SYNTHETIC EXTRACELLULAR VESICLES FOR NOVEL THERAPIES

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No.: 62/538,669, filed July 29, 2017, the contents of which are incorporated by reference.

SEQUENCE LISTING

[0002] The instant application contains a Sequence Listing which has been submitted electronically in ASCII format and is hereby incorporated by reference in its entirety. Said ASCII copy, created on July 19, 2018, is named 064189-9131_SL.txt and is 263,276 bytes in size.

BACKGROUND

[0003] Exosomes are natural membranous vesicles with a diameter of 30-200 nm. They are generated through inward invagination of endosomal membranes which form

multivesicular bodies (MVBs), followed by release into the extracellular milieu upon fusion of the MVBs with the plasma membrane. As endogenous nanocarriers secreted by various types of cells, exosomes play important roles in cell-cell communication through transfer of mRNA, miRNA, receptors, enzymes, cytokines, etc. Importantly, the membrane of exosome is characterized by a phospholipid bilayer and abundant tetraspanin CD9 on its surface, facilitating direct membrane fusion with target cells. This fusion mode circumvents the endosomal-lysosomal pathway required for the synthetic vehicles and promotes cellular delivery of therapeutic agents. Thus, exosome and other extracellular vesicles are under investigation as therapeutic treatments.

SUMMARY OF THE DISCLOSURE

[0004] Provided herein are novel extracellular vesicles that can simultaneously target both a pathological cell such as a cancer or an immune cell for combinatorial

immunotherapy. Relative to conventional, immunotherapeutic bispecific antibodies with geometrically and orientationally defined antigen-binding arms, the multivalent dual-targeted vesicles of this disclosure are displayed on a spherical surface and have higher potential to promote formation of immunological synapses as well as enhanced efficacy to activate immune cells. Combined with immune checkpoint inhibitors, such bispecific extracellular vesicles are engineered to augment efficacy of immunotherapy. Therefore, the engineered multifunctional extracellular vesicles represent novel nanomedicines with enhanced efficacy and safety, leading to the development of first-in-class immunotherapeutics for cancer and other diseases and disorders.

[0005] In one aspect, this disclosure provides an isolated, engineered extracellular vesicle comprising, or alternatively consisting essentially of, or yet further consisting of one or more antigen binding domain(s) fused to an extracellular vesicle addressing domain. Non-limiting examples of the extracellular vesicle domains are from the group of vesicles that include one or more from the group of: an exosome, a liposome, a microvesicle, and an apoptotic body. The antigen binding domains are fused to the extracellular vesicle addressing domain by chemical or recombinant techniques. The isolated, engineered vesicles can be modified and isolated from a variety of cell types, e.g., prokaryotic or eukaryotic, e.g., eukaryotic such as mammalian such as human, canine, equine, feline, bovine, rat, murine, ovine, and simian. Additional examples include yeast cells, bacterial cells and plant cells. Non-limiting examples include Expi293F cells, HeLa cells, HEK293T, MDA-MB-231, immature dendritic cells, and stem cells.

[0006] In one aspect, the one or more antigen binding domains are selected from the group of: an antibody, a multi-specific antibody, a monoclonal antibody, an scFv antibody fragment, a single domain antibody, a heavy chain variable domain (VH), a light chain variable domain (VL), a bispecific antibody, or a bispecific antibody fragment, a multi- specific antibody fragment, Fab, F(ab)'2, Fab', and F _v . antibody fragment, or an equivalent of each thereof. Non-limiting examples of antibodies and fragments and derivatives thereof are of the group of antibodies: anti-HER2; anti-HER3; anti-EGFR; anti-CD3; anti-CD 16; anti- CD4; anti-CD8; anti-CDl la; anti-CD19; anti-CD20; anti-CD25; anti-CD33; anti-CD40; anti- CD40L; anti-CD70; anti-CD 123; anti-EpCAM; anti-CLL-1; anti-CTLA-4; anti-PD-1; anti- PD-L1; anti-OX40; anti-GITR; anti-ICOS; anti-B7-H3; anti-B7-H4; anti-LAG3; anti-TIM3; anti-PSMA; anti-factor IXa; anti-factor X; and anti-folate receptor, fragments or derivatives thereof.

[0007] In another aspect, the antigen binding domain specifically recognizes and binds an immune cell. In a further aspect, the engineered vesicle comprises, or alternatively consists essentially of, or yet further consists of different antigen binding domains, e.g., one or more specific to a cancer or tumor cell and one or more specific to an immune cell.

[0008] Examples of antigen binding domains include those that bind an antigen of the group of: a tumor antigen, a cancer antigen, an antigen expressed on an immune cell, activated coagulation factor IX, factor X, an antigen involved in immune regulation such as a cell surface receptor that mediates the reaction of an immune cell (e.g., a T cell, a

macrophage or a natural killer cell) or a checkpoint inhibitor, e.g., PDL1, CTLA-4, B7-H3, B7-H4, LAG3, PD1, TIM-3, or a checkpoint activator, e.g. CD40, OX40, GITR, and ICOS.

[0009] When the antigen binding domain is specific for a cancer antigen, examples of such include a cancer antigen is selected from the groups of breast cancer, lung cancer, colorectal cancer, kidney cancer, prostate cancer, brain cancer, pancreatic cancer, ovarian cancer, liver cancer, bladder cancer, lymphoma, melanoma, a solid malignant cancer or a blood cancer. Specific examples include HER2 or EGFR expressed on breast cancer or colorectal cancer.

[0010] When the antigen binding domain is specific for an immune cell, non-limiting examples of immune cells are selected from the group of: a CD3+ T cell, a CD16+ cell, a CD 16+ NK cell, a CD4 cell, a CD8 cell, a CD 19 cell, a CD20 cell, or a B cell.

[0011] In a further aspect, the engineered vesicles contain an effective amount of a therapeutic agent. Non-limiting examples of such include small molecular immune checkpoint modulators, a small molecular chemotherapeutic drug, an RNA-based

therapeutics (siRNA, or miRNA), a therapeutic protein, a therapeutic peptide, an immune regulatory factor, an immune checkpoint inhibitor, an immune agonist, anti-PDl, anti-PDLl, anti-CTLA4 siRNA, an inhibitor of indoleamine-pyrrole 2,3-dioxygenase (IDO) such as GDC-0919 and indoximod, an agonist of Toll-like receptors (TLR) TLRs such as Motolimod, and Resiquimod. More than one therapeutic agent can be encapsulated in the vesicle. For example, in one aspect, the more than one therapeutic agent is selected to target both tumor cell and tumor stroma cells in a solid tumor for synergistic anti-tumor effect. In another aspect, the more than one therapeutic agents are selected to block two immune checkpoint inhibitors simultaneously, e.g., anti-PDl, anti-PDLl and anti-CTLA4 siRNA. In one aspect the plurality targets the immune checkpoint inhibitors are anti-PDLl and anti-CTLA4. [0012] Also provided herein are methods for the preparing and isolating the engineered vesicles and compositions containing them. In one aspect, the vesicles are processed by freeze-drying.

[0013] The compositions comprising, or alternatively consisting essentially of, or yet further consisting of the engineered vesicles can further comprise, or alternatively consist essentially of, or yet further consist of an effective amount of a therapeutic agent to work in combination with the engineered vesicle. These can be combined with carriers, such as a pharmaceutically acceptable carrier.

[0014] The compositions are useful for treating a disease or eliciting an immune response by administering an effective amount of a disease-relevant engineered vesicle, that is, wherein the engineered vesicle expresses an antigen binding domain specific to a disease to be treated. For example the vesicle would comprise, or alternatively consist essentially of, or yet further consist of an antigen binding domain specific for a specific tumor or cancer antigen when the disease to be treated is cancer. The methods and compositions are useful to treat or inhibit the progression of cancer, hyperplasia, neurodegenerative disease,

Alzheimer's disease, cardiovascular disease, metabolic disease, vasculitis, viral infection, fungal infection, bacterial infection, diabetic retinopathy, macular degeneration, autoimmune disease, edema, pulmonary hypertension, sepsis, myocardial angiogenesis, plaque

neovascularization, restenosis, neointima formation after vascular trauma, telangiectasia, hemophiliac joints, angiofibroma, fibrosis associated with chronic inflammation, lung fibrosis, deep venous thrombosis or wound granulation.

[0015] In a particular embodiment, the compositions and methods are useful in cancer immunotherapy and the engineered vesicle displays an antigen binding domain for the cancer cell and an antigen binding domain specific for the immune cell. In a further aspect, the engineered vesicle comprises, or alternatively consists essentially of, or yet further consists of a therapeutic agent to treat the cancer. More than one therapeutic agent can be encapsulated in the vesicle. For example, in one aspect, engineered vesicles are administered wherein more than one therapeutic agent is selected to target both tumor cell and tumor stroma cells in a solid tumor for synergistic anti-tumor effect. In another aspect, an effective amount of an engineered vesicle is administered having more than one therapeutic agents to block two immune checkpoint inhibitors simultaneously, e.g., anti-PDl, anti-PD-Ll and anti-CTLA4 siRNA. In one aspect, the plurality targets the immune checkpoint inhibitors are anti-PDLl siRNA and anti-CTLA4 siRNA.

[0016] Also provided are fusion polypeptides that are useful to recombinantly prepare the engineered vesicles and polynucleotides encoding the polypeptides. In one aspect the polynucleotide encodes a fusion polypeptide comprising, or alternatively consisting essentially of, or yet further consisting of: an immune effector cell binding domain or an antigen binding domain, a linker polypeptide, and an exosome addressing domain. In one aspect, the polynucleotide encodes a fusion polypeptide that comprises, or alternatively consists essentially of, or yet further consists of an antigen binding domain that specifically recognize and bind an antigen of the group of: a tumor antigen, a cancer antigen, an activated coagulation factor IX, and factor X. Non-limiting examples of cancer antigens are selected from the groups of breast cancer, lung cancer, colorectal cancer, kidney cancer, prostate cancer, brain cancer, pancreatic cancer, a solid malignant cancer or a blood cancer. In a further aspect, the cancer is a breast cancer or a colorectal cancer, and the antigen is HER2 or EGFR expressed on the cancer cell. The polynucleotides can be operatively linked to regulatory elements to drive expression of the polynucleotide and can be further contained within a vector, e.g. a plasmid or a viral vector. Host cells containing the polynucleotides and/or polypeptides and methods of expressing the polynucleotides are further provided herein, as well as the polypeptides encoded by the polynucleotides. The host cells are prokaryotic or eukaryotic cells. The polynucleotides and polypeptides can further comprise, or alternatively consist essentially of, or yet further consist of a detectable and/or a purification label.

[0017] In a particular aspect, the antigen binding domain specifically recognizes and binds a receptor present on a CD3+ T cell or a CD 16+ NK cell.

[0018] Linker polypeptides can be present in the fusion polypeptide.

[0019] In a yet further aspect, the antigen binding domain comprises, or alternatively consists essentially of, or yet further consists of an anti-HER2 scFv antibody fragment or an anti-EGFR scFv antibody fragment.

[0020] In another aspect, the fusion polypeptide comprises: an immune effector binding domain, first linker polypeptide, an antigen binding domain, a second linker, and an exosome membrane protein or polypeptide. In a further aspect, the fusion polypeptide comprises, or alternatively consists essentially of, or yet further consists of a myc polypeptide protein tag derived from the c-myc gene product and/or a human influenza hemagglutinin epitope.

[0021] Further provided are polynucleotides encoding the fusion polypeptides, vectors and host cells containing them as well as recombinant methods for expressing the fusion polypeptides.

[0022] Also provided is a method to prepare the engineered exosome by transducing a population of cells comprising, or alternatively consisting essentially of, or yet further consisting of vesicles, such as exosomes, with a vector comprising, or alternatively consisting essentially of, or yet further consisting of the polynucleotides encoding the fusion

polypeptides as described above and then isolating the transduced vesicles. In a further aspect, the method comprises, or alternatively consists essentially of, or yet further consists of chemical conjugation of the antigen binding domains to the an exosome membrane protein or polypeptide located on exterior of the vesicle.

[0023] In a further aspect, the method comprises, or alternatively consists essentially of, or yet further consists of encapsulating a therapeutic agent into the engineered vesicle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIGS. 1A-1B are structures of the bispecific exosomes. FIG. 1A: A bispecific antibody was fused with exosomal membrane protein for surface display. FIG. IB: Two distinct scFv antibodies were separately fused with the same or different exosomal proteins for surface display.

[0025] FIGS. 2A-2B show a general description of the fusion polypeptides. As depicted in the schemes, representative tags include: HA, FLAG, and 6XHis (SEQ ID NO: 1).

Representative linkers include:

(GGGGS)n, n=0-5 (SEQ ID NO: 2)

(GGGS)n, n=0-6 (SEQ ID NO: 3)

(GGS)n, n=0-7 (SEQ ID NO: 4)

(EAAAK)n, n=0-4 (SEQ ID NO: 5) PSGQAGAAASESLFVS HAY (SEQ ID NO: 6)

GSTSGSGKPGSGEGS (SEQ ID NO: 7)

Representative types of antibody fragments (antigen binding fragments) include: single-chain variable fragment (scFv); heavy chain variable domain (VH); light chain variable domain (VL); single-domain antibody; and a multi-specific antibody fragment. Representative antigen binding domains include: anti-HER2; anti-HER3; anti-EGFR; anti-CD3; anti-CD 16; anti-CD4; anti-CD8; anti-CDl la; anti-CD19; anti-CD20; anti-CD25; anti-CD33; anti-CD40; anti-CD40L; anti-CD70; anti-CD 123; anti-EpCAM; anti-CLL-1; anti-CTLA-4; anti-PD-1; anti-PD-Ll; anti-OX40; anti-GITR; anti-ICOS; anti-B7-H3; anti-B7-H4; anti-LAG3; anti- TEVI3; anti-PSMA; anti-factor IXa; anti-factor X; and anti-folate receptor, fragments and derivatives thereof. Representative exosomal membrane proteins (also termed herein as an "extracellular vesicle addressing domain") include: platelet-derived growth factor receptor (PDGFR); lysosomal-associated membrane protein 2b (Lamp2b); lactadherin-ClC2 domain; CD13; and CD9.

[0026] FIG. 3 is a schematic of a bispecific exosome nanoparticles for novel cancer immunotherapy. TAA is tumor-associated antigen.

[0027] FIG. 4A is a schematic of a bispecific antibody-targeted exosomes for cancer immunotherapy.

[0028] FIG. 4B depicts a method to encapsulate the therapeutic drug or payload into the exosomes.

[0029] FIG. 5 depicts schemes of fusion proteins for exosome engineering.

Abbrevations: Platelet-derived growth factor receptors (PDGFR) are cell surface tyrosine kinase receptors for members of the platelet-derived growth factor (PDGF) family. Exosomal membrane protein (trans-membrane domain (TMD)) of PDGFR 49 aa, widely used to express protein on cell membrane surface. HA is human influenza hemagglutinin epitope. Myc is a polypeptide protein tag derived from the c-myc gene product.

[0030] FIG. 6 is a Western blot of bispecific exosomes targeting HER2 and CD3. Lanes from left to right are as follows: 1. native exosome; 2. anti-CD3 exosomes; 3. anti-HER2 exosomes; 4. bispecific exosome anti-CD3 and anti-HER2; and 5. bispecific exosome anti- HER2 and anti-CD3.

[0031] FIG. 7 is a Western blot of bispecific exosomes targeting HER2 and CD3. Lanes are as follows: 1. blank exosome; 2. bispecific exosome anti-CD3 and anti-HER2 exosomes; 3. anti-HER2 exosomes; and 4. anti-CD3 exomes.

[0032] FIG. 8 is flow cytometry analysis of generated bispecific exosomes targeting HER2 and CD3.

[0033] FIG. 9 is flow cytometry analysis of the generated monospecific and bispecific exosomes targeting HER2 and CD3

[0034] FIG. 10 shows the size distribution of the isolated monospecific and bispecific exosomes by nanoparticle tracking analysis (NT A).

[0035] FIG. 11 shows fluorescence microscopy of the interaction between HCC1954 cells (dark) and Jurkat cells (light) in the presence of (from left to right) PBS, 1 : 1 mixture of anti-HER2 and anti-CD3 mono-specific exosomes, anti-HER2/anti-CD3 bispecific exosomes, and anti-CD3/anti-HER2 bispecific exosomes. 0.1 μg/μL exosome in 100 μΕ.

[0036] FIG. 12 shows fluorescence microscopy of the interaction between SK-BR-3 cells (dark) and Jurkat cells (light) in the presence of anti-CD3/anti-HER2 bispecific exosomes (right) or a mixture of anti-HER2 and anti-CD3 mono-specific exosomes (left).

[0037] FIG. 13 depicts results pertaining to in vitro cytotoxicity of anti-CD3/anti-HER2 bispecific exosomes or a mixture of anti-HER2 and anti-CD3 mono-specific exosomes against HCC 1954 and MDA-MB-468 cell lines. E:T=8: 1 48h

[0038] FIG. 14 depicts results pertaining to in vitro cytotoxicity of anti-CD3/anti-HER2 and anti-HER2/anti-CD3 bispecific exosomes or a mixture of anti-HER2 and anti-CD3 mono-specific exosomes against SK-BR-3 and MDA-MB-468 cell lines.

[0039] FIG. 15 shows schemes of scFv-PDGFR fusion proteins. PDGFR: Platelet- derived growth factor receptors. HA: human influenza hemagglutinin epitope, myc: a polypeptide protein tag derived from the c-myc gene product, linker: GGGGS or a repeate thereof. [0040] FIG. 16 shows a western blot of the generated exosomes. Lanes from left to right are: 1. Blank exosomes; 2. Anti-EGFR exosomes; 3. Anti-CD3 exosomes; 4. Anti- EGFR/ Anti-CD3 co-transfected exosomes; 5. Anti-EGFR/anti-CD3 bispecific exosomes; and 6. Anti-CD3/anti-EGFR bispecific exosomes.

[0041] FIG. 17A-C : FIG. 17A shows flow cytometry analysis bispecific exosomes targeting EGFR and CD3 and anti-CD3 and anti-EGFR monospecific exosomes at a concentration of 0.1 μg/uL exosome in 100 μΕ. FIG. 17B shows additional flow cytometry analysis bispecific exosomes targeting EGFR and CD3 and anti-CD3 and anti-EGFR monospecific exosomes at a concentration of 0.1 μg/uL exosome in 100 μΕ. FIG. 17C shows in vitro cytotoxicity results of anti-CD3/anti-EGFR bispecific exosomes or mixture of monospecific anti-CD3 and anti-EGFR exosomes against MDA-MB-468 and -453 cell lines.

Tumor cell was peripheral blood mononuclear cell (PBMC) =1 : 10, incubated 40 h, then measured by MTT.

[0042] FIG. 18. Shows size distribution of the isolated native exosomes and bispecific exosomes targeting EGFR and CD3 by nanoparticle tracking analysis (NTA).

[0043] FIG. 19 shows fluorescence microscopy of the interaction between MDA-MB- 468 (bottom row) or -453 (top row) cells (dark) and Jurkat cells (light) in the presence of anti-CD3/anti-EGFR bispecific exosomes (right column) or mixture of mono-specific anti- CD3 and anti-EGFR exosomes (left column). Concentrations were 0.1 μg/uL exosome in 100 μL.

[0044] FIG. 20 Shows in vitro cytotoxicity results of anti-CD3/anti-EGFR bispecific exosomes or mixture of mono-specific anti-CD3 and anti-EGFR exosomes against MDA- MB-468 and -453 cell lines. Tumor cell was peripheral blood mononuclear cell (PBMC) =1 : 8, incubated 48 h, then measured by MTT.

[0045] FIG. 21 shows schemes of fusion proteins for exosome engineering. Lysosomal- associated membrane protein 2b (Lamp2b) is an exosomal membrane protein. FLAG is a short, hydrophilic protein epitope tag or label.

[0046] FIG. 22 shows a western blot of the generated exosomes. Lane assignments are: 1. anti-EGFR exosomes; 2. anti-CD3 exosomes; and 3. anti-CD3/anti -EGFR bispecific exosomes. [0047] FIG. 23 shows a flow cytometry analysis of the generated bispecific and monospecific exosomes if this disclosure.

[0048] FIG. 24 Shows in vitro cytotoxicity results of anti-CD3/anti-EGFR bispecific exosomes or mixture of mono-specific anti-CD3 and anti-EGFR exosomes against MDA- MB-468 and -453 cell lines.

[0049] FIG. 25 depicts native exosomes and bispecific exosomes targeting EGFR and CD3. Negative staining transmission electron microscopy image of native exosomes and the generated Bispecific Exosome aCD3xaEGFR.

[0050] FIG. 26 shows the size distribution of the generated bispecific exosome aCD3xaHER2 as evaluated through nanoparticle tracking analysis.

[0051] FIG. 27 shows a negative staining transmission electron microscopy image of the generated Bispecific Exosome aCD3xaHER2. Refer to transmission electron microscopy (TEM).

[0052] FIG. 28 shows fluorescence microscope images of the interaction between SK- BR-3 cells (dark) and Jurkat cells (light) in the presence of (from left to right) PBS, 1 : 1 mixture of anti-HER2 and anti-CD3 mono-specific exosomes, and anti-CD3/anti-HER2 bispecific exosomes. 0.1 μg/μL exosome in 100 μL .

[0053] FIG. 29 shows in vitro cytotoxicity of anti-CD3/anti-HER2 bispecific exosomes. Non-activated hPBMC were incubated with HCC-1954 cells (HER2 ⁺ ) at an E:T ratio of 10 for 40 hours in the presence of bispecific exosomes or a mixture of monospecific exosomes. After removing hPBMC suspension, the cell viabilities of target cells were measured through MTT assays.

[0054] FIG. 30 shows in vitro cytotoxicity of anti-CD3/anti-HER2 bispecific exosomes. Non-activated hPBMC were incubated with SK-BR-3, BT-474, and HCC1954 cells at an E:T ratio of 10 for 40 hours in the presence of bispecific exosomes. After removing hPBMC suspension, the cell viabilities of target cells were measured through MTT assays.

[0055] FIG. 31 depicts bispecific exosomes targeting EGFR and CD3. Zeta potential analysis of the generated bispecific exosomes aCD3xaEGFR. [0056] FIG. 32A-B: FIG. 32. A shows flow cytometric analysis of EGFR expression for various TNBC cell lines. FIG. 32B shows in vitro cytotoxicity of the bispecific exosomes for different TNBC cell lines. Non-activated hPBMCs were incubated with different TNBC cell lines at an E:T ratio of 10 for 40 hours in the presence of bispecific exosomes. After removing hPBMCs suspension, cell viabilities of target cells were measured through MTT assays.

[0057] FIGS. 33A-33E relate to bispecific exosomes targeting EGFR and CD3 and in vitro characterization of T-cell activation mediated by anti-CD3/anti-EGFR bispecific exosomes. Non-activated hPBMCs were incubated with bispecific exosomes or a mixture of monospecific exosomes in the absence or presence of MDA-MB-468 cells (EGFR ⁺ ) and MDA-BD-453 cells (EGFR ^" ) at an E:T ratio of 10 for 20 hours. Expression levels of CD23 and CD69 on T-cell surface were analyzed by flow cytometry. FIGS. 33A, 33B and 33E show MDA-MB-468 cell-dependent activation of T cells by the generated bispecifc exosomes as evaluated by T-cell surface activation markers CD25 (FIG. 33A) and CD69 (FIG. 33B), and secreted IFN-γ (FIG. 33E). The percentages of CD25+and CD69+T cells were analyzed by flow cytometry. The levels of secreted IFN-γ in culture media were determined by ELISA. FIGS. 33C and 33D show dose-dependent activation of T cells by the generated bispecific exosomes as evaluated by T-cell surface activation markers CD25 (FIG. 33 A) and CD69 (FIG. 33B), and secreted IFN-γ (FIG. 33E). *** P<0.001 with respect to the absence of target cells or with the negative control cells. One-way ANOVA with Tukey post hoc tests was used to compare mean ± SD.

[0058] FIGS. 34A-34C show in vivo efficacy comparison of aCD3/aEGFR bispecific exosomes in three human triple negative breast cancer (TNBC) xenograft models, MDA-MB- 468 (FIG. 34A), BT20 (FIG. 34B) and MDA-MB-231(FIG. 34C). Two-four days after subcutaneous implantation of 5x 10 ⁶ MD A-MB-468/BT20 cancer cells or 1.5 x lO ⁶ MDA- MB-231 cells in 50% Matrigel respectively, female NSG mice (n=5) received one

intraperitoneal (IP) injection of 20x 10 ⁶ non-activated human PBMCs. One days after the PBMCs injection, mice were treated intravenously with six doses of aCD3/aEGFR bispciifc exosomes (10 mg/kg) or PBS every other day. Tumors were measured thrice a week with calipers. Each data point represents mean tumor volume in each group. ***P < 0.001, ** P=0.0011, or P=0.0020, with respect to the PBS control group. Student t test with repeated measures was used to compare mean ± SD of two groups.

[0059] FIG. 35 depicts bispecific exosomes targeting EGFR and CD3. Bispecific binding of the anti-CD3/anti-EGFR exosomes based on antibody-Lamp2b fusion. Right panel: fluorescence (FL) and brightfield (BF) microscope images of MDA-MB-468 cells (dark) and Jurkat cells (light) in the presence of anti-CD3/anti-EGFR bispecific exosomes. Left panel: a mixture of anti-CD3 exosomes and anti-EGFR exosomes at 1 : 1 ratio was used as a negative control.

DETAILED DESCRIPTION

Definitions

[0060] 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 this invention will be limited only by the appended claims.

[0061] The detailed description of the invention is divided into various sections only for the reader's convenience and disclosure found in any section may be combined with that in another section. 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 disclosure 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 by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.

[0062] All numerical designations, e.g., pH, temperature, time, concentration, and molecular weight, including ranges, are approximations which are varied ( + ) or ( - ) by increments of 0.1 or 1.0, where appropriate. It is to be understood, although not always explicitly stated, that all numerical designations are preceded by the term "about." It also is to be understood, although not always explicitly stated, that the reagents described herein are merely exemplary and that equivalents of such are known in the art. [0063] 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 cell" includes a plurality of cells.

Definitions

[0064] The following definitions assist in defining the meets and bounds of the inventions as described herein. Unless specifically noted, the embodiments describing "cell-derived vesicles" shall include "exosomes," "liposomes, and "microvesicles" alone or in

combination. When the term "exosome" is used as an example, it is understood that liposomes and microvesicles can be substituted therein.

[0065] The term "about" when used before a numerical designation, e.g., temperature, time, amount, concentration, and such other, including a range, indicates approximations which may vary by ( + ) or ( - ) 10 %, 5 % or 1 %.

[0066] The terms "administering" or "administration" in reference to delivering engineered vesicles to a subject include any route of introducing or delivering to a subject the engineered vesicles to perform the intended function. Administration can be carried out by any suitable route, including orally, intranasally, parenterally (intravenously, intramuscularly, intraperitoneally, or subcutaneously), intracranially, or topically. Additional routes of administration include intraorbital, infusion, intraarterial, intracapsular, intracardiac, intra derma], mirapu!monary, intraspinal, intrasternai, intrathecal, intrauterine, intravenous, subarachnoid, subcapsular, subcutaneous, transmucosal, or transtracheal. Administration includes self-administration and the administration by another.

[0067] "Comprising" or "comprises" is intended to mean that the compositions, for example media, and methods include the recited elements, but not excluding others.

"Consisting essentially of when used to define compositions and methods, shall mean excluding other elements of any essential significance to the combination for the stated purpose. Thus, a composition consisting essentially of the elements as defined herein would not exclude other materials or steps that do not materially affect the basic and novel characteristic(s) of the claimed invention. "Consisting of shall mean excluding more than trace elements of other ingredients and substantial method steps. Embodiments defined by each of these transition terms are within the scope of this disclosure. [0068] As used herein, the term "modified" or "engineered" relative to naturally- occurring cell-derived vesicles, refers to cell-derived vesicles (e.g., extracellular vesicles such as exosomes, liposomes and/or microvesicles) that have been altered such that they differ from a naturally occurring cell-derived vesicles.

[0069] The term "polypeptide" is used interchangeably with the term "protein" and in its broadest sense refers to a compound of two or more subunit amino acids, amino acid analogs or peptidomimetics. The subunits may be linked by peptide bonds. In another embodiment, the subunit may be linked by other bonds, e.g., ester, ether, etc. As used herein the term "amino acid" refers to natural and/or unnatural or synthetic amino acids, including glycine and both the D and L optical isomers, amino acid analogs and peptidomimetics. A peptide of three or more amino acids is commonly called an oligopeptide if the peptide chain is short. If the peptide chain is long, the peptide is commonly called a polypeptide or a protein. The term "peptide fragment," as used herein, also refers to a peptide chain.

[0070] The phrase "equivalent polypeptide" or "equivalent peptide fragment" or simply "equivalent" referring to a protein or peptide, refers to protein, polynucleotide, or peptide fragment which hybridizes to the exemplified polynucleotide or peptide fragment under stringent conditions and which exhibit similar biological activity in vivo, e.g., approximately 100%, or alternatively, over 90% or alternatively over 85% or alternatively over 70%, as compared to the standard or control biological activity. Additional embodiments within the scope of this invention are identified by having more than 60%, or alternatively, more than 65%), or alternatively, more than 70%, or alternatively, more than 75%, or alternatively, more than 80%), or alternatively, more than 85%>, or alternatively, more than 90%, or alternatively, more than 95%, or alternatively more than 97%, or alternatively, more than 98% or 99% sequence homology. Percentage homology can be determined by sequence comparison using programs such as BLAST run under appropriate conditions. In one aspect, the program is run under default parameters.

[0071] The term "polynucleotide" refers to a polymeric form of nucleotides of any length, either deoxyribonucleotides or ribonucleotides or analogs thereof. Polynucleotides can have any three-dimensional structure and may perform any function, known or unknown. The following are non-limiting examples of polynucleotides: a gene or gene fragment (for example, a probe, primer, or EST), exons, introns, messenger RNA (mRNA), transfer RNA, ribosomal RNA, ribozymes, cDNA, RNAi, siRNA, recombinant polynucleotides, branched polynucleotides, plasmids, vectors, isolated DNA of any sequence, isolated RNA of any sequence, nucleic acid probes and primers. A polynucleotide can comprise, or alternatively consist essentially of, or yet further consist of modified nucleotides, such as methylated nucleotides and nucleotide analogs. If present, modifications to the nucleotide structure can be imparted before or after assembly of the polynucleotide. The sequence of nucleotides can be interrupted by non-nucleotide components. A polynucleotide can be further modified after polymerization, such as by conjugation with a labeling component. The term also refers to both double- and single-stranded molecules. Unless otherwise specified or required, any embodiment of this invention that is a polynucleotide encompasses both the double-stranded form and each of two complementary single-stranded forms known or predicted to make up the double-stranded form.

[0072] A polynucleotide is composed of a specific sequence of four nucleotide bases: adenine (A); cytosine (C); guanine (G); thymine (T); and uracil (U) for thymine when the polynucleotide is RNA. Thus, the term "polynucleotide sequence" is the alphabetical representation of a polynucleotide molecule. This alphabetical representation can be input into databases in a computer having a central processing unit and used for bioinformatics applications such as functional genomics and homology searching.

[0073] "Anti-cancer therapeutic" refers to any drug useful in the treatment of cancer. Various kinds of anti-cancer drugs are alkylating agents (cisplatin, chlorambucil,

procarbazine, carmustine etc.), antimetabolites (methotrexate, cytarabine, gemcitabine etc.), anti -microtubule agents (vinblastine,paclitaxel etc.), topoisomerase inhibitors (etoposide, doxorubicin etc.), and cytotoxic agents (bleomycin, mitomycin etc.).

[0074] "Homology" or "identity" or "similarity" are synonymously and refers to sequence similarity between two peptides or between two nucleic acid molecules. Homology can be determined by comparing a position in each sequence which may be aligned for purposes of comparison. When a position in the compared sequence is occupied by the same base or amino acid, then the molecules are homologous at that position. A degree of homology between sequences is a function of the number of matching or homologous positions shared by the sequences. An "unrelated" or "non-homologous" sequence shares less than 40% identity, or alternatively less than 25% identity, with one of the sequences of the present invention.

[0075] A polynucleotide or polynucleotide region (or a polypeptide or polypeptide region) has a certain percentage (for example, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%) or 99%) of "sequence identity" to another sequence means that, when aligned, that percentage of bases (or amino acids) are the same in comparing the two sequences. This alignment and the percent homology or sequence identity can be determined using software programs known in the art, for example those described in Ausubel et al. eds. (2007) Current Protocols in Molecular Biology. Preferably, default parameters are used for alignment. One alignment program is BLAST, using default parameters. In particular, programs are BLASTN and BLASTP, using the following default parameters: Genetic code = standard; filter = none; strand = both; cutoff = 60; expect = 10; Matrix = BLOSUM62; Descriptions = 50 sequences; sort by = HIGH SCORE; Databases = non-redundant, GenBank + EMBL + DDBJ + PDB + GenBank CDS translations + SwissProtein + SPupdate + PIR. Details of these programs can be found at the following Internet address:

http://www.ncbi.nlm.nih.gov/blast/Blast.cgi, last accessed on November 26, 2007.

Biologically equivalent polynucleotides are those having the specified percent homology and encoding a polypeptide having the same or similar biological activity.

[0076] A "gene" refers to a polynucleotide containing at least one open reading frame (ORF) that is capable of encoding a particular polypeptide or protein after being transcribed and translated. Any of the polynucleotide or polypeptide sequences described herein may be used to identify larger fragments or full-length coding sequences of the gene with which they are associated. Methods of isolating larger fragment sequences are known to those of skill in the art.

[0077] The term "express" refers to the production of a gene product such as RNA or a polypeptide or protein.

[0078] As used herein, "expression" refers to the process by which polynucleotides are transcribed into mRNA and/or the process by which the transcribed mRNA is subsequently being translated into peptides, polypeptides, or proteins. If the polynucleotide is derived from genomic DNA, expression may include splicing of the mRNA in an eukaryotic cell. [0079] "Cancer associated antigen," "tumor antigen," or "cancer antigen" refers to an antigenic substance produced in tumor cells, i.e., it triggers an immune response in the host. Non-limiting examples include alphafetoprotein (AFP), carcinoembryonic antigen, CA-125, MUC-1, epithelial tumor antigen, tyrosinase, and melanoma-associated antigen.

[0080] A "gene product" or alternatively a "gene expression product" refers to the RNA when a gene is transcribed or amino acid (e.g., peptide or polypeptide) generated when a gene is transcribed and translated.

[0081] "Small molecular immune checkpoint modulators" are small molecules (less than 900 daltons) capable of modulating an "immune checkpoint" or regulator of immune activation. "Immune checkpoint" may refer to a receptor target. Non-limiting examples of immune checkpoints include PD-1/PD-L1, CTLA4, CD27, CD28, CD40, CD122, CD 137, OX40, GITR, ICOS, A2AR, B7-H3, B7-H4, BTLA, CTLA-4, IDO, KIR, LAG3, TIM-3, and VISTA. "Immune checkpoint inhibitors" refers to small molecules or macromolecules which act as inhibitors of an immune checkpoint.

[0082] "Immune regulatory factor" refers the a protein which regulates the immune system.

[0083] "Immune agonist" refers to an agent which can stimulate the immune system.

[0084] The term "encode" as it is applied to polynucleotides refers to a polynucleotide which is said to "encode" a polypeptide if, in its native state or when manipulated by methods well known to those skilled in the art, it can be transcribed and/or translated to produce the mRNA for the polypeptide and/or a fragment thereof. The antisense strand is the

complement of such a nucleic acid, and the encoding sequence can be deduced there from.

[0085] Applicants have provided herein the polypeptide and/or polynucleotide sequences for use in gene and protein transfer and expression techniques described below. It should be understood, although not always explicitly stated that the sequences provided herein can be used to provide the expression product as well as substantially identical sequences that produce a protein that has the same biological properties. These "biologically equivalent" or "biologically active" polypeptides are encoded by equivalent polynucleotides as described herein. They may possess at least 60%, or alternatively, at least 65%, or alternatively, at least 70%), or alternatively, at least 75%, or alternatively, at least 80%>, or alternatively at least 85%, or alternatively at least 90%, or alternatively at least 95% or alternatively at least 98%, identical primary amino acid sequence to the reference polypeptide when compared using sequence identity methods run under default conditions. Specific polypeptide sequences are provided as examples of particular embodiments. Modifications to the sequences to amino acids with alternate amino acids that have similar charge. Additionally, an equivalent polynucleotide is one that hybridizes under stringent conditions to the reference

polynucleotide or its complement. Alternatively, an equivalent polypeptide or protein is one that is expressed from an equivalent polynucleotide.

[0086] "Hybridization" refers to a reaction in which one or more polynucleotides react to form a complex that is stabilized via hydrogen bonding between the bases of the nucleotide residues. The hydrogen bonding may occur by Watson-Crick base pairing, Hoogstein binding, or in any other sequence-specific manner. The complex may comprise, or alternatively consist essentially of, or yet further consist of two strands forming a duplex structure, three or more strands forming a multi-stranded complex, a single self-hybridizing strand, or any combination of these. A hybridization reaction may constitute a step in a more extensive process, such as the initiation of a PC reaction, or the enzymatic cleavage of a polynucleotide by a ribozyme.

[0087] Examples of stringent hybridization conditions include: incubation temperatures of about 25°C to about 37°C; hybridization buffer concentrations of about 6x SSC to about lOx SSC; formamide concentrations of about 0% to about 25%; and wash solutions from about 4x SSC to about 8x SSC. Examples of moderate hybridization conditions include: incubation temperatures of about 40°C to about 50°C; buffer concentrations of about 9x SSC to about 2x SSC; formamide concentrations of about 30% to about 50%; and wash solutions of about 5x SSC to about 2x SSC. Examples of high stringency conditions include:

incubation temperatures of about 55°C to about 68°C; buffer concentrations of about lx SSC to about O. lx SSC; formamide concentrations of about 55% to about 75%; and wash solutions of about lx SSC, O. lx SSC, or deionized water. In general, hybridization incubation times are from 5 minutes to 24 hours, with 1, 2, or more washing steps, and wash incubation times are about 1, 2, or 15 minutes. SSC is 0.15 M NaCl and 15 mM citrate buffer. It is understood that equivalents of SSC using other buffer systems can be employed. [0088] "Homology" or "identity" or "similarity" refers to sequence similarity between two peptides or between two nucleic acid molecules. Homology can be determined by comparing a position in each sequence which may be aligned for purposes of comparison. When a position in the compared sequence is occupied by the same base or amino acid, then the molecules are homologous at that position. A degree of homology between sequences is a function of the number of matching or homologous positions shared by the sequences. An "unrelated" or "non-homologous" sequence shares less than 40% identity, or alternatively less than 25% identity, with one of the sequences of the present invention.

[0089] A "vector" is defined as any molecule that can carry inserted polynucleotides into a host cell. Examples of vectors are liposomes, micelles, biocompatible polymers, including natural polymers and synthetic polymers; lipoproteins; polypeptides; polysaccharides;

lipopolysaccharides; artificial viral envelopes; metal particles; and bacteria, or viruses, such as baculovirus, adenovirus and retrovirus, bacteriophage, cosmid, plasmid, fungal vectors and other recombination vehicles typically used in the art which have been described for expression in a variety of eukaryotic and prokaryotic hosts, and may be used for gene therapy as well as for simple protein expression.

[0090] A polynucleotide of this invention can be delivered to a cell or tissue using a gene delivery vehicle. "Gene delivery," "gene transfer," "transducing," and the like as used herein, are terms referring to the introduction of an exogenous polynucleotide (sometimes referred to as a "transgene") into a host cell, irrespective of the method used for the introduction. Such methods include a variety of well-known techniques such as vector- mediated gene transfer (by, e.g., viral infection/transfection, or various other protein-based or lipid-based gene delivery complexes) as well as techniques facilitating the delivery of "naked" polynucleotides (such as electroporation, "gene gun" delivery and various other techniques used for the introduction of polynucleotides). The introduced polynucleotide may be stably or transiently maintained in the host cell. Stable maintenance typically requires that the introduced polynucleotide either contains an origin of replication compatible with the host cell or integrates into a replicon of the host cell such as an extrachromosomal replicon (e.g., a plasmid) or a nuclear or mitochondrial chromosome. A number of vectors are known to be capable of mediating transfer of genes to mammalian cells, as is known in the art and described herein. [0091] A "viral vector" is defined as a recombinantly produced virus or viral particle that comprises, or alternatively consists essentially of, or yet further consists of a polynucleotide to be delivered into a host cell, either in vivo, ex vivo or in vitro. Examples of viral vectors include retroviral vectors, adenovirus vectors, adeno-associated virus vectors, alphavirus vectors and the like. Alphavirus vectors, such as Semliki Forest virus-based vectors and Sindbis virus-based vectors, have also been developed for use in gene therapy and immunotherapy. See, Schlesinger and Dubensky (1999) Curr. Opin. Biotechnol. 5:434-439 and Ying, et al. (1999) Nat. Med. 5(7):823-827. In aspects where gene transfer is mediated by a retroviral vector, a vector construct refers to the polynucleotide comprising, or alternatively consisting essentially of, or yet further consisting of the retroviral genome or part thereof, and a therapeutic gene.

[0092] As used herein, "retroviral mediated gene transfer" or "retroviral transduction" carries the same meaning and refers to the process by which a gene or nucleic acid sequences are stably transferred into the host cell by virtue of the virus entering the cell and integrating its genome into the host cell genome. The virus can enter the host cell via its normal mechanism of infection or be modified such that it binds to a different host cell surface receptor or ligand to enter the cell. As used herein, retroviral vector refers to a viral particle capable of introducing exogenous nucleic acid into a cell through a viral or viral-like entry mechanism.

[0093] Retroviruses carry their genetic information in the form of RNA; however, once the virus infects a cell, the RNA is reverse-transcribed into the DNA form which integrates into the genomic DNA of the infected cell. The integrated DNA form is called a provirus.

[0094] In aspects where gene transfer is mediated by a DNA viral vector, such as an adenovirus (Ad) or adeno-associated virus (AAV), a vector construct refers to the

polynucleotide comprising, or alternatively consisting essentially of, or yet further consisting of the viral genome or part thereof, and a transgene. Adenoviruses (Ads) are a relatively well characterized, homogenous group of viruses, including over 50 serotypes. See, e.g.,

International PCT Application No. WO 95/27071. Ads do not require integration into the host cell genome. Recombinant Ad derived vectors, particularly those that reduce the potential for recombination and generation of wild-type virus, have also been constructed. See, International PCT Application Nos. WO 95/00655 and WO 95/11984. Wild-type AAV has high infectivity and specificity integrating into the host cell's genome. See, Hermonat and Muzyczka (1984) Proc. Natl. Acad. Sci. USA 81:6466-6470 and Lebkowski et al. (1988) Mol. Cell. Biol. 8:3988-3996.

[0095] Vectors that contain both a promoter and a cloning site into which a

polynucleotide can be operatively linked are well known in the art. Such vectors are capable of transcribing RNA in vitro or in vivo, and are commercially available from sources such as Stratagene (La Jolla, CA) and Promega Biotech (Madison, WI). In order to optimize expression and/or in vitro transcription, it may be necessary to remove, add or alter 5' and/or 3' untranslated portions of the clones to eliminate extra, potential inappropriate alternative translation initiation codons or other sequences that may interfere with or reduce expression, either at the level of transcription or translation. Alternatively, consensus ribosome binding sites can be inserted immediately 5' of the start codon to enhance expression.

[0096] A "plasmid" is an extra-chromosomal DNA molecule separate from the chromosomal DNA which is capable of replicating independently of the chromosomal DNA. In many cases, it is circular and double-stranded. Plasmids provide a mechanism for horizontal gene transfer within a population of microbes and typically provide a selective advantage under a given environmental state. Plasmids may carry genes that provide resistance to naturally occurring antibiotics in a competitive environmental niche, or alternatively the proteins produced may act as toxins under similar circumstances.

[0097] "Plasmids" used in genetic engineering are called "plasmid vectors". Many plasmids are commercially available for such uses. The gene to be replicated is inserted into copies of a plasmid containing genes that make cells resistant to particular antibiotics and a multiple cloning site (MCS, or polylinker), which is a short region containing several commonly used restriction sites allowing the easy insertion of DNA fragments at this location. Another major use of plasmids is to make large amounts of proteins. In this case, researchers grow bacteria containing a plasmid harboring the gene of interest. Just as the bacterium produces proteins to confer its antibiotic resistance, it can also be induced to produce large amounts of proteins from the inserted gene. This is a cheap and easy way of mass-producing a gene or the protein it then codes for. [0098] The terms "culture" or "culturing" refer to the in vitro propagation of cells or organisms on or in media of various kinds. It is understood that the descendants of a cell grown in culture may not be completely identical {i.e., morphologically, genetically, or phenotypically) to the parent cell.

[0099] "Liposomes" are microscopic vesicles consisting of concentric lipid bilayers. Structurally, liposomes range in size and shape from long tubes to spheres, with dimensions from a few hundred Angstroms to fractions of a millimeter. Vesicle-forming lipids are selected to achieve a specified degree of fluidity or rigidity of the final complex providing the lipid composition of the outer layer. These are neutral (cholesterol) or bipolar and include phospholipids, such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and sphingomyelin (SM) and other types of bipolar lipids including but not limited to dioleoylphosphatidylethanolamine (DOPE), with a hydrocarbon chain length in the range of 14-22, and saturated or with one or more double C=C bonds. Examples of lipids capable of producing a stable liposome, alone, or in combination with other lipid components are phospholipids, such as hydrogenated soy phosphatidylcholine (HSPC), lecithin, phosphatidylethanolamine, lysolecithin, lysophosphatidylethanol-amine,

phosphatidyl serine, phosphatidylinositol, sphingomyelin, cephalin, cardiolipin, phosphatidic acid, cerebrosides, distearoylphosphatidylethan-olamine (DSPE),

dioleoylphosphatidylcholine (DOPC), dipalmitoylphosphatidylcholine (DPPC),

palmitoyloteoylphosphatidylcholine (POPC), palmitoyloleoylphosphatidylethanolamine (POPE) and dioleoylphosphatidylethanolamine 4-(N-maleimido-triethyl)cyclohexane-l- carboxylate (DOPE-mal). Additional non-phosphorous containing lipids that can become incorporated into liposomes include stearylamine, dodecylamine, hexadecylamine, isopropyl myristate, triethanolamine-lauryl sulfate, alkyl-aryl sulfate, acetyl palmitate, glycerol ricinoleate, hexadecyl stereate, amphoteric acrylic polymers, polyethyloxylated fatty acid amides, and the cationic lipids mentioned above (DDAB, DODAC, DMRIE, DMTAP, DOGS, DOTAP (DOTMA), DOSPA, DPTAP, DSTAP, DC-Chol). Negatively charged lipids include phosphatidic acid (PA), dipalmitoylphosphatidylglycerol (DPPG),

dioteoylphosphatidylglycerol and (DOPG), dicetylphosphate that are able to form vesicles. Typically, liposomes can be divided into three categories based on their overall size and the nature of the lamellar structure. The three classifications, as developed by the New York Academy Sciences Meeting, "Liposomes and Their Use in Biology and Medicine,"

December 1977, are multi-lamellar vesicles (MLVs), small uni-lamellar vesicles (SUVs) and large uni-lamellar vesicles (LUVs).

[0100] As used herein the term "apoptotic body" intends the vesicles that are produced when a cell breaks down. Apoptotic bodies consist of cytoplasm with tightly packed organelles with or without a nuclear fragment.

[0101] An extracellular vesicle addressing domain (also referred to herein as an

"exosomal membrane protein" or "exosome addressing domain") is a peptide or a protein that targets other peptides or proteins of interests to the surface of extracellular vesicle, or mediate distribution of other peptides or proteins of interests on extracellular vesicles. Non-limiting examples of such include platelet-derived growth factor receptor (PDGFR), Lam2b, lactadherin C1C2 domain, CD 13 and CD9. Examples of the amino acid sequences of the polypeptides and encoding nucleic acids are provided in the sequence listings of the fusion polypeptides, provided herein. Also intended are biological equivalents of these sequences, wherein a biological equivalent nucleic acid, polynucleotide or oligonucleotide or peptide is one having at least 80 % sequence identity, or alternatively at least 85 % sequence identity, or alternatively at least 90 % sequence identity, or alternatively at least 92 % sequence identity, or alternatively at least 95 % sequence identity, or alternatively at least 97 % sequence identity, or alternatively at least 98 % sequence identity to the reference nucleic acid, polynucleotide, oligonucleotide or peptide. In alternative embodiment, the equivalent or biological equivalent hybridizes to the reference polynucleotide or oligonucleotide or its complement under conditions of high stringency. In a further aspect, the equivalent or biological equivalent is a peptide encoded by a polynucleotide that hybridizes to the polynucleotide encoding the reference peptide or its complement under conditions of high stringency.

[0102] As used herein the term "fused" intends conjugated or joined by a chemical bond, for example a covalent bond.

[0103] As used herein, the term "antigen binding domain" refers to any protein or polypeptide domain that can specifically bind to an antigen target or cell surface receptor. Non-limiting examples include an antibody, an antibody fragment, a single domain antibody, a bispecific antibody, a fragment of a bispecific antibody, an scFv antibody fragment, a heavy chain variable domain (VH), a light chain variable domain (VL). Non-limiting examples of the amino acid sequence and polynucleotides encoding such are provided herein. Also intended within the scope of this disclosure are biological equivalents of the exemplified polypeptide and polynucleotide sequences.

[0104] In one aspect, the antigen binding domain binds to an antigenic determinant or epitope on an immune cell, such as an T cell, NK cell, a CD4+ T cell, a CD8+ T cell, a CD 19+ cell, a CD20+ cell, a macrophage, or a B cell. Non-limiting examples of the amino acid sequence and polynucleotides encoding such are provided herein. Also intended within the scope of this disclosure are biological equivalents of the exemplified polypeptide and polynucleotide sequences.

[0105] As used herein, the terms "antigen binding domain, ""antibody," "antibodies" and "immunoglobulin" includes whole antibodies and any antigen binding fragment or a single chain thereof. Thus the term "antibody" includes any protein or peptide containing molecule that comprises at least a portion of an immunoglobulin molecule. The terms "antibody," "antibodies" and "immunoglobulin" also include immunoglobulins of any isotype, fragments of antibodies which retain specific binding to antigen, including, but not limited to, Fab, Fab', F(ab) ₂ , Fv, scFv, dsFv, Fd fragments, dAb, VH, VL, VhH, and V-NAR domains; minibodies, diabodies, triabodies, tetrabodies and kappa bodies; multi-specific antibody fragments formed from antibody fragments and one or more isolated. Examples of such include, but are not limited to a complementarity determining region (CDR) of a heavy or light chain or a ligand binding portion thereof, a heavy chain or light chain variable region, a heavy chain or light chain constant region, a framework (FR) region, or any portion thereof, at least one portion of a binding protein, chimeric antibodies, humanized antibodies, single-chain antibodies, and fusion proteins comprising, or alternatively consisting essentially of, or yet further consisting of an antigen-binding portion of an antibody and a non-antibody protein. The variable regions of the heavy and light chains of the immunoglobulin molecule contain a binding domain that interacts with an antigen. The constant regions of the antibodies (Abs) may mediate the binding of the immunoglobulin to host tissues.

[0106] "Fusion polypeptide" refers to polypeptides created through the joining of two or more genes that originally coded for separate polypeptides. [0107] The antibodies can be polyclonal, monoclonal, multi-specific (e.g., bispecific antibodies), and antibody fragments, so long as they exhibit the desired biological activity. Antibodies can be isolated from any suitable biological source, e.g., murine, rat, sheep and canine.

[0108] As used herein, "monoclonal antibody" refers to an antibody obtained from a substantially homogeneous antibody population. Monoclonal antibodies are highly specific, as each monoclonal antibody is directed against a single determinant on the antigen. The antibodies may be detectably labeled, e.g., with a radioisotope, an enzyme which generates a detectable product, a fluorescent protein, and the like.

[0109] Monoclonal antibodies may be generated using hybridoma techniques or recombinant DNA methods known in the art. A hybridoma is a cell that is produced in the laboratory from the fusion of an antibody -producing lymphocyte and a non-antibody producing cancer cell, usually a myeloma or lymphoma. A hybridoma proliferates and produces a continuous sample of a specific monoclonal antibody. Alternative techniques for generating or selecting antibodies include in vitro exposure of lymphocytes to antigens of interest, and screening of antibody display libraries in cells, phage, or similar systems.

[0110] The term "human antibody" as used herein, is intended to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. The human antibodies disclosed herein may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo). However, the term "human antibody" as used herein, is not intended to include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences. Thus, as used herein, the term "human antibody" refers to an antibody in which substantially every part of the protein (e.g., CDR, framework, C _L , C _H domains (e.g., C _HI , C _H2 , C _H3 ), hinge, (VL, VH)) is substantially non- immunogenic in humans, with only minor sequence changes or variations. Similarly, antibodies designated primate (monkey, baboon, chimpanzee, etc.), rodent (mouse, rat, rabbit, guinea pig, hamster, and the like) and other mammals designate such species, sub-genus, genus, sub-family, family specific antibodies. Further, chimeric antibodies include any combination of the above. Such changes or variations optionally retain or reduce the immunogenicity in humans or other species relative to non-modified antibodies. Thus, a human antibody is distinct from a chimeric or humanized antibody. It is pointed out that a human antibody can be produced by a non-human animal or prokaryotic or eukaryotic cell that is capable of expressing functionally rearranged human immunoglobulin (e.g., heavy chain and/or light chain) genes. Further, when a human antibody is a single chain antibody, it can comprise, or alternatively consist essentially of, or yet further consist of a linker peptide that is not found in native human antibodies. For example, an Fv can comprise, or alternatively consist essentially of, or yet further consist of a linker peptide, such as two to about eight glycine or other amino acid residues, which connects the variable region of the heavy chain and the variable region of the light chain. Such linker peptides are considered to be of human origin.

[0111] As used herein, a human antibody is "derived from" a particular germline sequence if the antibody is obtained from a system using human immunoglobulin sequences, e.g., by immunizing a transgenic mouse carrying human immunoglobulin genes or by screening a human immunoglobulin gene library. A human antibody that is "derived from" a human germline immunoglobulin sequence can be identified as such by comparing the amino acid sequence of the human antibody to the amino acid sequence of human germline immunoglobulins. A selected human antibody typically is at least 90% identical in amino acids sequence to an amino acid sequence encoded by a human germline immunoglobulin gene and contains amino acid residues that identify the human antibody as being human when compared to the germline immunoglobulin amino acid sequences of other species (e.g., murine germline sequences). In certain cases, a human antibody may be at least 95%, or even at least 96%, 97%, 98%, or 99% identical in amino acid sequence to the amino acid sequence encoded by the germline immunoglobulin gene. Typically, a human antibody derived from a particular human germline sequence will display no more than 10 amino acid differences from the amino acid sequence encoded by the human germline immunoglobulin gene. In certain cases, the human antibody may display no more than 5, or even no more than 4, 3, 2, or 1 amino acid difference from the amino acid sequence encoded by the germline immunoglobulin gene.

[0112] A "human monoclonal antibody" refers to antibodies displaying a single binding specificity which have variable and constant regions derived from human germline immunoglobulin sequences. The term also intends recombinant human antibodies. Methods to making these antibodies are known in the art.

[0113] The term "recombinant human antibody" as used herein, includes all human antibodies that are prepared, expressed, created or isolated by recombinant means, such as antibodies isolated from an animal (e.g., a mouse) that is transgenic or transchromosomal for human immunoglobulin genes or a hybridoma prepared therefrom, antibodies isolated from a host cell transformed to express the antibody, e.g., from a transfectoma, antibodies isolated from a recombinant, combinatorial human antibody library, and antibodies prepared, expressed, created or isolated by any other means that involve splicing of human

immunoglobulin gene sequences to other DNA sequences. Such recombinant human antibodies have variable and constant regions derived from human germline immunoglobulin sequences. In certain embodiments, however, such recombinant human antibodies can be subjected to in vitro mutagenesis (or, when an animal transgenic for human Ig sequences is used, in vivo somatic mutagenesis) and thus the amino acid sequences of the VH and VL regions of the recombinant antibodies are sequences that, while derived from and related to human germline VH and VL sequences, may not naturally exist within the human antibody germline repertoire in vivo. Methods to making these antibodies are known in the art.

[0114] As used herein, chimeric antibodies are antibodies whose light and heavy chain genes have been constructed, typically by genetic engineering, from antibody variable and constant region genes belonging to different species.

[0115] As used herein, the term "humanized antibody" or "humanized immunoglobulin" refers to a human/non-human chimeric antibody that contains a minimal sequence derived from non-human immunoglobulin. For the most part, humanized antibodies are human immunoglobulins (recipient antibody) in which residues from a variable region of the recipient are replaced by residues from a variable region of a non-human species (donor antibody) such as mouse, rat, rabbit, or non-human primate having the desired specificity, affinity and capacity. Humanized antibodies may comprise, or alternatively consist essentially of, or yet further consist of residues that are not found in the recipient antibody or in the donor antibody. The humanized antibody can optionally also comprise, or alternatively consist essentially of, or yet further consist of at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin, a non-human antibody containing one or more amino acids in a framework region, a constant region or a CDR, that have been substituted with a correspondingly positioned amino acid from a human antibody. In general, humanized antibodies are expected to produce a reduced immune response in a human host, as compared to a non-humanized version of the same antibody. The humanized antibodies may have conservative amino acid substitutions which have substantially no effect on antigen binding or other antibody functions. Conservative substitutions groupings include: glycine-alanine, valine-leucine-isoleucine, phenylalanine-tyrosine, lysine-arginine, alanine-valine, serine-threonine and asparagine-glutamine.

[0116] The terms "polyclonal antibody" or "polyclonal antibody composition" as used herein refer to a preparation of antibodies that are derived from different B-cell lines. They are a mixture of immunoglobulin molecules secreted against a specific antigen, each recognizing a different epitope.

[0117] "Small molecular chemotherapy drug" as used herein refers to a drug of less than about 900 daltons in mass useful in the treatment of cancer. Non-limiting examples include taxol, cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicin, doxorubicin, daunorubicin, dihydroxy anthracin dione, mitoxantrone, mithramycin, actinomycin D, 1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol, and puromycin, antimetabolites (such as methotrexate, 6-mercaptopurine, 6-thioguanine, cytarabine, fludarabin, 5- fluorouracil, decarbazine, hydroxyurea, asparaginase, gemcitabinc, cladribine), alkylating agents (such as mechlorethamine, thioepa, chloramhucil, melphalan, carmustine (BSNU), lomustine (CCNU), cyclophosphamide, busulfan, dibromomannitol, streptozotocin, dacarbazine (DTIC), procarbazine, mitomycin C, cisplatin and other platinum derivatives, such as carboplatin), antibiotics (such as dactinomycin (formerly actinomycin), bleomycin, daunorubicin (formerly daunomycin), doxorubicin, idarubicin, mithramycin, mitomycin, mitoxantrone, plicamycin, anthramycin (AMC)), diphtheria toxin and related molecules (such as diphtheria A chain and active fragments thereof and hybrid molecules), ricin toxin (such as ricin A or a deglycosylated ricin A chain toxin), cholera toxin, a Shiga-like toxin (SLT-I, SLT-II, SLT-IIV), LT toxin, C3 toxin, Shiga toxin, pertussis toxin, tetanus toxin, soybean Bowman-Birk protease inhibitor, Pseudomonas exotoxin, alorin, saporin, modeccin, gelanin, abrin A chain, modeccin A chain, alpha-sarcin, Aleurites fordii proteins, dianthin proteins, Phytolacca americanaprotems (PAPI, PAPII, and PAP-S), momordica charantia inhibitor, curcin, crotin, sapaonaria officinalis inhibitor, gelonin, mitogellin, restrietocin, phenomycin, enomycin toxins and mixed toxins.

[0118] As used herein, the term "antibody derivative," or simply "derivative" in reference to an antibody comprises a full-length antibody or a fragment of an antibody, wherein one or more of the amino acids are chemically modified by alkylation, pegylation, acylation, ester formation or amide formation or the like, e.g., for linking the antibody to a second molecule. This includes, but is not limited to, pegylated antibodies, cysteine-pegylated antibodies, and variants thereof.

[0119] A "linker" or "peptide linker" or "linker polypeptide" refers to a peptide sequence linked to either the N-terminus or the C-terminus of a polypeptide sequence. In one aspect, the linker is from about 1 to about 20 amino acid residues long or alternatively 2 to about 10, about 3 to about 5 amino acid residues long. Examples of peptide linkers include

(GGGGS)n, n=0-5 (SEQ ID NO: 2); (GGGS)n, n=0-6 (SEQ ID NO: 3); (GGS)n, n=0-7 (SEQ ID NO: 4); (EAAAK)n, n=0-4 (SEQ ID NO: 5); PSGQAGAAASESLFVSNHAY (SEQ ID NO: 6); and GSTSGSGKPGSGEGS (SEQ ID NO: 7).

[0120] HER2 or human epidermal growth factor receptor 2, is a gene that is known to play a role in the development of breast cancer. The HER2 gene makes HER2 proteins. HER2 proteins are receptors on breast cells. The protein coding sequence of the gene is known in the art, e.g., see genecards.org/cgi-bin/carddisp. pl?gene=ERBB2, last accessed on March 28, 2016. Antibodies and fragments to the HER2 receptor are known in the art.

[0121] The term "EGFR" or "epidermal growth factor receptor" refers to the human protein having a GenBank Gene ID No. 1956 or any mammal homologue. Antibodies and fragments thereof that bind EGFR are known in the art.

[0122] "Isolated" referring to fusion proteins or vesicles, refers to a protein or vesicle that has been isolated, not necessarily purified, from the cell and/or biological matrix in which it was previously contained.

[0123] As used herein, the term "label" intends a directly or indirectly detectable compound or composition that is conjugated directly or indirectly to the composition to be detected or isolated, e.g., N-terminal histidine tags (N-His), HA tag, FLAG tag, 6XHis tag (SEQ ID NO: 1), magnetically active isotopes, e.g., ¹¹⁵ Sn, ¹¹⁷ Sn and ¹¹⁹ Sn, a non-radioactive isotopes such as ¹³ C and ¹⁵ N, polynucleotide or protein such as an antibody so as to generate a "labeled" composition. The term also includes sequences conjugated to the polynucleotide that will provide a signal upon expression of the inserted sequences, such as green fluorescent protein (GFP) and the like. The label may be detectable by itself (e.g., radioisotope labels or fluorescent labels) or, in the case of an enzymatic label, may catalyze chemical alteration of a substrate compound or composition which is detectable. The labels can be suitable for small scale detection or more suitable for high-throughput screening. As such, suitable labels include, but are not limited to magnetically active isotopes, non-radioactive isotopes, radioisotopes, fluorochromes, chemiluminescent compounds, dyes, and proteins, including enzymes. The label may be simply detected or it may be quantified. A response that is simply detected generally comprises a response whose existence merely is confirmed, whereas a response that is quantified generally comprises a response having a quantifiable (e.g., numerically reportable) value such as an intensity, polarization, and/or other property. In luminescence or fluorescence assays, the detectable response may be generated directly using a luminophore or fluorophore associated with an assay component actually involved in binding, or indirectly using a luminophore or fluorophore associated with another (e.g., reporter or indicator) component. Examples of luminescent labels that produce signals include, but are not limited to bioluminescence and chemiluminescence. Detectable luminescence response generally comprises a change in, or an occurrence of a luminescence signal. Suitable methods and luminophores for luminescently labeling assay components are known in the art and described for example in Haugland, Richard P. (1996) Handbook of Fluorescent Probes and Research Chemicals (6 ^th ed). Examples of luminescent probes include, but are not limited to, aequorin and luciferases.

[0124] Examples of suitable fluorescent labels include, but are not limited to, fluorescein, rhodamine, tetramethylrhodamine, eosin, erythrosin, coumarin, methyl-coumarins, pyrene, Malacite green, stilbene, Lucifer Yellow, Cascade Blue™, and Texas Red. Other suitable optical dyes are described in the Haugland, Richard P. (1996) Handbook of Fluorescent Probes and Research Chemicals (6 ^th ed.).

[0125] In another aspect, the fluorescent label is functionalized to facilitate covalent attachment to a cellular component present in or on the surface of the cell or tissue such as a cell surface marker. Suitable functional groups, include, but are not limited to, isothiocyanate groups, amino groups, haloacetyl groups, maleimides, succinimidyl esters, and sulfonyl halides, all of which may be used to attach the fluorescent label to a second molecule. The choice of the functional group of the fluorescent label will depend on the site of attachment to either a linker, the agent, the marker, or the second labeling agent.

[0126] In some aspects, "label" refers to a purification label that aids in the purification of the compound to which it is attached. The label may impart the compound with physical properties supporting its purification through techniques including, but not limited to, affinity chromatography, ion-exchange chromatography, and reverse or regular phase liquid chromatography.

[0127] As used herein, the term "contacting" refers to combining or mixing, in this case a cell with a polynucleotide or a biological sample with a vesicle.

[0128] "Bispecific" refers to a property of an antibody wherein the antibody can simultaneously bind two different types of antigen. "Multi-specific" refers to the binding of more than one type of antigen.

[0129] "Eukaryotic cells" comprise all of the life kingdoms except monera. They can be easily distinguished through a membrane-bound nucleus. Animals, plants, fungi, and protists are eukaryotes or organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. The most characteristic membrane-bound structure is the nucleus. Examples include of a eukaryotic cell include yeast, higher plant, insect and mammalian cells. Non-limiting examples of eukaryotic cells or hosts include mammalian such as simian, bovine, porcine, murine, rat, or human. Also included are avian and reptilian. Additoinal non-limiting examples include Expi293F cells, HeLa cells, HEK293T, MDA- MB-231, immature dendritic cells, and stem cells.

[0130] "Prokaryotic cells" that usually lack a nucleus or any other membrane-bound organelles and are divided into two domains, bacteria and archaea. In addition to

chromosomal DNA, these cells can also contain genetic information in a circular loop called on episome. Bacterial cells are very small, roughly the size of an animal mitochondrion (about 1-2 μπι in diameter and 10 μπι long). Prokaryotic cells feature three major shapes: rod shaped, spherical, and spiral. Instead of going through elaborate replication processes like eukaryotes, bacterial cells divide by binary fission. Examples include but are not limited to Bacillus bacteria, E. coli bacterium, and Salmonella bacterium.

[0131] Non-limiting examples of eukaryotic and prokaryotic cells include bacterial cells, yeast cells, insect cells, animal cells, mammalian cells, murine cells, rat cells, sheep cells, simian cells and human cells. Examples of bacterial cells include Escherichia coli,

Salmonella enterica and Streptococcus gordonii. The cells can be purchased from a commercial vendor such as the American Type Culture Collection (ATCC, Rockville Maryland, USA) or cultured from an isolate using methods known in the art. Examples of suitable eukaryotic cells include, but are not limited to 293T HEK cells, as well as the hamster cell line BHK-21; the murine cell lines designated NIH3T3, NSO, CI 27, the simian cell lines COS, Vero; and the human cell lines HeLa, PER.C6 (commercially available from Crucell) U-937 and Hep G2. A non-limiting example of insect cells include Spodoptera frugiperda. Examples of yeast useful for expression include, but are not limited to

Saccharomyces, Schizosaccharomyces, Hansenula, Candida, Torulopsis, Yarrow ia, or Pichia. See e.g., U.S. Patent Nos. 4,812,405; 4,818,700; 4,929,555; 5,736,383; 5,955,349; 5,888,768 and 6,258,559. Examples of plant cells include grape cells, grapefruit cells, ginger cells and carrot cells. See the web address ncbi.nlm.nih.gov/pmc/articles/PMC4851829; NCT01294072; and NCT01668849.The term "immune effector cells" refers to cells capable of binding an antigen and which mediate an immune response. These cells include, but are not limited to, T cells, B cells, monocytes, macrophages, NK cells and cytotoxic T lymphocytes (CTLs), for example CTL lines, CTL clones, and CTLs from tumor, inflammatory, or other infiltrates. Certain diseased tissue expresses specific antigens and CTLs specific for these antigens have been identified.

[0132] The term "immune effector molecule" as used herein, refers to molecules capable of antigen-specific binding, and includes antibodies, T cell antigen receptors, B cell antigen receptors, and MHC Class I and Class II molecules.

[0133] "Immune response" broadly refers to the antigen-specific responses of lymphocytes to foreign substances. The terms "immunogen" and "immunogenic" refer to molecules with the capacity to elicit an immune response. All immunogens are antigens, however, not all antigens are immunogenic. An immune response disclosed herein can be humoral (via antibody activity) or cell-mediated (via T cell activation). The response may occur in vivo or in vitro. The skilled artisan will understand that a variety of macromolecules, including proteins, nucleic acids, fatty acids, lipids, lipopolysaccharides and polysaccharides have the potential to be immunogenic. The skilled artisan will further understand that nucleic acids encoding a molecule capable of eliciting an immune response necessarily encode an immunogen. The artisan will further understand that immunogens are not limited to full- length molecules, but may include partial molecules. The compositions of this disclosure can be used to induce an immune response in a subject in need thereof by administering an effective amount of the appropriate engineered extracellular vesicle.

[0134] The terms "patient," "subject," or "mammalian subject" are used interchangeably herein and include any mammal in need of the treatment or prophylactic methods described herein (e.g., methods for the treatment or prophylaxis of cancer, hemophilia). Such mammals include, particularly humans (e.g., fetal humans, human infants, human teens, human adults, etc.). Other mammals in need of such treatment or prophylaxis can include non-human mammals such as dogs, cats, or other domesticated animals, horses, livestock, laboratory animals (e.g., lagomorphs, non-human primates, etc.), and the like. The subject may be male or female.

[0135] The term "purified population," relative to naturally occurring vesicles, as used herein refers to plurality of vesicles that have undergone one or more processes of selection for the enrichment or isolation of the desired vesicle population relative to some or all of some other component with which engineered extracellular vesicles are normally found in culture media or in nature. Alternatively, "purified" can refer to the removal or reduction of residual undesired components found in the conditioned media (e.g., cell debris, soluble proteins, etc.). A "highly purified population" as used herein, refers to a population of vesicles in which at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99% or 100% of cell debris and soluble proteins (e.g., proteins derived from fetal bovine serum and the like) in the conditioned media along with the cell-derived vesicles are removed.

[0136] The terms "treatment," "treat," "treating," etc. as used herein, include but are not limited to, alleviating a symptom of a disease or condition (e.g., cancer) or a condition associated with cancer and/or reducing, suppressing, inhibiting, lessening, ameliorating or affecting the progression, severity, and/or scope of the disease or condition. "Treatments" refer to one or both of therapeutic treatment and can separately relate to prophylactic or preventative measures as desired. Prevention may not be obtainable for certain diseased or conditions and for those conditions, prevention is excluded from the term treatment. In one aspect, prevention is excluded from the terms "treatment, treat, or treating." Subjects in need of treatment include those already affected by a disease or disorder or undesired

physiological condition as well as those in which the disease or disorder or undesired physiological condition is to be prevented.

[0137] The phrase "first line" or "second line" or "third line" refers to the order of treatment received by a patient. First line therapy regimens are treatments given first, whereas second or third line therapy are given after the first line therapy or after the second line therapy, respectively. The National Cancer Institute defines first line therapy as "the first treatment for a disease or condition. In patients with cancer, primary treatment can be surgery, chemotherapy, radiation therapy, or a combination of these therapies. First line therapy is also referred to those skilled in the art as "primary therapy and primary treatment." See National Cancer Institute website at www.cancer.gov, last visited on May 1, 2008.

Typically, a patient is given a subsequent chemotherapy regimen because the patient did not show a positive clinical or sub-clinical response to the first line therapy or the first line therapy has stopped.

[0138] As described in more detail below, the engineered vesicles can contain

chemotherapeutic agents. The following are non-limiting examples of such. Cetuximab (FMC-C225) is marketed under the name Erbitux®. Cetuximab is a chimeric (mouse/human) monoclonal antibody, an epidermal growth factor receptor (EGFR) inhibitor, given by intravenous injection for treatment of metastatic colorectal cancer and head and neck cancer. Cetuximab is manufactured and distributed in North America by ImClone and Bristol-Myers Squibb, while in the rest of the world distribution is by Merck KGaA. In one aspect, an equivalent of cetuximab is an antibody directed to EGFR, or a small molecule targeting EGFR or inhibiting EGFR. In another aspect, an equivalent of cetuximab may also include homologs of cetuximab, mutant cetuximab, recombinant cetuximab that retains substantially the same function of cetuximab. Panitumumab (INN), formerly ABX-EGF, is a fully human monoclonal antibody specific to the epidermal growth factor receptor. Panitumumab is manufactured by Amgen and marketed as Vectibix. In one aspect, an equivalent of panitumumab is an antibody directed to EGFR, or a small molecule targeting EGFR or inhibiting EGFR. In another aspect, an equivalent of panitumumab may also include homologs of panitumumab, mutant panitumumab, recombinant panitumumab that retains substantially the same function of panitumumab. Irinotecan (CPT-11) is sold under the trade name of Camptosar®. It is a semi -synthetic analogue of the alkaloid camptothecin, which is activated by hydrolysis to SN-38 and targets topoisomerase I. Chemical equivalents are those that inhibit the interaction of topoisomerase I and DNA to form a catalytically active topoisomerase I-DNA complex. Chemical equivalents inhibit cell cycle progression at G2-M phase resulting in the disruption of cell proliferation. An equivalent of irinotecan is a composition that inhibits a topoisomerase. Non-limiting examples of an equivalent of irinotecan include topotecan, camptothecin and lamellarin D, etoposide, or doxorubicin. Oxaliplatin (trans-/-diaminocyclohexane oxalatoplatinum; L-OUP; CAS No. 61825-94-3) is sold under the trade name of Elotaxin. It is a platinum derivative that causes cell

cytotoxicity. Oxaliplatin forms both inter- and intra-strand cross links in DNA, which prevent DNA replication and transcription, causing cell death. Non-limiting examples of an equivalent of oxaliplatin include carboplatin and cisplatin. Topoisomerase inhibitors are agents designed to interfere with the action of topoisomerase enzymes (topoisomerase I and II), which are enzymes that control the changes in DNA structure by catalyzing the breaking and rejoining of the phosphodiester backbone of DNA strands during the normal cell cycle. In one aspect, topoisomerase inhibitors include irinotecan, topotecan, camptothecin and lamellarin D, or compounds targeting topoisomerase IA. In another aspect, topoisomerase inhibitors include etoposide, doxorubicin or compounds targeting topoisomerase II.

Pyrimidine antimetabolite includes, without limitation, fluorouracil (5-FU), its equivalents and prodrugs. In one embodiment, a pyrimidine antimetabolite is a chemical that inhibits the use of a pyrimidine. The presence of antimetabolites can have toxic effects on cells, such as halting cell growth and cell division, so these compounds can be used as chemotherapy for cancer. Fluorouracil (5-FU) belongs to the family of therapy drugs called pyrimidine based anti-metabolites. It is a pyrimidine analog, which is transformed into different cytotoxic metabolites that are then incorporated into DNA and RNA thereby inducing cell cycle arrest and apoptosis. Chemical equivalents are pyrimidine analogs which result in disruption of DNA replication. Chemical equivalents inhibit cell cycle progression at S phase resulting in the disruption of cell cycle and consequently apoptosis. Equivalents to 5-FU include prodrugs, analogs and derivative thereof such as 5'-deoxy-5-fluorouridine (doxifluroidine), 1- tetrahydrofuranyl-5-fluorouracil (ftorafur), Capecitabine (Xeloda), S-l (MBMS-247616, consisting of tegafur and two modulators, a 5-chloro-2,4-dihydroxypyridine and potassium oxonate), ralititrexed (tomudex), nolatrexed (Thymitaq, AG337), LY231514 and ZD9331, as described for example in Papamicheal (1999) The Oncologist 4:478-487. "5-FU based adjuvant therapy" refers to 5-FU alone or alternatively the combination of 5-FU with other treatments, that include, but are not limited to radiation, methyl-CCNU, leucovorin, oxaliplatin, irinotecin, mitomycin, cytarabine, levamisole. Specific treatment adjuvant regimens are known in the art as FOLFOX, FOLFOX4, FOLFIRI, MOF (semustine (methyl- CCNU), vincrisine (Oncovin) and 5-FU). For a review of these therapies see Beaven and Goldberg (2006) Oncology 20(5):461-470. An example of such is an effective amount of 5- FU and Leucovorin. Other chemotherapeutics can be added, e.g., oxaliplatin or irinotecan. Capecitabine is a prodrug of (5-FU) that is converted to its active form by the tumor-specific enzyme PynPase following a pathway of three enzymatic steps and two intermediary metabolites, 5'-deoxy-5-fluorocytidine (5'-DFCR) and 5'-deoxy-5-fluorouridine (5'-DFUR). Capecitabine is marketed by Roche under the trade name Xeloda®. A therapy comprising, or alternatively consisting essentially of, or yet further consisting of a pynmidine

antimetabolite includes, without limitation, a pynmidine antimetabolite alone or alternatively the combination of a pynmidine antimetabolite with other treatments, that include, but are not limited to, radiation, methyl-CCNU, leucovorin, oxaliplatin, irinotecin, mitomycin, cytarabine, levamisole. Specific treatment adjuvant regimens are known in the art as

FOLFOX, FOLFOX4, FOLFOX6, FOLFIRI, MOF (semustine (methyl-CCNU), vincrisine (Oncovin) and 5-FU). For a review of these therapies see Beaven and Goldberg (2006) Oncology 20(5):461-470. An example of such is an effective amount of 5-FU and

Leucovorin. Other chemotherapeutics can be added, e.g., oxaliplatin or irinotecan. FOLFIRI is a chemotherapy regimen for treatment of colorectal cancer. It is made up of the following drugs: FOL - folinic acid (leucovorin), a vitamin B derivative used as a "rescue" drug for high doses of the drug methotrexate and that modulates/potentiates/reduces the side effects of fluorouracil; 5 - fluorouracil (5-FU), a pyrimidine analog and antimetabolite which incorporates into the DNA molecule and stops synthesis; and IRI - irinotecan (Camptosar), a topoisom erase inhibitor, which prevents DNA from uncoiling and duplicating. FOLFOX is a chemotherapy regimen for treatment of colorectal cancer, is made up of the following drugs: FOL - folinic acid (leucovorin), 5 - fluorouracil (5-FU), and OX- oxaliplatin. FOLFOXFIRI is a chemotherapy regimen for treatment of colorectal cancer, is made up of the following drugs: FOL - folinic acid (leucovorin), 5 - fluorouracil (5-FU), OX- oxaliplatin and IRI - irinotecan (Camptosar).

[0139] As used herein, the term "microRNAs" or "miRNAs" refers to post- transcriptional regulators that typically bind to complementary sequences in the three prime untranslated regions (3' UTRs) of target messenger RNA transcripts (mRNAs), usually resulting in gene silencing. Typically, miRNAs are short, non-coding ribonucleic acid (RNA) molecules, for example, 21 or 22 nucleotides long. The terms "microRNA" and "miRNA" are used interchangeably.

[0140] In one aspect, the therapeutic agent is a short interfering RNA, also known as siRNA. Methods to prepare and screen interfering RNA and select for the ability to block polynucleotide expression are known in the art and non-limiting examples of which are shown below. These interfering RNA are provided by this invention alone or in combination with a suitable vector or within a host cell. Compositions containing the RNAi are further provided. RNAi is useful to knock-out or knock-down select functions in a cell or tissue as known in the art.

[0141] siRNA sequences can be designed by obtaining the target mRNA sequence and determining an appropriate siRNA complementary sequence. siRNAs of the invention are designed to interact with a target sequence, meaning they complement a target sequence sufficiently to hybridize to that sequence. An siRNA can be 100% identical to the target sequence. However, homology of the siRNA sequence to the target sequence can be less than 100%) as long as the siRNA can hybridize to the target sequence. Thus, for example, the siRNA molecule can be at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100%) identical to the target sequence or the complement of the target sequence. Therefore, siRNA molecules with insertions, deletions or single point mutations relative to a target may also be used. The generation of several different siRNA sequences per target mRNA is recommended to allow screening for the optimal target sequence. A homology search, such as a BLAST search, should be performed to ensure that the siRNA sequence does not contain homology to any known mammalian gene. In one aspect, the targets of the siRNA is of the group of anti-PDl, anti-PDL2 and anti-CTLA4.

[0142] Researchers have determined that certain characteristics are common in siRNA molecules that effectively silence their target gene (Duxbury (2004) J. Surgical Res. 1 17:339- 344; Ui-Tei et al. (2004) Nucl. Acids Res. 32:936-48). As a general guide, siRNAs that include one or more of the following conditions are particularly useful in gene silencing in mammalian cells: GC ratio of between 45-55%, no runs of more than 9 G/C residues, G/C at the 5' end of the sense strand; A/U at the 5' end of the antisense strand; and at least 5 A/U residues in the first 7 bases of the 5 ' terminal of the antisense strand.

[0143] siRNA are, in general, from about 10 to about 30 nucleotides in length. For example, the siRNA can be 10-30 nucleotides long, 12-28 nucleotides long, 15-25 nucleotides long, 19-23 nucleotides long, or 21-23 nucleotides long. When an siRNA contains two strands of different lengths, the longer of the strands designates the length of the siRNA. In this situation, the unpaired nucleotides of the longer strand would form an overhang.

[0144] The term siRNA includes short hairpin RNAs (shRNAs). shRNAs comprise a single strand of RNA that forms a stem-loop structure, where the stem consists of the complementary sense and antisense strands that comprise a double-stranded siRNA, and the loop is a linker of varying size. The stem structure of shRNAs generally is from about 10 to about 30 nucleotides long. For example, the stem can be 10-30 nucleotides long, 12-28 nucleotides long, 15-25 nucleotides long, 19-23 nucleotides long, or 21-23 nucleotides long.

[0145] Tools to assist siRNA design are readily available to the public. For example, a computer-based siRNA design tool is available on the internet at www.dharmacon.com, last accessed on November 26, 2007.

[0146] As used herein, the term "homogeneous" in reference to a population of engineered vesicles refers to population of vesicles that have the same identify or a similar amount of one or more antigen binding domain(s) and/or payload. A homogenous population is one wherein about 65%>, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%), about 98%), or 100% of the vesicles share the one or more antigen binding domain(s) and/or payload. [0147] As used herein, the term "heterogeneous" in reference to a population of engineered vesicles refers to population of vesicles that have differing identity or differing amount of one or more antigen binding domain(s) and/or payload.

[0148] As used herein, the term "pharmaceutically acceptable carrier" refers to any of the standard pharmaceutical carriers such as sterile solutions, tablets, coated tablets, and capsules. Typically such carriers contain excipients such as starch, milk, sugar, certain types of clay, gelatin, stearic acids or salts thereof, magnesium or calcium stearate, talc, vegetable fats or oils, gums, glycols, or other known excipients. Such carriers may also include flavor and color additives or other ingredients. Examples of pharmaceutically acceptable carriers include, but are not limited to, the following: water, saline, buffers, inert, nontoxic solids (e.g., mannitol, talc). Compositions comprising, or alternatively consisting essentially of, or yet further consisting of such carriers are formulated by well-known conventional methods. Depending on the intended mode of administration and the intended use, the compositions may be in the form of solid, semi-solid, or liquid dosage forms, such, for example, as powders, granules, crystals, liquids, suspensions, liposomes, pastes, creams, salves, etc., and may be in unit-dosage forms suitable for administration of relatively precise dosages.

[0149] An "effective amount" intends an amount sufficient to effect beneficial or desired results. An effective amount can be administered in one or more administrations, applications or dosages. Such delivery is dependent on a number of variables including the time period for which the individual dosage unit is to be used, the bioavailability of the therapeutic agent, the route of administration, etc. It is understood, however, that specific dose levels of the therapeutic agents of the present invention for any particular subject depends upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, and diet of the subject, the time of administration, the rate of excretion, the drug combination, and the severity of the particular disorder being treated and form of administration. Treatment dosages generally may be titrated to optimize safety and efficacy. Typically, dosage-effect relationships from in vitro and/or in vivo tests initially can provide useful guidance on the proper doses for patient administration. In general, one will desire to administer an amount of the compound that is effective to achieve a serum level commensurate with the concentrations found to be effective in vitro.

Determination of these parameters is well within the skill of the art. These considerations, as well as effective formulations and administration procedures are well known in the art and are described in standard textbooks.

[0150] As used herein, the term "vector" refers to a non-chromosomal nucleic acid comprising, or alternatively consisting essentially of, or yet further consisting of an intact replicon such that the vector may be replicated when placed within a cell, for example by a process of transformation. Vectors may be viral or non-viral. Viral vectors include plasmids, retroviruses, lentiviruses, adenoviruses, herpesvirus, bacculoviruses, modified

bacculoviruses, papovirus, or otherwise modified naturally occurring viruses. Exemplary non-viral vectors for delivering nucleic acid include naked DNA; DNA complexed with cationic lipids, alone or in combination with cationic polymers; anionic and cationic liposomes; DNA-protein complexes and particles comprising, or alternatively consisting essentially of, or yet further consisting of DNA condensed with cationic polymers such as heterogeneous polylysine, defined-length oligopeptides, and polyethylene imine, in some cases contained in liposomes; and the use of ternary complexes comprising, or alternatively consisting essentially of, or yet further consisting of a virus and polylysine-DNA.

[0151] A "viral vector" is defined as a recombinantly produced virus or viral particle that comprises a polynucleotide to be delivered into a cell, either in vivo, ex vivo or in vitro.

Examples of viral vectors include retroviral vectors, lentiviral vectors, adenovirus vectors, adeno-associated virus vectors, alphavirus vectors and the like. Alphavirus vectors, such as Semliki Forest virus-based vectors and Sindbis virus-based vectors, have also been developed for use in gene therapy and immunotherapy. See, Schlesinger and Dubensky (1999) Curr. Opin. Biotechnol. 5:434-439 and Ying, et al. (1999) Nat. Med. 5(7):823-827.

[0152] Extracellular cell-derived vesicles, also referred to as extracellular vesicles, are membrane surrounded structures that are released by cells in vitro and in vivo. Extracellular vesicles can contain proteins, lipids, and nucleic acids and can mediate intercellular communication between different cells, including different cell types, in the body. Two types of extracellular vesicles are exosomes and microvesicles. Exosomes range in size from approximately 30 nm to about 200 nm. Exosomes are released from a cell by fusion of multivesicular endosomes (MVE) with the plasma membrane. Microvesicles, on the other hand, are released from a cell upon direct budding from the plasma membrane (PM). Microvesicles are typically larger than exosomes and range from approximately 100 nm to 1 μιη. Also intended within this term are liposomes and apoptotic bodies.

Modes for Carrying Out the Disclosure

[0153] This disclosure provides an isolated engineered extracellular vesicle comprising, or alternatively consisting essentially of, or yet further consisting of one or more antigen binding domain(s) fused to an extracellular vesicle addressing domain (also termed as an exosomal membrane protein) expressed on the surface of the vesicle. FIGS. 1A, IB, 3 and 4A schematically show the general structures of the engineered extracellular vesicles. The extracellular vesicles can be one or more of an exosome, a liposome, a microvesicle, and an apoptotic body. In one aspect, the extracellular vesicle is an exosome and the diameter is from about 30 nm to 300 nm. In one aspect the vesicle further comprises, or alternatively consists essentially of, or yet further consists of a purification and/or a detectable label. Examples of such are described herein, e.g., HA, FLAG and 6xHis (SEQ ID NO: 1).

[0154] The vesicles can be isolated from a eukaryotic or a prokaryotic cell. Examples of eukaryotic cells are a mammalian cell, a yeast cell or a plant cell. An example of a prokaryotic cell is a bacterial cell. Non-limiting examples include Expi293F cells, HeLa cells, HEK293T, MDA-MB-231, immature dendritic cells, and stem cells.

[0155] In one aspect, the one or more antigen binding domains are the same or different. FIG. 1A shows an engineered vesicle have all the same antigen binding domains. FIG. IB shows an engineered vesicle wherein the antigen binding domains that are different (2 non- identical scFv antibodies). The one or more antigen binding domains are selected from the group of: an antibody, a multi-specific antibody, a monoclonal antibody, an antibody derivative, an antibody fragment, a multi-specific antibody fragment, an scFv antibody fragment, a single domain antibody, a bispecific antibody, or a bispecific antibody fragment, a VH domain, a VL domain, and these are non-limited by species. In one aspect the antibody, fragment, or derivative is from a human antibody or a humanized antibody. The antigen binding domains can also be murine, bovine, ovine or human or from any other appropriate species. In one aspect, the antibody is a monoclonal antibody, a derivative, or a fragment thereof. In another aspect, the antibody, derivative or fragment thereof is a human antibody, a humanized antibody or a derivative of each thereof. [0156] Non-limiting examples of antibodies and fragments and derivatives thereof that are used for the antigen binding domains are of the group of antibodies: anti-HER2; anti- HER3; anti-EGFR; anti-CD3; anti-CD 16; anti-CD4; anti-CD8; anti-CD 11a; anti-CD 19; anti- CD20; anti-CD25; anti-CD33; anti-CD40; anti-CD40L; anti-CD70; anti-CD 123; anti- EpCAM; anti-CLL-1; anti-CTLA-4; anti-PD-1; anti-PD-Ll ; anti-OX40; anti-GITR; anti- ICOS; anti-B7-H3; anti-B7-H4; anti-LAG3; anti-TIM3; anti-PSMA; anti-factor IXa; anti- factor X; and anti-folate receptor, fragments and derivatives thereof.

[0157] In one aspect, the vesicle contains more than one antigen binding domains fused to the vesicle and the plurality of the domains are identical to each other, see for example FIG. 1A. In another aspect, the vesicle comprises, or alternatively consists essentially of, or yet further consists of more than one antigen binding domains fused to the vesicle, and wherein at least two of the plurality of the domains are different from each other, as shown for example in FIG. IB. In a further aspect, the antigen binding domain contains a bispecific antibody that binds to independent and distinct targets (see, e.g., FIGS. 1A and 3).

[0158] The antigen binding domains are selected to specifically recognize and bind an antigen of the group of: a tumor antigen; a cancer antigen; an antigen expressed on an immune cell; an antigen expressed on an immune effector cell; an activated coagulation factor IX; factor X; PDl; PDLl; CTLA4; and an antigen involved in immune regulation of a cell from the group of: a T cell, a macrophage, a NK cell, CD4+ T cell, CD8+ T cell, CD 19+ cell, CD20+ cell, and a B cell, or a checkpoint inhibitor, e.g., PDLl, CTLA-4, B7-H3, B7- H4, LAG3, PDl, TIM-3, or a checkpoint activator, e.g. CD40, OX40, GITR, ICOS. In a further aspect, the antigen binding domain specifically recognizes and binds a cancer antigen that can be selected from the groups of breast cancer, lung cancer, colorectal cancer, kidney cancer, prostate cancer, brain cancer, pancreatic cancer, a solid malignant cancer or a blood cancer. In a further aspect, the cancer is a breast cancer or a colorectal cancer, and the antigen binding domain specifically recognizes and binds HER2 or EGFR. Additional non- limiting examples of antibodies and fragments and derivatives thereof are of the group of antibodies: anti-HER3; anti-CD3; anti-CD16; anti-CD4; anti-CD8; anti-CDl la; anti-CD19; anti-CD20; anti-CD25; anti-CD33; anti-CD40; anti-CD40L; anti-CD70; anti-CD 123; anti- EpCAM; anti-CLL-1; anti-CTLA-4; anti-PD-1; anti-PD-Ll ; anti-OX40; anti-GITR; anti- ICOS; anti-B7-H3; anti-B7-H4; anti-LAG3; anti-TIM3; anti-PSMA; anti-factor IXa; anti- factor X; anti-folate receptor, and fragments and derivatives thereof. Antibodies and fragments thereof directed to HER2 and EGFR are known in the art and commercially available. Exemplary amino acid sequences of these antigen binding domain are provided below in the sequences of exemplary fusion polypeptides. Biological equivalents of such polypeptides are also within the scope of this disclosure.

[0159] In a further aspect, the engineered vesicle comprises, or alternatively consists essentially of, or yet further consists of more than one antigen binding domain that are different, and wherein a first plurality of antigen binding domains selectively recognize and bind a tumor or cancer associated antigen and a second plurality of antigen binding domains recognize an antigen expressed on an immune cell. Non-limiting examples of cancer antigens are selected from the group of breast cancer, lung cancer, colorectal cancer, kidney cancer, prostate cancer, brain cancer, pancreatic cancer, a solid malignant cancer or a blood cancer and the antigen expressed on an immune cell is selected from the group of a T cell, a macrophage, a NK cell, CD4+ T cell, CD8+ T cell, CD 19+ cell, CD20+ cell, and a B cell. In a specific embodiment, the cancer is a breast cancer or a colorectal cancer, and the antigen binding domain is specific to the HER2 or EGFR cell surface receptors. Non-limiting examples of antibodies and fragments and derivatives thereof are of the group of antibodies: anti-HER2; anti-HER3; anti-EGFR; anti-CD3; anti-CD 16; anti-CD4; anti-CD8; anti-CDl la; anti-CD 19; anti-CD20; anti-CD25; anti-CD33; anti-CD40; anti-CD40L; anti-CD70; anti- CD 123; anti-EpCAM; anti-CLL-1 ; anti-CTLA-4; anti-PD-1 ; anti-PD-Ll ; anti-OX40; anti- GITR; anti-ICOS; anti-B7-H3; anti-B7-H4; anti-LAG3; anti-TIM3; anti-PSMA; anti-factor IXa; anti-factor X; anti-folate receptor, and fragments and derivatives thereof. In a further aspect, the antigen binding domain is specific to the HER2 or EGFR cell surface receptors and the antigen binding domain specific to an immune cell is a CD3+ T cell or an CD 16+ (NK cell). FIG. 4 depicts this embodiment.

[0160] The vesicle also comprises, or alternatively consists essentially of, or yet further consists of an extracellular vesicle addressing domain (also referred to herein as an exosomal membrane protein). Non-limiting examples of such include platelet-derived growth factor receptor (PDGFR), Lam2b, lactadherin C1C2 domain, CD 13 and CD9. Examples of the amino acid sequences of the polypeptides and encoding nucleic acids are provided in the sequence listings of the fusion polypeptides, provided herein. Biological equivalents of these sequences are within the scope of this disclosure.

[0161] The vesicles can further comprise, or alternatively consist essentially of, or yet further consist of located N- or C-terminal to the antigen binding domains one or more linker polypeptide. Non-limiting examples of such include (GGGGS)n, n=0-5 (SEQ ID NO: 2); (GGGS)n, n=0-6 (SEQ ID NO: 3); (GGS)n, n=0-7 (SEQ ID NO: 4); (EAAAK)n, n=0-4 (SEQ ID NO: 5); PSGQAGAAASESLFVSNHAY (SEQ ID NO: 6) and GSTSGSGKPGSGEGS (SEQ ID NO: 7); and equivalents of each thereof.

[0162] The vesicles can also comprise, or alternatively consist essentially of, or yet further consist of a detectable label and/or purification tag (or label) for imaging or purification. Examples of such are provided infra, e.g., HA, FLAG and 6XHis tags (SEQ ID NO: 1).

[0163] In yet further aspect, the vesicles comprise, or alternatively consist essentially of, or yet further consist of a myc polypeptide or protein, or an equivalent of each thereof.

Exemplary sequences are provided herein.

[0164] As depicted in FIGS. 1A, IB, 3 and 4, in one aspect the vesicles further comprise, or alternatively consist essentially of, or yet further consist of an effective amount of a therapeutic agent or "payload." Non-limiting examples of therapeutic agents are selected from a small molecular immune checkpoint modulators, a small molecular chemotherapy drug, an RNA-based therapeutic (siRNA, or miRNA), a therapeutic protein, a therapeutic peptide, an immune regulatory factor, an immune checkpoint inhibitor, an immune agonist, anti- PD1 siRNA, anti-PDLl siRNA, anti-CTLA4 siRNA, an inhibitor of indoleamine- pyrrole 2,3 -di oxygenase (IDO), GDC-0919, an indoximod, an agonist of Toll-like receptors (TLR) TLRs, Motolimod, and Resiquimod. Additional examples are provided herein.

[0165] One or more therapeutic agent can be encapsulated in the vesicle, examples of such are disclosed herein. In one aspect, the more than one therapeutic agent is selected to target both tumor cell and tumor stroma cells in a solid tumor for synergistic anti-tumor effect. In another aspect, the more than one therapeutic agents are selected to block two immune checkpoint inhibitors simultaneously. Examples of immune checkpoint inhibitors are anti-PDLl siRNA and anti-CTLA4 siRNA. Antibodies, Antigen Binding Fragments and Methods of Production

[0166] In some aspects, antigen binding fragments (antibodies, fragments and derivatives thereof as described herein) are known in the art or commercially available. However, it may be necessary to produce the antigen binding fragment that is selective for the target. The following description describes techniques known in the art for such production.

[0167] Antibodies can be generated using conventional techniques known in the art and are well-described in the literature. Several methodologies exist for production of polyclonal antibodies. For example, polyclonal antibodies are typically produced by immunization of a suitable mammal such as, but not limited to, chickens, goats, guinea pigs, hamsters, horses, mice, rats, and rabbits. An antigen is injected into the mammal, induces the B-lymphocytes to produce immunoglobulins specific for the antigen. Immunoglobulins may be purified from the mammal's serum.

[0168] Variations of this methodology include modification of adjuvants, routes and site of administration, injection volumes per site and the number of sites per animal for optimal production and humane treatment of the animal. For example, adjuvants typically are used to improve or enhance an immune response to antigens. Most adjuvants provide for an injection site antigen depot, which allows for a stow release of antigen into draining lymph nodes. Other adjuvants include surfactants which promote concentration of protein antigen molecules over a large surface area and immunostimulatory molecules. Non-limiting examples of adjuvants for polyclonal antibody generation include Freund's adjuvants, Ribi adjuvant system, and Titermax. Polyclonal antibodies can be generated using methods known in the art some of which are described in U.S. Pat. Nos. 7,279,559; 7,119, 179; 7,060,800; 6,709,659; 6,656,746; 6,322,788; 5,686,073; and 5,670,153.

[0169] Monoclonal antibodies can be generated using conventional hybridoma techniques known in the art and well-described in the literature. For example, a hybridoma is produced by fusing a suitable immortal cell line (e.g., a myeloma cell line such as, but not limited to, Sp2/0, Sp2/0-AG14, NSO, NS1, NS2, AE-1, L.5, P3X63Ag8,653, Sp2 SA3, Sp2 MAI, Sp2 SSI, Sp2 SA5, U397, MIA 144, ACT IV, MOLT4, DA-1, JURKAT, WEHI, K-562, COS, RAJI, NIH 313, HL-60, MLA 144, NAM AIWA, NEURO 2A, CHO, PerC.6, YB2/0) or the like, or heteromyelomas, fusion products thereof, or any cell or fusion cell derived there from, or any other suitable cell line as known in the art (see, those at the following web addresses, e.g., atcc.org, lifetech.com, last accessed on Nov. 26, 2007), with antibody producing cells, such as, but not limited to, isolated or cloned spleen, peripheral blood, lymph, tonsil, or other immune or B cell containing cells, or any other cells expressing heavy or light chain constant or variable or framework or CDR sequences, either as endogenous or heterologous nucleic acid, as recombinant or endogenous, viral, bacterial, algal, prokaryotic, amphibian, insect, reptilian, fish, mammalian, rodent, equine, ovine, goat, sheep, primate, eukaryotic, genomic DNA, cDNA, rDNA, mitochondrial DNA or RNA, chloroplast DNA or RNA, hnRNA, mRNA, tRNA, single, double or triple stranded, hybridized, and the like or any combination thereof. Antibody producing cells can also be obtained from the peripheral blood or, in particular embodiments, the spleen or lymph nodes, of humans or other suitable animals that have been immunized with the antigen of interest and then screened for the activity of interest. Any other suitable host cell can also be used for expressing-heterologous or endogenous nucleic acid encoding an antibody, specified fragment or variant thereof, of the present disclosure. The fused cells (hybridomas) or recombinant cells can be isolated using selective culture conditions or other suitable known methods, and cloned by limiting dilution or cell sorting, or other known methods.

[0170] Other suitable methods of producing or isolating antibodies of the requisite specificity can be used, including, but not limited to, methods that select recombinant antibody from a peptide or protein library (e.g., but not limited to, a bacteriophage, ribosome, oligonucleotide, cDNA, or the like, display library; e.g., as available from various commercial vendors such as MorphoSys (Martinsreid/Planegg, Del.), Biolnvent (Lund, Sweden), Affitech (Oslo, Norway) using methods known in the art. Art known methods are described in the patent literature some of which include U.S. Pat. Nos. 4,704,692; 5,723,323; 5,763,192; 5,814,476; 5,817,483; 5,824,514; and 5,976,862. Alternative methods rely upon immunization of transgenic animals (e.g., SCID mice, Nguyen et al. (1977) Microbiol.

Immunol. 41 :901-907 (1997); Sandhu et al. (1996) Crit, Rev. Biotechnol. 16:95-118; Eren et al. (1998) Mumma 93 : 154-161 that are capable of producing a repertoire of human antibodies, as known in the art and/or as described herein. Such techniques, include, but are not limited to, ribosome display Wanes et al. (1997) Proc. Natl. Acad. Sci. USA 94:4937- 4942; Hanes et al. (1998) Proc. Natl. Acad. Sci. USA 95: 14130-14135); single cell antibody producing technologies (e.g., selected lymphocyte antibody method ("SLAM") (U.S. Pat. No. 5,627,052; Wen et al. (1987) J. Immunol 17:887-892; Babcook et al. (1996) Proc. Natl. Acad. Sci. USA 93 :7843-7848); gel microdroplet and flow cytometry (Powell et al. (1990)

Biotechnol. 8:333-337; One Cell Systems, (Cambridge, Mass.); Gray et al. (1995) J. Imm. Meth. 182: 155-163; and Kenny et al. (1995) Bio. Technol. 13 :787-790); B-cell selection (Steenbakkers et al. (1994) Molec. Biol. Reports 19: 125-134).

[0171] Antibody derivatives of the present disclosure can also be prepared by delivering a polynucleotide encoding an antibody disclosed herein to a suitable host such as to provide transgenic animals or mammals, such as goats, cows, horses, sheep, and the like, that produce such antibodies in their milk. These methods are known in the art and are described for example in U.S. Pat. Nos. 5,827,690; 5,849,992; 4,873,316; 5,849,992; 5,994,616; 5,565,362; and 5,304,489.

[0172] The term "antibody derivative" includes post-translational modification to linear polypeptide sequence of the antibody or fragment. For example, U.S. Pat. No. 6,602,684 Bl describes a method for the generation of modified glycol-forms of antibodies, including whole antibody molecules, antibody fragments, or fusion proteins that include a region equivalent to the Fc region of an immunoglobulin, having enhanced Fe-mediated cellular toxicity, and glycoproteins so generated.

[0173] The antibodies disclosed herein also include derivatives that are modified by the covalent attachment of any type of molecule to the antibody such that covalent attachment does not prevent the antibody from generating an anti-idiotypic response. Antibody derivatives include, but are not limited to, antibodies that have been modified by

glycosylation, acetylation, pegylation, phosphorylation, amidation, derivatization by known protecting/blocking groups, proteolytic cleavage, linkage to a cellular ligand or other protein, etc. Additionally, the derivatives may contain one or more non-classical amino acids.

[0174] Antibody derivatives also can be prepared by delivering a polynucleotide disclosed herein to provide transgenic plants and cultured plant cells (e.g., but not limited to tobacco, maize, and duckweed) that produce such antibodies, specified portions or variants in the plant parts or in cells cultured therefrom. For example, Cramer et al. (1999) Curr. Top. Microbol. Immunol. 240:95-118 and references cited therein, describe the production of transgenic tobacco leaves expressing large amounts of recombinant proteins, e.g., using an inducible promoter. Transgenic maize have been used to express mammalian proteins at commercial production levels, with biological activities equivalent to those produced in other recombinant systems or purified from natural sources. See, e.g., Hood et al. (1999) Adv. Exp. Med. Biol. 464: 127-147 and references cited therein. Antibody derivatives have also been produced in large amounts from transgenic plant seeds including antibody fragments, such as single chain antibodies (scFv's), including tobacco seeds and potato tubers. See, e.g., Conrad et al. (1998) Plant Mol. Biol. 38: 101-109 and references cited therein. Thus, antibodies can also be produced using transgenic plants, according to know methods.

[0175] Antibody derivatives also can be produced, for example, by adding exogenous sequences to modify immunogenicity or reduce, enhance or modify binding, affinity, on-rate, off-rate, avidity, specificity, half-life, or any other suitable characteristic. Generally part or all of the non-human or human CDR sequences are maintained while the non-human sequences of the variable and constant regions are replaced with human or other amino acids or variable or contstant regions from other isotypes.

[0176] In general, the CDR residues are directly and most substantially involved in influencing antigen binding. Humanization or engineering of antibodies can be performed using any known method such as, but not limited to, those described in U.S. Pat. Nos.

5,723,323; 5,976,862; 5,824,514; 5,817,483; 5,814,476; 5,763,192; 5,723,323; 5,766,886; 5,714,352; 6,204,023; 6,180,370; 5,693,762; 5,530, 101; 5,585,089; 5,225,539; and

4,816,567.

[0177] Chimeric, humanized or primatized antibodies of the present disclosure can be prepared based on the sequence of a reference monoclonal antibody prepared using standard molecular biology techniques. DNA encoding the heavy and light chain immunoglobulins can be obtained from the hybridoma of interest and engineered to contain non-reference (e.g., human) immunoglobulin sequences using standard molecular biology techniques. For example, to create a chimeric antibody, the murine variable regions can be linked to human constant regions using methods known in the art (U.S. Pat. No. 4,816,567). To create a humanized antibody, the murine CDR regions can be inserted into a human framework using methods known in the art (U.S. Pat. No. 5,225,539 and U.S. Pat. Nos. 5,530, 101; 5,585,089; 5,693,762; and 6, 180,370). Similarly, to create a primatized antibody the murine CDR regions can be inserted into a primate framework using methods known in the art (WO 93/02108 and WO 99/55369).

[0178] Techniques for making partially to fully human antibodies are known in the art and any such techniques can be used. According to one embodiment, fully human antibody sequences are made in a transgenic mouse which has been engineered to express human heavy and light chain antibody genes. Multiple strains of such transgenic mice have been made which can produce different classes of antibodies. B cells from transgenic mice which are producing a desirable antibody can be fused to make hybridoma cell lines for continuous production of the desired antibody. (See for example, Russel et al. (2000) Infection and Immunity April 2000: 1820-1826; Gallo et al. (2000) European J. of Immun. 30:534-540; Green (1999) J. of Immun. Methods 231 : 11-23; Yang et al. (1999A) J. of Leukocyte Biology 66:401-410; Yang (1999B) Cancer Research 59(6): 1236-1243; Jakobovits (1998) Advanced Drug Reviews 31 :33-42; Green and Jakobovits (1998) J. Exp. Med. 188(3):483-495;

Jakobovits (1998) Exp. Opin. Invest. Drugs 7(4):607-614; Tsuda et al. (1997) Genomics 42:413-421; Sherman-Gold (1997) Genetic Engineering News 17(14); Mendez et al. (1997) Nature Genetics 15: 146-156; Jakobovits (1996) Weir's Handbook of Experimental

Immunology, The Integrated Immune System Vol. IV, 194.1-194.7; Jakobovits (1995) Current Opinion in Biotechnology 6:561-566; Mendez et al. (1995) Genomics 26:294-307; Jakobovits (1994) Current Biology 4(8):761-763; Arbones et al. (1994) Immunity 1(4):247- 260; Jakobovits (1993) Nature 362(6417):255-258; Jakobovits et al. (1993) Proc. Natl. Acad. Sci. USA 90(6):2551-2555; and U.S. Pat. No. 6,075, 181.)

[0179] The antibodies disclosed herein also can be modified to create chimeric antibodies. Chimeric antibodies are those in which the various domains of the antibodies' heavy and light chains are coded for by DNA from more than one species. See, e.g., U.S. Pat. No. 4,816,567.

[0180] Alternatively, the antibodies disclosed herein can also be modified to create veneered antibodies. Veneered antibodies are those in which the exterior amino acid residues of the antibody of one species are judiciously replaced or "veneered" with those of a second species so that the antibodies of the first species will not be immunogenic in the second species thereby reducing the immunogenicity of the antibody. Since the antigenicity of a protein is primarily dependent on the nature of its surface, the immunogenicity of an antibody could be reduced by replacing the exposed residues which differ from those usually found in another mammalian species antibodies. This judicious replacement of exterior residues should have little, or no, effect on the interior domains, or on the interdomain contacts. Thus, ligand binding properties should be unaffected as a consequence of alterations which are limited to the variable region framework residues. The process is referred to as "veneering" since only the outer surface or skin of the antibody is altered, the supporting residues remain undisturbed.

[0181] The procedure for "veneering" makes use of the available sequence data for human antibody variable domains compiled by Kabat et al. (1987) Sequences of Proteins of Immunological interest, 4th ed., Bethesda, Md., National Institutes of Health, updates to this database, and other accessible U.S. and foreign databases (both nucleic acid and protein). Non-limiting examples of the methods used to generate veneered antibodies include EP 519596; U.S. Pat. No. 6,797,492; and described in Padlan et al. (1991) Mol. Immunol. 28(4- 5):489-498.

[0182] The term "antibody derivative" also includes "diabodies" which are small antibody fragments with two antigen-binding sites, wherein fragments comprise, or alternatively consist essentially of, or yet further consist of a heavy chain variable domain (VH) connected to a light chain variable domain (VL) in the same polypeptide chain. (See for example, EP 404,097; WO 93/11161; and Hollinger et al. (1993) Proc. Natl. Acad. Sci. USA 90:6444-6448.) 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. (See also, U.S. Pat. No. 6,632,926 to Chen et al., which discloses antibody variants that have one or more amino acids inserted into a hypervariable region of the parent antibody and a binding affinity for a target antigen which is at least about two fold stronger than the binding affinity of the parent antibody for the antigen).

[0183] The term "antibody derivative" further includes engineered antibody molecules, fragments and single domains such as scFv, dAbs, nanobodies, minibodies, Unibodies, and Affibodies & Hudson (2005) Nature Biotech 23(9): 1126-36; U.S. Pat. Application

Publication No. 2006/0211088; PCT International Application Publication No. WO

2007/059782; U.S. Pat. No. 5,831,012). [0184] The term "antibody derivative" further includes "linear antibodies." The procedure for making linear antibodies is known in the art and described in Zapata et al. (1995) Protein Eng. 8(10): 1057-1062. Briefly, these antibodies comprise, or alternatively consist essentially of, or yet further consist of a pair of tandem Ed segments (V _H -C _H 1-VH- C _H I) which form a pair of antigen binding regions. Linear antibodies can be bispecific or monospecific.

[0185] The antibodies disclosed herein can be recovered and purified from recombinant cell cultures by known methods including, but not limited to, protein A purification, ammonium sulfate or ethanol precipitation, acid extraction, anion or cation exchange chromatography, phosphocellulose chromatography, hydrophobic interaction

chromatography, affinity chromatography, hydroxylapatite chromatography and lectin chromatography. High performance liquid chromatography ("HPLC") can also be used for purification.

[0186] Antibodies of the present disclosure include naturally purified products, products of chemical synthetic procedures, and products produced by recombinant techniques from a eukaryotic host, including, for example, yeast, higher plant, insect and mammalian cells, or alternatively from a prokaryotic host as described above. A number of antibody production systems are described in Birch & Radner (2006) Adv. Drug Delivery Rev. 58: 671-685.

[0187] If an antibody being tested binds with protein or polypeptide, then the antibody being tested and the antibodies provided by this disclosure are equivalent. It also is possible to determine without undue experimentation, whether an antibody has the same specificity as the antibody disclosed herein by determining whether the antibody being tested prevents an antibody disclosed herein from binding the protein or polypeptide with which the antibody is normally reactive. If the antibody being tested competes with the antibody disclosed herein as shown by a decrease in binding by the monoclonal antibody disclosed herein, then it is likely that the two antibodies bind to the same or a closely related epitope. Alternatively, one can pre-incubate the antibody disclosed herein with a protein with which it is normally reactive, and determine if the antibody being tested is inhibited in its ability to bind the antigen. If the antibody being tested is inhibited then, in all likelihood, it has the same, or a closely related, epitopic specificity as the antibody disclosed herein. [0188] The term "antibody" also is intended to include antibodies of all immunoglobulin isotypes and subclasses. Particular isotypes of a monoclonal antibody can be prepared either directly by selecting from an initial fusion, or prepared secondarily, from a parental hybridoma secreting a monoclonal antibody of different isotype by using the sib selection technique to isolate class switch variants using the procedure described in Steplewski et al. (1985) Proc. Natl. Acad. Sci. USA 82:8653 or Spira et al. (1984) J. Immunol. Methods 74:307. Alternatively, recombinant DNA techniques may be used.

[0189] The variable region of the antibodies of the present disclosure can be modified by mutating amino acid residues within the VH and/or VL CDR 1, CDR 2 and/or CDR 3 regions to improve one or more binding properties (e.g., affinity) of the antibody. Mutations may be introduced by site-directed mutagenesis or PCR-mediated mutagenesis and the effect on antibody binding, or other functional property of interest, can be evaluated in appropriate in vitro or in vivo assays. In certain embodiments, conservative modifications are introduced and typically no more than one, two, three, four or five residues within a CDR region are altered. The mutations may be amino acid substitutions, additions or deletions.

[0190] Framework modifications can be made to the antibodies to decrease

immunogenicity, for example, by "backmutating" one or more framework residues to the corresponding germline sequence.

[0191] In addition, the antibodies disclosed herein may be engineered to include modifications within the Fc region to alter one or more functional properties of the antibody, such as serum half-fife, complement fixation, Fc receptor binding, and/or antigen-dependent cellular cytotoxicity. Such modifications include, but are not limited to, alterations of the number of cysteine residues in the hinge region to facilitate assembly of the light and heavy chains or to increase or decrease the stability of the antibody (U.S. Pat. No. 5,677,425) and amino acid mutations in the Fc hinge region to decrease the biological half-life of the antibody (U.S. Pat. No. 6, 165,745).

[0192] Antibodies can be produced by inducing in vivo production in the lymphocyte population or by screening recombinant immunoglobulin libraries or panels of highly specific binding reagents (Orlandi et al, PNAS 86: 3833-3837 (1989); Winter, G. et al, Nature, 349: 293-299 (1991)). [0193] Alternatively, techniques for the production of single chain antibodies may be used. Single chain antibodies (scF _v s) comprise, or alternatively consist essentially of, or yet further consist of a heavy chain variable region and a light chain variable region connected with a linker peptide (typically around 5 to 25 amino acids in length). In the scF _v , the variable regions of the heavy chain and the light chain may be derived from the same antibody or different antibodies. scF _v s may be synthesized using recombinant techniques, for example by expression of a vector encoding the scF _v in a host organism such as E. coli. DNA encoding scF _v can be obtained by performing amplification using a partial DNA encoding the entire or a desired amino acid sequence of a DNA selected from a DNA encoding the heavy chain or the variable region of the heavy chain of the above-mentioned antibody and a DNA encoding the light chain or the variable region of the light chain thereof as a template, by PCR using a primer pair that defines both ends thereof, and further performing amplification combining a DNA encoding a polypeptide linker portion and a primer pair that defines both ends thereof, so as to ligate both ends of the linker to the heavy chain and the light chain, respectively. An expression vector containing the DNA encoding scF _v and a host

transformed by the expression vector can be obtained according to conventional methods known in the art.

[0194] Antigen binding fragments may also be generated, for example the

F(ab') ₂ fragments which can be produced by pepsin digestion of the antibody molecule and the Fab fragments which can be generated by reducing the disulfide bridges of the

F(ab') ₂ fragments. Alternatively, Fab expression libraries may be constructed to allow rapid and easy identification of monoclonal Fab fragments with the desired specificity (Huse et al.,

Science, 256: 1275-1281 (1989)).

[0195] Various immunoassays may be used for screening to identify antibodies having the desired specificity. Numerous protocols for competitive binding or immunoradiometric assays using either polyclonal or monoclonal antibodies with established specificities are well known in the art. Such immunoassays typically involve the measurement of complex formation between HLA-G, or any fragment or oligopeptide thereof and its specific antibody. A two-site, monoclonal-based immunoassay utilizing monoclonal antibodies specific to two non-interfering HLA-G epitopes may be used, but a competitive binding assay may also be employed (Maddox et al., J. Exp. Med., 158: 1211-1216 (1983)). [0196] The antibodies disclosed herein can be purified to homogeneity. The separation and purification of the antibodies can be performed by employing conventional protein separation and purification methods.

[0197] By way of example only, the antibody can be separated and purified by appropriately selecting and combining use of chromatography columns, filters, ultrafiltration, salt precipitation, dialysis, preparative polyacrylamide gel electrophoresis, isoelectric focusing electrophoresis, and the like. Strategies for Protein Purification and

Characterization: A Laboratory Course Manual, Daniel R. Marshak et al. eds., Cold Spring Harbor Laboratory Press (1996); Antibodies: A Laboratory Manual. Ed Harlow and David Lane, Cold Spring Harbor Laboratory (1988).

[0198] Examples of chromatography include affinity chromatography, ion exchange chromatography, hydrophobic chromatography, gel filtration chromatography, reverse phase chromatography, and adsorption chromatography. In one aspect, chromatography can be performed by employing liquid chromatography such as HPLC or FPLC.

[0199] In one aspect, a Protein A column or a Protein G column may be used in affinity chromatography. Other exemplary columns include a Protein A column, Hyper D, POROS, Sepharose F. F. (Pharmacia) and the like.

Fusion Polypeptides and Polynucleotides Encoding Them

[0200] Also provided herein is a fusion polypeptide comprising, or alternatively consisting essentially of, or yet further consisting of: an antigen binding domain, a linker polypeptide, and an exosome addressing domain. In one aspect, the fusion polypeptide further comprises, consists essentially of, or yet further consists of more than one antigen binding domains and optionally more than one linker polypeptides. In a yet further aspect, the fusion polypeptide further comprising, or alternatively consisting essentially of, or yet further consisting of a purification and/or a detectable label. Non-limiting examples are provided infra, e.g., HA, FLAG and 6XHis. In yet a further aspect, the fusion polypeptide further comprises, or alternatively consists essentially of, or yet further consists of a myc protein or polypeptide. FIGS. 2B, 5, 15, and 21 are non-limiting examples of embodiments of the fusion polypeptides. Amino acid sequences of the polypeptides and polynucleotides encoding these embodiments are provided herein. Also provided are the fusion polypeptides depicted in the Exemplary Fusion Polypeptide section, and equivalents of each thereof. Also provided herein are these amino acid and polynucleotide sequences encoding the

polypeptides, as well as equivalents of each thereof.

[0201] In a further aspect, the one or more antigen binding domains are selected from the group of: an antibody, a multi-specific antibody, a multi-specific antibody fragment,an antibody fragment, a VH, a VL, an scFv antibody fragment, a single domain antibody, a bispecific antibody, or a bispecific antibody fragment, a monoclonal antibody or a derivative thereof. In one aspect the antibody, fragment, or derivative is from a human antibody or a humanized antibody. The antigen binding domains can also be murine, bovine, ovine or human or from any other appropriate species. In one aspect, the antibody is a monoclonal antibody, a derivative, or a fragment thereof. In another aspect, the antibody, derivative or fragment thereof is a human antibody, a humanized antibody or a derivative of each thereof.

[0202] Non-limiting examples of antibodies and fragments and derivatives thereof in the fusion polypeptide that are used for the antigen binding domains are of the group of antibodies: anti-HER2; anti-HER3; anti-EGFR; anti-CD3; anti-CD16; anti-CD4; anti-CD8; anti-CDl la; anti-CD19; anti-CD20; anti-CD25; anti-CD33; anti-CD40; anti-CD40L; anti- CD70; anti-CD 123; anti-EpCAM; anti-CLL-1 ; anti-CTLA-4; anti-PD-1 ; anti-PD-Ll ; anti- OX40; anti-GITR; anti-ICOS; anti-B7-H3; anti-B7-H4; anti-LAG3; anti-TIM3; anti-PSMA; anti-factor IXa; anti-factor X; or anti-folate receptor.

[0203] In one aspect, the fusion polypeptide comprises, or alternatively consists essentially of, or yet further consists of more than one antigen binding domains, that may be the same or different from each other. In a further aspect, polypeptide comprises, or alternatively consists essentially of, or yet further consists of an antigen binding domain that is a bispecific antibody that binds to independent and distinct targets (see, e.g., FIG. 21).

[0204] The antigen binding domains of the fusion polypeptides are selected to specifically recognize and bind an antigen of the group of: a tumor antigen; a cancer antigen; an antigen expressed on an immune cell; an antigen expressed on an immune effector cell; an activated coagulation factor IX; factor X; PD1 ; PDL1 ; CTLA4; and an antigen involved in immune regulation of a cell from the group of: a T cell, a macrophage, a NK cell, CD4+ T cell, CD8+ T cell, CD 19+ cell, CD16+cell, CD20+ cell, and a B cell. In a further aspect, the antigen binding domain specifically recognizes and binds a cancer antigen that can be selected from the groups of breast cancer, lung cancer, colorectal cancer, kidney cancer, prostate cancer, brain cancer, pancreatic cancer, a solid malignant cancer or a blood cancer. In a further aspect, the cancer is a breast cancer or a colorectal cancer, and the antigen binding domain specifically recognizes and binds HER2 or EGFR. Additional non-limiting examples of antibodies and fragments and derivatives thereof are of the group of antibodies: anti-HER3; anti-CD3; anti-CD 16; anti-CD4; anti-CD8; anti-CD 1 1a; anti-CD 19; anti-CD20; anti-CD25; anti-CD33; anti-CD40; anti-CD40L; anti-CD70; anti-CD 123; anti-EpCAM; anti- CLL-1 ; anti-CTLA-4; anti-PD-1 ; anti-PD-Ll ; anti-OX40; anti-GITR; anti-ICOS; anti-B7-H3; anti-B7-H4; anti-LAG3; anti-TIM3; anti-PSMA; anti -factor IXa; anti -factor X; anti-folate receptor, and fragments or derivatives thereof. Antibodies and fragments thereof directed to HER2 and EGFR are known in the art and commercially available. Exemplary amino acid sequences of these antigen binding domain are provided below in the sequences of exemplary fusion polypeptides. Biological equivalents of such polypeptides are also within the scope of this disclosure.

[0205] In a further aspect, the fusion polypeptide comprises, or alternatively consists essentially of, or yet further consists of more than one antigen binding domain that are different, and wherein an antigen binding domain selectively recognizes and bind a tumor or cancer associated antigen and the second antigen binding domain recognizes an antigen expressed on an immune cell. Non-limiting examples of cancer antigens are selected from the group of breast cancer, lung cancer, colorectal cancer, kidney cancer, prostate cancer, brain cancer, pancreatic cancer, a solid malignant cancer or a blood cancer and the antigen expressed on an immune cell is selected from the group of a T cell, a macrophage, a NK cell, CD4+ T cell, CD8+ T cell, CD 16+ cell, CD 19+ cell, CD20+ cell, and a B cell. FIG. 4 depicts one aspect of this embodiment. In a specific embodiment, the cancer is a breast cancer or a colorectal cancer, and the antigen binding domain is specific to the HER2 or EGFR cell surface receptors. Non-limiting examples of antibodies and fragments and derivatives thereof are of the group of antibodies: anti-HER2; anti-HER3; anti -EGFR; anti- CD3; anti-CD16; anti-CD4; anti-CD8; anti-CDl la; anti-CD19; anti-CD20; anti-CD25; anti- CD33; anti-CD40; anti-CD40L; anti-CD70; anti-CD 123; anti-EpCAM; anti-CLL-1 ; anti- CTLA-4; anti-PD-1 ; anti-PD-Ll ; anti-OX40; anti-GITR; anti-ICOS; anti-B7-H3; anti-B7-H4; anti-LAG3; anti-TIM3; anti-PSMA; anti -factor IXa; anti -factor X; anti-folate receptor, and fragments and derivatives thereof. In a further aspect, the antigen binding domain is specific to the HER2 or EGFR cell surface receptors and the antigen binding domain specific to an immune cell is a CD3+ T cell or an CD 16+ (NK cell).

[0206] The fusion polypeptide also comprises, or alternatively consists essentially of, or yet further consists of an extracellular vesicle addressing domain (also referred to herein as an exosomal membrane protein). Non-limiting examples of such include platelet-derived growth factor receptor (PDGFR), Lam2b, lactadherin C1C2 domain, CD 13 and CD9. Examples of the amino acid sequences of the polypeptides and encoding nucleic acids are provided in the sequence listings of the fusion polypeptides, provided herein. Biological equivalents of these sequences are within the scope of this disclosure.

[0207] The fusion polypeptides also can comprise, or alternatively consist essentially of, or yet further consist of (located N- or C-terminal to the antigen binding domains) one or more linker polypeptide. Non-limiting examples of such include (GGGGS)n, n=0-5 (SEQ ID NO: 2); (GGGS)n, n=0-6 (SEQ ID NO: 3); (GGS)n, n=0-7 (SEQ ID NO: 4); (EAAAK)n, n=0-4 (SEQ ID NO: 5); PSGQAGAAASESLFVSNHAY (SEQ ID NO: 6) and

GSTSGSGKPGSGEGS (SEQ ID NO: 7); and equivalents of each thereof.

[0208] In yet further aspect, the fusion polypeptides comprise, or alternatively consist essentially of, or yet further consist of a myc polypeptide or protein, or an equivalent of each thereof. Exemplary sequences are provided herein.

[0209] Also provided are polynucleotides encoding the fusion polypeptides. The polynucleotides can be operatively linked to regulatory elements to drive expression of the polynucleotide and can be further contained within a vector, e.g. a plasmid or a viral vector. Host cells, prokaryotic and eukaryotic cells, containing the polynucleotides and/or polypeptides and methods of expressing the polynucleotides are further provided herein, as well as the polypeptides encoded by the polynucleotides. The polynucleotides and polypeptides can further comprise, or alternatively consist essentially of, or yet further consist of a detectable and/or a purification label. Examples of such are provided infra. The polynucleotides are useful to prepare the vesicles and for recombinant production of the fusion polypeptides by transducing a cell with the polynucleotide contained within an expression vector and culturing the cell under conditions that promote expression of the polynucleotide. The vesicles can be further isolated from the culture media.

Methods for Preparing the Engineered Extracellular Vesicles

[0210] Also provided are recombinant methods to prepare an extracellular vesicle of this disclosure, the method comprising, or alternatively consisting essentially of, or yet further consisting of contacting a cell comprising, or alternatively consisting essentially of, or yet further consisting of the extracellular vesicle with an effective amount of the polynucleotide encoding a fusion polypeptide and expressing the polynucleotide on the vesicle. The cells can be eukaryotic or prokaryotic, mammalian, reptilian, avian, human, plant, or bacterial. They can be of any appropriate species, e.g. canine, feline, murine, equine or human, for example. In one aspect, the method further comprises, or alternatively consists essentially of, or yet further consists of isolating the extracellular vesicle from the engineered vesicle from the cell culture media. Methods for such are described herein.

[0211] Bispecific exosomes could be expressed in any types of eukaryotic cells through transient or stable transfection of the generated expression constructs for antibody-membrane protein fusions. For example, in addition to Expi293F cells, HeLa cells, HEK293T, MDA- MB-231, immature dendritic cells, and stem cells could be utilized for production of the extracellular vesicles such as bispecific exosomes. Cells expressing bispecific exosomes are grown in chemically defined medium or medium supplemented with exosome-depleted serum. The exosomes released into the culture media are purified using different approaches, including differential centrifugation, density-gradient- or cushion-based ultracentifugation, precipitation with commercial kits (ExoQuick™ and Total Exosome Isolation™), and affinity and size exclusion chromatography.

[0212] In addition to above genetic engineering approach, bispecific exosomes could be prepared through chemical conjugation. Native or endogenous exosomes released by various types of cells could be isolated using above mentioned approaches. Antigen binding fragments, e.g., bispecific antibodies or two distinct monoclonal antibodies could be recombinantly expressed and purified from prokaryotic or eukaryotic cells. Using chemical linkers with groups reactive to antibodies and exosome surface for covalent attachments, the bispecific exosomes could be generated and purified through affinity and size exclusion chromatography.

[0213] In one aspect and as an example only, native vesicles, e.g., exosomes, are purified from culture media of cells such as Expi293 cells through differential centrifugation and ultracentrifugation. Antigen binding fragments, e.g. bispecific antibodies (e.g. anti-CD3/anti- EGFR scFv) are expressed from Expi293 cells through transient transfection with constructed expression vector, followed by Ni-NTA affinity chromatography. 100 μL. of purified exosomes (0.2 mg/mL) in PBS are mixed with tetrazine-PEG5-NHS ester (10 μL., 200 μΜ) at room temperature for 60 minutes. The free tetrazine-PEG5-NHS ester is removed by passing the mixture through size exclusion chromatography using a Superdex 200 Increase 10/300 GL column. 100 μL. of purified bispecific antibody (1 mg/ml) in PBS would be mixed with trans-cyclooctene-PEG4-NHS ester (10 μL., 400 μΜ) at room temperature for 60 minutes. The free trans-cyclooctene-PEG4-NHS ester is removed by passing the mixture through size exclusion chromatography using a Superdex 200 Increase 10/300 GL column. The exosomes labeled with tetrazin-PEG5 and the bispecific antibody labeled with trans-cyclooctene-PEG4 are incubated at a molar ratio of (1 :2000) for 120 minutes at room temperature. The exosome- antibody conjugates are isolated by size exclusion chromatography using a Superdex 200 Increase 10/300 GL column.

Isolation of Extracellular Vesicles

[0214] The purified populations of cell-derived vesicles (e.g., exosomes and/or microvesicles) of the present disclosure can be isolated using any method known by those in the art. Non-limiting examples include differential centrifugation by ultracentrifugation (Thery et al. (2006) Curr. Protoc. Cell Biol. 30:3.22.1-3.22.29; Witmer et al. (2013) J.

Extracellular v.2), sucrose gradient purification (Escola et al. (1998) J. Biol. Chem.

273 :20121-20127), and combination filtration/concentration (Lamparski et al. (2002) J.

Immunol. Methods 270:211-226).

[0215] After isolation, the cell-derived vesicles, e.g., exosomes can be concentrated to provide a purified population of cell-derived vesicles. Any appropriate method can be used to concentrate the cell-derived vesicles, e.g. exosomes. Non-limiting examples of such include centrifugation, ultrafiltration, filtration, differential centrifugation and column filtration. Further sub-populations can be isolated using antibodies or other agents that are specific for a specific marker expressed by the desired exosome population.

[0216] In some embodiments, the methods disclosed herein further comprise, or alternatively consist essentially of, or yet further consist of formulating the purified population of cell-derived vesicles by mixing the population with a carrier and/or a therapeutic agent. Non-limiting examples are suitable carriers are described below. In addition or alternatively, the exosome composition can be combined with trehalose for enhanced stability, e.g., at a concentration of about 15 nM to about 50 nM of trehalose in carrier (e.g., PBS), or alternatively about 25 nM of trehalose in carrier (e.g., PBS). Methods to formulate exosomes with trehalose are described in Bosch et al. (2016) "Trehaolose prevents aggregation of exosomes and cryodamage" Scientific Reports 6, Article number 36162, doe: 10.1038/srep36162, incorporated herein by reference.

Encapsulation of Therapeutics Agents

[0217] FIG. 4B is a schematic of methods to encapsulate therapeutic drugs into the vesicles.

[0218] Electroporation: For example, 10μg of exosome (approximately 10 ⁹ ) and 10μg of siRNA were mixed in 200ul electroporation buffer (1.15 mM potassium phosphate pH=7.2, 25mM potassium chloride, 21% Optiprep, ImM EDTA). The siRNA-Exosome mixture was electroporated in 4mm cuvette, at 400V, 125μΡ, and the cuvette was immediately transferred to ice. Exosomes were recovered from mixture by 30kDa protein concentrator.

[0219] Incubation: Purified exosomes (0.2 mg/mL) were first mixed with drugs (10 mM Resiquimod) in 200 μL. PBS. The mixture was incubated at 37 °C for 1 hour with shaking. Excess free drug was separated from drug-encapsulated exosomes by size exclusion chromatography using a Superdex 200 Increase 10/300 GL column (GE Healthcare, Buckinghamshire, UK).

[0220] Sonication: Purified exosomes (0.2 mg/mL) were first mixed with drugs (10 mM Resiquimod) in 200 μL. PBS. The mixture was sonicated (20% power, 6 cycles of 4 s pulse/2 s pause), cooled down on ice for 2 min, and then sonicated again using Misonix Ultrasonic Liquid Processor S-4000 (Misonix, Inc. N.Y. USA). After sonication, Drug-encapsulated exosome solution was incubated at 37 °C for 30 min to allow for recovery of the exosomal membrane. Excess free drug was separated from drug-encapsulated exosomes by size exclusion chromatography using a Superdex 200 Increase 10/300 GL column (GE

Healthcare, Buckinghamshire, UK).

[0221] Freeze-thaw: Purified exosomes (0.2 mg/mL) were first mixed with drugs (10 mM Resiquimod) in 200 [iL PBS. The mixture was incubated for 20 min on ice, then rapidly freezed at-80 °C, and thawed at RT. The freeze-thaw cyclewas repeated five times. After sonication, drug-encapsulated exosome solution was incubated at 37 °C for 30 min to allow for recovery of the exosomal membrane. Excess free drug was separated from drug- encapsulated exosomes by size exclusion chromatography using a Superdex 200 Increase 10/300 GL column (GE Healthcare, Buckinghamshire, UK).

Formulations and Pharmaceutical Compositions

[0222] The present disclosure provides purified populations of extracellular vesicles. In some embodiments, the population of vesicles is substantially homogeneous. In other embodiments, the population of vesicles is heterogeneous.

[0223] The purified populations of vesicles can be purified on the basis of average size of the vesicles in the composition.

[0224] The compositions disclosed herein may further comprise, or alternatively consist essentially of, or yet further consist of a carrier, for example, a pharmaceutically acceptable carrier. In some embodiments, more than one pharmaceutically acceptable carrier can be used. Any pharmaceutically acceptable carrier known to those of skill in the art or described herein.

[0225] In some embodiments, the pharmaceutically acceptable carrier is a preservative, for example, a polymeric preservative or a stabilizing agent.

[0226] In some embodiments, the pharmaceutically acceptable carrier is selected from the group consisting of a polyethylene glycol (PEG, e.g., PEG 150 Distearate), honey, a large molecular weight protein (e.g., bovine serum albumin or soy protein), polyvinyl alcohol, glyceryl monostearate, hyaluronic acid, glycerin, preferably vegetable-derived, proteins, preferably hydrolyzed proteins, (e.g., soy protein and silk protein), vasoline, citrosept, parabens, xanthan gum, i-carregaan, phytagel, Carbopol polymers, and polyvinyl pyrrolidone.

[0227] In some embodiments, exosomes are preserved in serum albumin. Non-limiting examples of serum albumins appropriate for preservation of exosomes include bovine serum albumin (BSA), human serum albumin (HSA), ovalbumin (OVA), and lactalbumin.

[0228] Pharmaceutically acceptable carriers may include biocompatible gelation agents including thermosensitive sol-gel reversible hydrogels such as aqueous solutions of poloxamers. In one aspect, the poloxamer is a nonionic triblock copolymer composed of a central hydrophobic chain of polyoxypropylene (e.g., (poly(propylene oxide)) flanked by two hydrophilic chains of polyoxyethylene (e.g., poly(ethylene oxide)). In one aspect, poloxamer has the formula

[0229] wherein a is from 10 to 100, 20 to 80, 25 to 70, or 25 to 70, or from 50 to 70; b is from 5 to 250, 10 to 225, 20 to 200, 50 to 200, 100 to 200, or 150 to 200. In another aspect, the poloxamer has a molecular weight from 2,000 to 15,000, 3,000 to 14,000, or 4,000 to 12,000. Poloxamers useful herein are sold under the tradename Pluronic® manufactured by BASF. Non-limiting examples of poloxamers useful herein include, but are not limited to, Pluronic®F68, P103, P105, P123, F 127, and L121.

[0230] In one aspect, the biocompatible gelation agent is an agent that is liquid prior to application to a subject (e.g., at room temperature or colder) and becomes a gel after application to the subject (e.g., at body temperature). In one embodiment, the biocompatible gelation agent is a hydrogel.

[0231] In some aspects, the pharmaceutically acceptable carrier is a pharmaceutically acceptable aqueous carrier such as water or an aqueous carrier. Examples of

pharmaceutically acceptable aqueous carrier include sterile water, saline, phosphate buffered saline, aqueous hyaluronic acid, Ringer's solution, dextrose solution, Hank's solution, and other aqueous physiologically balanced salt solutions. In some embodiments, the

pharmaceutically acceptable aqueous carrier is Normosol™-R. [0232] Nonaqueous pharmaceutically acceptable carriers include, fixed oils, vegetable oils such as olive oil and sesame oil, triglycerides, propylene glycol, polyethylene glycol, and injectable organic esters such as ethyl oleate can also be used.

[0233] Pharmaceutically acceptable carriers can also contain minor amounts of additives, such as substances that enhance isotonicity, chemical stability, or cellular stability. Examples of buffers include phosphate buffer, bicarbonate buffer and Tris buffer, while examples of preservatives include thimerosol, cresols, formalin and benzyl alcohol. In certain aspects, the pH can be modified depending upon the mode of administration. In some aspect, the composition has a pH in the physiological pH range, such as pH 7 to 9.

[0234] In one aspect, depending on the type of a pharmaceutically acceptable carrier used, the compositions described herein can comprise, or alternatively consist essentially of, or yet further consist of about 0.1-100%, 0.1-50%, or 0.1-30%, such as 0.1 %, 0.25 %, 0.5 %, 0.75%, 1 %, 2 %, 5 %, 7 %, 10 %, 15 %, 20 %, 25 %, 30 %, 40 %, 45 % , 50 % , 55 % , 60 % , 65 % , 70 % , 75 % , 80 %, 85 %, 90 % or 95 % of the pharmaceutically acceptable carrier used in the total weight of the composition, or any range between two of the numbers (end point inclusive).

[0235] In some embodiments, any one of the above listed pharmaceutically acceptable carriers is expressly excluded.

[0236] In some embodiments, the vesicles described herein are frozen (e.g., snap-frozen) or freeze-dried (e.g., lyophilized) to promote stability, preserve activity and increase shelf- life. One skilled in the art would understand how to reconstitute the lyophilized product before use.

[0237] In some embodiments, the populations of vesicles described herein are used immediately after isolation. In other embodiments, the populations of cell-derived vesicles are cryopreserved (e.g. frozen), for example, using any cryopreservation techniques well- known to those skilled in the art. In some embodiments, all or substantially of the cells and/or cellular debris are removed from the culture medium prior to cryopreservation. In some embodiments, all or substantially of the cells and/or cellular debris are removed from the culture medium after cryopreservation. Applications and Uses

[0238] The vesicles of this disclose have various in vitro and in vivo uses. For example, the vesicles can be used to determine if a particular vesicle therapy will be effective by contacting a biological sample suspect of containing the cells or tissue to be treated (e.g., cancer cells) with an vesicle engineered to target that cell and then assaying for effectiveness of the therapy, e.g., by determining if cell growth has been inhibited or an immune response has been elicited in the appropriate tissue. Thus, this disclosure also provides an isolated complex comprising, or alternatively consisting essentially of, or yet further consisting of a vesicle as described herein complexed to the target cell or tissue to be treated.

[0239] The vesicles have various therapeutic uses as well. In one aspect, a method is provided for treating a subject in need thereof or inducing an immune response in a subject in need thereof, comprising, or alternatively consisting essentially of, or yet further consisting of, administering to the subject an effective amount of the isolated engineered vesicles or a composition of this disclosure, wherein the vesicle an antigen binding domain specific to a disease to be treated. In a further aspect, the subject has been selected for the therapy by diagnostic criteria as determined by the treating physician or health care professional.

[0240] Further provided is a method for cancer immunotherapy for a subject in need thereof, comprising, or alternatively consisting essentially of, or yet further consisting of, administering an effective amount of a vesicle or composition containing the same, wherein the vesicle expresses a cancer targeted antigen binding domain and an antigen binding domain that binds an immune cell, such as an immune effector cell. In a further aspect, the vesicles comprise, or alternatively consist essentially of, or yet further consist of an anticancer chemotherapeutic agent. The therapies can be administered as a first line, second line, third line, fourth line or fifth line therapy. Additional chemotherapeutic agents may be subsequently administered as determined by the treating physician. Non-limiting examples of chemotherapeutic agents include Actinomycin, All-trans retinoic acid, azacitidin,

azathioprine, bleomycin, bortezomib, carboplatin, capecitabine, cisplatin, chlorambucil, cyclophosphamide, cytarabine, daunorubicin, docetaxel, doxifluridine, doxorubicin, epirubicin, epothilone, etoposide, fluorouracil, gemcitabine, hydroxyurea, idarubicin, imatinib, irinotecan, mechlorethamine, mercaptopurine, methotrexate, mitoxantrone, oxaliplatin, paclitaxel, pemetrexed, teniposide, tioguanine, topotecan, valrubicin, vemurafenib, vinblastine, vincristine, vindesine, and vinorelbine.

[0241] The vesicles can further comprise, or alternatively consist essentially of, or yet further consist of immune regulatory factors to augment the vescicle-mediated cancer immunotherapy. The exosomes can be are mono-specific or bi-specific exosomes.

Bispecificity is achieved by either fusing bispecific antibody with exosomal membrane proteins, or separately fusing distinct scFv antibody with the same or different exosomal membrane proteins. The bispecific exosomes can be used to target both the cancer cell and immune cells. One antibody scFv, is capable to recruit the activity of a human immune effector cell by specifically binding to an effector antigen on the human immune effector cell, and a second bispecific scFv, specifically binds to a target antigen on the target cell, resulting in the redirection of immune effector cell to kill targeted cancer cells.

[0242] For the fusion expression of bi-specific scFvs, two kinds of orientation are generated. Depending on the specificity of the antibody scFv selected, the resulting bispecific exosomes can bind to breast, lung, colorectal, kidney, prostate, brain, pancreas, or solid malignant tumor cells or blood cancer cells for immune cell-mediated killing. For breast and colorectal cancer, in one aspect, the targets are FLER2 positive cells, EGFR positive cells or others. HER2 and EGFR are chosen as tumor targets and CD3 ⁺ T cells are the immune effector cells. FIER2 positive cancer cell lines include SK-BR-3 cells,

HCC1954 cells. MDA-MB-468 is HER2 negative cells; EGFR positive cells include MDA- MB-468 cells. MDA-MB-453 is EGFR negative cell. The immune effector cell include for example, CD3+ T cell, CD 16+ NK cell or others.

[0243] The vesicles are therapeutic for a variety of diseases selected from the group of: cancer, hyperplasia, neurodegenerative disease, Alzheimer's disease, cardiovascular disease, metabolic disease, vasculitis, viral infection, fungal infection, bacterial infection, diabetic retinopathy, macular degeneration, autoimmune disease, edema, pulmonary hypertension, sepsis, myocardial angiogenesis, plaque neovascularization, restenosis, neointima formation after vascular trauma, telangiectasia, hemophiliac joints, angiofibroma, fibrosis associated with chronic inflammation, lung fibrosis, deep venous thrombosis or wound granulation. [0244] The vesicles and compositions herein can be administered to the subject by any method known by those of skill in the art. In some embodiments, the compositions are administered by intravenous injection, direct injection, intramuscular injection, intracranial injection, or topically.

[0245] In one aspect, the bispecific exosomes are loaded with anti-cancer drugs and can be used to target two different antigens on a same tumor cell for more effective target tumor therapy. The bispecific exosomes loaded with anti-cancer drugs can be used to target both tumor cell and tumor stroma cells in a solid tumor for synergistic anti-tumor effect. The tumor stroma is composed of different cell types, such as fibroblasts, pericytes, endothelial cells and immune cells, including T cells, granulocytes and macrophages. The bispecific exosomes also can be used to modulate tumor immune microenvironment by blocking two immune checkpoint simultaneously, such as Anti-PDL1/Anti-CTLA4 bispecific exosomes. The Anti-PDLl and CTLA4 bispecific exosome encapsulated with immune agonists can be used to activate tumor immune microenvironment. Bispecific exosomes can bind to both the activated coagulation factor IX and to factor X, mediating the activation of factor X, which can be used for the treatment of haemophilia A.

[0246] By redirecting T cells or other immune effector cells (e.g. NK cells), bispecific exosomes can be used to treat cancer, hyperplasia, neurodegenerative disease, Alzheimer's disease, cardiovascular disease, metabolic disease, vasculitis, viral infection, fungal infection, bacterial infection, diabetic retinopathy, macular degeneration, autoimmune disease, edema, pulmonary hypertension, sepsis, myocardial angiogenesis, plaque neovascularization, restenosis, neointima formation after vascular trauma, telangiectasia, hemophiliac joints, angiofibroma, fibrosis associated with chronic inflammation, lung fibrosis, deep venous thrombosis or wound granulation.

[0247] The engineered exosomes with distinct bispecific antibodies and payloads demonstrate such unique extracellular vesicles as a general and versatile platform for development of novel immuno-nanoparticles with high potency. Applications of exosomes in clinic can be further expanded through leveraging a broad scope of mono- and multifunctional antibodies and therapeutic agents. The exosomes are developed to have transformative impact in the development of next-generation immuno-nanomedicines with desired pharmacological properties. Furthermore, bispecific exosome-based technology can treat many different types of cancer as well. Those antibody-directed bispecific exosomes may allow tissue- and cell-specific engaging of immune effector cells in a safe and highly efficient manner, opening doors to novel cancer immunotherapies.

[0248] To achieve therapeutically effective concentrations in cytosol, the developed synthetic exosome nanoparticles linked with tumor-specific peptides and antibodies require fast internalization through endocytosis and subsequent escape from the endosomal- lysosomal pathway, which have been proven challenging. Moreover, they are prone to induce robust immune responses due to their foreign antigen nature and can be rapidly cleared from circulatory system through absorbed complement, coagulation, opsonins factors, and neutralizing antibodies. In contrast, exosome-mediated delivery relies on direct membrane fusion to target cells, circumventing the endosomal-lysosomal pathway and boosting cellular delivery of therapeutics. Moreover, the nanoscale exosomes carrying a substantial amount of therapeutic agents can extravasate into tumor interstitium and diffuse in tumor tissue without inducing phagocytosis by the mononuclear phagocyte system. In particular, exosomes produced from immature DCs tend to show significantly reduced immunogenic activity due to the lack of major histocompatibility complex (MHC) class II and co-stimulatory molecules on their membrane surface. Clinically, exosomes isolated from patients' cells are unlikely to have immunogenicity issues encountered with artificial nanocarriers. Thus, these unique features for exosomes can be exploited for development of new anti-tumor nanomedicines with improved efficacy and safety.

[0249] Applicant generated novel exosome nanoparticles that can simultaneously target both cancer and immune effector cells for combinatorial immunotherapy. Relative to conventional, immunotherapeutic bispecific antibodies with geometrically and orientationally defined antigen-binding arms, the multivalent dual-targeted exosomes displayed on spherical exosomes have higher potential to promote formation of immunological synapses as well as enhanced efficacy to activate immune cells. Combined with immune checkpoint inhibitors, such bispecific exosomes are likely to augment efficacy of immunotherapy. Therefore, the engineered multifunctional exosomes represent novel nanomedicines with enhanced efficacy and safety, leading to the development of first-in-class immunotherapeutics for cancer.

[0250] The engineered exosomes with distinct bispecific antibodies and payloads demonstrate such unique extracellular vesicles as a general and versatile platform for development of novel immuno-nanoparticles with high potency. Applications of exosomes in clinic can be further expanded through leveraging a broad scope of mono- and multifunctional antibodies and therapeutic agents. These inventions will have transformative impact in the development of next-generation immuno-nanomedicines with desired pharmacological properties. Furthermore, bispecific exosome-based technology can be extended to treat many different types of cancer as well. Those antibody-directed bispecific exosomes may allow tissue- and cell-specific engaging of immune effector cells in a safe and highly efficient manner, opening doors to novel cancer immunotherapies.

[0251] The methods are useful to treat any appropriate subject and the vesicles and antigen binding domains are specific to the species of the subject to be treated. Examples of subjects include mammals such as canines, felines, equines or human patients.

[0252] The following examples are provided to illustrate, and not limit the inventions as described herein.

EXAMPLES

[0253] Given developing resistance of tumor cells to current chemotherapeutic and targeted therapeutic agents, novel cancer therapies with enhanced potency and specificity are substantially required. This disclosure addresses the overarching challenge of revolutionizing treatment regimens by replacing them with ones that are more effective, less toxic, and impact survival. Exosomes are endogenous nanoparticles secreted by many types of cells and play important roles in intercellular communication. Exosome-mediated delivery relies on direct membrane fusion to target cells, circumventing endosomal-lysosomal pathway required for synthetic vehicles and promoting cellular delivery of therapeutic agents. Moreover, compared with synthetic virus, lipid and polymeric nanomedicines which are immunogenic due to their foreign antigen nature, exosomes exhibit significantly reduced immunogenicity. In particular, exosomes derived from patients' own immature dendritic cells are expected to induce no immune responses. As disclosed herein, Applicant generated innovative bispecific exosome nanoparticles as a highly potent form of immunotherapeutics with excellent safety profiles. By creatively combining exosome nanotechnology with protein engineering, bispecific exosome nanoparticles were generated that redirect immune effector cells towards cancer cells for killing. Relative to conventional immunotherapeutic antibodies with defined orientation and geometry for their distinct antigen-binding arms, the multivalent dual-targeted antibodies displayed on spherical exosomes can promote formation of immunological synapses as well as enhanced efficacy to activate immune cells. Moreover, by effectively delivering immune checkpoint inhibitors, such bispecific exosomes are likely to augment efficacy of immunotherapy. The resulting exosomes display superb efficacy towards target cells and minimal toxicity, leading to the development of first-in-class immunotherapeutics for cancer and a broadly applicable and highly versatile technology for next-generation immuno-nanomedicines.

Molecular cloning

[0254] To construct scFv-PDGFR fusion proteins (FIG. 5 and 15), the DNA fragments encoding the anti-F£ER2 single-chain antibody (scFv), anti-EGFR scFv and anti-CD3 were amplified by polymerase chain reaction (PCR). The DNA fragments encoding anti- HER2/anti-CD3, anti-CD3/anti-HER2, anti-EGFR/anti-CD3 and anti-CD3/anti-EGFR bispecific scFvs were generated by overlap extension PCR with the amplified anti-F£ER2, anti-EGFR and anti-CD3. Three repeats of glycine linker (GGGGS) ₃ (SEQ ID NO: 8) were added between anti-F£ER2, anti-EGFR scFv and anti-CD3 scFv. One glycine linker

(GGGGS) (SEQ ID NO: 9) was added to the C-termini of the antibodies. The resulting genes were inserted into the pDisplay vector between Bglll and Sail by in-frame ligation.

[0255] To construct scFv-Lamp2b fusion proteins (FIG. 21), the DNA fragment encoding mouse Lamp2b was amplified by PCR. The DNA sequence of Lamp2b was added to the C-termini of anti-EGFR scFv, anti-CD3 scFv, anti-EGFR/anti-CD3 and anti-CD3/anti- EGFR bi-specific scFvs by overlap extension PCR. The resulting DNA fragments encoding scFv-Lamp2b fusion proteins were inserted into pcDNA3.1 vector with a FLAG tag added into the N-termini by in-frame ligation.

[0256] The resulting plasmids were confirmed by DNA sequencing. Transfection

[0257] ScFv-PDGFR and scFv-Lamp2b fusion proteins were expressed through transient transfection of Expi293F cells. Expi293F cells were cultured at 37°C with 8% C0 ₂ in Expi293 expression medium in shaker flask (125 rpm). For every 75 millions of Expi293F cells, 30 ug of plasmids encoding fusion proteins and 80 ul of ExpiFectamine 293 reagent were used for transfection, and transfection enhancers were added after 16-18 hours. Culture media containing secreted exosomes were harvested every 3 days for twice after transfection.

Exosome Purification

[0258] Exosomes were purified from culture media by differential centrifugation processes. Media were centrifuged at 4000 g for 30 min, and then at 12,000 g for 40 min to remove cell debris. The resulting supernatant was then spun at 120,000 g for 2h, and a pellet was recovered after the ultracentrifugation. The supernatant was aspirated and the pellet was washed and then resuspended with PBS. The purified exosomes were then analyzed and used for experimental procedures.

Western blotting

[0259] Western blotting (FIG. 6, 7, 16, 22, and 25,: Protein concentrations of purified exosomes were measured using Bradford assay kit. 5 ug of exosomes were loaded onto SDS- PAGE gel. Following electrophoresis, the proteins were transferred to a polyvinylidene difluoride (PVDF) membrane. The membrane was then blocked for 1 h at room temperature with 5% BSA in PBS with 0.05% Tween-20, and incubated overnight at 4°C with the following primary antibodies: anti-HA (Thermo Fisher Scientific, 1 : 1000), anti-FLAG (Thermo Fisher Scientific, 1 : 1000), anti-CD63(H5C6), Biolegend; anti-CD81(1.3.3.22) Thermo Fisher; anti-CD9(D801 A), Cell Signaling Technology. Secondary antibodies were incubated for 1 h at room temperature. Washes after antibody incubations were done with an orbital shaker, three times at 5-min intervals, with PBS containing 0.05% Tween-20.

Membranes were developed with chemiluminescent reagents. For the blotting of HA tag, FLAG tag and CD9, exosome samples were boiled in LDS sample buffer with dithiothreitol (DTT). For the blotting of CD81 and CD63, exosome samples were boiled in LDS sample buffer without DTT.

Nanoparticle Tracking Analysis (NTA)

[0260] NTA was carried out using the Nanosight NS200-HS system (NanoSight) on exosomes resuspended in PBS at a concentration of -20 μg/ml, and were further diluted from 10- to 100-fold for analysis. The system focused a laser beam through a suspension of the particles of interest. These were visualized by light scattering, using a conventional optical microscope aligned normally to the beam axis, which collected light scattered from every particle in the field of view. A video recorded all events for further analysis by NTA software. The Brownian motion of each particle was tracked between frames, ultimately allowing calculation of the size through application of the Stokes-Einstein equation.

[0261] FIGS. 10, 18 and 26 were acquired via Nanoparticle Tracking Analysis (NTA): Size distribution of exosomes was analyzed through dynamic light scattering (DLS) using Nanosight LM10 (Malvern Instruments, UK) according to the manufacturer's instructions. Exosomes suspended in PBS were diluted from 10- to 1000-fold for analysis. Samples were injected to NTA instrument. Ten replicates of analysis by 60 seconds each were performed. PBS was used as a control. The system focused a laser beam through a suspension of the particles of interest. These were visualized by light scattering, using a conventional optical microscope aligned normally to the beam axis, which collected light scattered from every particle in the field of view. A video recorded all events for further analysis by NTA software. The Brownian motion of each particle was tracked between frames, ultimately allowing calculation of the size through application of the Stokes-Einstein equation.

Transmission electron microscopy (TEM)

[0262] Transmission electron microscopy (TEM): TEM grids (FIGS. 19 and 27) were pretreated by placing 20 μL of the 0.1% poly-lysine solution on the grid and incubating for 10 minutes. Residual solvent was removed with filter paper. Exosome samples were prepared for TEM analysis by placing 20 μL of the sample solution on 200 μπι mesh grids and incubating for 15 minutes. Residual solvent was removed from the grids with filter paper. After that, 20 μL of 2% Uranyl Acetate solution was placed on the grids for 5 minutes. After incubation, solution was removed with filter paper and exosome samples were loaded to Jeol 201 OF TEM (JEOL, Peabody, MA) for analysis.

Flow cytometry

[0263] Cells were incubated with exosomes at the concentration of 0.1 μg/μl for 1 h at 4°C. Excess exosomes were washed away with 2% FBS in PBS. Exosome-bound cells were identified with anti-HA/Flag antibodies (Thermo Fisher Scientific) at 0.1 μg/μl, and revealed by Alexa Fluor 488-conjugated anti-Mouse secondary antibody at 0.1 μg/μl (Thermo Fisher Scientific). To measure the cell-surface expression level of HER2, cells were stained with Herceptin and FITC conjugated anti-Human IgG (H+L) (Thermo Fisher Scientific) at 0.1 μg/μl for 1 h at 4°C. To measure the cell-surface expression level of EGFR, cells were stained with anti-EGFR Mouse antibody (BioLegend) and Alexa Fluor 488-conjugated anti- Mouse secondary antibody at 0.1 μg/μl for 1 h at 4°C. To measure the cell-surface expression level of CD3, cells were stained with FITC conjugated anti-Human CD3 antibody (BioLegend) at indicated concentration for 1 h at 4°C. Cell samples were analyzed using FACSCalibur. FACS data was analyzed with FlowJo.

[0264] The binding affinity of bispecific exosomes on breast cancer cells (MDA-MB- 453, MDA-MB231, MDA-MB-468, HCC 1954, SK-BR-3 and BT20) and human T cells (Jurkat) were determined by flow cytometry (FIG. 8,9,17A and 36A). Cells were incubated with 0.1 mg/mL exosomes in PBS with 0.2% FBS for 1 h at 4 °C. After washing twice with PBS containing 0.2% FBS, cells were incubated with anti-HA antibody (2-2.2.14) (Thermo Fisher) for 1 h at 4 °C. After washing twice with PBS containing 0.2% FBS, the cells were incubated with Alexa Fluor 488 labeled Anti-Mouse IgG H&L (abl50113, Abeam) for 30 min at 4 °C. Fluorescence signals were analyzed using LSR II Flow Cytometer (BD biosciences) and FlowJo VIO software (Treestar).

Fluorescence imaging

[0265] SK-BR-3 (HER2+), HCC-1954 (HER2+), MDA-MB-468 (EGFR+, HER2-) and MDA-MB-453 (EGFR-) cells were stained with CFSE, and Jurkat (CD3+) cells Q x lO ⁶ ) were stained with Mito Tracker Red following manufacturer's protocol. Jurkat cells were incubated with bi-specific exosomes (0.1 μg/μl) in 100 μΐ of PBS for 30 min at 4°C. As negative controls, Jurkat cells were incubated with a 1 : 1 mixture of anti-HER2/anti-EGFR and anti-CD3 mono-specific exosomes (0.05 μg/μl each). After washing with 1 mL of cold PBS, the Jurkat cells were resuspended with 300 μΐ of RPMI1640 media with 10% FBS, then mixed with SK-BR-3, HCC-1954, MDA-MB-468 or MDA-MB-453 cells (1 ^χ 10 ⁵ ) in the same media (300 μΐ). The cell mixtures were added into 24-well plates on top of cover slips, and incubated at 37°C and 5% C0 ₂ . After 6 h, cover slips were gently washed with PBS three times to remove free Jurkat cells, and fixed with 4% PFA. The cover slips were mounted onto glass slides and imaged using Leica SP8 confocal microscope.

[0266] SK-BR-3 (HER2+) AND MDA-MB-468 (EGFR+, HER2-) cells were stained with Mito Tracker Red, and Jurkat (CD3+) cells (1 x 10 ⁶ ) were stained with CFSE following manufacturer's protocol (FIGS. 11, 12 and 28). Jurkat cells were incubated with bi-specific exosomes (0.1 μg/μl) in 100 μΐ of PBS for 30 min at 4°C. As negative controls, Jurkat cells were incubated with a 1 : 1 mixture of anti-HER2 and anti-CD3 mono-specific exosomes (0.05 μg/μl each). After washing with 1 mL of cold PBS, the Jurkat cells were resuspended with 300 μΐ of RPMI1640 media with 10% FBS, then mixed with SK-BR-3, or MDA-MB-468 cells (1 x 10 ⁵ ) in the same media (300 μΐ). The cell mixtures were added into 24-well plates on top of cover slips, and incubated at 37°C and 5% C0 ₂ . After 6 h, cover slips were gently washed with PBS three times to remove free Jurkat cells, and fixed with 4% PFA. The cover slips were mounted onto glass slides and imaged using a fluorescent microscope (Eclipse Ti, Nikon).

[0267] MDA-MB-468 (EGFR+) and MDA-MB-453 (EGFR-) cells were stained with MitoTracker Red (Biolegend), and Jurkat (CD3+) cells (1 ^χ 10 ⁶ ) were stained with

carboxyfluorescein succinimidyl ester (CFSE, Biolegend) (FIG. 20 and 39 ) following manufacturer's protocol. Jurkat cells were incubated with bi-specific exosomes (0.1 μg/μl) in 100 μΐ of PBS for 30 min at 4°C. As negative controls, Jurkat cells were incubated with a 1 : 1 mixture of anti-EGFR and anti-CD3 mono-specific exosomes (0.05 μg/μl each). After washing with 1 mL of cold PBS, the Jurkat cells were resuspended with 300 μΐ of RPMI1640 media with 10% FBS, then mixed with MDA-MB-468 or MDA-MB-453 (1 x 10 ⁵ ) in the same media (300 μΐ). The cell mixtures were added into 24-well plates on top of cover slips, and incubated at 37°C and 5% C0 ₂ . After 6 h, cover slips were gently washed with PBS three times to remove free Jurkat cells, and fixed with 4% PFA. The cover slips were mounted onto glass slides and imaged using Leica SP8 confocal microscope.

[0268]

In vitro cytotoxicity assay

[0269] Purified human peripheral blood mononuclear cells (PBMCs) were purchased from HemaCare Corporation (Los Angeles, CA). Non-activated PBMCs (effector cells) were washed and incubated in flasks in RPMI1640 media with 10 % FBS for 2 hours to remove adherent cells. SK-BR-3 (HER2+), HCC-1954 (HER2+), BT-474 (HER2+), and MDA-MB- 468 (FIER2-) cells (target cells) were dissociated with 0.05 % tryspin/EDTA solution and washed with RPMI1640 with 10 % FBS. Non-activated human PBMCs were mixed with target cells at an E:T ratio of 10 in 100 μΐ, and incubated with different concentrations of bi- specific exosomes, as well as mixtures of mono-specific exosomes, for 40 hours at 37°C. Cytotoxicity of each well was measured by MTT assay. Briefly, 96-well plates were washed three times with PBS to remove PBMC suspension, and 100 μΐ/well of RPMI1640 media (10% FBS) with 0.5 mg/ml MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was added. The plates were incubated for 4 h at 37°C. 100 μΐ of lysis buffer (20% sodium dodecyl sulfate (SDS) in 50% Ν,Ν-dimethylformamide, containing 0.5% [v:v] 80% acetic acid and 0.4% [v:v] IN HCL) was added to each well and incubated at 37°C. After 4 h incubation, absorbance at 570 nm was measured by the plate reader.

[0270] Percent cell viability was calculated by: % Cell viability = (Absorbance _expt -

Absorbance untreated control cells ^~ Absorbance backgrOUnd)/( Absorbance untreated control cells -

Absorbance background)-

[0271] In vitro cytotoxicity assay: Purified human peripheral blood mononuclear cells (PBMCs) were purchased from HemaCare Corporation (Los Angeles, CA). Non-activated PBMCs (effector cells) were washed and incubated in flasks in RPMI1640 media with 10 % FBS for 2 hours to remove adherent cells. MDA-MB-468 (EGFR+), BT20 (EGFR+), MDA- MB-231 (EGFR+), and MDA-MB-453 (EGFR-) cells (target cells) (FIG. 17B and 36B) were dissociated with 0.05 % tryspin/EDTA solution and washed with RPMI1640 with 10 % FBS. Non-activated human PBMCs were mixed with target cells at an E:T ratio of 8 in 100 μΐ, and incubated with different concentrations of bi-specific exosomes, as well as mixtures of mono-specific exosomes, for 40 hours at 37°C. Cytotoxicity of each well was measured by MTT assay. Briefly, 96-well plates were washed three times with PBS to remove PBMC suspension, and 100 μΐ/well of RPMI1640 media (10% FBS) with 0.5 mg/ml MTT (3-(4,5- Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was added. The plates were incubated for 4 h at 37°C. 100 μΐ of lysis buffer (20% sodium dodecyl sulfate (SDS) in 50% Ν,Ν-dimethylformamide, containing 0.5% [v:v] 80% acetic acid and 0.4% [v:v] IN HCL) was added to each well and incubated at 37°C. After 4 h incubation, absorbance at 570 nm was measured by the plate reader.

T cell activation assay

[0272] Freshly-thawed human PBMCs were incubated with target cells in the presence of bispecific exosomes or control monospecific exosomes. After 20 h, cells were labeled with FITC-conjugated anti-CD3, APC-Cy7-conjugated anti-human CD25, APC-conjugated anti- human CD69 (Biolegend) and analyzed by flow cytometry. The release of IFN-γ in the cultured supernatant was measured by enzyme-linked immunosorbent assay (ELISA) kit (R&D System). Results are shown as mean of duplicated samples (FIG. 37).

Zeta potential analysis

[0273] A Zetasizer Nano ZS (Malvern Instruments, U.K.) was used to determine the zeta potential of the exosomes (FIG. 34). Sample solution was loaded to a new Zeta-potential DTS1070 cell and inserted into Zetasizer Nano ZS.

In vivo efficacy study

[0274] All efficacy studies (FIG. 38) were conducted with 6 to 8-week-old female NSG (NOD.Cg-Prkdcscid I12rgtmlWjl/SzJ) mice (Jackson Laboratory). Human breast cancer cell lines (MDA-MB-468, BT20, MDA-MB-231) were used to evaluate the in vivo efficacy of the a-CD3/a-EGFR bispecific exosomes. For MDA-MB-468, BT20 and MDA-MB-231 xenograft tumor models, 5 l0 ⁶ MDA-MB-468 cells or BT20 cells or 1.5 lO ⁶ MDA-MB-231 cells in 50% Matrigel (BD Bioscience) were subcutaneously implanted into the right buttock of the mice, respectively. When the tumor size reach around 80-120 mm ³ after 15-30 days, 20 x 10 ⁶ non-activated human PBMCs were injected into mice via intraperitoneal injection. One day later, mice were administered intravenously with six doses of a-CD3/a-EGFR bispecific exosomes (10 mg/kg) or PBS every other day. Tumors were measured three times weekly by calipers. Tumor volume was calculated based on length ^χ width ^χ width/2. All procedures were approved by USC Animal Care and Use Committee.

Equivalents

[0275] Unless otherwise defined, 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.

[0276] The inventions illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms "comprising," "including," "containing," etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

[0277] Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification, improvement and variation of the inventions embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications, improvements and variations are considered to be within the scope of this invention. The materials, methods, and examples provided here are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention.

[0278] The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.

[0279] All publications, patent applications, patents, and other references mentioned herein are expressly incorporated by reference in their entirety, including all formulas and figures, to the same extent as if each were incorporated by reference individually. In case of conflict, the present specification, including definitions, will control.

[0280] Other embodiments are set forth within the following claims.

[0281] The below section contains color text highlighted to indicate the termini of amino acid and polynucleotide segments of embodiments of this disclosure.

Exemplary Protein and Polypeptide Sequences

Platelet derived growth factor receptor beta (PDGFRB) (Entrez gene: 5159; RefSeq: NM_002609, NP_002600), Lysosome-associated membrane protein 2 Variant B (LAMP2b) (Entrez gene: 3920; RefSeq: NM_013995, NP_054701), Milk fat globule-EGF factor 8 protein (Mfge8) also known as lactadherin (Entrez gene: 4240; RefSeq: NM_001114614, NM_001310319, NM_001310320, NM_001310321, NM_005928, NP_054701 ,

NP_001108086, NP_001297248, NP_001297249, NP_001297250, NP_005919), CD13 also known as Alanyl aminopeptidase, membrane (ANPEP) (Entrez gene: 290; RefSeq:

NM_001150, NP_001141), CD9 (Entrez gene: 928; RefSeq: NM_001769, NM_001330312, NP 001317241, NP 001760), anti-CD3 scFV, anti-HER2 scFV, anti-EGFR scFV, Human epidermal growth factor receptor 2 (HER2) (Entrez gene: 2064; RefSeq: NP_001005862, NP_001276865, NP_001276866, NP_001276867, NP_004439), Human epidermal growth factor receptor 3 (HER3) (Entrez gene: 2065; RefSeq: NP_001005915, NP_001973), Epidermal growth factor receptor (EGFR) (Entrez gene: 1956; RefSeq: NP 001333826, NP_001333827, NP_001333828, NP_001333829, NP_001333870), Cluster of differentiation 3d (CD3d) (Entrez gene: 915; RefSeq: NP_000723, NP_001035741), Cluster of

differentiation 3e (CD3e) (Entrez gene: 916; RefSeq: NP 000724), Cluster of differentiation 3g (CD3g) (Entrez gene: 917; RefSeq: NP 000064), Cluster of differentiation 16a (CD16a) (Entrez gene 2214; RefSeq: NP_000560, NP_001121064, NP_001121065, NP_001121067, NP_001121068), Cluster of differentiation 16b (CD16b) (Entrez gene: 2215; RefSeq:

NP_000561, NP_001231682, NP_001257964, NP_001257965, NP_001257966), Cluster of differentiation 4 (CD4) (Entrez gene: 920; RefSeq: NP_000607, NP_001181943,

NP_001181944, NP_001181945, NP_001181946), Cluster of differentiation 8a (CD8a) (Entrez gene: 925; RefSeq: NP_001139345, NP_001759, NP_741969), Cluster of

differentiation 8b (CD8b) (Entrez gene: 926; RefSeq: NP_001171571, NP_004922,

NP_742099, NP_742100, NP_757362 ), Cluster of differentiation 11a (CD1 la) (Entrez gene: 3683; RefSeq: NP_001107852, NP_002200), Cluster of differentiation 19 (CD19) (Entrez gene:930; RefSeq: NP_001171569, NP_001761), Cluster of differentiation 20 (CD20) (Entrez gene: 931; RefSeq: NP 068769, NP 690605), Interleukin-2 receptor alpha chain (CD25) (Entrez gene: 3559; RefSeq: NP_000408, NP_001295171, NP_001295172), Cluster of differentiation 33 (CD33) (Entrez gene: 945; RefSeq: NP_001076087, NP_001171079, NP_001763), Cluster of differentiation 40 (CD40) (Entrez gene: 958; RefSeq: NP_001241, NP_001289682, NP_001309350, NP_001309351, NP_690593), CD40 ligand (CD40L) (Entrez gene: 959; RefSeq: NP_000065), Cluster of differentiation 70 (CD70) (Entrez gene: 970; RefSeq: NP_001243, NP_001317261), Interleukin-3 receptor alpha (CD123) (Entrez gene: 3563; RefSeq: NP_001254642, NP_002174), Epithelial cell adhesion molecule

(EpCAM) (Entrez gene: 4072; RefSeq: NP_002345), C-type lectin domain family 12 member A (CLL-1) (Entrez gene: 160364; RefSeq: NP_001193939, NP_001287659,

NP_612210NP_963917), Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) (Entrez gene: 1493; RefSeq: NP_001032720, NP_005205), Programmed cell death protein 1 (PD-1) (Entrez gene: 5133; RefSeq: NP 005009), Programmed death-ligand 1 (PD-L1) (Entrez gene: 29126; RefSeq: NP_001254635, NP_001300958, NP_054862), Tumor necrosis factor receptor superfamily, member 4 (OX40) (Entrez gene: 7293; RefSeq: NP_003318), Glucocorticoid-induced TNFR-related protein (GITR) (Entrez gene: 8784; RefSeq:

NP 004186, NP 683699, NP 683700), Inducible T-cell COStimulator (ICOS) (Entrez gene: 29851; RefSeq: NP_036224), Cluster of Differentiation 276 (B7-H3) (Entrez gene: 80381; RefSeq: NP_001019907, NP_001316557, NP_001316558, NP_079516), V-set domain- containing T-cell activation inhibitor 1 (B7-H4) (Entrez gene: 79679; RefSeq:

NP_001240778, NP_001240779, NP_078902), Lymphocyte-activation gene 3 (LAG3) (Entrez gene: 3902; RefSeq: NP 002277), T-cell immunoglobulin and mucin-domain containing-3 (TEVI-3) (Entrez gene: 84868; RefSeq: NP_116171), Prostate-specific membrane antigen (PSMA) (Entrez gene: 2346; RefSeq: NP_001014986, NP_001 180400, NP_001180401, NP_001180402, NP_004467), Factor IX (Entrez gene: 2158; RefSeq:

NP_000124, NP_001300842), Factor X (Entrez gene: 2159; RefSeq: NP_000495,

NP_001299603, NP_001299604), Folate receptor alpha (FOLR1) (Entrez gene: 2348;

RefSeq: NP_000793, NP_057936, NP_057937, NP_057941), Folate receptor beta (FOLR2) (Entrez gene: 2350; RefSeq: NP_000794, NP_001107006, NP_001107007, NP_001107008), Folate receptor gamma (FOLR3) (Entrez gene: 2352; RefSeq: NP_000795, NP_001304974).

HA-tag DNA sequence: 5'-TATCCATATGATGTTCCAGATTATGCT-3' (SEQ ID NO: 33) or 5'-TAC CCA TAG GAT GTT CCA GAT TAG GCT-3'(SEQ ID NO: 34), amino acid sequence is YPYDVPDYA (SEQ ID NO: 35)

FLAG-tag DNA sequence: GACTACAAAGACGATGACGACAAG (SEQ ID NO: 36), amino acid sequence is DYKDDDDK (SEQ ID NO: 89) (1012 Da). Additionally, it may be used in tandem, commonly the 3xFLAG peptide: DYKDFIDG-DYKDHD/- DYKDDDDK(SEQ ID NO: 37).

6XHis-tag Protein sequence: HHHHHH (SEQ ID NO: 1)