bond links a Cys present in the linker with a Cys of the MHC heavy chain polypeptide. [00681] Aspect 18. A chimeric molecule of aspect 17, wherein the first polypeptide chain comprises a linker between the peptide epitope and the β2M polypeptide, and wherein the disulfide bond links a Cys substituted for Gly2 in the linker with a Cys substituted for Tyr84 of the MHC heavy chain polypeptide. [00682] Aspect 19. A chimeric molecule of any one of aspects 1-18, wherein the first and the second polypeptides are covalently linked to one another via at least 2 disulfide bonds. [00683] Aspect 20. The chimeric molecule of aspect 19, wherein: [00684] a) a first disulfide bond is between: i) a Cys present in a linker between the peptide epitope and the first MHC class I polypeptide, wherein the first MHC class I polypeptide is a β2M polypeptide; and ii) a Cys residue introduced via a Y84C substitution in the second MHC class I polypeptide, wherein the second MHC class I polypeptide is an MHC Class I heavy chain polypeptide; and [00685] b) a second disulfide bond is between: i) a Cys residue introduced into the β2M polypeptide via an R12C substitution; and ii) a Cys residue introduced into the MHC Class I heavy chain polypeptide via an A236C substitution. [00686] Aspect 21. A chimeric molecule of aspect 18 or 20, wherein the linker comprises the amino acid sequence GCGGS (SEQ ID NO:373). [00687] Aspect 22. A chimeric molecule of aspect 21, wherein the linker comprises the amino acid sequence GCGGS(GGGGS)n (SEQ ID NO:206), where n is an integer from 1 to 10. [00688] Aspect 23. A chimeric molecule of any one of aspects 1-22, wherein the peptide epitope has a length of from about 4 amino acids to about 25 amino acids (e.g., 4 amino acids (aa), 5 aa, 6 aa, 7 aa, 8 aa, 9 aa, 10 aa, 11 aa, 12 aa, 13 aa, 14 aa, 15 aa, 16 aa, 17 aa, 18 aa, 19 aa, 20 aa, 21 aa, 22 aa, 23 aa, 24 aa, or 25 aa, including within a range of from 4 to 20 aa., from 6 to 18 aa., from 8 to 15 aa. from 8 to 12 aa., from 5 to 10 aa., from 10 to 15 aa., from 15 to 20 aa., from 10 to 20 aa., or from 15 to 25 aa. in length). [00689] Aspect 24. A chimeric molecule of any one of aspects 1-23, wherein the first or the second MHC polypeptide comprises: [00690] a) an amino acid sequence having at least 95% amino acid sequence identity to the HLA-A*0101, HLA-A*0201, HLA-A*0201, HLA-A*1101, HLA-A*2301, HLA-A*2402, HLA- A*2407, HLA-A*3303, or HLA-A*3401 amino acid sequence depicted in FIG.7A; or [00691] b) an amino acid sequence having at least 95% amino acid sequence identity to the HLA-B*0702, HLA-B*0801, HLA-B*1502, HLA-B*3802, HLA-B*4001, HLA-B*4601, or HLA- B*5301 amino acid sequence depicted in FIG.8A; or [00692] c) an amino acid sequence having at least 95% amino acid sequence identity to the HLA-C*0102, HLA-C*0303, HLA-C*0304, HLA-C*0401, HLA-C*0602, HLA-C*0701, HLA-C*0702, HLA-C*0801, or HLA-C*1502 depicted in FIG.9A. [00693] Aspect 25. A chimeric molecule of any of aspects 1-24, wherein the first MHC polypeptide is a β2M polypeptide, and wherein the second MHC polypeptide comprises an amino acid sequence having at least 95% amino acid sequence identity to an HLA-A*2402 polypeptide. [00694] Aspect 26. A chimeric molecule of any one of aspects 1-24, wherein the first MHC polypeptide is a β2M polypeptide, and wherein the second MHC polypeptide is an HLA-A*1101 polypeptide. [00695] Aspect 27. A chimeric molecule of any one of aspects 1-24 wherein the first MHC polypeptide is a β2M polypeptide, and wherein the second MHC polypeptide comprises an amino acid sequence having at least 95% amino acid sequence identity to an HLA-A*3303 polypeptide. [00696] Aspect 28. A chimeric molecule of any one of aspects 1-24, wherein the first MHC polypeptide is a β2M polypeptide, and wherein the second MHC polypeptide comprises an amino acid sequence having at least 95% amino acid sequence identity to an HLA-A*0201 polypeptide. [00697] Aspect 29. A chimeric molecule of any one of aspects 1-28, wherein the immunomodulatory polypeptide is a variant IL-2 polypeptide comprising: i) an H16A substitution and an F42A substation; or ii) an H16T substitution and an F42A substitution. [00698] Aspect 30. A chimeric molecule of any one of aspects 1-29, wherein the epitope is a peptide of an antigen encoded by a virus or a bacterium. [00699] Aspect 31. A chimeric molecule of aspect 30, wherein the epitope is a peptide of a viral antigen. [00700] Aspect 32. A chimeric molecule of aspect 31, where the viral antigen is a cytomegalovirus (CMV) polypeptide. [00701] Aspect 33. A chimeric molecule of aspect 32, wherein the CMV polypeptide is a CMV pp65 polypeptide. [00702] Aspect 34. A chimeric molecule of aspect 33, wherein the peptide has the amino acid sequence NLVPMVATV (SEQ ID NO:172) and has a length of 9 amino acids. [00703] Aspect 35. A chimeric molecule of any of aspects 1-34, wherein at least one of the one or more immunomodulatory domains is a variant immunomodulatory polypeptide that exhibits reduced affinity to a cognate co-immunomodulatory polypeptide compared to the affinity of a corresponding wild-type immunomodulatory polypeptide for the cognate co-immunomodulatory polypeptide, [00704] and wherein the epitope binds to a T-cell receptor (TCR) on a T cell with an affinity of at least 10 ^-7 M, [00705] such that: [00706] i) the T-cell modulatory multimeric polypeptide binds to a first T cell with an affinity that is at least 25% higher than the affinity with which the T-cell modulatory multimeric polypeptide binds a second T cell, [00707] wherein the first T cell expresses on its surface the cognate co-immunomodulatory polypeptide and a TCR that binds the epitope with an affinity of at least 10 ^-7 M, and [00708] wherein the second T cell expresses on its surface the cognate co-immunomodulatory polypeptide but does not express on its surface a TCR that binds the epitope with an affinity of at least 10 ^-7 M; and/or [00709] ii) the ratio of the binding affinity of a control TMMP, wherein the control comprises a wild-type immunomodulatory polypeptide, to a cognate co-immunomodulatory polypeptide to the binding affinity of the TMMP comprising a variant of the wild-type immunomodulatory polypeptide to the cognate co-immunomodulatory polypeptide, when measured by bio-layer interferometry, is in a range of from 1.5:1 to 10 ⁶ :1. [00710] Aspect 36. A chimeric molecule of aspect 35, wherein: [00711] a) the TMMP binds to the first T cell with an affinity that is at least 50%, at least 2-fold, at least 5-fold, or at least 10-fold higher than the affinity with which it binds the second T cell; and/or [00712] b) the variant immunomodulatory polypeptide binds the co-immunomodulatory polypeptide with an affinity of from about 10 ^-4 M to about 10 ^-7 M, from about 10 ^-4 M to about 10 ^-6 M, from about 10 ^-4 M to about 10 ^-5 M; and/or [00713] c) wherein the ratio of the binding affinity of a control TMMP, wherein the control comprises a wild-type immunomodulatory polypeptide, to a cognate co-immunomodulatory polypeptide to the binding affinity of the TMMP comprising a variant of the wild-type immunomodulatory polypeptide to the cognate co-immunomodulatory polypeptide, when measured by bio-layer interferometry, is at least 10:1, at least 50:1, at least 10 ² :1, or at least 10 ³ :1. [00714] Aspect 37. A chimeric molecule of any of aspects 1-36, wherein the CAR comprises: a) an extracellular domain comprising the antigen-binding domain; b) a transmembrane region; and c) a cytoplasmic domain comprising an intracellular signaling domain. [00715] Aspect 38. A chimeric molecule of aspect 37, wherein the cytoplasmic domain comprises one or more co-stimulatory polypeptides. [00716] Aspect 39. A chimeric molecule of aspect 37 or aspect 38, wherein the intracellular signaling domain comprises: i) a signaling domain from the zeta chain of human CD3. [00717] Aspect 40. A chimeric molecule of aspect 38, wherein the costimulatory polypeptide is selected from CD28, 4-1BB, and OX-40. [00718] Aspect 41. A chimeric molecule of any of aspects 37-40, wherein the CAR is a single polypeptide chain CAR. [00719] Aspect 42. A chimeric molecule of any of aspects 37-40, wherein the CAR comprises at least two polypeptide chains. [00720] Aspect 43. A chimeric molecule of any of aspects 37-42, wherein the cancer-associated antigen is selected from AFP, BCMA, CD10, CD117, CD123, CD133, CD128, CD171, CD19, CD20, CD22, CD30, CD33, CD34, CD38, CD5, CD56, CD7, CD70, CD80, CD86, CEA, CLD18, CLL-1, cMet, EGFR, EGFRvIII, EpCAM, EphA2, GD-2, glypican-3, GPC3, HER-2, kappa immunoglobulin, LeY, LMP1, mesothlin, MG7, MUC1, NKG2D ligand, PD-L1, PSCA, PSMA, ROR1, ROR1R, TACI, and VEGFR2. [00721] Aspect 44. A chimeric molecule of any one of aspects 1-42, wherein the TMMP comprises two heterodimers. [00722] Aspect 45. A chimeric molecule of aspect 44, wherein both heterodimers comprise an Ig Fc polypeptide, and wherein the heterodimers are covalently bound by one or more disulfide bonds between the Ig Fc polypeptides of the first and second heterodimers. [00723] Aspect 46. A chimeric molecule of any one of aspects 1-45, wherein the one or more nucleic acids is attached to a thiol moiety present at the C-terminus of the first and/or the second polypeptide. [00724] Aspect 47. A chimeric molecule of any one of aspects 1-46, wherein the one or more nucleic acids are mRNA. [00725] Aspect 48. A chimeric molecule of aspect 47, wherein the mRNA comprises one or more of a backbone modification, a modified base, and a modified sugar. [00726] Aspect 49. A chimeric molecule of any one of aspects 1-46, wherein the nucleotide sequence encoding the CAR is operably linked to a promoter. [00727] Aspect 50. A chimeric molecule of aspect 49, wherein the promoter is constitutive. [00728] Aspect 51. A chimeric molecule of aspect 49, wherein the promoter is regulatable. [00729] Aspect 52. A method for making a chimeric molecule of any of aspects 1-51, wherein the method comprises covalently linking the nucleic acid at or near the C-terminus of the first or the second polypeptide of the TMMP, wherein the nucleic acid is modified to include a first reactive coupling group, wherein the first or the second polypeptide of the TMMP comprises a second reactive coupling group, wherein the covalent linkage is via the first reactive coupling group and the second reactive coupling group. [00730] Aspect 53. A method of aspect 52, wherein the first reactive coupling group comprises an amine moiety and wherein the second reactive coupling group comprises a carboxyl moiety. [00731] Aspect 54. A method of aspect 52, wherein the first reactive coupling group comprises a thiol moiety and wherein the second reactive coupling group comprises a thiol moiety. [00732] Aspect 55. A method of aspect 52, wherein the first reactive coupling group comprises an alkyne moiety and wherein the second reactive coupling group comprises an azide moiety. [00733] Aspect 56. A method of selectively modulating the activity of T cell specific for an epitope, the method comprising contacting the T cell with a chimeric molecule according to any one of aspects 1-51, wherein said contacting selectively modulates the activity of the epitope-specific T cell. [00734] Aspect 57. A method according to aspect 56, wherein the step of contacting is carried out in vitro. [00735] Aspect 58. A method according to aspect 56, wherein the step of contacting is carried out in vivo. [00736] Aspect 59. A method of treating a patient having a cancer, the method comprising administering to the patient a therapeutically effective amount of a pharmaceutical composition comprising a chimeric molecule according to any one of aspects 1-51. [00737] Aspect 60. A method of treating a patient having a cancer according to aspect 56, further comprising the step of administering to the patient a therapeutically effective amount of a pharmaceutical composition comprising a TMMP in accordance with any of aspects 1-44, wherein the TMMP has the same epitope as the chimeric molecule. [00738] Aspect 61. A method of treating a patient having a cancer according to aspect 59 or aspect 60, wherein the patient does not undergo a lymphodepleting regimen prior to the step of administering the chimeric molecule. [00739] Aspect 62. A method of treating a patient having a cancer according to aspect 59 or aspect 60, wherein the patient does undergo a lymphodepleting regimen prior to the step of administering the chimeric molecule. [00740] Aspect 63. A method according to any of aspects aspect 59-62, wherein said administering steps are each independently selected from the group consisting of intramuscular, intravenous, peritumoral, or intratumoral. [00741] Aspect 64. An in vivo method of making genetically modified cytotoxic T cells comprising the step of administering to the patient an effective amount of a pharmaceutical composition comprising a chimeric molecule according to any one of aspects 1-51. [00742] Aspect 65. A method according to aspect 64, further comprising the step of administering to the patient a composition comprising a TMMP in accordance with any of aspects 1-44, wherein the TMMP has the same epitope as the chimeric molecule. [00743] Aspect 66. An in vitro method of making a composition comprising a quantity of genetically modified cytotoxic T cells comprising the step of: [00744] (i) obtaining a composition comprising a quantity of T cells, [00745] (ii) increasing the quantity of T cells comprising a T-cell receptor (TCR) specific for a preselected antigen by contacting the T cells with a composition comprising a T-cell modulatory polypeptide that largely binds to and activates only the T cells comprising a T-cell receptor (TCR) specific for a preselected antigen, [00746] (iii) admixing with the quantity of T cells a quantity of chimeric molecules according to any of aspects 1-51 to create a composition comprising a quantity of genetically modified cytotoxic T cells, [00747] wherein the preselected antigen has the same peptide epitope as the chimeric molecules. [00748] Aspect 67. A method according to aspect 66, wherein the T-cell modulatory polypeptide is a T cell multimeric polypeptide (TMMP) in accordance with any of aspects 1-51. [00749] Aspect 68. A method according to aspect 66 or aspect 67, wherein prior to step (iii), a separation is performed to at least partially separate the T cells that comprise a T-cell receptor (TCR) specific for a preselected antigen (collectively, “target T cells”) from T cells comprising a T-cell receptor (TCR) that is not specific for the preselected antigen. [00750] Aspect 69. A method according to any one of aspects 66-68, wherein after step (iii) is performed, a separation is performed to at least partially separate the quantity of genetically modified cytotoxic T cells for genetically modified cytotoxic T cells that comprise a T-cell receptor (TCR) specific for a preselected antigen (collectively, “genetically modified target T cells”) from genetically modified and unmodified T cells comprising a T-cell receptor (TCR) that is not specific for the preselected antigen. [00751] Aspect 70. A method according to aspect 68 or aspect 69, wherein step of at least partially separating comprises the step of binding the Target T cells to a polypeptide that binds to the TCR of the target T cells. [00752] While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto.