CHEUNG NAI-KONG V (US)
SANTICH BRIAN (US)
WHAT IS CLAIMED IS: 1. An ex vivo armed T cell that is coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody, wherein the at least one type of anti- CD3 multi-specific antibody includes a CD3 binding domain comprising a heavy chain immunoglobulin variable domain (VH) and a light chain immunoglobulin variable domain (VL), wherein (a) the VH comprises a VH-CDR1 sequence of SEQ ID NO: 1, a VH-CDR2 sequence of SEQ ID NO: 2, and a VH-CDR3 sequence of SEQ ID NO: 3, and (b) the VL comprises a VL-CDR1 sequence of SEQ ID NO: 4, a VL-CDR2 sequence of SEQ ID NO: 5, and a VL-CDR3 sequence of SEQ ID NO: 6, wherein the at least one type of anti-CD3 multi-specific antibody is an immunoglobulin comprising two heavy chains and two light chains, wherein each of the light chains is fused to a single chain variable fragment (scFv), and wherein the ex vivo armed T cell is or has been cryopreserved. 2. The ex vivo armed T cell of claim 1, wherein the ex vivo armed T cell is a helper T cell, a cytotoxic T cell, a memory T cell, a stem-cell-like memory T cell, an effector memory T cell, a regulatory T cell, a Natural killer T cell, a Mucosal associated invariant T cell, an EBV-specific cytotoxic T cell (EBV-CTL), an αβ T cell, or a γδ T cell. 3. The ex vivo armed T cell of claim 1 or 2, wherein the ex vivo armed T cell has been cryopreserved for a period of about 2 hours to about 6 months. 4. An ex vivo armed T cell that is coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody, wherein the at least one type of anti- CD3 multi-specific antibody includes a CD3 binding domain comprising a heavy chain immunoglobulin variable domain (VH) and a light chain immunoglobulin variable domain (VL), wherein (a) the VH comprises a VH-CDR1 sequence of SEQ ID NO: 1, a VH-CDR2 sequence of SEQ ID NO: 2, and a VH-CDR3 sequence of SEQ ID NO: 3, and (b) the VL comprises a VL-CDR1 sequence of SEQ ID NO: 4, a VL-CDR2 sequence of SEQ ID NO: 5, and a VL-CDR3 sequence of SEQ ID NO: 6, wherein the at least one type of anti-CD3 multi-specific antibody is an immunoglobulin comprising two heavy chains and two light chains, wherein each of the light chains is fused to a single chain variable fragment (scFv), and wherein the ex vivo armed T cell is a γδ T cell. 5. The ex vivo armed T cell of claim 4, wherein the ex vivo armed T cell is generated by contacting peripheral blood mononuclear cells with zoledronate and IL-15. 6. The ex vivo armed T cell of claim 5, wherein the IL-15 is administered as an IL15Rα- IL15 complex. 7. The ex vivo armed T cell of any one of claims 1-6, wherein at least one scFv of the at least one type of anti-CD3 multi-specific antibody comprises the CD3 binding domain. 8. The ex vivo armed T cell of claim 7, wherein at least one scFv of the at least one type of anti-CD3 multi-specific antibody comprises a DOTA binding domain. 9. An ex vivo armed T cell that is coated or complexed with an effective arming dose of at least two types of anti-CD3 multi-specific antibodies, wherein each of the at least two types of anti-CD3 multi-specific antibodies includes a CD3 binding domain comprising a heavy chain immunoglobulin variable domain (VH) and a light chain immunoglobulin variable domain (VL), wherein (a) the VH comprises a VH-CDR1 sequence of SEQ ID NO: 1, a VH-CDR2 sequence of SEQ ID NO: 2, and a VH-CDR3 sequence of SEQ ID NO: 3, and (b) the VL comprises a VL-CDR1 sequence of SEQ ID NO: 4, a VL-CDR2 sequence of SEQ ID NO: 5, and a VL-CDR3 sequence of SEQ ID NO: 6, and wherein each of the at least two types of anti-CD3 multi-specific antibodies is an immunoglobulin comprising two heavy chains and two light chains, wherein each of the light chains is fused to a single chain variable fragment (scFv). 10. The ex vivo armed T cell of claim 9, comprising 2, 3, 4, or 5 types of anti-CD3 multi- specific antibodies. 11. The ex vivo armed T cell of any one of claims 9-10, wherein at least one scFv of each of the at least two types of anti-CD3 multi-specific antibodies comprises the CD3 binding domain. 12 The ex vivo armed T cell of claim 11, wherein one or more of the at least two types of anti-CD3 multi-specific antibodies comprises a DOTA binding domain. 13. The ex vivo armed T cell of claim 12, wherein one or more of the at least two types of anti-CD3 multi-specific antibodies comprise a scFv that includes the DOTA binding domain. 14. An ex vivo armed T cell that is coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody, wherein the at least one type of anti- CD3 multi-specific antibody includes a CD3 binding domain comprising a heavy chain immunoglobulin variable domain (VH) and a light chain immunoglobulin variable domain (VL), wherein (a) the VH comprises a VH-CDR1 sequence of SEQ ID NO: 1, a VH-CDR2 sequence of SEQ ID NO: 2, and a VH-CDR3 sequence of SEQ ID NO: 3, and (b) the VL comprises a VL-CDR1 sequence of SEQ ID NO: 4, a VL-CDR2 sequence of SEQ ID NO: 5, and a VL-CDR3 sequence of SEQ ID NO: 6, wherein the at least one type of anti-CD3 multi-specific antibody is an immunoglobulin comprising two heavy chains and two light chains, wherein each of the light chains is fused to a single chain variable fragment (scFv), wherein at least one scFv of the at least one type of anti-CD3 multi-specific antibody comprises the CD3 binding domain, and wherein at least one scFv of the at least one type of anti-CD3 multi-specific antibody comprises a DOTA binding domain. 15. The ex vivo armed T cell of any one of claims 9-14, wherein the ex vivo armed T cell is a helper T cell, a cytotoxic T cell, a memory T cell, a stem-cell-like memory T cell, an effector memory T cell, a regulatory T cell, a Natural killer T cell, a Mucosal associated invariant T cell, an EBV-specific cytotoxic T cell (EBV-CTL), an αβ T cell, or a γδ T cell. 16. The ex vivo armed T cell of claim 8 or 12-15, wherein the DOTA binding domain comprises the amino acid sequence of any one of SEQ ID NOs: 77-80. 17. The ex vivo armed T cell of any one of claims 1-8 or 14-16, wherein the at least one type of anti-CD3 multi-specific antibody binds one or more additional target antigens. 18. The ex vivo armed T cell of any one of claims 9-13, 15 or 16, wherein the at least two types of anti-CD3 multi-specific antibodies bind two or more additional target antigens. 19. The ex vivo armed T cell of claim 17 or 18, wherein the additional target antigens are selected from the group consisting of CD3, GPA33, HER2/neu, GD2, MAGE-1, MAGE-3, BAGE, GAGE-1, GAGE-2, MUM-1, CDK4, N-acetylglucosaminyltransferase, p15, gp75, beta-catenin, ErbB2, cancer antigen 125 (CA-125), carcinoembryonic antigen (CEA), RAGE, MART (melanoma antigen), MUC-1, MUC-2, MUC-3, MUC-4, MUC-5ac, MUC-16, MUC- 17, tyrosinase, Pmel 17 (gp100), GnT-V intron V sequence (N- acetylglucoaminyltransferase V intron V sequence), Prostate cancer psm, PRAME (melanoma antigen), β-catenin, EBNA (Epstein-Barr Virus nuclear antigen) 1-6, LMP2, p53, lung resistance protein (LRP), Bcl-2, prostate specific antigen (PSA), Ki-67, CEACAM6, colon-specific antigen-p (CSAp), HLA- DR, CD40, CD74, CD138, EGFR, EGP-1, EGP-2, VEGF, PlGF, insulin-like growth factor (ILGF), tenascin, platelet-derived growth factor, IL-6, CD20, CD19, PSMA, CD33, CD123, MET, DLL4, Ang-2, HER3, IGF-1R, CD30, TAG-72, SPEAP, CD45, L1-CAM, Lewis Y (Ley) antigen, E-cadherin, V-cadherin, GPC3, EpCAM, CD4, CD8, CD21, CD23, CD46, CD80, HLA-DR, CD74, CD22, CD14, CD15, CD16, CD123, TCR gamma/delta, NKp46, KIR, CD56, DLL3, PD-1, PD-L1, CD28, CD137, CD99, GloboH, CD24, STEAP1, B7H3, Polysialic Acid, OX40, OX40-ligand, peptide MHC complexes (with peptides derived from TP53, KRAS, MYC, EBNA1-6, PRAME, MART, tyronsinase, MAGEA1-A6, pmel17, LMP2, or WT1), and a DOTA-based hapten. 20. The ex vivo armed T cell of any one of claims 1-19, wherein the VH of the CD3 binding domain comprises the amino acid sequence of any one of SEQ ID NOs: 7-32, and/or wherein the VL of the CD3 binding domain comprises the amino acid sequence of any one of SEQ ID NOs: 33-70. 21. The ex vivo armed T cell of any one of claims 1-20, wherein the at least one type of anti CD3 multi specific antibody or one or more of the at least two types of anti CD3 multi specific antibodies comprise a heavy chain (HC) amino acid sequence comprising SEQ ID NO: 82, SEQ ID NO: 84, SEQ ID NO: 86, SEQ ID NO: 88, SEQ ID NO: 90, SEQ ID NO: 94, SEQ ID NO: 96, SEQ ID NO: 98, SEQ ID NO: 100, SEQ ID NO: 115, SEQ ID NO: 117, SEQ ID NO: 119, SEQ ID NO: 121, SEQ ID NO: 123, SEQ ID NO: 125, SEQ ID NO: 127, SEQ ID NO: 129, SEQ ID NO: 131, SEQ ID NO: 133, SEQ ID NO: 135, SEQ ID NO: 137, SEQ ID NO: 139, SEQ ID NO: 141, SEQ ID NO: 143, SEQ ID NO: 145, SEQ ID NO: 147, SEQ ID NO: 149, SEQ ID NO: 151, SEQ ID NO: 153, SEQ ID NO: 155, SEQ ID NO: 157, SEQ ID NO: 163, SEQ ID NO: 165, SEQ ID NO: 167, SEQ ID NO: 169, or a variant thereof having one or more conservative amino acid substitutions, and/or a light chain (LC) amino acid sequence comprising SEQ ID NO: 81, SEQ ID NO: 83, SEQ ID NO: 85, SEQ ID NO: 87, SEQ ID NO: 89, SEQ ID NO: 93, SEQ ID NO: 95, SEQ ID NO: 97, SEQ ID NO: 99, SEQ ID NO: 114, SEQ ID NO: 116, SEQ ID NO: 118, SEQ ID NO: 120, SEQ ID NO: 122, SEQ ID NO: 124, SEQ ID NO: 126, SEQ ID NO: 128, SEQ ID NO: 130, SEQ ID NO: 132, SEQ ID NO: 134, SEQ ID NO: 136, SEQ ID NO: 138, SEQ ID NO: 140, SEQ ID NO: 142, SEQ ID NO: 144, SEQ ID NO: 146, SEQ ID NO: 148, SEQ ID NO: 150, SEQ ID NO: 152, SEQ ID NO: 154, SEQ ID NO: 156, SEQ ID NO: 162, SEQ ID NO: 164, SEQ ID NO: 166, SEQ ID NO: 168, or a variant thereof having one or more conservative amino acid substitutions. 22. The ex vivo armed T cell of claim 21, wherein the at least one type of anti-CD3 multi- specific antibody, or one or more of the at least two types of anti-CD3 multi-specific antibodies comprise a HC amino acid sequence and a LC amino acid sequence selected from the group consisting of: SEQ ID NO: 82 and SEQ ID NO: 81, SEQ ID NO: 84 and SEQ ID NO: 83, SEQ ID NO: 86 and SEQ ID NO: 85, SEQ ID NO: 88 and SEQ ID NO: 87, SEQ ID NO: 90 and SEQ ID NO: 89, SEQ ID NO: 94 and SEQ ID NO: 93, SEQ ID NO: 96 and SEQ ID NO: 95 SEQ ID NO: 98 and SEQ ID NO: 97, SEQ ID NO: 100 and SEQ ID NO: 99, SEQ ID NO: 115 and SEQ ID NO: 114, SEQ ID NO: 117 and SEQ ID NO: 116, SEQ ID NO: 119 and SEQ ID NO: 118, SEQ ID NO: 121 and SEQ ID NO: 120, SEQ ID NO: 123 and SEQ ID NO: 122, SEQ ID NO: 125 and SEQ ID NO: 124, SEQ ID NO: 127 and SEQ ID NO: 126, SEQ ID NO: 129 and SEQ ID NO: 128, SEQ ID NO: 131 and SEQ ID NO: 130, SEQ ID NO: 133 and SEQ ID NO: 132, SEQ ID NO: 135 and SEQ ID NO: 134, SEQ ID NO: 137 and SEQ ID NO: 136, SEQ ID NO: 139 and SEQ ID NO: 138, SEQ ID NO: 141 and SEQ ID NO: 140, SEQ ID NO: 143 and SEQ ID NO: 142, SEQ ID NO: 145 and SEQ ID NO: 144, SEQ ID NO: 147 and SEQ ID NO: 146, SEQ ID NO: 149 and SEQ ID NO: 148, SEQ ID NO: 151 and SEQ ID NO: 150, SEQ ID NO: 153 and SEQ ID NO: 152, SEQ ID NO: 155 and SEQ ID NO: 154, SEQ ID NO: 157 and SEQ ID NO: 156, SEQ ID NO: 163 and SEQ ID NO: 162, SEQ ID NO: 165 and SEQ ID NO: 164, SEQ ID NO: 167 and SEQ ID NO: 166, SEQ ID NO: 169 and SEQ ID NO: 168, respectively. 23. The ex vivo armed T cell of claim 21, wherein the at least one type of anti-CD3 multi- specific antibody, or one or more of the at least two types of anti-CD3 multi-specific antibodies comprise a first LC amino acid sequence, a first HC amino acid sequence, a second LC amino acid sequence, and a second HC amino acid sequence selected from the group consisting of SEQ ID NO: 114, SEQ ID NO: 115, SEQ ID NO: 116, and SEQ ID NO: 117; SEQ ID NO: 118, SEQ ID NO: 119, SEQ ID NO: 120, and SEQ ID NO: 121; SEQ ID NO: 122, SEQ ID NO: 123, SEQ ID NO: 124, and SEQ ID NO: 125; SEQ ID NO: 126, SEQ ID NO: 127, SEQ ID NO: 128, and SEQ ID NO: 129; SEQ ID NO: 130, SEQ ID NO: 131, SEQ ID NO: 132, and SEQ ID NO: 133; SEQ ID NO: 134, SEQ ID NO: 135, SEQ ID NO: 136, and SEQ ID NO: 137; SEQ ID NO: 138, SEQ ID NO: 139, SEQ ID NO: 140, and SEQ ID NO: 141; SEQ ID NO: 142, SEQ ID NO: 143, SEQ ID NO: 144, and SEQ ID NO: 145; SEQ ID NO: 146, SEQ ID NO: 147, SEQ ID NO: 148, and SEQ ID NO: 149; SEQ ID NO: 150, SEQ ID NO: 151, SEQ ID NO: 152, and SEQ ID NO: 153; SEQ ID NO: 154, SEQ ID NO: 155, SEQ ID NO: 156, and SEQ ID NO: 157; SEQ ID NO: 162, SEQ ID NO: 163, SEQ ID NO: 164, and SEQ ID NO: 165; and SEQ ID NO: 166, SEQ ID NO: 167, SEQ ID NO: 168, and SEQ ID NO: 169; respectively. 24. The ex vivo armed T cell of any one of claims 1-23, wherein the at least one type of anti-CD3 multi-specific antibody exhibits surface densities between about 500 to about 20,000 molecules per T cell or wherein the at least two types of anti-CD3 multi-specific antibodies exhibit surface densities between about 1,500 to 10,000 molecules per T cell. 25. The ex vivo armed T cell of any one of claims 1-24, wherein the effective arming dose of the at least one type of anti-CD3 multi-specific antibody or the at least two types of anti- CD3 multi-specific antibodies is between about 0.05μg/106 T cells to about 5μg/106 T cells. 26. A method for tracking ex vivo armed T cells in a subject in vivo comprising (a) administering to the subject an effective amount of the ex vivo armed T cell of any one of claims 8 or 12-25, wherein the ex vivo armed T cell is configured to localize to a tissue expressing one or more target antigens recognized by the at least one type of anti-CD3 multi- specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; (b) administering to the subject an effective amount of a radiolabeled DOTA-based hapten, wherein the radiolabeled DOTA-based hapten is configured to bind to the at least one type of anti-CD3 multi-specific antibody or one or more of the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; and (c) determining the biodistribution of the ex vivo armed T cell in the subject by detecting radioactive levels emitted by the radiolabeled DOTA-based hapten that are higher than a reference value. 27. A method for tracking ex vivo armed T cells in a subject in vivo comprising (a) administering to the subject an effective amount of a complex comprising the ex vivo armed T cell of any one of claims 8 or 12-25 and a radiolabeled DOTA-based hapten, wherein the complex is configured to localize to a tissue expressing one or more target antigens recognized by the at least one type of anti-CD3 multi-specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; and (b) determining the biodistribution of the ex vivo armed T cell in the subject by detecting radioactive levels emitted by the complex that are higher than a reference value. 28. A method for detecting tumors in a subject in need thereof comprising (a) administering to the subject an effective amount of the ex vivo armed T cell of any one of claims 8 or 12-25, wherein the ex vivo armed T cell is configured to localize to a tissue expressing one or more target antigens recognized by the at least one type of anti-CD3 multi- specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; (b) administering to the subject an effective amount of a radiolabeled DOTA-based hapten, wherein the radiolabeled DOTA-based hapten is configured to bind to the at least one type of anti-CD3 multi-specific antibody or one or more of the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; and (c) detecting the presence of tumors in the subject by detecting radioactive levels emitted by the radiolabeled DOTA-based hapten that are higher than a reference value. 29. A method for detecting tumors in a subject in need thereof comprising (a) administering to the subject an effective amount of a complex comprising the ex vivo armed T cell of any one of claims 8 or 12-25 and a radiolabeled DOTA-based hapten, wherein the complex is configured to localize to a tissue expressing one or more target antigens recognized by the at least one type of anti-CD3 multi-specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; and (b) detecting the presence of tumors in the subject by detecting radioactive levels emitted by the complex that are higher than a reference value. 30. A method for assessing the in vivo durability or persistence of ex vivo armed T cells in a subject comprising (a) administering to the subject an effective amount of the ex vivo armed T cell of any one of claims 8 or 12-25, wherein the ex vivo armed T cell is configured to localize to a tissue expressing one or more target antigens recognized by the at least one type of anti-CD3 multi- specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; (b) administering to the subject a first effective amount of a radiolabeled DOTA- based hapten, wherein the radiolabeled DOTA-based hapten is configured to bind to the at least one type of anti-CD3 multi-specific antibody or one or more of the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; and (c) detecting radioactive levels emitted by the radiolabeled DOTA-based hapten that are higher than a reference value at a first time point; (d) detecting radioactive levels emitted by the radiolabeled DOTA-based hapten that are higher than a reference value at a second time point; and (e) determining that the ex vivo armed T cells show in vivo durability or persistence when the radioactive levels emitted by the radiolabeled DOTA-based hapten at the second time point are comparable to that observed at the first time point. 31. The method of claim 30, further comprising administering to the subject a second effective amount of the radiolabeled DOTA-based hapten after step (c). 32. A method for assessing the in vivo durability or persistence of ex vivo armed T cells in a subject comprising (a) administering to the subject an effective amount of a complex comprising the ex vivo armed T cell of any one of claims 8 or 12-25 and a radiolabeled DOTA-based hapten, wherein the complex is configured to localize to a tissue expressing one or more target antigens recognized by the at least one type of anti-CD3 multi-specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell; (b) detecting radioactive levels emitted by the complex that are higher than a reference value at a first time point; (c) detecting radioactive levels emitted by the complex that are higher than a reference value at a second time point; and (d) determining that the ex vivo armed T cells show in vivo durability or persistence when the radioactive levels emitted by the complex at the second time point are comparable to that observed at the first time point. 33. The method of any one of claims 26-32, wherein the radioactive levels emitted by the complex or the radiolabeled DOTA-based hapten are detected using positron emission tomography or single photon emission computed tomography. 34. The method of any one of claims 26-33, wherein the radioactive levels emitted by the complex or the radiolabeled DOTA-based hapten are detected between 4 to 24 hours after the complex or the radiolabeled DOTA-based hapten is administered. 35. The method of any one of claims 26-34, wherein the radioactive levels emitted by the complex or the radiolabeled DOTA-based hapten are expressed as the percentage injected dose per gram tissue ( %ID/g). 36. A method for detecting the presence of a DOTA-based hapten in a subject that has been administered the ex vivo armed T cell of any one of claims 8 or 12-25 comprising (a) administering to the subject an effective amount of a DOTA-based hapten, wherein the DOTA-based hapten comprises a radionuclide, and is configured to localize to the ex vivo armed T cell; and (b) detecting the presence of the DOTA-based hapten in the subject by detecting radioactive levels emitted by the DOTA-based hapten that are higher than a reference value, wherein the ex vivo armed T cell is configured to localize to a tumor expressing one or more target antigens recognized by the at least one type of anti-CD3 multi-specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell. 37. A method for detecting the presence of a DOTA-based hapten in a subject that has been administered a complex comprising the ex vivo armed T cell of any one of claims 8 or 12-25 and a DOTA-based hapten including a radionuclide, comprising detecting the presence of the DOTA-based hapten in the subject by detecting radioactive levels emitted by the complex that are higher than a reference value, wherein the ex vivo armed T cell is configured to localize to a tumor expressing one or more target antigens recognized by the at least one type of anti-CD3 multi-specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell. 38. The method of claim 36 or 37, wherein the radioactive levels emitted by the DOTA- based hapten or complex are detected using positron emission tomography (PET) or single photon emission computed tomography (SPECT). 39. The method of any one of claims 36-38, further comprising quantifying radioactive 40. The method of any one of claims 36-39, further comprising quantifying radioactive levels emitted by the DOTA-based hapten or the complex that is localized in one or more normal tissues or organs of the subject, wherein the one or more normal tissues or organs are selected from the group consisting of heart, muscle, gallbladder, esophagus, stomach, small intestine, large intestine, liver, pancreas, lungs, bone, bone marrow, kidneys, urinary bladder, brain, skin, spleen, thyroid, and soft tissue. 41. The method of claim 40, further comprising determining biodistribution scores by computing a ratio of the radioactive levels emitted by the DOTA-based hapten or complex that is localized to the tumor relative to the radioactive levels emitted by the DOTA-based hapten or complex that is localized in the one or more normal tissues or organs of the subject. 42. The method of claim 41, further comprising calculating estimated absorbed radiation doses for the tumor and the one or more normal tissues or organs of the subject based on the biodistribution scores. 43. The method of claim 42, further comprising computing a therapeutic index for the DOTA-based hapten or complex based on the estimated absorbed radiation doses for the tumor and the one or more normal tissues or organs of the subject. 44. The method of any one of claims 26-43, wherein the DOTA-based hapten is selected from the group consisting of benzyl-DOTA, NH2-benzyl (Bn) DOTA, DOTA- desferrioxamine, DOTA-Phe-Lys(HSG)-D-Tyr-Lys(HSG)-NH2, Ac-Lys(HSG)D-Tyr- Lys(HSG)-Lys(Tscg-Cys)-NH2, DOTA-D-Asp-D-Lys(HSG)-D-Asp-D-Lys(HSG)-NH2; DOTA-D-Glu-D-Lys(HSG)-D-Glu-D-Lys(HSG)-NH2, DOTA-D-Tyr-D-Lys(HSG)-D-Glu- D-Lys(HSG)-NH2, DOTA-D-Ala-D-Lys(HSG)-D-Glu-D-Lys(HSG)-NH2, DOTA-D-Phe-D- Lys(HSG)-D-Tyr-D-Lys(HSG)-NH2, Ac-D-Phe-D-Lys(DOTA)-D-Tyr-D-Lys(DOTA)-NH2, Ac-D-Phe-D-Lys(DTPA)-D-Tyr-D-Lys(DTPA)-NH2, Ac-D-Phe-D-Lys(Bz-DTPA)-D-Tyr- D-Lys(Bz-DTPA)-NH2, Ac-D-Lys(HSG)-D-Tyr-D-Lys(HSG)-D-Lys(Tscg-Cys)- NH2, DOTA-D-Phe-D-Lys(HSG)-D-Tyr-D-Lys(HSG)-D-Lys(Tscg-Cys)-NH2, (Tscg-Cys)- D-Phe-D-Lys(HSG)-D-Tyr-D-Lys(HSG)-D-Lys(DOTA)-NH2, Tscg-D-Cys-D-Glu-D- Lys(HSG)-D-Glu-D-Lys(HSG)-NH2, (Tscg-Cys)-D-Glu-D-Lys(HSG)-D-Glu-D-Lys(HSG)- NH2, Ac-D-Cys-D-Lys(DOTA)-D-Tyr-D-Ala-D-Lys(DOTA)-D-Cys-NH2, Ac-D-Cys-D- Lys(DTPA)-D-Tyr-D-Lys(DTPA)-NH2, Ac-D-Lys(DTPA)-D-Tyr-D-Lys(DTPA)-D- Lys(Tscg-Cys)-NH2, Ac-D-Lys(DOTA)-D-Tyr-D-Lys(DOTA)-D-Lys(Tscg-Cys)-NH2, DOTA-RGD, DOTA-PEG-E(c(RGDyK))2, DOTA-8-AOC-BBN, DOTA-PESIN, p-NO2- benzyl-DOTA, DOTA-biotin-sarcosine (DOTA-biotin), 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid mono (N-hydroxysuccinimide ester) (DOTA-NHS), and DOTATyrLysDOTA 45. A method for determining the antibody binding capacity of the ex vivo armed T cell of any one of claims 1-25 in vitro comprising contacting the ex vivo armed T cell with an agent that binds to the at least one type of anti-CD3 multi-specific antibody or the at least two types of anti-CD3 multi-specific antibodies of the ex vivo armed T cell, wherein the agent is directly or indirectly linked to a detectable label, and determining the antibody binding capacity of the ex vivo armed T cell by detecting the level or intensity of signal emitted by the detectable label. 46. A method for treating cancer or inhibiting tumor growth or metastasis in a subject in need thereof comprising administering to the subject an effective amount of the ex vivo armed T cell of any one of claims 1-25. 47. A method for treating cancer or inhibiting tumor growth or metastasis in a subject in need thereof comprising (a) administering to the subject a first effective amount of an ex vivo armed T cell, (b) administering to the subject a second effective amount of the ex vivo armed T cell about 72 hours after administration of the first effective amount of the ex vivo armed T cell, (c) administering to the subject a third effective amount of the ex vivo armed T cell about 96 hours after administration of the second effective amount of the ex vivo armed T cell, and (d) repeating steps (a)-(c) for at least three additional cycles, wherein the ex vivo armed T cell is coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody, wherein the at least one type of anti-CD3 multi-specific antibody includes a CD3 binding domain comprising a heavy chain immunoglobulin variable domain (VH) and a light chain immunoglobulin variable domain (VL), wherein (i) the VH comprises a VH-CDR1 sequence of SEQ ID NO: 1, a VH-CDR2 sequence of SEQ ID NO: 2, and a VH-CDR3 sequence of SEQ ID NO: 3, and (ii) the VL comprises a VL-CDR1 sequence of SEQ ID NO: 4, a VL-CDR2 sequence of SEQ ID NO: 5, and a VL-CDR3 sequence of SEQ ID NO: 6, and wherein the at least one type of anti-CD3 multi-specific antibody is an immunoglobulin comprising two heavy chains and two light chains, wherein each of the light chains is fused to a single chain variable fragment (scFv), and wherein at least one scFv of the at least one type of anti-CD3 multi-specific antibody comprises the CD3 binding domain. 48. A method for treating cancer or inhibiting tumor growth or metastasis in a subject in need thereof comprising (a) administering to the subject a first effective amount of the ex vivo armed T cell of any one of claims 1-25, (b) administering to the subject a second effective amount of the ex vivo armed T cell about 72 hours after administration of the first effective amount of the ex vivo armed T cell, (c) administering to the subject a third effective amount of the ex vivo armed T cell about 96 hours after administration of the second effective amount of the ex vivo armed T cell, and (d) repeating steps (a)-(c) for at least three additional cycles. 49. The method of claim 47 or 48, wherein the subject exhibits sustained cancer remission after completion of step (d). 50. The method of any one of claims 46-49, wherein the ex vivo armed T cell is administered intravenously, intraperitoneally, subcutaneously, intramuscularly, or intratumorally. 51. The method of any one of claims 46-50, further comprising separately, simultaneously, or sequentially administering an additional cancer therapy. 52. The method of claim 51, wherein the additional cancer therapy is selected from among chemotherapy, radiation therapy, immunotherapy, monoclonal antibodies, anti-cancer nucleic acids or proteins, anti-cancer viruses or microorganisms, and any combinations thereof. 53. The method of claim 51 or 52, wherein the additional cancer therapy is an immune checkpoint inhibitor selected from among pembrolizumab, nivolumab, cemiplimab, atezolizumab, avelumab, durvalumab, and ipilimumab. 54. The method of any one of claims 46-53, further comprising administering a cytokine to the subject, optionally wherein the cytokine is selected from the group consisting of interferon α, interferon β, interferon ^, complement C5a, IL-2, TNFα, CD40L, IL12, IL-23, IL15, IL17, CCL1, CCL11, CCL12, CCL13, CCL14-1, CCL14-2, CCL14-3, CCL15-1, CCL15-2, CCL16, CCL17, CCL18, CCL19, CCL2, CCL20, CCL21, CCL22, CCL23-1, CCL23-2, CCL24, CCL25-1, CCL25-2, CCL26, CCL27, CCL28, CCL3, CCL3Ll, CCL4, CCL4L1, CCL5, CCL6, CCL7, CCL8, CCL9, CCR10, CCR2, CCR5, CCR6, CCR7, CCR8, CCRL1, CCRL2, CX3CL1, CX3CR, CXCL1, CXCL10, CXCL11, CXCL12, CXCL13, CXCL14, CXCL15, CXCL16, CXCL2, CXCL3, CXCL4, CXCL5, CXCL6, CXCL7, CXCL8, CXCL9, CXCR1, CXCR2, CXCR4, CXCR5, CXCR6, CXCR7 and XCL2. 55. The method of claim 54, wherein the cytokine is administered prior to, during, or subsequent to administration of the ex vivo armed T cell. 56. The method of any one of claims 46-55, wherein the ex vivo armed T cell is autologous, non-autologous, or derived in vitro from lymphoid progenitor cells. 57. The method of any one of claims 46-56, wherein the subject is diagnosed with, or is suspected of having cancer. 58. The method of claim 57, wherein the cancer or tumor is a carcinoma, sarcoma, a melanoma, or a hematopoietic cancer. 59. The method of claim 57 or claim 58, wherein the cancer is selected from the group consisting of osteosarcoma, Ewing’s sarcoma, adrenal cancers, bladder cancers, blood cancers, bone cancers, brain cancers, breast cancers, carcinoma, cervical cancers, colon cancers, colorectal cancers, corpus uterine cancers, ear, nose and throat (ENT) cancers, endometrial cancers, esophageal cancers, gastrointestinal cancers, head and neck cancers, Hodgkin's disease, intestinal cancers, kidney cancers, larynx cancers, leukemias, liver cancers, lymph node cancers, lymphomas, lung cancers, melanomas, mesothelioma, myelomas, nasopharynx cancers, neuroblastomas, non-Hodgkin's lymphoma, oral cancers, ovarian cancers, pancreatic cancers, penile cancers, pharynx cancers, prostate cancers, rectal cancers, seminomas, skin cancers, stomach cancers, teratomas, testicular cancers, thyroid cancers, uterine cancers, vaginal cancers, vascular tumors, and metastases thereof. 60. The method of any one of claims 46-59, wherein cytokine levels released by the ex vivo armed T cell are reduced compared to unarmed T cells mixed with an anti-CD3 multi- specific antibody. |
EATs of the Present Technology [00144] The present disclosure provides ex vivo armed T cells (EATs) that are coated or complexed with an effective arming dose of multi-specific (e.g., bispecific) antibodies that bind to CD3 and at least one additional target antigen (e.g., antigen that is expressed by tumor cells and/or a DOTA-based hapten). The EATs of the present disclosure may be armed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody described herein. In certain embodiments, the EATs of the present disclosure may be armed with an effective arming dose of at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more types of anti-CD3 multi- specific antibodies described herein. [00145] T cells are lymphocytes that mature in the thymus and are chiefly responsible for cell-mediated immunity. T cells are involved in the adaptive immune system. The T cells included in the EATs of the presently disclosed subject matter can be any type of T cells, including, but not limited to, T helper cells, cytotoxic T cells, memory T cells (including central memory T cells), stem-cell-like memory T cells (or stem-like memory T cells), and two types of effector memory T cells: e.g., T EM cells and TEMRA cells, Regulatory T cells (also known as suppressor T cells), Natural killer T cells, Mucosal associated invariant T (MAIT) cells, EBV-specific cytotoxic T cells (EBV-CTLs), αβ T cells and γδ T cells. Cytotoxic T cells (CTL or killer T cells) are a subset of T lymphocytes capable of inducing the death of infected somatic or tumor cells. [00146] In any and all embodiments of the EATs disclosed herein, the at least one type of anti-CD3 multi-specific antibody exhibits surface densities between about 500 to about 20,000 molecules per T cell or between about 1,500 to 10,000 molecules per T cell. In certain embodiments, the at least one type of anti-CD3 multi-specific antibody exhibits surface densities of about 500, about 550, about 600, about 650, about 700, about 750, about 800, about 850, about 900, about 950, about 1000, about 1250, about 1500, about 1750, about 2000, about 2250, about 2500, about 2750, about 3000, about 3250, about 3500, about 3750, about 4000, about 4250, about 4500, about 4750, about 5000, about 5500, about 6000, about 6500, about 7000, about 7500, about 8000, about 8500, about 9000, about 9500, about 10,000, about 11,000, about 12,000, about 13,000, about 14,000, about 15,000, about 16,000, about 17,000, about 18,000, about 19,000, about 20,000, about 25,000, about 30,000, or about 35,000 molecules per T cell. Values and ranges intermediate to the recited values are also contemplated. [00147] In any and all embodiments of the EATs disclosed herein, T cells are armed ex vivo with the at least one type of anti-CD3 multi-specific antibody at doses (e.g., effective arming dose) ranging between about 0.05μg/10 6 T cells to about 5μg/10 6 T cells. In certain embodiments, T cells are armed ex vivo with the at least one type of anti-CD3 multi-specific antibody at a dose (e.g., effective arming dose) of about 0.05μg/10 6 T cells, about 0.06μg/10 6 T cells, about 0.07μg/10 6 T cells, about 0.08μg/10 6 T cells, about 0.09μg/10 6 T cells, about 0.1 μg/10 6 T cells, about 0.2 μg/10 6 T cells, about 0.3 μg/10 6 T cells, about 0.4 μg/10 6 T cells, about 0.5 μg/10 6 T cells, about 0.6 μg/10 6 T cells, about 0.7 μg/10 6 T cells, about 0.8 μg/10 6 T cells, about 0.9 μg/10 6 T cells, about 1.0 μg/10 6 T cells, about 1.5 μg/10 6 T cells, about 2.0 μg/10 6 T cells, about 2.5 μg/10 6 T cells, about 3.0 μg/10 6 T cells, about 3.5 μg/10 6 T cells, about 4.0 μg/10 6 T cells, about 4.5 μg/10 6 T cells, or about 5.0 μg/10 6 T cells. Values and ranges intermediate to the recited values are also contemplated. Additionally or alternatively, in some embodiments, T cells are armed ex vivo by contacting T cells with an effective arming dose of the at least one type of anti-CD3 multi-specific antibody for about 5-60 minutes at room temperature. In certain embodiments, T cells are armed ex vivo by contacting T cells with an effective arming dose of the at least one type of anti-CD3 multi- specific antibody for about 5 mins, about 10 mins, about 15 mins, about 20 mins, about 25 mins, about 30 mins, about 35 mins, about 40 mins, about 45 mins, about 50 mins, about 55 mins, or about 60 mins at room temperature. Values and ranges intermediate to the recited values are also contemplated. [00148] Additionally or alternatively, in some embodiments, the EATs are freshly prepared or have been cryopreserved. In certain embodiments, the EATs are cryopreserved for a period of about 2 hours to about 1 or more years In some embodiments the EATs are cryopreserved for a period of at least 2 hours, at least 3 hours, at least 4 hours, at least 5 hours, at least 6 hours, at least 7 hours, at least 8 hours, at least 9 hours, at least 10 hours, at least 12 hours, at least 24 hours, at least 48 hours, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 1 week, at least 2 weeks, at least 3 weeks, at least 5 weeks, at least 1 month, at least 2 months, at least 3 months, at least 4 months, at least 5 months, at least 6 months, at least 7 months, at least 8 months, at least 9 months, at least 10 months, at least 11 months, or at least 12 months. Values and ranges intermediate to the recited values are also contemplated. [00149] The EATs can be generated using peripheral donor lymphocytes, e.g., those disclosed in Panelli et al., J Immunol 164:495-504 (2000); Panelli et al., J Immunol 164:4382-4392 (2000) (disclosing lymphocyte cultures derived from tumor infiltrating lymphocytes (TILs) in tumor biopsies). The EATs can be autologous, non-autologous (e.g., allogeneic), or derived in vitro from lymphoid progenitor or stem cells. [00150] The unpurified source of T cells may be any source known in the art, such as the bone marrow, fetal, neonate or adult or other hematopoietic cell source, e.g., fetal liver, peripheral blood or umbilical cord blood. Various techniques can be employed to separate the cells. For instance, negative selection methods can remove non-immune cells initially. Monoclonal antibodies are particularly useful for identifying markers associated with particular cell lineages and/or stages of differentiation for both positive and negative selections. [00151] A large proportion of terminally differentiated cells can be initially removed by a relatively crude separation. For example, magnetic bead separations can be used initially to remove large numbers of irrelevant cells. Suitably, at least about 80%, usually at least 70% of the total hematopoietic cells will be removed prior to cell isolation. [00152] Procedures for separation include, but are not limited to, density gradient centrifugation; resetting; coupling to particles that modify cell density; magnetic separation with antibody-coated magnetic beads; affinity chromatography; cytotoxic agents joined to or used in conjunction with a mAb, including, but not limited to, complement and cytotoxins; and panning with antibody attached to a solid matrix, e.g., plate, chip, elutriation or any other convenient technique. [00153] Techniques for separation and analysis include, but are not limited to, flow cytometry, which can have varying degrees of sophistication, e.g., a plurality of color channels, low angle and obtuse light scattering detecting channels, impedance channels. [00154] The cells can be selected against dead cells, by employing dyes associated with dead cells such as propidium iodide (PI). Usually, the cells are collected in a medium comprising 2% fetal calf serum (FCS) or 0.2% bovine serum albumin (BSA) or any other suitable (e.g., sterile), isotonic medium. [00155] Administration. EATs of the presently disclosed subject matter can be provided systemically or directly to a subject for treating or preventing a neoplasia. In certain embodiments, EATs are directly injected into an organ of interest (e.g., an organ affected by a neoplasia). Alternatively or additionally, the EATs are provided indirectly to the organ of interest, for example, by administration into the circulatory system (e.g., the tumor vasculature) or into the solid tumor. Expansion and differentiation agents can be provided prior to, during or after administration of cells and compositions to promote maintenance/survival of T cells in vitro or in vivo. [00156] EATs of the presently disclosed subject matter can be administered in any physiologically acceptable vehicle, systemically or regionally, normally intravascularly, intraperitoneally, intrathecally, or intrapleurally, although they may also be introduced into bone or other convenient site. In certain embodiments, at least 1 × 10 5 cells, at least 1 × 10 6 cells or 1 × 10 10 or more cells can be administered. A cell population comprising EATs can comprise a purified population of cells. Those skilled in the art can readily determine the percentage of EATs in a cell population using various well-known methods, such as fluorescence activated cell sorting (FACS). The ranges of purity in cell populations comprising EATs can be from about 50% to about 55%, from about 55% to about 60%, from about 65% to about 70%, from about 70% to about 75%, from about 75% to about 80%, from about 80% to about 85%; from about 85% to about 90%, from about 90% to about 95%, or from about 95 to about 100%. Dosages can be readily adjusted by those skilled in the art (e.g., a decrease in purity may require an increase in dosage). The EATs can be introduced by injection, catheter, or the like. If desired, factors can also be included, including, but not limited to, interleukins, e.g., IL-2, IL-3, IL 6, IL-11, IL-7, IL-12, IL-15, IL-21, as well as the other interleukins, the colony stimulating factors, such as G-, M- and GM-CSF, interferons, e.g., γ- interferon. [00157] In certain embodiments, compositions of the presently disclosed subject matter comprise pharmaceutical compositions comprising EATs coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody described herein and a pharmaceutically acceptable carrier. Administration can be autologous or non- autologous. For example, EATs coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody described herein and compositions comprising thereof can be obtained from one subject, and administered to the same subject or a different, compatible subject. Peripheral blood derived EATs of the presently disclosed subject matter can be administered via localized injection, including catheter administration, systemic injection, localized injection, intravenous injection, or parenteral administration. When administering a pharmaceutical composition of the presently disclosed subject matter (e.g., a pharmaceutical composition comprising EATs coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody described herein), it can be formulated in a unit dosage injectable form (solution, suspension, emulsion). [00158] Formulations. EATs coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody described herein and compositions comprising thereof can be conveniently provided as sterile liquid preparations, e.g., isotonic aqueous solutions, suspensions, emulsions, dispersions, or viscous compositions, which may be buffered to a selected pH. Liquid preparations are normally easier to prepare than gels, other viscous compositions, and solid compositions. Additionally, liquid compositions are somewhat more convenient to administer, especially by injection. Viscous compositions, on the other hand, can be formulated within the appropriate viscosity range to provide longer contact periods with specific tissues. Liquid or viscous compositions can comprise carriers, which can be a solvent or dispersing medium containing, for example, water, saline, phosphate buffered saline, polyol (for example, glycerol, propylene glycol, liquid polyethylene glycol, and the like) and suitable mixtures thereof. [00159] Sterile injectable solutions can be prepared by incorporating the compositions of the presently disclosed subject matter, e.g., a composition comprising EATs, in the required amount of the appropriate solvent with various amounts of the other ingredients, as desired. Such compositions may be in admixture with a suitable carrier, diluent, or excipient such as sterile water, physiological saline, glucose, dextrose, or the like. The compositions can also be lyophilized. The compositions can contain auxiliary substances such as wetting, dispersing, or emulsifying agents (e.g., methylcellulose), pH buffering agents, gelling or viscosity enhancing additives, preservatives, flavoring agents, colors, and the like, depending upon the route of administration and the preparation desired. Standard texts, such as “REMINGTON' S PHARMACEUTICAL SCIENCE”, 17th edition, 1985, incorporated herein by reference, may be consulted to prepare suitable preparations, without undue experimentation. [00160] Various additives which enhance the stability and sterility of the compositions, including antimicrobial preservatives, antioxidants, chelating agents, and buffers, can be added. Prevention of the action of microorganisms can be ensured by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, and the like. Prolonged absorption of the injectable pharmaceutical form can be brought about by the use of agents delaying absorption, for example, aluminum monostearate and gelatin. According to the presently disclosed subject matter, however, any vehicle, diluent, or additive used would have to be compatible with the EATs of the presently disclosed subject matter. [00161] The compositions can be isotonic, i.e., they can have the same osmotic pressure as blood and lacrimal fluid. The desired isotonicity of the compositions of the presently disclosed subject matter may be accomplished using sodium chloride, or other pharmaceutically acceptable agents such as dextrose, boric acid, sodium tartrate, propylene glycol or other inorganic or organic solutes. Sodium chloride is suitable particularly for buffers containing sodium ions. [00162] Viscosity of the compositions, if desired, can be maintained at the selected level using a pharmaceutically acceptable thickening agent. Methylcellulose can be used because it is readily and economically available and is easy to work with. Other suitable thickening agents include, for example, xanthan gum, carboxymethyl cellulose, hydroxypropyl cellulose, carbomer, and the like. The concentration of the thickener can depend upon the agent selected. The important point is to use an amount that will achieve the selected viscosity. The choice of suitable carriers and other additives will depend on the exact route of administration and the nature of the particular dosage form, e.g., liquid dosage form (e.g., whether the composition is to be formulated into a solution, a suspension, gel or another liquid form, such as a time release form or liquid-filled form). [00163] Those skilled in the art will recognize that the components of the compositions should be selected to be chemically inert and will not affect the viability or efficacy of the EATs as described in the presently disclosed subject matter. This will present no problem to those skilled in chemical and pharmaceutical principles, or problems can be readily avoided by reference to standard texts or by simple experiments (not involving undue experimentation), from this disclosure and the documents cited herein. [00164] One consideration concerning the therapeutic use of the EATs of the presently disclosed subject matter is the quantity of cells necessary to achieve an optimal effect. The quantity of cells to be administered will vary for the subject being treated. In certain embodiments, from about 10 2 to about 10 12 , from about 10 3 to about 10 11 , from about 10 4 to about 10 10 , from about 10 5 to about 10 9 , or from about 10 6 to about 10 8 EATs of the presently disclosed subject matter are administered to a subject. More effective cells may be administered in even smaller numbers. In some embodiments, at least about 1 × 10 8 , about 2 × 10 8 , about 3 × 10 8 , about 4 × 10 8 , about 5 × 10 8 , about 1 × 10 9 , about 5 × 10 9 , about 1 × 10 10 , about 5 × 10 10 , about 1 × 10 11 , about 5 × 10 11 , about 1 × 10 12 or more EATs of the presently disclosed subject matter are administered to a human subject. The precise determination of what would be considered an effective dose may be based on factors individual to each subject, including their size, age, sex, weight, and condition of the particular subject. Dosages can be readily ascertained by those skilled in the art from this disclosure and the knowledge in the art. Generally, EATs are administered at doses that are nontoxic or tolerable to the patient. [00165] The skilled artisan can readily determine the amount of cells and optional additives, vehicles, and/or carrier in compositions to be administered in methods of the presently disclosed subject matter. Typically, any additives (in addition to the active cell(s) and/or agent(s)) are present in an amount of from about 0.001% to about 50% by weight) solution in phosphate buffered saline, and the active ingredient is present in the order of micrograms to milligrams, such as from about 0.0001 wt % to about 5 wt %, from about 0.0001 wt% to about 1 wt %, from about 0.0001 wt% to about 0.05 wt%, from about 0.001 wt% to about 20 wt %, from about 0.01 wt% to about 10 wt %, or from about 0.05 wt% to about 5 wt %. [00166] Toxicity. For any composition to be administered to an animal or human, and for any particular method of administration, toxicity should be determined, such as by determining the lethal dose (LD) and LD50 in a suitable animal model e.g., rodent such as mouse; and, the dosage of the composition(s), concentration of components therein and timing of administering the composition(s), which elicit a suitable response. Such determinations do not require undue experimentation from the knowledge of the skilled artisan, this disclosure and the documents cited herein. And, the time for sequential administrations can be ascertained without undue experimentation. Optimally, an effective amount (e.g., dose) of an EAT described herein will provide therapeutic benefit without causing substantial toxicity to the subject. Toxicity of the EAT described herein can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., by determining the LD 50 (the dose lethal to 50% of the population) or the LD 100 (the dose lethal to 100% of the population). The dose ratio between toxic and therapeutic effect is the therapeutic index. The data obtained from these cell culture assays and animal studies can be used in formulating a dosage range that is not toxic for use in human. The dosage of the EAT described herein lies within a range of circulating concentrations that include the effective dose with little or no toxicity. The dosage can vary within this range depending upon the dosage form employed and the route of administration utilized. The exact formulation, route of administration and dosage can be chosen by the individual physician in view of the subject’s condition. See, e.g., Fingl et al., In: The Pharmacological Basis of Therapeutics, Ch.1 (1975). Anti-CD3 Multi-specific Antibodies Useful in Arming the EATs of the Present Technology [00167] Anti-CD3 multi-specific antibodies that arm the EATs of the present technology include, e.g., but are not limited to, monoclonal, chimeric, humanized, bispecific antibodies, trispecific antibodies, or tetraspecific antibodies that specifically bind a CD3 target polypeptide, a homolog, derivative or a fragment thereof. In any and all embodiments of the EATs disclosed herein, the anti-CD3 multi-specific antibody that arms the EATs of the present technology is an immunoglobulin comprising two heavy chains and two light chains, wherein each of the light chains is fused to a single chain variable fragment (scFv) Such an anti-CD3 multi-specific antibody includes a CD3 binding domain comprising a heavy chain immunoglobulin variable domain (V H ) and a light chain immunoglobulin variable domain (VL). Additionally or alternatively, in some embodiments, at least one scFv of the anti-CD3 multi-specific antibody disclosed herein comprises the CD3 binding domain. The CDR sequences of the V H and V L of the CD3 binding domain based on the IMGT annotation system are summarized below: [00168] FIG.33 shows exemplary amino acid sequences of anti-CD3 multi-specific antibodies that are useful for arming the EATs of the present technology. [00169] In some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology include a CD3 binding domain comprising a heavy chain immunoglobulin variable domain (VH) and a light chain immunoglobulin variable domain (V L ), wherein (a) the V H comprises a V H -CDR1 sequence of SEQ ID NO: 1, a V H -CDR2 sequence of SEQ ID NO: 2, and a VH-CDR3 sequence of SEQ ID NO: 3, and/or (b) the VL comprises a VL-CDR1 sequence of SEQ ID NO: 4, a VL-CDR2 sequence of SEQ ID NO: 5, and a V L -CDR3 sequence of SEQ ID NO: 6. [00170] Exemplary heavy chain immunoglobulin variable domain amino acid sequences of the anti-CD3 antibodies of the present technology include: huOKT3 (SEQ ID NO: 7) QVQLVQSGGGVVQPGRSLRLSCKASGYTFTRYTMHWVRQAPGKCLEWIGYINPSRG YTNYNQKFKDRFTISRDNSKNTAFLQMDSLRPEDTGVYFCARYYDDHYSLDYWGQ GTPVTVSS huOKT3-DS (SEQ ID NO: 8) QVQLVQSGGGVVQPGRSLRLSCKASGYTFTRYTMHWVRQAPGKGLEWIGYINPSRG YTNYNQKFKDRFTISRDNSKNTAFLQMDSLRPEDTGVYFCARYYDDHYSLDYWGQ GTPVTVSS VH-1 (humanness 85.7%) (SEQ ID NO: 9) QVQLQQSGAEVAKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYAQKFQGRATLTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG QGTTLTVSS VH-2 (humanness 85.7%) (SEQ ID NO: 10) QVQLQQSGAEVAKPGASVKVSCKASGYTFTRYTMHWVRQAPGQGLEWMGYINPS RGYTNYNQKFKDRATLTRDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYW GQGTTLTVSS VH-3 (humanness 85.7%) (SEQ ID NO: 11) QVQLVQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRATMTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG QGTTLTVSS VH-4 (humanness 85.7%) (SEQ ID NO: 12) QVQLQQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRVTLTTDTSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG QGTTLTVSS VH-1 H105 (humanness 85.7%) (SEQ ID NO: 13) QVQLQQSGAEVAKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYAQKFQGRATLTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG CGTTLTVSS VH-2 H105 (humanness 85.7%) (SEQ ID NO: 14) QVQLQQSGAEVAKPGASVKVSCKASGYTFTRYTMHWVRQAPGQGLEWMGYINPS RGYTNYNQKFKDRATLTRDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYW GCGTTLTVSS VH 3 H105 (h 857%) (SEQ ID NO 15) QVQLVQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRATMTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG CGTTLTVSS VH-4 H105 (humanness 85.7%) (SEQ ID NO: 16) QVQLQQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRVTLTTDTSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG CGTTLTVSS VH-1 H44 (humanness 85.7%) (SEQ ID NO: 17) QVQLQQSGAEVAKPGASVKMSCKASGYTFTRYTMHWVRQAPGQCLEWIGYINPSR GYTNYAQKFQGRATLTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG QGTTLTVSS VH-2 H44 (humanness 85.7%) (SEQ ID NO: 18) QVQLQQSGAEVAKPGASVKVSCKASGYTFTRYTMHWVRQAPGQCLEWMGYINPSR GYTNYNQKFKDRATLTRDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG QGTTLTVSS VH-3 H44 (humanness 85.7%) (SEQ ID NO: 19) QVQLVQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQCLEWIGYINPSR GYTNYNQKFKDRATMTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG QGTTLTVSS VH-4 H44 (humanness 85.7%) (SEQ ID NO: 20) QVQLQQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQCLEWIGYINPSR GYTNYNQKFKDRVTLTTDTSISTAYMELSRLRSDDTAVYYCARYYDDHYSLDYWG QGTTLTVSS VH-1 H100B (humanness 85.7%) (SEQ ID NO: 21) QVQLQQSGAEVAKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYAQKFQGRATLTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSCDYWG QGTTLTVSS VH 2 H100B (h 857%) (SEQ ID NO 22) QVQLQQSGAEVAKPGASVKVSCKASGYTFTRYTMHWVRQAPGQGLEWMGYINPS RGYTNYNQKFKDRATLTRDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSCDYW GQGTTLTVSS VH-3 H100B (humanness 85.7%) (SEQ ID NO: 23) QVQLVQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRATMTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSCDYWG QGTTLTVSS VH-4 H100B (humanness 85.7%) (SEQ ID NO: 24) QVQLQQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRVTLTTDTSISTAYMELSRLRSDDTAVYYCARYYDDHYSCDYWG QGTTLTVSS VH-1 H100 (humanness 85.7%) (SEQ ID NO: 25) QVQLQQSGAEVAKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYAQKFQGRATLTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHCSLDYWG QGTTLTVSS VH-2 H100 (humanness 85.7%) (SEQ ID NO: 26) QVQLQQSGAEVAKPGASVKVSCKASGYTFTRYTMHWVRQAPGQGLEWMGYINPS RGYTNYNQKFKDRATLTRDKSISTAYMELSRLRSDDTAVYYCARYYDDHCSLDYW GQGTTLTVSS VH-3 H100 (humanness 85.7%) (SEQ ID NO: 27) QVQLVQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRATMTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHCSLDYWG QGTTLTVSS VH-4 H100 (humanness 85.7%) (SEQ ID NO: 28) QVQLQQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRVTLTTDTSISTAYMELSRLRSDDTAVYYCARYYDDHCSLDYWG QGTTLTVSS VH 1 H101 (h 857%) (SEQ ID NO 29) QVQLQQSGAEVAKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYAQKFQGRATLTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLCYWG QGTTLTVSS VH-2 H101 (humanness 85.7%) (SEQ ID NO: 30) QVQLQQSGAEVAKPGASVKVSCKASGYTFTRYTMHWVRQAPGQGLEWMGYINPS RGYTNYNQKFKDRATLTRDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLCYW GQGTTLTVSS VH-3 H101 (humanness 85.7%) (SEQ ID NO: 31) QVQLVQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRATMTTDKSISTAYMELSRLRSDDTAVYYCARYYDDHYSLCYWG QGTTLTVSS VH-4 H101 (humanness 85.7%) (SEQ ID NO: 32) QVQLQQSGAEVKKPGASVKMSCKASGYTFTRYTMHWVRQAPGQGLEWIGYINPSR GYTNYNQKFKDRVTLTTDTSISTAYMELSRLRSDDTAVYYCARYYDDHYSLCYWG QGTTLTVSS [00171] Exemplary light chain immunoglobulin variable domain amino acid sequences of the anti-CD3 antibodies of the present technology include: huOKT3 (SEQ ID NO: 33) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQTPGKAPKRWIYDTSKLASGV PSRFSGSGSGTDYTFTISSLQPEDIATYYCQQWSSNPFTFGCGTKLQITR huOKT3-DS (SEQ ID NO: 34) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQTPGKAPKRWIYDTSKLASGV PSRFSGSGSGTDYTFTISSLQPEDIATYYCQQWSSNPFTFGQGTKLQITR VL-1 (humanness 85.2%) (SEQ ID NO: 35) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKRLIYDTSKLASG VPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-2 (humanness 85.2%) (SEQ ID NO: 36) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKLLIYDTSKLASG VPSRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-3 (humanness 85.2%) (SEQ ID NO: 37) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLLIYDTSKLASGVP SRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-4 (humanness 85.2%) (SEQ ID NO: 38) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLLIYDTSKLASGVP SRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-5 (humanness 85.2%) (SEQ ID NO: 39) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKRWIYDTSKLASGV PSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-6 (humanness 85.2%) (SEQ ID NO: 40) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLWIYDTSKLASGV PSRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-1 L100 (humanness 85.2%) (SEQ ID NO: 41) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKRLIYDTSKLASG VPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGCGTKLEINR VL-2 L100 (humanness 85.2%) (SEQ ID NO: 42) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKLLIYDTSKLASG VPSRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGCGTKLEINR VL-3 L100 (humanness 85.2%) (SEQ ID NO: 43) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLLIYDTSKLASGVP SRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGCGTKLEINR VL-4 L100 (humanness 85.2%) (SEQ ID NO: 44) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLLIYDTSKLASGVP SRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGCGTKLEINR VL-5 L100 (humanness 85.2%) (SEQ ID NO: 45) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKRWIYDTSKLASGV PSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGCGTKLEINR VL-6 L100 (humanness 85.2%) (SEQ ID NO: 46) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLWIYDTSKLASGV PSRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGCGTKLEINR VL-1 L43 (humanness 85.2%) (SEQ ID NO: 47) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKCPKRLIYDTSKLASG VPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-2 L43 (humanness 85.2%) (SEQ ID NO: 48) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKCPKLLIYDTSKLASGV PSRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-3 L43 (humanness 85.2%) (SEQ ID NO: 49) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKCPKLLIYDTSKLASGVP SRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-4 L43 (humanness 85.2%) (SEQ ID NO: 50) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKCPKLLIYDTSKLASGVP SRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-5 L43 (humanness 85.2%) (SEQ ID NO: 51) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKCPKRWIYDTSKLASGV PSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-6 L43 (humanness 85.2%) (SEQ ID NO: 52) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKCPKLWIYDTSKLASGV PSRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-1 L49 (humanness 85.2%) (SEQ ID NO: 53) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKRLICDTSKLASG VPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-2 L49 (humanness 85.2%) (SEQ ID NO: 54) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKLLICDTSKLASGV PSRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-3 L49 (humanness 85.2%) (SEQ ID NO: 55) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLLICDTSKLASGVP SRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-4 L49 (humanness 85.2%) (SEQ ID NO: 56) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLLICDTSKLASGVP SRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-5 L49 (humanness 85.2%) (SEQ ID NO: 57) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKRWICDTSKLASGV PSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-6 L49 (humanness 85.2%) (SEQ ID NO: 58) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLWICDTSKLASGV PSRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-1 L50 (humanness 85.2%) (SEQ ID NO: 59) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKRLIYCTSKLASG VPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-2 L50 (humanness 85.2%) (SEQ ID NO: 60) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKLLIYCTSKLASGV PSRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-3 L50 (humanness 85.2%) (SEQ ID NO: 61) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLLIYCTSKLASGVP SRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-4 L50 (humanness 85.2%) (SEQ ID NO: 62) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLLIYCTSKLASGVP SRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-5 L50 (humanness 85.2%) (SEQ ID NO: 63) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKRWIYCTSKLASGV PSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-6 L50 (humanness 85.2%) (SEQ ID NO: 64) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKLWIYCTSKLASGV PSRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-1 L46 (humanness 85.2%) (SEQ ID NO: 65) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKCLIYDTSKLASG VPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-2 L46 (humanness 85.2%) (SEQ ID NO: 66) DIQMTQSPSSLSASVGDRVTMTCSASSSVSYMNWYQQKPGKAPKCLIYDTSKLASG VPSRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-3 L46 (humanness 85.2%) (SEQ ID NO: 67) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKCLIYDTSKLASGVP SRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-4 L46 (humanness 85.2%) (SEQ ID NO: 68) DIQLTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKCLIYDTSKLASGVP SRFSGSGSGTDFTLTISSMQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-5 L46 (humanness 85.2%) (SEQ ID NO: 69) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKCWIYDTSKLASGV PSRFSGSGSGTDFTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR VL-6 L46 (humanness 85.2%) (SEQ ID NO: 70) DIQMTQSPSSLSASVGDRVTITCSASSSVSYMNWYQQKPGKAPKCWIYDTSKLASGV PSRFSGSGSGTDYTLTISSLQPEDFATYYCQQWSSNPFTFGSGTKLEINR [00172] Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology include a CD3 binding domain comprising a heavy chain immunoglobulin variable domain (VH) and a light chain immunoglobulin variable domain (V L ), wherein: (a) the V H comprises an amino acid sequence selected from any one of SEQ ID NOs: 7-32; and/or (b) the V L comprises an amino acid sequence selected from any one of SEQ ID NOs: 33-70. [00173] In certain embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology includes one or more of the following characteristics: (a) a light chain immunoglobulin variable domain sequence that is at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to the light chain immunoglobulin variable domain sequence of any one of SEQ ID NOs: 33-70; and/or (b) a heavy chain immunoglobulin variable domain sequence that is at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to the heavy chain immunoglobulin variable domain sequence of any one of SEQ ID NOs: 7-32. In another aspect, one or more amino acid residues in the immunoglobulin-related compositions provided herein are substituted with another amino acid. The substitution may be a “conservative substitution” as defined herein. [00174] In some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology bind to the extracellular domain of a CD3 polypeptide. In certain embodiments, the epitope is a conformational epitope or non-conformational epitope. In some embodiments, the CD3 polypeptide has the amino acid sequence of SEQ ID NO: 71. [00175] NCBI Ref: NP_000724.1 Homo sapiens T-cell surface glycoprotein CD3 epsilon chain precursor (SEQ ID NO: 71) [00176] MQSGTHWRVLGLCLLSVGVWGQDGNEEMGGITQTPYKVSISGTTVILTC PQYPGSEILWQHNDKNIGGDEDDKNIGSDEDHLSLKEFSELEQSGYYVCYPRGSKPE DANFYLYLRARVCENCMEMDVMSVATIVIVDICITGGLLLLVYYWSKNRKAKAKPV TRGAGAGGRQRGQNKERPPPVPNPDYEPIRKGQRDLYSGLNQRRI [00177] Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibodies bind to the extracellular domain of a CD3 polypeptide. In certain embodiments, the extracellular domain comprises a CD3ε subunit including a linear stretch of sequence on the F-G loop. In some embodiments, the CD3ε subunit may comprise three discontinuous regions: residues 79ε-85ε (the F-G loop), residue 34ε (the first residue of the ßC strand), and residues 46ε and 48ε (the C’-D loop). [00178] In any of the above embodiments, the anti-CD3 multi-specific antibodies further comprises a Fc domain of any isotype, e.g., but are not limited to, IgG (including IgG1, IgG2, IgG3, and IgG4). [00179] Non-limiting examples of constant region sequences include: [00180] Human IgG1 constant region, Uniprot: P01857 (SEQ ID NO: 72) ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVL QSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAK TKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPR EPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK [00181] Human IgG2 constant region, Uniprot: P01859 (SEQ ID NO: 73) ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQ SSGLYSLSSVVTVPSSNFGTQTYTCNVDHKPSNTKVDKTVERKCCVECPPCPAPPVA GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVEVHNAKTKPR EEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAPIEKTISKTKGQPREPQVY TLPPSREEMTKNQVSLTCLVKGFYPSDISVEWESNGQPENNYKTTPPMLDSDGSFFL YSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK [00182] Human IgG3 constant region, Uniprot: P01860 (SEQ ID NO: 74) ASTKGPSVFPLAPCSRSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVL QSSGLYSLSSVVTVPSSSLGTQTYTCNVNHKPSNTKVDKRVELKTPLGDTTHTCPRC PEPKSCDTPPPCPRCPEPKSCDTPPPCPRCPEPKSCDTPPPCPRCPAPELLGGPSVFLFP P KPKDTLMISRTPEVTCVVVDVSHEDPEVQFKWYVDGVEVHNAKTKPREEQYNSTFR VVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKTKGQPREPQVYTLPPSREEM TKNQVSLTCLVKGFYPSDIAVEWESSGQPENNYNTTPPMLDSDGSFFLYSKLTVDKS RWQQGNIFSCSVMHEALHNRFTQKSLSLSPGK [00183] Human IgG4 constant region, Uniprot: P01861 (SEQ ID NO: 75) [00184] ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVH TFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPSC PAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHN AKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQP REPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDS DGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK [00185] Human Ig kappa constant region, Uniprot: P01834 (SEQ ID NO: 76) TVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTE QDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC [00186] In some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology comprise a heavy chain constant region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or is 100% identical to SEQ ID NOs: 72-75. Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology comprise a light chain constant region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or is 100% identical to SEQ ID NO: 76. In certain embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology contain an IgG1 constant region comprising one or more amino acid substitutions selected from the group consisting of N297A and K322A. Additionally or alternatively, in some embodiments, the immunoglobulin-related compositions contain an IgG4 constant region comprising a S228P mutation. [00187] Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibodies comprises a DOTA binding domain. The DOTA binding domain may include a V H having the amino acid sequence of SEQ ID NO: 77 and/or a V L having the amino acid sequence of SEQ ID NO: 78. [00188] HVQLVESGGGLVQPGGSLRLSCAASGFSLTDYGVHWVRQAPGKGLEWL GVIWSGGGTAYNTALISRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARRGSYPYN YFDAWGCGTLVTVSS (SEQ ID NO: 77) [00189] QAVVTQEPSLTVSPGGTVTLTCGSSTGAVTASNYANWVQQKPGQCPRGLI GGHNNRPPGVPARFSGSLLGGKAALTLLGAQPEDEAEYYCALWYSDHWVIGGGTK LTVLG (SEQ ID NO: 78) [00190] In certain embodiments, the DOTA binding domain is a scFv and/or may comprise an amino acid sequence selected from the group consisting of: HVQLVESGGGLVQPGGSLRLSCAASGFSLTDYGVHWVRQAPGKGLEWLGVIWSGG GTAYNTALISRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARRGSYPYNYFDAWGC GTLVTVSSGGGGSGGGGSGGGGSQAVVTQEPSLTVSPGGTVTLTCGSSTGAVTAS NYANWVQQKPGQCPRGLIGGHNNRPPGVPARFSGSLLGGKAALTLLGAQPEDEAEY YCALWYSDHWVIGGGTKLTVLG (SEQ ID NO: 79); and HVQLVESGGGLVQPGGSLRLSCAASGFSLTDYGVHWVRQAPGKGLEWLGVIWSGG GTAYNTALISRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARRGSYPYNYFDAWGC GTLVTVSSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSQAVVTQEPSLTVSPGG TVTLTCGSSTGAVTASNYANWVQQKPGQCPRGLIGGHNNRPPGVPARFSGSLLGGK AALTLLGAQPEDEAEYYCALWYSDHWVIGGGTKLTVLG (SEQ ID NO: 80). *(G4S)3 linker sequence is shown in boldface [00191] Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibody comprises a heavy chain (HC) amino acid sequence comprising SEQ ID NO: 82, SEQ ID NO: 84, SEQ ID NO: 86, SEQ ID NO: 88, SEQ ID NO: 90, SEQ ID NO: 94, SEQ ID NO: 96, SEQ ID NO: 98, SEQ ID NO: 100, SEQ ID NO: 115, SEQ ID NO: 117, SEQ ID NO: 119, SEQ ID NO: 121, SEQ ID NO: 123, SEQ ID NO: 125, SEQ ID NO: 127, SEQ ID NO: 129, SEQ ID NO: 131, SEQ ID NO: 133, SEQ ID NO: 135, SEQ ID NO: 137, SEQ ID NO: 139, SEQ ID NO: 141, SEQ ID NO: 143, SEQ ID NO: 145, SEQ ID NO: 147, SEQ ID NO: 149, SEQ ID NO: 151, SEQ ID NO: 153, SEQ ID NO: 155, SEQ ID NO: 157, SEQ ID NO: 163, SEQ ID NO: 165, SEQ ID NO: 167, SEQ ID NO: 169, or a variant thereof having one or more conservative amino acid substitutions. Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibody comprises a light chain (LC) amino acid sequence comprising SEQ ID NO: 81, SEQ ID NO: 83, SEQ ID NO: 85, SEQ ID NO: 87, SEQ ID NO: 89, SEQ ID NO: 93, SEQ ID NO: 95, SEQ ID NO: 97, SEQ ID NO: 99, SEQ ID NO: 114, SEQ ID NO: 116, SEQ ID NO: 118, SEQ ID NO: 120, SEQ ID NO: 122, SEQ ID NO: 124, SEQ ID NO: 126, SEQ ID NO: 128, SEQ ID NO: 130, SEQ ID NO: 132, SEQ ID NO: 134, SEQ ID NO: 136, SEQ ID NO: 138, SEQ ID NO: 140, SEQ ID NO: 142, SEQ ID NO: 144, SEQ ID NO: 146, SEQ ID NO: 148, SEQ ID NO: 150, SEQ ID NO: 152, SEQ ID NO: 154, SEQ ID NO: 156, SEQ ID NO: 162, SEQ ID NO: 164, SEQ ID NO: 166, SEQ ID NO: 168, or a variant thereof having one or more conservative amino acid substitutions. [00192] In other embodiments, the anti-CD3 multi-specific antibody comprises (a) a LC sequence that is at least 80% at least 85% at least 90% at least 95% or at least 99% identical to the LC sequence present in SEQ ID NO: 81, SEQ ID NO: 83, SEQ ID NO: 85, SEQ ID NO: 87, SEQ ID NO: 89, SEQ ID NO: 93, SEQ ID NO: 95, SEQ ID NO: 97, SEQ ID NO: 99, SEQ ID NO: 114, SEQ ID NO: 116, SEQ ID NO: 118, SEQ ID NO: 120, SEQ ID NO: 122, SEQ ID NO: 124, SEQ ID NO: 126, SEQ ID NO: 128, SEQ ID NO: 130, SEQ ID NO: 132, SEQ ID NO: 134, SEQ ID NO: 136, SEQ ID NO: 138, SEQ ID NO: 140, SEQ ID NO: 142, SEQ ID NO: 144, SEQ ID NO: 146, SEQ ID NO: 148, SEQ ID NO: 150, SEQ ID NO: 152, SEQ ID NO: 154, SEQ ID NO: 156, SEQ ID NO: 162, SEQ ID NO: 164, SEQ ID NO: 166, or SEQ ID NO: 168; and/or (b) a HC sequence that is at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to the HC sequence present in SEQ ID NO: 82, SEQ ID NO: 84, SEQ ID NO: 86, SEQ ID NO: 88, SEQ ID NO: 90, SEQ ID NO: 94, SEQ ID NO: 96, SEQ ID NO: 98, SEQ ID NO: 100, SEQ ID NO: 115, SEQ ID NO: 117, SEQ ID NO: 119, SEQ ID NO: 121, SEQ ID NO: 123, SEQ ID NO: 125, SEQ ID NO: 127, SEQ ID NO: 129, SEQ ID NO: 131, SEQ ID NO: 133, SEQ ID NO: 135, SEQ ID NO: 137, SEQ ID NO: 139, SEQ ID NO: 141, SEQ ID NO: 143, SEQ ID NO: 145, SEQ ID NO: 147, SEQ ID NO: 149, SEQ ID NO: 151, SEQ ID NO: 153, SEQ ID NO: 155, SEQ ID NO: 157, SEQ ID NO: 163, SEQ ID NO: 165, SEQ ID NO: 167, or SEQ ID NO: 169. [00193] Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibody comprises a HC amino acid sequence and a LC amino acid sequence selected from the group consisting of: SEQ ID NO: 82 and SEQ ID NO: 81, SEQ ID NO: 84 and SEQ ID NO: 83, SEQ ID NO: 86 and SEQ ID NO: 85, SEQ ID NO: 88 and SEQ ID NO: 87, SEQ ID NO: 90 and SEQ ID NO: 89, SEQ ID NO: 94 and SEQ ID NO: 93, SEQ ID NO: 96 and SEQ ID NO: 95, SEQ ID NO: 98 and SEQ ID NO: 97, SEQ ID NO: 100 and SEQ ID NO: 99, SEQ ID NO: 115 and SEQ ID NO: 114, SEQ ID NO: 117 and SEQ ID NO: 116, SEQ ID NO: 119 and SEQ ID NO: 118, SEQ ID NO: 121 and SEQ ID NO: 120, SEQ ID NO: 123 and SEQ ID NO: 122, SEQ ID NO: 125 and SEQ ID NO: 124, SEQ ID NO: 127 and SEQ ID NO: 126, SEQ ID NO: 129 and SEQ ID NO: 128, SEQ ID NO: 131 and SEQ ID NO: 130, SEQ ID NO: 133 and SEQ ID NO: 132, SEQ ID NO: 135 and SEQ ID NO: 134, SEQ ID NO: 137 and SEQ ID NO: 136, SEQ ID NO: 139 and SEQ ID NO: 138, SEQ ID NO: 141 and SEQ ID NO: 140, SEQ ID NO: 143 and SEQ ID NO: 142, SEQ ID NO: 145 and SEQ ID NO: 144, SEQ ID NO: 147 and SEQ ID NO: 146, SEQ ID NO: 149 and SEQ ID NO: 148, SEQ ID NO: 151 and SEQ ID NO: 150, SEQ ID NO: 153 and SEQ ID NO: 152, SEQ ID NO: 155 and SEQ ID NO: 154, SEQ ID NO: 157 and SEQ ID NO: 156, SEQ ID NO: 163 and SEQ ID NO: 162, SEQ ID NO: 165 and SEQ ID NO: 164, SEQ ID NO: 167 and SEQ ID NO: 166, and SEQ ID NO: 169 and SEQ ID NO: 168, respectively. [00194] Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibody comprise a first LC amino acid sequence, a first HC amino acid sequence, a second LC amino acid sequence, and a second HC amino acid sequence selected from the group consisting of SEQ ID NO: 114, SEQ ID NO: 115, SEQ ID NO: 116, and SEQ ID NO: 117; SEQ ID NO: 118, SEQ ID NO: 119, SEQ ID NO: 120, and SEQ ID NO: 121; SEQ ID NO: 122, SEQ ID NO: 123, SEQ ID NO: 124, and SEQ ID NO: 125; SEQ ID NO: 126, SEQ ID NO: 127, SEQ ID NO: 128, and SEQ ID NO: 129; SEQ ID NO: 130, SEQ ID NO: 131, SEQ ID NO: 132, and SEQ ID NO: 133; SEQ ID NO: 134, SEQ ID NO: 135, SEQ ID NO: 136, and SEQ ID NO: 137; SEQ ID NO: 138, SEQ ID NO: 139, SEQ ID NO: 140, and SEQ ID NO: 141; SEQ ID NO: 142, SEQ ID NO: 143, SEQ ID NO: 144, and SEQ ID NO: 145; SEQ ID NO: 146, SEQ ID NO: 147, SEQ ID NO: 148, and SEQ ID NO: 149; SEQ ID NO: 150, SEQ ID NO: 151, SEQ ID NO: 152, and SEQ ID NO: 153; SEQ ID NO: 154, SEQ ID NO: 155, SEQ ID NO: 156, and SEQ ID NO: 157; SEQ ID NO: 162, SEQ ID NO: 163, SEQ ID NO: 164, and SEQ ID NO: 165; and SEQ ID NO: 166, SEQ ID NO: 167, SEQ ID NO: 168, and SEQ ID NO: 169; respectively. [00195] Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present disclosure bind one or more additional target antigens selected from the group consisting of CD3, GPA33, HER2/neu, GD2, MAGE-1, MAGE-3, BAGE, GAGE-1, GAGE-2, MUM-1, CDK4, N-acetylglucosaminyltransferase, p15, gp75, beta-catenin, ErbB2, cancer antigen 125 (CA-125), carcinoembryonic antigen (CEA), RAGE, MART (melanoma antigen), MUC-1, MUC-2, MUC-3, MUC-4, MUC-5ac, MUC-16, MUC-17, tyrosinase, Pmel 17 (gp100), GnT-V intron V sequence (N- acetylglucoaminyltransferase V intron V sequence), Prostate cancer psm, PRAME (melanoma antigen), β-catenin, EBNA (Epstein-Barr Virus nuclear antigen) 1-6, LMP2, p53, lung resistance protein (LRP), Bcl-2, prostate specific antigen (PSA), Ki-67, CEACAM6, colon-specific antigen-p (CSAp), HLA-DR, CD40, CD74, CD138, EGFR, EGP-1, EGP-2, VEGF, PlGF, insulin-like growth factor (ILGF), tenascin, platelet-derived growth factor, IL- 6 CD20 CD19 PSMA CD33 CD123 MET DLL4 Ang-2 HER3 IGF-1R CD30 TAG- 72, SPEAP, CD45, L1-CAM, Lewis Y (Le y ) antigen, E-cadherin, V-cadherin, GPC3, EpCAM, CD4, CD8, CD21, CD23, CD46, CD80, HLA-DR, CD74, CD22, CD14, CD15, CD16, CD123, TCR gamma/delta, NKp46, KIR, CD56, DLL3, PD-1, PD-L1, CD28, CD137, CD99, GloboH, CD24, STEAP1, B7H3, Polysialic Acid, OX40, OX40-ligand, peptide MHC complexes (with peptides derived from TP53, KRAS, MYC, EBNA1-6, PRAME, MART, tyronsinase, MAGEA1-A6, pmel17, LMP2, or WT1), or a small molecule DOTA-based hapten. [00196] In some aspects, the anti-CD3 multi-specific antibodies that arm the EATs described herein contain structural modifications to facilitate rapid binding and cell uptake and/or slow release. In some aspects, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology (e.g., an antibody) may contain a deletion in the CH2 constant heavy chain region to facilitate rapid binding and cell uptake and/or slow release. Additionally or alternatively, in some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs described herein are bispecific antibodies, trispecific antibodies, or tetraspecific antibodies. [00197] In any of the above embodiments of the anti-CD3 multi-specific antibodies that arm the EATs of the present technology, the anti-CD3 multi-specific antibodies may be optionally conjugated to an agent selected from the group consisting of isotopes, dyes, chromagens, contrast agents, drugs, toxins, cytokines, enzymes, enzyme inhibitors, hormones, hormone antagonists, growth factors, radionuclides, metals, liposomes, nanoparticles, RNA, DNA or any combination thereof. [00198] In some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology bind specifically to at least one CD3 polypeptide. In some embodiments, the anti-CD3 multi-specific antibodies that arm the EATs of the present technology bind at least one CD3 polypeptide with a dissociation constant (K D ) of about 10 −3 M, 10 −4 M, 10 −5 M, 10 −6 M, 10 −7 M, 10 −8 M, 10 −9 M, 10 −10 M, 10 −11 M, or 10 −12 M. In some embodiments, the antibodies comprise a human antibody framework region. Uses of the EATs of the Present Technology [00199] In one aspect, the present disclosure provides a method for determining the antibody binding capacity of any embodiment of the ex vivo armed T cell described herein in vitro comprising (a) contacting the ex vivo armed T cell with an agent that binds to any embodiment of the anti-CD3 multi-specific antibody disclosed herein that is present on the ex vivo armed T cell, wherein the agent is directly or indirectly linked to a detectable label, and (b) determining the antibody binding capacity of the ex vivo armed T cell by detecting the level or intensity of signal emitted by the detectable label. The detectable label may be spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radioactive, fluorescent, chemifluorescent, or chemiluminescent label. In some embodiments, the antibody binding capacity is quantified using flow cytometry or mean fluorescence intensity (MFI)-flow cytometry. [00200] In one aspect, the present disclosure provides a method for tracking ex vivo armed T cells in a subject in vivo comprising (a) administering to the subject an effective amount of any embodiment of the ex vivo armed T cell described herein, wherein the ex vivo armed T cell is configured to localize to a tissue expressing one or more target antigens recognized by any embodiment of the anti-CD3 multi-specific antibody disclosed herein that is present on the ex vivo armed T cell; (b) administering to the subject an effective amount of a DOTA- based hapten, wherein the DOTA-based hapten is configured to bind to the anti-CD3 multi- specific antibody that is present on the ex vivo armed T cell, and comprises or is directly or indirectly linked to a detectable label; and (c) determining the biodistribution of the ex vivo armed T cell in the subject by detecting signal emitted by the detectable label of the DOTA- based hapten that is localized to the ex vivo armed T cells and/or is higher than a reference value. The detectable label may be spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radioactive, fluorescent, chemifluorescent, or chemiluminescent label. [00201] In one aspect, the present disclosure provides a method for tracking ex vivo armed T cells in a subject in vivo comprising (a) administering to the subject an effective amount of a complex comprising any embodiment of the ex vivo armed T cell described herein and a DOTA-based hapten, wherein the complex is configured to localize to a tissue expressing one or more target antigens recognized by any embodiment of the anti-CD3 multi-specific antibody disclosed herein that is present on the ex vivo armed T cell and wherein the DOTA- based hapten is configured to bind to the anti-CD3 multi-specific antibody that is present on the ex vivo armed T cell and comprises or is directly or indirectly linked to a detectable label; and (b) determining the biodistribution of the ex vivo armed T cell in the subject by detecting signal emitted by the complex that is localized to the ex vivo armed T cells and/or is higher than a reference value. The detectable label may be spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radioactive, fluorescent, chemifluorescent, or chemiluminescent label. [00202] In one aspect, the present disclosure provides a method for detecting tumors in a subject in need thereof comprising (a) administering to the subject an effective amount of any embodiment of the ex vivo armed T cell described herein, wherein the ex vivo armed T cell is configured to localize to a tissue expressing one or more target antigens recognized by any embodiment of the anti-CD3 multi-specific antibody disclosed herein that is present on the ex vivo armed T cell; (b) administering to the subject an effective amount of a DOTA-based hapten, wherein the DOTA-based hapten is configured to bind to the anti-CD3 multi-specific antibody that is present on the ex vivo armed T cell, and comprises or is directly or indirectly linked to a detectable label; and (c) detecting the presence of tumors in the subject by detecting signal emitted by the detectable label of the DOTA-based hapten that is localized to the tumor and/or is higher than a reference value. The detectable label may be spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radioactive, fluorescent, chemifluorescent, or chemiluminescent label. [00203] In one aspect, the present disclosure provides a method for detecting tumors in a subject in need thereof comprising (a) administering to the subject an effective amount of a complex comprising any embodiment of the ex vivo armed T cell described herein and a DOTA-based hapten, wherein the complex is configured to localize to a tissue expressing one or more target antigens recognized by any embodiment of the anti-CD3 multi-specific antibody disclosed herein that is present on the ex vivo armed T cell and wherein the DOTA- based hapten is configured to bind to the anti-CD3 multi-specific antibody that is present on the ex vivo armed T cell, and comprises or is directly or indirectly linked to a detectable label; and (b) detecting the presence of tumors in the subject by detecting signal emitted by the complex that is localized to the tumor and/or is higher than a reference value. The detectable label may be spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radioactive, fluorescent, chemifluorescent, or chemiluminescent label. [00204] In one aspect, the present disclosure provides a method for assessing the in vivo durability or persistence of ex vivo armed T cells in a subject comprising (a) administering to the subject an effective amount of any embodiment of the ex vivo armed T cell described herein, wherein the ex vivo armed T cell is configured to localize to a tissue expressing one or more target antigens recognized by any embodiment of the anti-CD3 multi-specific antibody disclosed herein that is present on the ex vivo armed T cell; (b) administering to the subject a first effective amount of a DOTA-based hapten, wherein the DOTA-based hapten is configured to bind to the anti-CD3 multi-specific antibody that is present on the ex vivo armed T cell, and comprises or is directly or indirectly linked to a detectable label; (c) detecting signal emitted by the detectable label of the DOTA-based hapten that is localized to the ex vivo armed T cells and is higher than a reference value at a first time point; (d) detecting signal emitted by the detectable label of the DOTA-based hapten that is localized to the ex vivo armed T cells and is higher than a reference value at a second time point; and (e) determining that the ex vivo armed T cells show in vivo durability or persistence when the signal emitted by the detectable label of the DOTA-based hapten at the second time point is comparable to that observed at the first time point. In certain embodiments, the method further comprising administering to the subject a second effective amount of the DOTA- based hapten after step (c). The detectable label may be spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radioactive, fluorescent, chemifluorescent, or chemiluminescent label. [00205] In one aspect, the present disclosure provides a method for assessing the in vivo durability or persistence of ex vivo armed T cells in a subject comprising (a) administering to the subject an effective amount of a complex comprising any embodiment of the ex vivo armed T cell described herein and a DOTA-based hapten, wherein the complex is configured to localize to a tissue expressing one or more target antigens recognized by any embodiment of the anti-CD3 multi-specific antibody disclosed herein that is present on the ex vivo armed T cell and wherein the DOTA-based hapten is configured to bind to the anti-CD3 multi- specific antibody that is present on the ex vivo armed T cell, and comprises or is directly or indirectly linked to a detectable label; (b) detecting signal emitted by the complex that is localized to the ex vivo armed T cells and is higher than a reference value at a first time point; (c) detecting signal emitted by the complex that is localized to the ex vivo armed T cells and is higher than a reference value at a second time point; and (d) determining that the ex vivo armed T cells show in vivo durability or persistence when the signal emitted by the complex at the second time point is comparable to that observed at the first time point. The detectable label may be spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radioactive, fluorescent, chemifluorescent, or chemiluminescent label. [00206] In one aspect, the present disclosure provides a method for detecting the presence of a DOTA-based hapten in a subject that has been administered any embodiment of the ex vivo armed T cell described herein comprising (a) administering to the subject an effective amount of a DOTA-based hapten, wherein the DOTA-based hapten comprises a radionuclide, and is configured to localize to the ex vivo armed T cell; and (b) detecting the presence of the DOTA-based hapten in the subject by detecting radioactive levels emitted by the DOTA- based hapten that are higher than a reference value, wherein the ex vivo armed T cell is configured to localize to a tissue expressing one or more target antigens recognized by any embodiment of the anti-CD3 multi-specific antibody disclosed herein that is present on the ex vivo armed T cell. In another aspect, the present disclosure provides a method for detecting the presence of a DOTA-based hapten in a subject that has been administered a complex comprising any embodiment of the ex vivo armed T cell described herein and a DOTA-based hapten including a radionuclide, comprising detecting the presence of the DOTA-based hapten in the subject by detecting radioactive levels emitted by the complex that are higher than a reference value, wherein the ex vivo armed T cell is configured to localize to a tissue expressing one or more target antigens recognized by any embodiment of the anti-CD3 multi- specific antibody disclosed herein that is present on the ex vivo armed T cell. [00207] Additionally or alternatively, in some embodiments, the method further comprises quantifying radioactive levels emitted by the DOTA-based hapten or complex that is localized to the tumor and/or radioactive levels emitted by the DOTA-based hapten or the complex that is localized in one or more normal tissues or organs of the subject. In certain embodiments, the one or more normal tissues or organs are selected from the group consisting of heart, muscle, gallbladder, esophagus, stomach, small intestine, large intestine, liver, pancreas, lungs, bone, bone marrow, kidneys, urinary bladder, brain, skin, spleen, thyroid, and soft tissue. In any of the preceding embodiments, the method further comprises determining biodistribution scores by computing a ratio of the radioactive levels emitted by the DOTA-based hapten or complex that is localized to the tumor relative to the radioactive levels emitted by the DOTA-based hapten or complex that is localized in the one or more normal tissues or organs of the subject. Additionally or alternatively, the method further comprises calculating estimated absorbed radiation doses for the tumor and the one or more normal tissues or organs of the subject based on the biodistribution scores. In some embodiments, the method further comprises computing a therapeutic index for the DOTA- based hapten or complex based on the estimated absorbed radiation doses for the tumor and the one or more normal tissues or organs of the subject. [00208] In some embodiments of the preceding methods disclosed herein, the radioactive levels emitted by the complex or the detectably labeled DOTA-based hapten are detected using positron emission tomography or single photon emission computed tomography. Additionally or alternatively, in some embodiments of the methods disclosed herein, the radioactive levels emitted by the complex or the radiolabeled DOTA-based hapten are detected between 2 to 120 hours after the complex or the radiolabeled DOTA-based hapten is administered. In certain embodiments of the methods disclosed herein, the radioactive levels emitted by the complex or the radiolabeled DOTA-based hapten are expressed as the percentage injected dose per gram tissue (%ID/g). The reference value may be calculated by measuring the radioactive levels present in non-tumor (normal) tissues, and computing the average radioactive levels present in non-tumor (normal) tissues ^ standard deviation. In some embodiments, the reference value is the standard uptake value (SUV). See Thie JA, J Nucl Med.45(9):1431-4 (2004). In some embodiments, the ratio of radioactive levels between a tumor and normal tissue is about 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1 or 100:1. [00209] Additionally or alternatively, in some embodiments of the methods disclosed herein, the ex vivo armed T cell, the complex or the detectably labeled DOTA-based hapten is administered intravenously, intramuscularly, intraarterially, intrathecally, intracapsularly, intraorbitally, intradermally, intraperitoneally, transtracheally, subcutaneously, intracerebroventricularly, orally, intratumorally, or intranasally. In certain embodiments, the ex vivo armed T cell, the complex or the detectably labeled DOTA-based hapten is administered into the cerebral spinal fluid or blood of the subject. [00210] Examples of DOTA-based haptens useful in the methods disclosed herein include, but are not limited to, benzyl-DOTA, NH 2 -benzyl (Bn) DOTA, DOTA-desferrioxamine, DOTA-Phe-Lys(HSG)-D-Tyr-Lys(HSG)-NH2, Ac-Lys(HSG)D-Tyr-Lys(HSG)-Lys(Tscg- Cys)-NH 2 , DOTA-D-Asp-D-Lys(HSG)-D-Asp-D-Lys(HSG)-NH 2 ; DOTA-D-Glu-D- Lys(HSG)-D-Glu-D-Lys(HSG)-NH 2 , DOTA-D-Tyr-D-Lys(HSG)-D-Glu-D-Lys(HSG)-NH 2 , DOTA-D-Ala-D-Lys(HSG)-D-Glu-D-Lys(HSG)-NH2, DOTA-D-Phe-D-Lys(HSG)-D-Tyr- D-Lys(HSG)-NH2, Ac-D-Phe-D-Lys(DOTA)-D-Tyr-D-Lys(DOTA)-NH2, Ac-D-Phe-D- Lys(DTPA)-D-Tyr-D-Lys(DTPA)-NH 2 , Ac-D-Phe-D-Lys(Bz-DTPA)-D-Tyr-D-Lys(Bz- DTPA)-NH2, Ac-D-Lys(HSG)-D-Tyr-D-Lys(HSG)-D-Lys(Tscg-Cys)-NH2, DOTA-D-Phe- D-Lys(HSG)-D-Tyr-D-Lys(HSG)-D-Lys(Tscg-Cys)-NH2, (Tscg-Cys)-D-Phe-D-Lys(HSG)- D-Tyr-D-Lys(HSG)-D-Lys(DOTA)-NH 2 , Tscg-D-Cys-D-Glu-D-Lys(HSG)-D-Glu-D- Lys(HSG)-NH 2 , (Tscg-Cys)-D-Glu-D-Lys(HSG)-D-Glu-D-Lys(HSG)-NH 2 , Ac-D-Cys-D- Lys(DOTA)-D-Tyr-D-Ala-D-Lys(DOTA)-D-Cys-NH2, Ac-D-Cys-D-Lys(DTPA)-D-Tyr-D- Lys(DTPA)-NH 2 , Ac-D-Lys(DTPA)-D-Tyr-D-Lys(DTPA)-D-Lys(Tscg-Cys)-NH 2 , Ac-D- Lys(DOTA)-D-Tyr-D-Lys(DOTA)-D-Lys(Tscg-Cys)-NH 2 , DOTA-RGD, DOTA-PEG- E(c(RGDyK))2, DOTA-8-AOC-BBN, DOTA-PESIN, p-NO2-benzyl-DOTA, DOTA-biotin- sarcosine (DOTA-biotin), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid mono (N- hydroxysuccinimide ester) (DOTA-NHS), and DOTATyrLysDOTA. [00211] In any and all embodiments of the methods disclosed herein, the subject is human. Adoptive Cell Therapy with the EATs of the Present Technology [00212] For treatment, the amount of the EATs provided herein administered is an amount effective in producing the desired effect, for example, treatment of a cancer or one or more symptoms of a cancer. An effective amount can be provided in one or a series of administrations of the EATs provided herein. An effective amount can be provided in a bolus or by continuous perfusion. For adoptive immunotherapy using EATs, cell doses in the range of about 10 4 to about 10 10 are typically infused. [00213] The EATs of the presently disclosed subject matter can be administered by any methods known in the art, including, but not limited to, pleural administration, intravenous administration, subcutaneous administration, intranodal administration, intratumoral administration, intrathecal administration, intrapleural administration, intraperitoneal administration, and direct administration to the thymus. In certain embodiments, the EATs and the compositions comprising thereof are intravenously administered to the subject in need. Methods for administering cells for adoptive cell therapies, including, for example, donor lymphocyte infusion and cellular immunotherapies, and regimens for administration are known in the art and can be employed for administration of the EATs provided herein. [00214] The presently disclosed subject matter provides various methods of using the EATs (e.g., T cells) provided herein, which are coated or complexed with an effective arming dose of at least one type of anti-CD3 multi-specific antibody described herein. For example, the presently disclosed subject matter provides methods of reducing tumor burden in a subject. In one non-limiting example, the method of reducing tumor burden comprises administering an effective amount of the presently disclosed EATs to the subject and optionally administering a suitable antibody targeted to the tumor, thereby inducing tumor cell death in the subject. In some embodiments, the EATs and the antibody are administered at different times. For example, in some embodiments, the EATs are administered and then the antibody is administered. In some embodiments, the antibody is administered 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 18 hours, 24 hours, 30 hours, 26 hours, 48 hours, 72 hours, 96 hours, or longer after the administration of the EATs. [00215] The presently disclosed EATs either alone or in combination with a suitable therapeutic antibody targeted to the tumor can reduce the number of tumor cells, reduce tumor size, and/or eradicate the tumor in the subject. In certain embodiments, the method of reducing tumor burden comprises administering an effective amount of EATs to the subject, thereby inducing tumor cell death in the subject. Non-limiting examples of suitable tumors include adrenal cancers, bladder cancers, blood cancers, bone cancers, osteosarcomas, brain cancers, breast cancers including triple negative breast cancer, carcinoma, cervical cancers, colon cancers, colorectal cancers, corpus uterine cancers, ear, nose and throat (ENT) cancers, endometrial cancers, esophageal cancers, Ewing’s sarcoma, gastrointestinal cancers including gastric cancer, head and neck cancers, Hodgkin's disease, intestinal cancers, kidney cancers, larynx cancers, acute and chronic leukemias including acute myeloid leukemia, liver cancers, lymph node cancers, lymphomas, lung cancers including non-small cell lung cancer, melanomas, mesothelioma, myelomas including multiple myeloma, nasopharynx cancers, neuroblastomas, non-Hodgkin's lymphoma, oral cancers, ovarian cancers, pancreatic cancers, penile cancers, pharynx cancers, prostate cancers, rectal cancers, sarcoma, seminomas, skin cancers, stomach cancers, teratomas, testicular cancers, thyroid cancers, uterine cancers, vaginal cancers, vascular tumors, and metastases thereof. In some embodiments, the cancer is a relapsed or refractory cancer. In some embodiments, the cancer is resistant to one or more cancer therapies, e.g., one or more chemotherapeutic drugs. [00216] The presently disclosed subject matter also provides methods of increasing or lengthening survival of a subject having a neoplasia (e.g., a tumor). In one non-limiting example, the method of increasing or lengthening survival of a subject having neoplasia (e.g., a tumor) comprises administering an effective amount of the presently disclosed EATs to the subject, thereby increasing or lengthening survival of the subject. The presently disclosed subject matter further provides methods for treating or preventing a neoplasia (e.g., a tumor) in a subject, comprising administering the presently disclosed EATs to the subject. [00217] Cancers whose growth may be inhibited using the EATs of the presently disclosed subject matter comprise cancers typically responsive to immunotherapy. Non-limiting examples of cancers for treatment include multiple myeloma, neuroblastoma, glioma, melanoma, sarcomas, acute myeloid leukemia, breast cancer, colon cancer, esophageal cancer, gastric cancer, non-small cell lung cancer, ovarian cancer, pancreatic cancer, prostate cancer, thyroid cancer, small cell lung cancer, and NK cell lymphoma. In certain embodiments, the cancer is triple negative breast cancer or ovarian cancer. In some embodiments, the cancer is prostate cancer. In some embodiments, the cancer is acute myeloid leukemia. In some embodiments, the cancer is ovarian cancer, sarcoma, non-small cell lung cancer, esophageal cancer, gastric cancer, colorectal cancer, or triple negative breast cancer. [00218] Additionally or alternatively, in some embodiments of the methods disclosed herein, the immune-activating cytokine levels released by the EATs of the present technology are lower compared to unarmed T cells mixed with an anti-CD3 multi-specific antibody, thus reducing the likelihood of CRS. Examples of immune-activating cytokines include granulocyte macrophage colony stimulating factor (GM-CSF), IFNα, IFN-β, IFN-γ, TNF-α, IL-2, IL-3, IL-6, IL-10, IL-11, IL-7, IL-12, IL-15, IL-21, interferon regulatory factor 7 (IRF7), and combinations thereof. [00219] Suitable human subjects for therapy typically comprise two treatment groups that can be distinguished by clinical criteria. Subjects with “advanced disease” or “high tumor burden” are those who bear a clinically measurable tumor. A clinically measurable tumor is one that can be detected on the basis of tumor mass (e.g., by palpation, CAT scan, sonogram, mammogram or X-ray; positive biochemical or histopathologic markers on their own are insufficient to identify this population). A pharmaceutical composition embodied in the presently disclosed subject matter is administered to these subjects to elicit an anti -tumor response, with the objective of palliating their condition. Ideally, reduction in tumor mass occurs as a result, but any clinical improvement constitutes a benefit. Clinical improvement comprises decreased risk or rate of progression or reduction in pathological consequences of the tumor. [00220] A second group of suitable subjects is known in the art as the “adjuvant group.” These are individuals who have had a history of neoplasia, but have been responsive to another mode of therapy. The prior therapy can have included, but is not restricted to, surgical resection, radiotherapy, and traditional chemotherapy. As a result, these individuals have no clinically measurable tumor. However, they are suspected of being at risk for progression of the disease, either near the original tumor site, or by metastases. This group can be further subdivided into high-risk and low-risk individuals. The subdivision is made on the basis of features observed before or after the initial treatment. These features are known in the clinical arts, and are suitably defined for each different neoplasia. Features typical of high-risk subgroups are those in which the tumor has invaded neighboring tissues, or who show involvement of lymph nodes. Another group has a genetic predisposition to neoplasia but has not yet evidenced clinical signs of neoplasia. For instance, women testing positive for a genetic mutation associated with breast cancer, but still of childbearing age, can wish to receive one or more of the EATs described herein in treatment prophylactically to prevent the occurrence of neoplasia until it is suitable to perform preventive surgery. [00221] The subjects can have an advanced form of disease, in which case the treatment objective can include mitigation or reversal of disease progression, and/or amelioration of side effects. The subjects can have a history of the condition, for which they have already been treated, in which case the therapeutic objective will typically include a decrease or delay in the risk of recurrence. [00222] In one aspect, the present disclosure provides a method for treating cancer or inhibiting tumor growth or metastasis in a subject in need thereof comprising administering to the subject an effective amount of any embodiment of the ex vivo armed T cell described herein. In another aspect, the present disclosure provides a method for treating cancer or inhibiting tumor growth or metastasis in a subject in need thereof comprising (a) administering to the subject a first effective amount of any and all embodiments of the ex vivo armed T cell described herein, (b) administering to the subject a second effective amount of the ex vivo armed T cell about 72 hours after administration of the first effective amount of the ex vivo armed T cell, (c) administering to the subject a third effective amount of the ex vivo armed T cell about 96 hours after administration of the second effective amount of the ex vivo armed T cell, and (d) repeating steps (a)-(c) for at least three additional cycles. In certain embodiments, the subject exhibits sustained cancer remission after completion of step (d). In certain embodiments, the subject is human. [00223] Additionally or alternatively, in some embodiments of the methods disclosed herein, the ex vivo armed T cell is autologous, non-autologous, or derived in vitro from lymphoid progenitor cells. [00224] Additionally or alternatively, in some embodiments of the methods disclosed herein, the ex vivo armed T cell is administered intravenously, intramuscularly, intraarterially, intrathecally, intracapsularly, intraorbitally, intradermally, intraperitoneally, transtracheally, subcutaneously, intracerebroventricularly, orally, intratumorally, or intranasally. In certain embodiments, the ex vivo armed T cell is administered into the cerebral spinal fluid or blood of the subject. In some embodiments, the subject is diagnosed with, or is suspected of having cancer. Exemplary cancers or tumors include, but are not limited to, carcinoma, sarcoma, melanoma, hematopoietic cancer, osteosarcoma, Ewing’s sarcoma, adrenal cancers, bladder cancers, blood cancers, bone cancers, brain cancers, breast cancers, carcinoma, cervical cancers, colon cancers, colorectal cancers, corpus uterine cancers, ear, nose and throat (ENT) cancers, endometrial cancers, esophageal cancers, gastrointestinal cancers, head and neck cancers, Hodgkin's disease, intestinal cancers, kidney cancers, larynx cancers, leukemias, liver cancers, lymph node cancers, lymphomas, lung cancers, melanomas, mesothelioma, myelomas, nasopharynx cancers, neuroblastomas, non-Hodgkin's lymphoma, oral cancers, ovarian cancers pancreatic cancers penile cancers pharynx cancers prostate cancers rectal cancers, seminomas, skin cancers, stomach cancers, teratomas, testicular cancers, thyroid cancers, uterine cancers, vaginal cancers, vascular tumors, and metastases thereof. [00225] Additionally or alternatively, in some embodiments, the method further comprises separately, simultaneously, or sequentially administering an additional cancer therapy. In some embodiments, the additional cancer therapy is selected from among chemotherapy, radiation therapy, immunotherapy, monoclonal antibodies, anti-cancer nucleic acids or proteins, anti-cancer viruses or microorganisms, and any combinations thereof. In certain embodiments, the additional cancer therapy is an immune checkpoint inhibitor selected from among pembrolizumab, nivolumab, cemiplimab, atezolizumab, avelumab, durvalumab, and ipilimumab. [00226] Additionally or alternatively, in certain embodiments, the method further comprises administering a cytokine to the subject. In some embodiments, the cytokine is administered prior to, during, or subsequent to administration of the ex vivo armed T cell. Examples of suitable cytokines include, but are not limited to, interferon α, interferon β, interferon ^, complement C5a, IL-2, TNFα, CD40L, IL12, IL-23, IL15, IL17, CCL1, CCL11, CCL12, CCL13, CCL14-1, CCL14-2, CCL14-3, CCL15-1, CCL15-2, CCL16, CCL17, CCL18, CCL19, CCL2, CCL20, CCL21, CCL22, CCL23-1, CCL23-2, CCL24, CCL25-1, CCL25-2, CCL26, CCL27, CCL28, CCL3, CCL3Ll, CCL4, CCL4L1, CCL5, CCL6, CCL7, CCL8, CCL9, CCR10, CCR2, CCR5, CCR6, CCR7, CCR8, CCRL1, CCRL2, CX3CL1, CX3CR, CXCL1, CXCL10, CXCL11, CXCL12, CXCL13, CXCL14, CXCL15, CXCL16, CXCL2, CXCL3, CXCL4, CXCL5, CXCL6, CXCL7, CXCL8, CXCL9, CXCR1, CXCR2, CXCR4, CXCR5, CXCR6, CXCR7 and XCL2. [00227] In any and all embodiments of the methods disclosed herein, in vivo or in vitro cytokine levels released by the ex vivo armed T cells are reduced compared to unarmed T cells mixed with an anti-CD3 multi-specific antibody. Kits [00228] The presently disclosed subject matter provides kits for the treatment of cancer. In certain embodiments, the kit comprises any and all embodiments of the anti-CD3 multi- specific antibody disclosed herein in unit dosage form and instructions for arming T cells with the same. Additionally or alternatively, in some embodiments, the kits may further comprise instructions for isolating T cells from an autologous or non-autologous donor, and agents for culturing, differentiating and/or expanding isolated T cells in vitro such as cell culture media, CD3/CD28 beads, zoledronate, cytokines such as IL-2, IL-15 (e.g., IL15Rα- IL15 complex), buffers, diluents, excipients, and the like. Additionally or alternatively, in some embodiments, the kits comprise any and all embodiments of the EATs described herein and instructions for using the same to treat cancer in a subject in need thereof. The instructions will generally include information about the use of the composition for the treatment or prevention of a neoplasia (e.g., solid tumor). [00229] In any of the preceding embodiments of the kits disclosed herein, the kit comprises a sterile container which contains a therapeutic agent disclosed herein (e.g., any and all embodiments of the anti-CD3 multi-specific antibody and/or EATs described herein); such containers can be boxes, ampules, bottles, vials, tubes, bags, pouches, blister-packs, or other suitable container forms known in the art. Such containers can be made of plastic, glass, laminated paper, metal foil, or other materials suitable for holding medicaments. Additionally or alternatively, in some embodiments, the instructions include at least one of the following: description of the therapeutic agent (e.g., any and all embodiments of the anti- CD3 multi-specific antibody and/or EATs described herein); dosage schedule and administration for treatment or prevention of a neoplasia (e.g., solid tumor) or symptoms thereof; precautions; warnings; indications; counter-indications; overdose information; adverse reactions; animal pharmacology; clinical studies; and/or references. The instructions may be printed directly on the container (when present), or as a label applied to the container, or as a separate sheet, pamphlet, card, or folder supplied in or with the container. EXAMPLES [00230] The present technology is further illustrated by the following Examples, which should not be construed as limiting in any way. Example 1: Materials and Methods [00231] T cells expansion ex vivo. Peripheral blood mononuclear cells (PBMCs) were separated from buffy coats (New York Blood Center) by Ficoll. These naïve T cells were purified from human PBMC using Pan T cell isolation kit (Miltenyi Biotec) and expanded by CD3/CD28 Dynabeads (Invitrogen, Carlsbad, CA) for 7 to 14 days in the presence of 30 IU/mL of IL-2 according to manufacturer’s instructions. Unless stated otherwise, these cultured T cells were used for all T cell experiments. [00232] Gamma delta (γδ) T cells activation. Gamma delta T cells were expanded through 2 different ways.1) Fresh PBMCs separated from buffy coats were cultured with 2μM of zoledronic acid and 800 IU/mL of IL-2 for 12 to 14 days according to protocols.2) Fresh PBMCs were cultured with 2μM of zoledronic acid and 30ng/mL of IL15Rα-IL15 complex for 12 to 14 days. Cultured PBMCs were harvested and their surface antigen expression examined using antibodies against human CD3, CD4, CD8, γδ T cell receptor (TCR), and αβ TCR. [00233] Autologous T cell activation. Naïve T cells were separated from unused cryopreserved peripheral blood stem cell collections with IRB approval. These cells were purified using Dynabeads untouched human T cell kit (Invitrogen, Carlsbad, CA) and expanded with CD3/CD28 Dynabeads (Invitrogen, Carlsbad, CA) and 30 IU/mL of IL-2 for 10 to 14 days. [00234] Tumor cell lines. Representative neuroblastoma cell line, IMR-32 (ATCC-CCL- 127), osteosarcoma cell line, 143B (ATCC-CRL-8303) and U-2 OS (ATCC-HTB-96), primitive neuroectodermal tumor cell line TC-71 (ATCC CRL-1598) and TC-32 (RRID:CVCL-7151), breast cancer cell line HCC1954 (ATCC-CRL-2338), acute monocytic leukemia (AML-M5a) cell line MOLM13, prostate cancer cell line LNCaP-AR(ATCC-CRL- 1740), and melanoma cell line M14 (UCLA-SO-M14) were used. All cells were authenticated by short tandem repeats profiling using PowerPlex 1.2 System (Promega, Madison, WI), and periodically tested for mycoplasma infection using a commercial kit (Lonza, Basel, Switzerland). The luciferase-labeled osteosarcoma cell line 143BLuc, melanoma cell line M14Luc, and neuroblastoma cell line IMR32Luc were generated by retroviral infection with an SFG-GF Luc vector. [00235] GD2-BsAb or HER2-BsAb were used for arming T cells. Hu3F8-BsAb specific for GD2 was built using the IgG-[L]-scFv format, in which the anti-CD3 huOKT3 single- chain variable fragment (scFv) was linked to the carboxyl end of the anti-GD2 hu3F8 IgG1 light chain, where the N297A mutation was introduced to remove glycosylation and the K322A to remove complement activation – a combination to reduce spontaneous cytokine release ( H. Xu et al., Cancer immunology research 3, 266 (Mar, 2015)). HER2-BsAb built with the IgG-[L]-scFv format, carried a VH identical to that of transtuzumab IgG1, again with both N297A and K322A mutations to silence Fc functions (A. Lopez-Albaitero et al., Oncoimmunology 6, e1267891 (2017)). Hu3F8xOKT3 and HerceptinxOKT3 chemical conjugates were made as previously described by Sen et al ( M. Yankelevich et al., Pediatr Blood Cancer 59, 1198 (2012); M. Sen et al., J Hematother Stem Cell Res 10, 247 (2001)). In these chemical conjugates, the mouse OKT3 antibody instead of huOKT3 was used. The other BsAbs were synthesized as previously described. (H. Xu et al., Cancer immunology research 3, 266 (2015), S. S. Hoseini, H. Guo, Z. Wu, M. N. Hatano, N. V. Cheung, Blood advances 2, 1250 (2018), Z. Wu, H. F. Guo, H. Xu, N. V. Cheung, Mol Cancer Ther 17, 2164 (2018); A. Lopez-Albaitero et al., OncoImmunology, 6(3):e1267891 (2017)). [00236] Antibody Dependent T cell mediated Cytotoxicity (ADTC). EAT-mediated cytotoxicity was performed using 51 Cr release as described previously (H. Xu et al., Cancer immunology research 3, 266 (Mar, 2015)), and EC 50 was calculated using SigmaPlot software. Target cell lines were cultured in RPMI-1640 (Cellgro) supplemented with 10% fetal bovine serum (FBS, Life Technologies, Carlsbad, CA) and harvested with EDTA/Trypsin. These target cells were labeled with sodium 51 Cr chromate (Amersham, Arlington Height, IL) at 100 µCi/10 6 cells at 37 ◦ C for 1 hour. After washing twice, these radiolabeled target cells were plated in 96-well plates. EATs were added to target cells at decreasing effector: target cell (E:T) ratios, at 2-fold dilutions from 50:1. After incubation at 37 ◦ C for 4 hours, the released 51 Cr was measured by a gamma counter (Packed Instrument, Downers Grove, IL). Percentage of specific lysis was calculated using the formula where cpm represented counts per minute of 51 Cr released. [00237] Total release of 51 Cr was assessed by lysis with 10% SDS (Sigma, St Louis, Mo) and background release was measured in the absence of effector cells and antibodies. [00238] Cytokine release assays. EAT-induced human cytokine release was analyzed in vitro and in vivo. Human Th1 cell released cytokines were analyzed by LEGENDplex TM Human Th1 Panel (Biolegend, San Diego, CA). Five human T cell cytokines including IL-2, IL-6 IL-10 IFN-γ and TNF-α were analyzed after arming or after exposure to target antigen(+) tumor cells (in vitro). Mouse serum cytokines were analyzed 4 hours after EAT injection. [00239] T cell arming. Ex vivo expanded polyclonal T cells were harvested between day 7 and day 14 and armed with each BsAb for 20 minutes at room temperature. After incubation, the T cells were washed with PBS twice. After washing, EATs were tested for cell surface density of BsAb (MFI) using anti-idiotype antibody or anti-human IgG Fc antibody. For quantification of surface bound BsAb, antibody binding capacity (ABC) by flow cytometry referenced to Quantum™ Simply Cellular® (QSC) microspheres. EATs were tested in vitro for cytotoxicity against the appropriate targets in ADTC assays. [00240] Cryopreservation and thawing of Ex vivo BsAb armed T cells (EAT). After arming with BsAbs, EATs were centrifuged at 1800 rpm for 5 minutes at 4℃ and the supernatant discarded. The cell pellet was resuspended in T cell freezing medium (90% of FCS and 10% DMSO) to achieve a cell concentration of 50 × 10 6 cells/1mL, chilled to 4 °C and aliquoted into 2 mL cryovials. Vials were immediately transferred to freeze at −80 °C for 24 hours before transferring to liquid nitrogen. After storage cryovials were thawed in a 37 °C water bath with gentle swirling for 1 minute. The thawed cells were transferred to F10 media and centrifuged at 1800 rpm for 5 minutes. Thawed cells were analyzed for viability, phenotype, antibody binding, and ADTC assays to determine the impact of cryopreservation on cellular performance. [00241] T cell transduction with tdTomato and click beetle red luciferase. T cells isolated from PBMCs were stimulated with CD3/CD28 Dynabeads (Invitrogen, Carlsbad, CA) for 24 hours. T cells were transduced with retroviral constructs containing tdTomato and click beetle red luciferase in RetroNectin-coated 6-well plates in the presence of IL-2 (100 IU/mL) and protamine sulfate (4µg/mL). Transduced T cells were cultured for 8 days before use in animal experiments. [00242] In vivo anti-tumor effects of EATs. All animal experiments were performed according to Institutional Animal Care and Use Committee (IACUC) guidelines. Tumors were suspended in Matrigel (Corning Corp, Tewksbury MA) and implanted in the flank of 6- 10 week-old BALB-Rag2 -/- IL-2R-γc-KO (BRG) mice (Taconic Biosciences, Germantown, NY) (D. Andrade et al., Arthritis Rheum 63, 2764 (Sep, 2011)). The following tumor lines and cell doses were used: 1 × 10 6 of 143BLuc, 5×10 6 IMR32-Luc, 5×10 6 M14Luc, 5×10 6 HCC1954, 5×10 6 TC-32 and 5×10 6 TC-71. Three different osteosarcoma and 2 different neuroblastoma patient-derived tumor xenografts (PDXs) established from fresh surgical specimens with IRB approval were also utilized. T cells were purified and expanded in vitro as described above. Prior to injection into mice, these T cells were analyzed by FACS for the frequencies of CD3+, CD8+, CD4+ populations. For arming, cultured T cells harvested after 7 to 14 days of ex vivo expansion were used. Treatment was initiated after tumors were established (average tumor volume of 100 mm 3 when measured using TM900 scanner) (Piera, Brussels, BE). When tumor growth reached 2 cm 3 or greater, mice were euthanized. CBC analyses, body weight, general activity, physical appearance and GVHD scoring were monitored. All animal experiments were repeated twice more with different donor’s T cells to ensure that our results were reliable. [00243] Bioluminescence imaging. Luc(+) T cell engraftment and trafficking were quantified after intravenous injection of 3 mg D-luciferin (Gold Biotechnology) on different days post T cell injection. Bioluminescence images were acquired using IVIS Spectrum CT In vivo Imaging System (Caliper Life Sciences, Waltham, MA) and overlaid onto visible light images, to allow Living image 2.60 (Xenogen, Alameda, CA) to quantify bioluminescence in the tumor regions of interest (ROI). The total counts (photon/s) over time were quantified, and the bioluminescence signals before T cell injection were used as baselines. [00244] Flow cytometry of blood, spleen and tumor. Peripheral blood, spleen and tumors were collected and analyzed by flow cytometry. Antibodies against human CD3, CD4, CD8, and CD45 (BD Bioscience) were used to quantify T cell engraftment and subpopulations. Fluorescence of stained cells was acquired using either a BD FACS Calibur TM or a BD LSRFORTESSA (BD Biosciences, Heidelberg, Germany) and analyzed using FlowJo software (FlowJo, LLC, Ashland, OR). [00245] Immunohistochemistry (IHC) for T cell infiltration. Harvested xenografts were tested for T cell infiltration using immunohistochemistry (IHC). Human CD3, CD4 and CD8 staining were performed using Discovery XT processor (Ventana Medical Systems, Oro Valley, AZ). Paraffin-embedded tumor sections were deparaffinized with EZPrep buffer (Ventana Medical Systems, Oro Valley, AZ), antigen retrieval was performed with CC1 buffer (Ventana Medical Systems, Oro Valley, AZ) and sections were blocked for 30 minutes with background buffer solution (Innovex). Anti-CD3 (DAKO, cat# A0452, 1.2μg/mL) antibody was applied, and sections were incubated for 5 hours, followed by 60 min incubation with biotinylated goat anti-rabbit IgG (Vector laboratories, cat# PK6101) at 1:200 dilution. Control antibody staining was done with biotinylated goat anti-rat IgG (Vector Labs, Burlingame, CA, cat#MKB-22258). All images were captured from tumor sections using Nikon ECLIPSE Ni-U microscope and NIS-Elements 4.0 imaging software. [00246] Statistics. Differences between groups indicated in the figures were tested for significance by one-way ANOVA or student's t-test, and survival outcomes were analyzed using GraphPad Prism 7.0. P -value < 0.05 was considered statistically significant. [00247] Bispecific antibodies. All BsAbs were synthesized as previously described (US Patent Application No.62/896415) (Hoseini et al., Blood advances 2, 1250-1258 (2018), Wu et al., Mol Cancer Ther 17, 2164-2175 (2018), Xu et al., Cancer Immunol Res 3, 266-277 (2015), and Lopez-Albaitero et al., OncoImmunology 6, e1267891). For each BsAb, scFv of huOKT3 was fused to the C-terminus of the light chain of human IgG1 via a C-terminal (G4S) 3 linker. N297A and K322A on Fc were generated with site-directed mutagenesis via primer extension in polymerase chain reactions. The nucleotide sequence encoding each BsAb was synthesized by GenScript and subcloned into a mammalian expression vector. Each BsAb was produced using Expi293 TM expression system (Thermo Fischer Scientific, Waltham, MA) separately. Antibodies were purified with protein A affinity column chromatography. The purity of BsAbs was evaluated by size-exclusion high performance liquid chromatography (SE-HPLC) and showed high levels of purity (>90%). The BsAbs remained stable after multiple freeze-thaw cycles. Biochemistry data of the BsAbs used in this study were summarized in FIG.46. [00248] Tumor cell lines. Neuroblastoma cell line, IMR-32 (ATCC Cat# CCL-127, RRID:CVCL_0346), osteosarcoma cell line, 143B (ATCC Cat# CRL-8303, RRID:CVCL_2270) and U-2 OS (ATCC Cat# HTB-96, RRID:CVCL_0042), primitive neuroectodermal tumor cell line TC-32 (RRID:CVCL-7151), breast cancer cell line HCC1954 (ATCC Cat# CRL-2338, RRID:CVCL_1259), gastric cancer cell line NCI-N87 (ATCC Cat# CRL-2338, RRID:CVCL_1259), acute monocytic leukemia (AML-M5a) cell line MOLM13 (DSMZ Cat# ACC-554, RRID:CVCL_2119), prostate cancer cell line LNCaP-AR (ATCC Cat# CRL-1740, RRID:CVCL_1379), and melanoma cell line M14 (NCI-DTP Cat# M14, RRID:CVCL_1395) were used for experiments. All cancer cells were authenticated by short tandem repeats profiling using PowerPlex 1.2 System (Promega, Madison, WI, Cat# DC8942), and periodically tested for mycoplasma infection using a commercial kit (Lonza, Basel, Switzerland, Cat# LT07-318). The luciferase-labeled melanoma cell line M14Luc and neuroblastoma cell line IMR32Luc were generated by retroviral infection with an SFG-GF Luc vector. [00249] In vivo experiments. All animal experiments were performed in compliance with Memorial Sloan Kettering Cancer Center’s institutional Animal Care and Use Committee (IACUC) guidelines. In vivo anti-tumor response was evaluated using cancer cell line- or patient-derived xenografts (CDXs or PDXs). Cancer cells suspended in Matrigel (Corning Corp, Tewksbury MA) or PDXs were implanted in the right flank of 6–10-week-old BALB- Rag2 -/- IL-2R-γc-KO (BRG) mice (Taconic Biosciences, Germantown, NY) (Andrade et al., Arthritis Rheum 63, 2764-2773 (2011)). The following cancer cell lines and cell doses were used: 1x10 6 of 143BLuc, 5x10 6 of IMR32Luc, 5x10 6 of HCC1954, 5x10 6 of LNCaP-AR, and 5x10 6 of TC-32. For mixed lineage CDX, 2.5x10 6 of IMR32Luc and 2.5x10 6 of HCC1954 were mixed and implanted into each mouse. Three osteosarcoma, one Ewing sarcoma family of tumors (EFT), and one breast cancer PDXs were established from fresh surgical specimens with MSKCC IRB approval. To avoid biological variables, only female mice were used for in vivo experiments except LNCaP-AR CDXs using male mice. Treatment was initiated after tumors were established, average tumor volume of 100 mm 3 when measured using TM900 scanner (Piera, Brussels, BE). Before treatment, mice with small tumors (<50 mm 3 ) or infection signs were excluded from the experiments, and the included mice were randomly assigned to each group. Tumor growth curves and overall survival was analyzed, and the overall survival was defined as the time from start of treatment to when tumor volume reached 2000 mm 3 . To define the well-being of mice, CBC analyses, body weight, general activity, physical appearance, and GVHD scoring were monitored. All animal experiments were repeated twice more with different donor’s T cells to ensure that our results were reliable. [00250] Immunohistochemistry (IHC) for T cell infiltration and HER2 expression. Harvested xenografts were Formalin-Fixed Paraffin-Embedded (FFPE) and tested for T cell infiltration using immunohistochemistry (IHC) IHC staining was performed by Molecular Cytology Core Facility of MSKCC using Discovery XT processor (Ventana Medical Systems, Oro Valley, AZ). FFPE tumor sections were deparaffinized with EZPrep buffer (Ventana Medical Systems, Oro Valley, AZ), antigen retrieval was performed with CC1 buffer (Ventana Medical Systems, Oro Valley, AZ), and sections were blocked for 30 minutes with background buffer solution (Innovex). Anti-CD3 antibody (Agilent, Cat# A0452, RRID: AB_2335677, 1.2μg/mL) and anti-HER2 (Enzo Life Sciences Cat#ALX-810- 227-L001, RRID: AB_11180914, 5μg/mL) were applied, and sections were incubated for 5 hours, followed by 60 min incubation with biotinylated goat anti-rabbit IgG (Vector laboratories, cat# PK6101) at 1:200 dilution. Control antibody staining was done with biotinylated goat anti-rat IgG (Vector Labs, Burlingame, CA, cat#MKB-22258). The detection was performed with DAB detection kit (Ventana Medical Systems, Oro Valley, AZ) according to manufacturer’s instruction. All images were captured from tumor sections using Nikon ECLIPSE Ni-U microscope and NIS-Elements 4.0 imaging software. Example 2: Ex vivo BsAb Armed T cells Acquired Target Antigen-specific Cytotoxicity [00251] Given the finite T cell receptor density on human T cells (J. D. Stone et al., J Immunol 187, 6281 (Dec 15, 2011)), the range and the optimal T cell surface density of BsAb as a function of arming dose was evaluated. Surface BsAb on EAT was analyzed using anti- idiotype or anti-human IgG Fc-specific antibodies for anti-GD2 BsAb armed T cells (GD2- EATs) or for anti-HER2 BsAb armed T cells (HER2-EATs), respectively. GD2-EATs and HER2-EATs showed increasing MFIs with increasing arming dose of either GD2-BsAb or HER2-BsAb, and more precise quantitation of BsAb density was measured as antibody- binding capacity (ABC) by flow cytometry referenced to anti-mouse quantum beads (FIG. 1A). Antibody-dependent T cell-mediated cytotoxicity (ADTC) was studied over a range of effector to target ratios (E:T ratios from 50:1 to 1.5:1) and BsAb arming doses (FIG.1B). GD2-EATs and HER2-EATs both showed strong cytotoxicity against GD2(+) HER2(+) osteosarcoma cell lines (U-2 OS), with maximal cytotoxicity by GD2-EATs or by HER2- EATs at arming BsAb doses between 0.05μg/10 6 T cells to 5μg/10 6 T cells, at BsAb surface densities between 500 to 20,000 molecules per T cell. When compared to unarmed T cells in the continual presence of BsAb, the potencies of GD2-EATs and HER2-EATs were ~10 fold lower (EC50); however, their maximal killing efficacy was comparable (FIGs.1C-1D). Example 3: Bispecific Antibody Format has Profound Effects on Anti-tumor Activity of EATs [00252] Anti-tumor potency of EATs armed with different anti-GD2 BsAb structural formats, all derived from the hu3F8 (anti-GD2) and huOKT (anti-CD3) sequences, were compared, including BiTE-monomer, BiTE-dimer, BiTE-Fc, IgG heterodimer, IgG chemical conjugate (hu3F8 × OKT3), IgG-[H]-scFv, and IgG-[L]-scFv (FIG.2A). [00253] Additionally, HER2-EATs armed with HER2 IgG chemical conjugates (Herceptin × OKT3) and compared to EATs armed with HER2 IgG-[L]-scFv formats. Anti-GD2 EATs armed with IgG-[L]-scFv and IgG chemical conjugate showed similar surface BsAb densities (ABC) as a function of arming dose; for HER2-EATs, IgG-[L]-scFv had higher ABC than IgG chemical conjugates (FIG.2B). Both GD2-EATs and HER-EATs armed with IgG-[L]- scFv format demonstrated superior potency and efficacy over EATs armed with each respective IgG chemical conjugate (FIG.2C). In vivo anti-tumor activities were then compared in PDX models (FIG.2D and FIGs.8A-8C). T cells armed with different structural formats of GD2-BsAbs or HER2-BsAbs were injected iv twice a week for 2 to 3 weeks. Each EATs were armed with a fixed dose at 2μg of each BsAb/2×10 7 T cells for equivalent ABCs among groups (1,000 to 10,000 molecules/ T cell). EAT therapy was well tolerated irrespective of BsAbs formats. GD2-EATs armed with IgG-[L]-scFv was superior over all other formats of GD2-BsAbs for tumor response and survival against both osteosarcoma PDX and against neuroblastoma PDXs. For HER2-EATs, IgG-[L]-scFv format was also more effective than IgG chemical conjugate, significant for tumor response (P<0.01) and for survival (P=0.0020) (FIG.2E). This difference in efficacy among GD2-EATs armed with different structural formats strongly correlated with the density of tumor infiltrating CD3(+) T cells (TILs) by IHC staining of neuroblastoma PDXs harvested on day 10 after the beginning of treatment (FIG.2F). GD2-EATs armed with IgG-[L]-scFv format showed significantly more abundant TILs compared to EATs armed with other formats of GD2- BsAb. Example 4: Autologous EATs Armed with Anti-GD2 IgG-[L]-scFv were Equally Effective In vivo [00254] With the IgG-[L]-scFv formatted GD2-BsAb, autologous EATs were generated using patient-derived T cells purified from cryopreserved PBMCs and expanded in vitro. Autologous GD2-EATs (0.1μg of GD2-BsAb/10 6 cells) were administered iv into mice xenografted with the corresponding patient’s neuroblastoma PDXs (FIG.2G). Autologous GD2-EATs suppressed tumor growth as well as EATs derived from unrelated donor, confirming that the anti-tumor property of EATs was independent of allogeneic ‘graft-versus- cancer’ effect. Since autologous T cell-PDX pairs are in short supply, the rest of the EAT experiments disclosed herein were performed using random donor T cells. Example 5: Ex vivo T cell Arming Reduces TNF-α Release by T cells Exposed to BsAbs [00255] Cytokine release was evaluated throughout each step of T cell arming: during the 20-minute incubation of T cells with BsAb (arming), after the wash with PBS, after co- culture with antigen-positive tumor cell lines (E:T ratio of 50:1), and finally after in vivo administration. TH1 cell cytokines (IL-2, IL-6, IL-10, IFN-γ, and TNF-α) released by T cells were measured in the supernatants after arming (Prewash) and after 2 nd washing step (Post wash) (FIG.1E). Although the released cytokine levels during arming were generally low, IFN-γ and TNF-α did increase, especially at high arming doses of GD2-BsAb, which were removed after two washing steps (FIG.9A). [00256] After 4 hours of co-culture with target cells at 37℃, T cell cytokines were measured again (FIG.1F). The cytokines surged after exposure to antigen-positive tumor cells. Unarmed T cells co-incubated with GD2-BsAb released more cytokines than GD2- EATs over a broad dose titration of GD2-BsAb (0.005 to 10 µg/10 6 cells) (FIG.9B). At the optimal arming doses (0.05 to 5µg/10 6 cells), GD2-BsAb plus unarmed T cells released median levels of 4,000 pg/mL of IL-2, 40,000 pg/mL of IFN-γ, and 20,000 pg/mL of TNF-α; in contrast, GD2-EATs released 1,500 pg/mL of IL-2, 15,000 pg/mL of IFN-γ and 2,000 pg/mL of TNF-α. While, the levels of IL-6 and IL-10 did not show significant difference among T cell groups. [00257] The in vivo cytokine release after 4 hours of GD2-EAT treatment (10µg of GD2- BsAb/2×10 7 cells) was next analyzed and compared with that released by unarmed T cells (2×10 7 cells) with iv GD2-BsAb (10µg) in GD2(+) osteosarcoma PDX mouse model (FIG. 1G). Both GD2-EATs and iv GD2-BsAb with unarmed T cells induced measurable cytokine release. Most notably, the major cytokine levels (IL-2, IL-6, IFN-γ and TNF-α) released by GD2-EATs were significantly lower (50%) than those released by the conventional iv GD2- BsAb plus unarmed T cell injection. Example 6: EATs Traffic into Tumors Bypassing their Initial Pulmonary Sequestration [00258] To quantitate how efficiently EATs traffic into solid tumors, luciferase transduced T cells and armed ex vivo with GD2-BsAb [Luc(+) GD2-EATs] were generated. After first iv injection of Luc(+) GD2-EATs (10μg of GD2-BsAb/2×10 7 cells) or Luc(+) unarmed T cells (2×10 7 cells) into neuroblastoma PDX bearing mice, subsequent T cells used were untransduced (FIG.3A). Without GD2-BsAb arming, Luc(+) unarmed T cells did not localize to tumors and dissipated. In contrast, Luc(+) GD2-EATs rapidly trafficked into GD2(+) tumors (FIG.3B), following a transient rest in the lungs on day 1, as the TILs signal increased over time to peak on day 4 (FIG.3C), while, Luc(+) unarmed T cells (2×10 7 cells) with iv GD2-BsAb (10μg) were visible in tumors by day 3 and peaking around day 6 and 7. As tumor regressed, the total bioluminescence of Luc(+) GD2-EATs also diminished (FIG. 3D). In a second set of T cell trafficking studies (FIG.3E), subtherapeutic dose of GD2- EATs in an osteosarcoma PDX model was tested by administering only 2 doses of GD2- EATs every 10 days. Luciferin signal of the tumor infiltrating GD2-EATs persisted over 36 days in mice with residual tumors (FIG.3F). Example 7: EATs Showed Potent Anti-tumor Activity with Minimal Toxicities In vivo [00259] Adoptive T cell cytotherapy using EATs was tested against a panel of xenograft mouse models (FIG.10A). GD2-EATs were tested against neuroblastoma PDXs (Piro20Lung), neuroblastoma cell line (IMR32Luc) xenografts, and melanoma cell line (M14Luc) xenografts (FIG.10B). HER2-EATs were tested against osteosarcoma PDXs (TEOSC1), breast cancer PDXs (M37), and osteosarcoma cell line (143B) xenografts (FIG. 10C). Beyond GD2 and HER2, EATs targeted to antigens including STEAP-1 (six transmembrane epithelial antigen prostate-1) on Ewing sarcoma cell line (TC71) were tested against each target cell line xenografts; in each instance, EATs showed potent anti-tumor effects (FIG.10D), without weight loss or adverse effects during follow-up period (FIG. 10E). Example 8: Critical Determinants for Effective EAT Therapy [00260] Anti-tumor activity of EAT depends on infused T cell number. To optimize preclinical treatment, different variables were assessed to study their impact on the therapeutic efficacy of EATs. First, the effect of infused EAT cell number was evaluated in osteosarcoma and neuroblastoma PDX models (FIGs.4A-4B). At an arming dose of 0.1µg of BsAb/10 6 cells, increasing cell dose of GD2-EATs or HER2-EATs (5×10 6 cells, 10 ×10 6 cells and 20×10 6 cells, respectively) were administered twice-weekly. Anti-tumor effect consistently increased with the number of EATs infused; while 20×10 6 of EATs were effective in eliminating these tumors, 5×10 6 and 10×10 6 of EATs were insufficient. This anti-tumor response was correlated with the percentage of human CD45(+) TILs, which was evident with 20×10 6 of GD2-EATs, but negligible with 5×10 6 of GD2-EATs. [00261] EAT efficacy in vivo is schedule dependent. To identify the optimal treatment schedule, neuroblastoma PDXs were treated with 3 different EAT schedules: arm 1, low intensity (1 dose/week); arm 2, standard (2 doses/week); or arm 3, dose-dense (3 doses/week), with GD2-EATs armed at fixed dose of 2μg of GD2-BsAb/2×10 7 cells (FIG. 4C). The dose-dense schedule (arm 3) demonstrated superior anti-tumor efficacy against rapidly growing PDXs compared to standard or low intensity schedules (P=0.0001), which also translated into survival benefit (P<0.0001). [00262] Enhancing EAT efficacy by supplemental EAT vs supplemental BsAb. Next, to test how many doses of EATs are needed to sustain anti-tumor effect and if supplemental BsAb injection can replace subsequent EATs, osteosarcoma PDXs were treated with three different schedules (FIGs.4D-4F): arm 1, two doses of EATs followed by 6 doses of iv BsAb; arm 2, 4 doses of EATs followed by 4 doses of BsAbs; arm 3, 8 doses of EATs. Arming doses were fixed at 10μg of BsAb/ 2×10 7 cells, while supplemental BsAb was fixed at 10µg per injection. In contrast to the rapid tumor growth with no treatment or 8 doses of unarmed T cells, two doses of GD2-EATs and HER2-EATs significantly suppressed tumor growth. However, additional doses of EATs were necessary for durable responses. Contrary to the mice treated with two doses of GD2-EATs and HER2-EATs showing short-term response, among those treated with 8 doses of EATs, 2 of 5 mice in GD2-EATs and 5 of 5 mice in HER2-EATs showed sustained remission past 6 months, confirming the superior dose effect of EATs not correctable by supplemental BsAb injections. Example 9: Following Cryopreservation EATs Retain Anti-tumor Properties [00263] To ensure transportability and clinical utility of EATs, cryopreserved EATs were tested for their viability, BsAb surface density, and tumoricidal properties. After thawing at 37 o C, EATs remained over 85% viable, irrespective of whether they were frozen for 2 hrs at - 80 o C or up to 3 months in liquid nitrogen. When these EATs (thawed EATs) were stained with anti-idiotype antibody or anti-human IgG Fc antibody, BsAb surface density remained comparable to freshly armed EATs (fresh EATs) by MFIs (FIG.11A). Although cytotoxicity of thawed EATs did diminish after cryopreservation and thawing (50% of maximal killing efficacy of fresh EATs) as a result of not enough recovery time after thawing, antigen-specificity was maintained (FIG.11B). Suitable recovery time after thawing include 1-2 days. [00264] In vivo anti-tumor efficacies of thawed EATs were evaluated using two different osteosarcoma PDX models. In the first PDX (OSOS1B PDX) model, both fresh and thawed GD2-EATs exerted potent anti-tumor effects and prolonged survival (FIG.11C). Four of 5 mice treated with thawed GD2-EATs showed long-term remission past 6 months post treatment. Interestingly, while mice treated with fresh GD2-EATs developed mild to moderate GVHD 1 to 2 months post treatment, mice treated with thawed GD2-EATs displayed no clinical signs of GVHD throughout the entire follow-up period, maintaining body weight, good coat condition and general activity (FIG.11D). When blood samples of each group were analyzed on day 45 post treatment (FIG.11E), thawed GD2-EAT treated mice displayed a predominance of CD8(+) T cells in the blood, while the fresh GD2-EAT group showed mostly CD4(+) T cells, correlating with their clinical manifestations of GVHD. In the second tumor model (FIG.11F), both thawed GD2-EATs and thawed HER2- EATs exerted strong anti-tumor effects against telangiectatic osteosarcoma PDXs. All tumors regressed without significant toxicities, and there were no signs of GVHD or tumor relapse past 4 months post treatment. Example 10: T cells armed with multiple BsAbs (Multi-EATs) achieved multi-specificity against multiple tumor targets [00265] Combinatorial EAT strategies. To further improve anti-tumor effects against solid tumors, strategies for overcoming tumor heterogeneity and target antigen downregulation or loss are needed. Multiple antigen-targeting EAT (multi-EAT) strategies to address these obstacles in single antigen targeted treatment were studied. Without wishing to be bound by theory, it is believed that BsAbs built on the same IgG-[L]-scFv platform should arm T cells through the identical huOKT3-scFv domain and thus exert comparable activation. Dual specificities were tested in two ways: by arming T cells with a combination of 2 different BsAbs (dual-EATs) and by combining two EATs each separately armed with a different BsAb (pooled-EATs), administered together or sequentially. GD2-BsAb and HER2-BsAb were used for arming, and in vitro cytotoxicity was tested. Pooled-EATs (GD2- EATs + HER2-EATs) or dual-EATs (GD2/HER2-EATs) showed comparable tumor cell killing against GD2(+) and/or HER2(+) tumor cell lines (FIGs.12A-12B). [00266] To evaluate in vivo anti-tumor effects of these combinatorial approaches, pooled- EATs were tested first, with 4 doses of EATs (2×10 7 cells per injection) armed at a fixed dose 0.5μg of total BsAb/10 6 cells (FIG.12C). Pooled-EATs (5μg/1×10 7 of GD2-EATs and 5μg/1×10 7 of HER2-EATs) showed a comparable anti-tumor response against GD2(+) HER2(+) osteosarcoma PDXs. 5 of 5 mice in the HER2-EATs group, none of 5 in the GD2- EATs group, and 2 of 5 in the pooled-EATs group (n=5) remained progression-free. The dual-EATs approach was also tested (FIGs.12D-12E). T cells were armed with either GD2- BsAb (10μg/2×10 7 T cells), HER2-BsAb (10μg/2×10 7 T cells), or a mixture of both BsAbs (dual-EATs, 10μg of GD2-BsAb and 10μg of HER2-BsAb /2×10 7 T cells) and evaluated in vivo. Additionally, sequential combination of EATs (HER2-EATs followed by GD2-EATs) was also compared. Dual-EATs approach did not compromise anti-tumor activities of either BsAb, nor did it increase toxicities. The dual-EATs (GD2/HER2-EATs) significantly suppressed osteosarcoma tumor growth, demonstrating comparable potency to GD2-EATs, HER2-EATs, and sequential combination of EATs. [00267] Multispecific EATs (multi-EATs) using a mixture of BsAbs. Furthermore, multi- EATs using multiple BsAbs, were constructed on the same IgG-[L]-scFv platform, targeting tumor antigens including GD2, HER2, CD33, or STEAP-1. Multi-EATs were evaluated for BsAb surface density (ABC) and in vitro cytotoxicity. As the number of BsAb for arming and arming doses of each BsAb increased, BsAb surface density has increased (FIG.5A). With more than 3 BsAbs at high arming doses (5µg of each BsAb/10 6 cells), surface density plateaued at approximately 33,500 molecules per T cell. [00268] To identify the range of optimal surface density of BsAbs for multi-EATs, ADTC was studied over a range of E:T ratios (from 50:1 to 1.5:1) and BsAb arming doses (FIG. 5B). Multi-EATs (armed with multiple BsAbs targeting tumor antigens including GD2, HER2, CD33, or STEAP-1) showed comparable cytotoxicity against CD33(+) leukemia cell line (Molm13) at arming doses of each BsAb between 0.05μg/10 6 T cells to 5μg/10 6 T cells, at ABCs between 1,500 to 30,000 molecules per T cell. At surface BsAb density between 1,500 to 10,000 molecules per T cell, multi-EATs showed the best tumoricidal activity. [00269] The anti-tumor activities of the multi-EATs were evaluated using multiple tumor cell lines (FIGs.5C-5D). Despite the presence of multiple BsAbs on the same EAT, killing potencies of multi-EATs against each target were comparable to those of monospecific EATs, although the maximal cytotoxicity (Emax) did vary depending on the specific target studied. [00270] Multi-specific EATs had comparable anti-tumor activity in vivo with reduced cytokine release. When multiple BsAbs were administered together, cytokine release could increase substantially. To determine clinical feasibility of multi-EATs, cytokine release was evaluated. See, e.g., D. W. Lee et al., Blood 124, 188 (2014); S. A. Grupp et al., N Engl J Med 368, 1509 (2013); J. N. Kochenderfer et al., Blood 119, 2709 (2012) (demonstrating that high cytokine release is a critical factor that adversely impacts the clinical feasibility of an immunotherapeutic agent). Cytokine release between multiple BsAbs mixed with unarmed T cells (co-incubation with 5 BsAbs) and multi-EATs (T cells armed with 5 BsAbs and washed) were compared. T cells were incubated for 20 minutes at arming doses of 0.05µg to 5µg of each BsAb/10 6 T cells, washed twice with PBS, and co-cultured with target cells (E: T ratio of 50:1) for 4 hours at 37℃. Low levels of cytokines were released during BsAb incubation and completely removed after wash (FIG.13A). After co-culture with target cells (IMR32-Luc), cytokine levels released by multi-EATs (IL-2, IFN-γ and TNF-α) were significantly lower than those by multiple BsAbs mixed with unarmed T cells (FIG.13B). [00271] In vivo potency of multi-EATs was tested in multiple tumor cell line xenograft mouse models (FIGs.6A-6B). At an arming dose of 2µg of each BsAb per 2×10 7 of T cells, multi-EATs (10μg of total BsAb/2×10 7 cells per injection) significantly suppressed tumor growth and exerted equivalent anti-tumor responses to monospecific EATs against the panel of target appropriate tumor xenografts. Multi-EATs improved tumor control and overall survival of mice harboring IMR32Luc or 143BLuc xenografts, suggesting that multi-EATs could potentially reduce or prevent tumor escape. [00272] To further examine if multi-EATs can overcome tumor heterogeneity, their anti- tumor activity against mixed cancer cell lines of GD2(+)HER(-) IMR32Luc and GD2 low HER2(+) HCC1954 (mixture in 1:1 ratio) were tested (FIGs.6C-6D). Compared to the low efficacy (Emax) of monospecific GD2-EATs and HER2-EATs, dual-EATs (GD2/HER2-EATs) and multi-EATs (against tumor antigens including GD2, HER2, CD33, STEAP-1) induced greater cytotoxicity in vitro. This increased cytotoxicity of EATs with multiple specificities translated into superior in vivo anti-tumor response against mixed cancer cell line xenografts. [00273] A mixture of two cell lines (2.5×10 6 of IMR32Luc and 2.5×10 6 of HCC1954) was subcutaneously implanted into mice and treated with GD2-EATs, HER2-EATs, dual-EATs (GD2/HER2-EATs), multi-EATs, and sequential combination of EATs (HER2-EATs followed by GD2-EATs), respectively (FIG.14). BsAb and T cells were fixed at 10µg per each BsAb and 2×10 7 T cells per injection. All EAT treatments were well tolerated irrespective of total BsAb doses for arming. While monospecific GD2-EATs failed to suppress tumor growth, dual-EATs, multi-EATs, and sequential combination of EATs successfully regressed tumors and significantly improved survival compared to monospecific EATs ( vs. HER2-EATs, P=0.0033; vs. GD2-EATs, P<0.0001), demonstrating the advantage of multi-targeting EAT strategies against heterogenous solid tumors. [00274] In vivo cytokine release by multi-EATs was also measured and compared to that of GD2-BsAb plus unarmed T cells, GD2-EATs, HER2-EATs, and unarmed T cells alone in GD2(+) HER2(+) osteosarcoma PDX model and mixed cancer cell line [(GD2(+)IMR32Luc and HER2(+) HCC1954)] xenograft model (FIGs.13C-13D). BsAb dose and T cell number were again fixed at 10µg for each BsAb and 2×10 7 for cell per injection. Multi-EATs (50μg of total BsAb/2×10 7 cells) released significantly lower levels of IL-2, IL-6, IFN-γ, and TNF-α than GD2-BsAb (10μg) plus T cells (2×10 7 cells), and there was no significant difference in cytokine release among EATs. Example 11: Ex vivo BsAb Armed ^δ T Cells are Equally Active as αβ T cells [00275] Since CD3 is present on diverse subpopulations of T cell types, the functionality of gamma delta ( γδ) T cells was tested. γδ T cells have reduced alloreactivities with potential as an allogeneic “off-the-shelf” T cell source (J. Fisher & J. Anderson, Frontiers in immunology 9, 1409 (2018)). After expansion from fresh PBMCs with IL-2 and zoledronate for 12 days, more than 90% of CD3(+) T cells were γδ TCR (+), and less than 10% were αβ TCR (+) (FIG.7A). The majority of γδ T cells were CD3(+) and CD4(-) CD8(-) double negative, contrasting with T cells expanded using CD3/CD28 beads where the majority were αβ T cells (>90%). After arming γδ T cells with GD2-BsAb (GD2-γδTs) or HER2-BsAb (HER2-γδTs), surface BsAb density was measured by flow cytometry. The MFIs were comparable to those of αβ-EATs (FIG.7B). In the presence of GD2-BsAb or HER2-BsAb, γδ T cells mediated potent tumoricidal activity against GD2(+) and/or HER2(+) tumor cell lines in vitro, with maximal cytotoxic efficiency of GD2-γδTs and HER2-γδTs achieved at arming doses between 0.05μg/1×10 6 cells to 5μg/1×10 6 cells (FIG.7C). [00276] The in vivo anti-tumor activity of GD2-γδTs and HER2-γδTs in osteosarcoma PDX models, was compared to corresponding αβ-EATs (FIG.15A-15B). Despite supplementary IL-2, GD2-γδTs and HER2-γδTs did not produce significant anti-tumor responses against antigen (+) tumors irrespective of additional zoledronate. Measurement of T cells in the blood and tumors after GD2-γδT therapy showed substantially fewer human CD45(+) T cells compared to GD2-αβTs by flow cytometry, suggesting a poor survival of γδ- EATs in vivo. [00277] However, when exogenous IL-15 (as IL15Rα-IL15 complex) was used instead of IL-2, in vivo survival and function of γδ-EATs were significantly improved (FIGs.7D-7F). γδ T cells expanded from fresh PBMCs using 2µM of zoledronate plus 30ng/mL of IL-15 for 12 to 14 days were armed with GD2-BsAb or HER2-BsAb and administered iv into xenografted mice, with 5µg of subcutaneous IL-15 or 1,000 IU of IL-2. GD2-γδTs and HER2-γδTs sustained with IL-15 exerted significant anti-tumor effects against GD2(+) HER2 (+) osteosarcoma PDXs without toxicities or weight loss, in contrast to the same EATs sustained with IL-2, demonstrating the potential utility of allogenic γδ-EATs instead of autologous T cells. Example 12: Osteosarcoma Cell Lines Tested Positive for GD2 and/or HER2 [00278] Osteosarcoma Cell lines. Representative human osteosarcoma cell lines, 143B (ATCC—CRL-8303), U-2 OS (ATCC—HTB-96), MG-63 (ATCC—CRL-1427), HOS (ATCC—CRL-1543), and Saos-2 (ATCC—HTB-85), and osteoblast cell line, hFOB 1.19 (CRL-1137), were purchased from ATCC (Manassa VA). All cells were authenticated by short tandem repeats profiling using PowerPlex 1.2 System (Promega, Madison, WI), and periodically tested for mycoplasma infection using a commercial kit (Lonza, Basel, Switzerland). The cells were cultured in RPMI1640 (Sigma) supplemented with 10% heat- inactivated fetal bovine serum (FBS, Life Technologies, Carlsbad, CA) at 37 ^C in a 5% CO2 humidified incubator. [00279] Flow cytometry. For flow cytometric analysis of antigen expression by human osteosarcoma cell lines, cells were harvested, cell viability was determined. 1×10 6 cells were stained with 1μg of antigen specific mAbs in a total volume of 100 μL for 30 min at 4 ◦ C. Anti-CD20 chimeric mAb, rituximab, or mouse IgG1 monoclonal antibody was used as isotype control. After washing with PBS, cells were re-incubated with 0.1µg PE-conjugated anti-human IgG Ab (Biolegend, San Diego, CA,409304). For each sample, 20,000 live cells were analyzed using a BD FACS Calibur TM (BD Biosciences, Heidelberg, Germany). Data were analyzed with FlowJo V10 software (Ashland, OR, USA) using geometric mean fluorescence intensity (MFI). The MFI for isotype control antibody was set to 5, and the MFIs for antibody binding were normalized based on isotype control. [00280] Effector cell preparation. Effector peripheral blood mononuclear cells (PBMC) were separated by ficoll from buffy coats purchased from the New York Blood Center. T cells were purified from PBMC using Pan T cell isolation kit (Miltenyi Biotec). These T cells were activated by CD3/CD28 Dynabeads (Invitrogen, Carlsbad, CA) for 7 to 14 days in the presence of 30 IU/mL of IL-2 according to manufacturer’s protocol. PBMCs aaand ATCs were analyzed by FACS for their proportion of CD3(+), CD4(+), CD8(+), and CD56(+) cells. [00281] Cytotoxicity assays ( 51 chromium release assay). Antibody dependent T cell- mediated cytotoxicity (ADTC) was assessed by 51 Cr release assay, and EC 50 was calculated using Sigma Plot software. Tumor cells were labeled with sodium 51 Cr chromate (Amersham, Arlington Height, IL) at 100 mCi/10 6 cells at 37 ◦ C for 1 hour. After two washes, tumor cells were plated in a 96-well plate before mixing with activated T cells (ATCs) at decreasing concentrations of T-BsAb. Effector to target cells ratio (E:T ratio) was 10:1, and cytotoxicity was analyzed after incubation at 37 ◦ C for 4 hours. The released 51 Cr was measured by a gamma counter (Packed Instrument, Downers Grove, IL). Percentage of specific lysis was calculated using the formula: 100% (experimental cpm - background cpm)/ (total cpm - background cpm), where cpm represented counts per minute of 51 Cr released. Total release of 51 Cr was assessed by lysis with 10% SDS (Sigma, St Louis, Mo) and background release was measured in the absence of effector cells and antibodies. [00282] Antibodies. For each BsAb, scFv of huOKT3 was fused to the C-terminus of the light chain of human IgG1 via a C-terminal (G 4 S) 3 linker (Orcutt KD et al., Protein Eng Des Sel 2010;23(4):221-8). N297A and K322A on Fc were generated with site-directed mutagenesis via primer extension in polymerase chain reactions (Reikofski J, Tao BY. Biotechnol Adv 1992;10(4):535-47). The nucleotide sequence encoding each BsAb was synthesized by GenScript and was subcloned into a mammalian expression vector. Each BsAb was produced using Expi293 TM expression system (Thermo Fisher Scientific) separately. Antibodies were purified with protein A affinity column chromatography. The purity of these antibodies was evaluated by size-exclusion high-performance liquid chromatography (SE-HPLC). GD2-BsAb was linked to the carboxyl end of the anti-GD2 hu3F8 IgG1 light chain (Xu H, Cheng M, Guo H, Chen Y, Huse M, Cheung NK. Cancer Immunol Res 2015;3(3):266-77), and HER2-BsAb linked to the anti-HER2 trastuzumab IgG1 light chain (Lopez-Albaitero A, Xu H, Guo H, Wang L, Wu Z, Tran H, et al., Oncoimmunology 2017;6(3):e1267891). Anti-GPA/anti-CD3 BsAb were used as a control BsAb for ADTC and in vivo animal experiments (Wu Z, Guo HF, Xu H, Cheung NV. Mol Cancer Ther 2018;17(10):2164-75). [00283] T cell arming. Ex vivo activated T cells were harvested between day 7 and day 14 and armed with each BsAb for 20 minutes at room temperature. After incubation, the T cells were washed with PBS twice. Properties of ex vivo bispecific antibody armed T cells (EATs) were tested with cell surface density of BsAb using idiotype antibodies and in vitro cytotoxicity against target antigens. For quantification of BsAb bound to T cells (antibody binding capacity, ABC), EATs were stained with anti-human IgG Fc antibody or anti- idiotypic antibody (A1G4 for hu3F8) and analyzed by flow cytometry along with Quantum™ Simply Cellular® (QSC) microspheres. [00284] In vivo experiments. All animal experiments were performed according to Institutional Animal Care and Use Committee (IACUC) guidelines. For in vivo experiments, BALB-Rag2 -/- IL-2R-γc-KO (DKO) mice (Taconic Biosciences, Germantown, NY) were used ( Andrade D et al., Arthritis Rheum 2011;63(9):2764-73). In vivo experiments were Tewksbury MA) and implanted in the flank of DKO mice. Besides tumor cell line xenografts, 3 different patient-derived tumor xenografts (PDXs) both positive for GD2 and HER2 were established from fresh surgical specimens with IRB approval. Tumor size was measured using TM900 scanner (Piera, Brussels, BE), and treatment was initiated when tumor size reached 100 mm 3 . Tumor growth curves and overall survival was analyzed, and overall survival was defined as the time from start of treatment to when tumor volume reached 2000 mm 3 . To define the well-being of mice, CBC analyses, changes in body weight, behavior and physical appearance were monitored. [00285] Flow cytometry of blood and tumor. Peripheral blood and tumors were collected and analyzed by flow cytometry. Anti-human antibodies against CD3, CD4, CD8, and CD45 (Biolegend, San Diego, CA) were used to define T cell engraftment and subpopulation, and anti-human PD-1 and PD-L1 antibodies (Biolegend, San Diego, CA) were used to quantify their expression by T cells and osteosarcoma tumor cells. Stained cells were processed with BD LSRFORTESSA (BD Biosciences, Heidelberg, Germany) and analyzed with FlowJo software (FlowJo, LLC, Ashland, OR). [00286] Immunohistochemical (IHC) staining. Formalin-fixed paraffin-embedded tumor sections were made, and immunohistochemical (IHC) staining for human CD3, CD4 and CD8 T cells was done to confirm T cell infiltration inside tumors. The IHC staining was performed using Discovery XT processor (Ventana Medical Systems, Oro Valley, AZ). Paraffin-embedded tumor sections were deparaffinized with EZPrep buffer (Ventana Medical Systems, Oro Valley, AZ), antigen retrieval was performed with CC1 buffer (Ventana Medical Systems, Oro Valley, AZ), and sections were blocked for 30 minutes with background buffer solution (Innovex). Anti-CD3 (DAKO, cat# A0452, 1.2μg/mL), anti-CD4 (Ventana, cat# A790-4423, 0.5μg/mL), and anti-CD8 (Ventana, cat#790-4460, 0.07μg/mL) were applied, and sections were incubated for 5 hours, followed by 60 min incubation with biotinylated goat anti-rabbit IgG (Vector laboratories, cat# PK6101) at 1:200 dilution. For PD-L1 staining, the sections were pre-treated with Leica Bond ER2 Buffer (Leica Biosystems) for 20 min at 100°C, stained with PD-L1 rabbit monoclonal antibody (Cell signaling, cat#29122, 2.5mg/mL) for 1 hour on Leica Bond RX (Leica Biosystems). Control antibody staining was done with biotinylated goat anti-rat IgG (Vector Labs, Burlingame, CA cat#MKB-22258) All images were captured from tumor sections using Nikon ECLIPSE Ni-U microscope and NIS-Elements 4.0 imaging software. Antigen positive cells were counted with Qupath 0.1.2. [00287] GD2 expression by IHC. Fresh frozen tumor sections were made using Tissue- Tek OCT (Miles Laboratories, Inc, Elkhart, IN) with liquid nitrogen and stored at -80°C. The tumor sections were stained with mouse IgG3 mAb 3F8 as previously described (Dobrenkov K, Ostrovnaya I, Gu J, Cheung IY, Cheung NK. Pediatr Blood Cancer 2016;63(10):1780-5). Stained slides were captured using a Nikon ECLIPSE Ni-U microscope and analyzed, and the tissue staining intensity was compared with positive and negative controls and scored from 0 to 4 according to 2 components: staining intensity and percentage of positive cells. Each sample was assessed and graded by 2 independent observers. [00288] Statistics. Differences among groups indicated in the figures were tested for significance by one-way ANOVA or student's t-test, and survival outcomes were analyzed using GraphPad Prism 7.0. P -value < 0.05 was considered statistically significant. [00289] To identify potential therapeutic targets for osteosarcoma, the expression of GD2, GD3, HER2, B7H3 (CD276), high-molecular weight melanoma antigen (HMW), chondroitin-sulfate proteoglycan-4 (GSPG-4), L1 cell adhesion molecule (L1CAM), glypican-3 (GPC-3), prostate-specific antigen (PSA), prostate-specific membrane antigen (PSMA), insulin-like growth factor 2 receptor (IGF2R), interleukin 11 receptor-α (IL-11Rα), and PD-L1 by osteosarcoma tumor cell lines was assessed (FIG.31). [00290] Surface antigens on osteosarcoma cell lines were semi-quantitated by flow cytometric analysis and normalized with the MFI for control antibody (FIG.23A). The majority of osteosarcoma cell lines expressed GD2 and/or HER2 antigen on their cell surface; binding intensities (MFIs) for GD2 was generally much lower than those for neuroblastoma cell lines, while MFIs for HER2 were less than HER2-positive breast cancer cell lines. Based on their MFIs, GD2, HER2, B7H3, CSPG4, L1CAM (CD171), and Lewis Y were chosen as tumor targets for further in vitro screening. Example 13: GD2-BsAb and HER2-BsAb Exerted Strong Cytotoxicity Against Osteosarcoma Cell Lines In vitro [00291] Osteosarcoma cell lines were used as targets in an ADTC assay using activated T cells (ATCs) (effector to target (E:T) ratio of 10:1) in the presence of decreasing concentrations of BsAbs (1μg/mL (5nM) and serial 10-fold dilutions). All tested BsAbs were made using the IgG(L)-scFv format with silenced Fc, and anti-GPA/anti-CD3 BsAb was used for control BsAb (Wu Z et al. Mol Cancer Ther 2018;17(10):2164-75). Among them, anti- GD2 and anti-HER2-BsAb showed the most potent ADTC against the panel of osteosarcoma cell lines (FIG.32 and FIG.23B). For GD2-targeted BsAb (GD2-BsAb), cytotoxicity was robust (EC50 of 0.2 to 0.5pM) for GD2(+) osteosarcoma cell lines (143B, U-2 OS, and M- 63), where maximal killing was observed between 5pM and 500pM. In contrast, cytotoxicity for cell lines with low expression of GD2 (Saos2, HOS, and hFOB [fetal osteoblast cell line]) was much weaker. Anti-HER2-BsAb (HER2-BsAb) also mediated potent ADTC against most of the osteosarcoma cell lines which were HER2 positive (143B, U-2 OS, MG-63, HOS, and Saos2) and against hFOB, with maximal cytotoxicity at 5pM to 500pM. EC50 (a measure of in vitro sensitivity to ADTC) was inversely correlated with MFIs of each target antigen. Although B7H3, L1CAM, CSPG-4, and Lewis Y were also overexpressed in some osteosarcoma cell lines, their respective ADTC potency was much weaker. Based on these findings, the targets GD2 and HER2 were chosen for further in-depth T cell-based immunotherapy studies. Example 14: GD2-BsAb and HER2-BsAb showed Potent Cytotoxicity against Osteosarcoma in vivo [00292] GD2-BsAb or HER2-BsAb suppressed osteosarcoma tumor growth in the presence of human T cells. Building on these in vitro ADTC assays, the in vivo anti-tumor effects of GD2-BsAb and HER2-BsAb against osteosarcoma xenografts was tested (FIG. 24A). In the first xenograft model, osteosarcoma 143B tumor cells were mixed with PBMCs and implanted subcutaneously (sc) into DKO mice. Mice were treated with intravenous (iv) GD2- or HER2-BsAb twice per week for 4 weeks. Osteosarcoma tumor growth was delayed by GD2-BsAb (P=0.0005) and HER2-BsAb (P=0.10) compared to control BsAb (anti- GPA/anti-CD3 BsAb). This finding was reproduced in a second tumor model where PBMCs were administered iv instead of s.c. (FIG.24B). Both BsAbs significantly suppressed tumor growth compared to controls (P=0.0025 and P=0.0248, respectively). [00293] Both GD2-BsAb and HER2-BsAb drove T cell into osteosarcoma xenografts. To test if GD2-BsAb and HER2-BsAb could drive exogenous T cells into osteosarcomas, T cell infiltration was investigated in tumors using IHC staining. CD3(+) TILs were detected in both GD2-BsAb- and HER2-BsAb-treated tumors, but not in tumors treated with control BsAb (FIG.24C). Serial T cell infiltration was investigated by staining tumors on days 6, 9, 16, 23 and 30 post treatment. After GD2-BsAb or HER2-BsAb treatment (FIG.24B), TILs substantially increased by day 9. While TILs showed CD4(+) T cell dominance on day 9, CD8(+) T cells became predominant at later time points (day 23 and day 30) (FIG.24D). [00294] High-dose BsAbs diminished anti-tumor activity of T cells. To study the dose- response relationship on T cell activity, CD3(+) T cells were incubated at 37 ◦ C for 24 hours in the presence of increasing concentrations of GD2-BsAb or HER2-BsAb [5×10 -5 µg/1×10 6 cells to 50µg/1×10 6 cells] and analyzed for cell death (annexin V and 7-aminoactinomycin D, 7-AAD), Fas-ligand (FasL), activation markers (CD25 and CD69), and exhaustion markers (PD-1, TIM-3, and LAG-3) (FIGs.28A-28D). T cells incubated in high concentrations of GD2-BsAb or HER2-BsAb showed increased frequencies of CD25(+), CD69(+), and CD25(+) and CD69(+) double positive populations compared to control T cells incubated without T-BsAbs. CD25 and CD69 expression surged when the concentration of T-BsAb was above 0.005μg/1×10 6 cells for GD2-BsAb and 0.5µg/1×10 6 cells for HER2-BsAb. On the other hand, the frequencies of 7AAD(+) and FasL(+) populations started to increase when both T-BsAb reached 0.5μg/1×10 6 cells. Among exhaustion markers, PD-1 expression on CD3(+) T cells rapidly increased with high concentrations of GD2-BsAb or HER2-BsAb. TIM-3 and LAG-3 also rose with increased BsAb concentrations. T cells exposed to high concentrations of BsAb expressed more PD-1, TIM-3, and LAG-3 than those exposed to lower concentrations of BsAb. These in vitro observations were validated in osteosarcoma xenografts treated with iv PBMCs and decreasing doses of BsAbs (FIG.24E). Anti-tumor effect of 100µg of HER2-BsAb was inferior to those of 25µg (P=0.0054). On the other hand, there was no significant difference over a wide dose range for GD2-BsAb (1 to 100 µg), although 25 µg seemed optimal. Example 15: Adoptive T Cell Therapy Using Ex vivo Armed T cells (EATs) Carrying GD2- BsAb or HER2-BsAb Effectively Suppressed Osteosarcoma Tumor Growth and Prolonged Survival [00295] EATs showed stable BsAb arming and potent cytotoxicity. Ex vivo activated T cells were armed with GD2-BsAb or HER2-BsAb and tested for cell surface density of each BsAb using anti-idiotype or anti-human IgG Fc antibodies, and their cytotoxicity was evaluated in a 4-hour 51 Cr release assay. GD2-BsAb armed T cells (GD2-EATs) and HER2- BsAb armed T cells (HER2-EATs) showed stable binding to idiotype antibody (FIG.29A). When in vitro cytotoxicity was tested, GD2-EATs and HER2-EATs both displayed strong antigen-specific cytotoxicity against osteosarcoma cell lines over a range of E:T ratios and over a range of antibody doses (FIG.29B). Maximum killing was observed between 0.05μg to 5μg/10 6 cells of BsAb arming concentration. To quantify the density of BsAb bound to T cells after arming, ABC was measured by flow cytometry and referenced to commercial quantum beads (FIGs.29C-29D). Optimal arming per T cell required 600 to 20,350 molecules for GD2-BsAb or HER2-BsAb, corresponding to 0.05μg/10 6 cells to 5μg/10 6 cells of BsAb; the molar amount of BsAb bound per T cell ranged from 1 to 35 zeptomoles (1×10- 21 ) for GD2-BsAb or HER2-BsAb. [00296] EATs exerted potent anti-tumor effects in vivo. To address the anti-tumor properties of EATs in vivo, their efficacy in multiple osteosarcoma PDX models was tested (FIG.25A). First, 143B cell line xenografts were treated with 20×10 6 of T cells armed with different concentrations (0.05 to 5µg/10 6 cells) of GD2-BsAb or HER2-BsAb (FIGs.25B- 25C). Most mice maintained their body weights throughout treatment and did not exhibit any significant clinical toxicities, contrasting to the separately administered BsAb and PBMC treatment (FIG.24E). Tumor growth was suppressed over a range of BsAb doses (0.05µg/10 6 cells to 5µg/10 6 cells) compared to the unarmed control group (ATCs only), (P <0.0001). Of note, the immunosuppressive effect of high-dose BsAb, particularly for HER2- EAT, was effaced by arming. Both EATs exerted significant tumor suppressing effects over a range of BsAb concentrations, and there was no significant difference among three different concentrations tested. [00297] Similar anti-tumor effects were observed when osteosarcoma PDX tumors were used (FIG.25D). PDX tumors treated with 6 doses of GD2-EATs or HER2-EATs showed complete ablation, translating into significant improvements in survival compared to control (anti-CEA/anti-CD3) BsAb armed T cells (P<0.0001). Again, there were no clinical toxicities during treatment. While all mice in the control group had to be euthanized due to tumor burden within 30 days of posttreatment, GD2-EATs and HER2-EATs regressed tumors and displayed long-term remission (P<0.0001).2 of 5 that received GD2-EATs and 5 of 5 that received HER2-EATs maintained remission past 180 days of observation. This strong in vivo anti-tumor activities of GD2-EATs and HER2-EATs were reproduced in another 2 different osteosarcoma PDX models. [00298] To test anti-tumor properties of GD2-EATs and HER2-EATs after freezing and thawing, GD2-BsAb or HER2-BsAb armed T cells were cryopreserved in liquid nitrogen (- 196°^). After 4 to 6 weeks, these EATs were thawed and tested their anti-tumor activities (FIG.25E). The cell viability after thawing was >85% and their MFI values of individual EATs were comparable to those of freshly armed EATs. When cytotoxicity was evaluated right after thawing, fresh unfrozen EATs had superior killing compared to cryopreserved EATs, being partly attributed to no recovery time for cryopreserved EATs. Yet, in vivo, thawed EATs exerted comparable anti-tumor activity to fresh unfrozen EATs against osteosarcoma PDXs. Example 16: Anti-PD-L1 Antibody Augmented Anti-tumor Immune Response of GD2-EATs and HER2- EATs against Osteosarcoma [00299] Although GD2-BsAb and HER2-BsAb recruited substantial numbers of T cells into the tumor and successfully suppressed tumor growth compared to control groups, some tumors were resistant or relapsed following the initial response. In these tumors, TILs showed predominance of CD8(+) T cells, the majority of which expressed PD-1 on their surface (FIG.17A-17C). Circulating CD3(+) T cells in peripheral blood on day 6, 9, 16, and day 23 post treatment showed gradual increase of PD-1 expression from less than 5% to over 75% after treatment with GD2-BsAb (FIG.17D). In addition to PD-1 expression on T cells, osteosarcoma xenografts were PD-L1 positive by IHC staining and FACS analyses and upregulated PD-L1 expression following BsAb treatment (FIGs.16A-16D). [00300] PD-L1 blockade augmented anti-tumor effect of EAT therapy. To test if ICIs can overcome T cell exhaustion related to treatment resistance, anti-PD-1 (pembrolizumab) or anti-PD-L1 (atezolizumab) monoclonal antibodies were combined with EATs to treat osteosarcoma xenografts (FIGs.18A-18B). GD2-EATs or HER2-EATs were administered twice a week for 3 weeks, and iv anti-PD-1 or anti-PD-L1 was initiated on day 9 post EAT treatment and given twice per week for 3 weeks, based on the anticipated upregulation of PD- 1 in T cells by day 9 (FIG.17E). Anti-PD-L1 plus GD2-EATs or HER2-EATs combination showed benefit over GD2-EATs or HER2-EATs alone (P=0.0257, respectively), while combination with anti-PD-1 had no significant benefit. Anti-PD-L1 combination resulted in significantly greater frequencies of T cells in tumors compared to GD2-EAT or HER2-EAT monotherapy, whereas anti-PD-1 combination did not (FIG.19C). Interestingly, GD2-EATs and GD2 EATs plus anti-PD-L1 combination appeared to eliminate GD2 high tumors while leaving GD2 low tumors behind (by IHC), but GD2-EATs plus anti-PD-1 combination did not show such effects (FIGs.19A-19B). [00301] Timing of anti-PD-L1 during GD2-EATs therapy affected anti-tumor response in vivo. Given the upregulation of PD-1/PD-L1 pathway following EATs therapy, three different time schedules of PD-1 blockades were tested (FIGs.27A-27C). GD2-EATs were given three times per week for 2 weeks. Six doses of anti-PD-1 or anti-PD-L1 were added either (1) concurrently (concurrent therapy, CT) or (2) sequentially after 6 doses of EATs (sequential therapy, ST), or (3) additional 6 doses of PD-1 blockades were administered post ST (sequential continuous therapy, SCT). Combination with anti-PD-1 had no effect, either using CT, ST or SCT regimens when compared to GD2-EATs alone. CT of anti-PD-L1 also failed to enhance efficacy of GD2-EATs. However, anti-PD-L1 given as ST slowed the tumor growth, and SCT significantly suppressed tumor growths compared to GD2-EATs alone (P=0.0149), which translated into improved survival. While none of the anti-PD-1 regimens improved survival over GD2-EATs, SCT of anti-PD-L1 significantly improved the survival for GD2-EATs (P=0.0009). [00302] To address the effect of ICIs on T cell infiltration into tumors, tumors were harvested when they reached 2000 mm 3 or on the last day of the experiment. TILs were analyzed by flow cytometry (FIG.27E). The frequencies of TILs differed by treatment: GD2-EATs recruited more T cells into the tumors compared to control-EATs (P=0.0295) or anti-PD-1 plus ATCs group (P=0.0236). CT of anti-PD-1 resulted in significantly fewer TILs than GD2-EATs (P=0.0194). With ST regimen, anti-PD-1 showed comparable TIL frequency with GD2-EATs (P=0.54); with SCT regimen, anti-PD-1 increased TIL frequency over GD2-EATs alone (P=0.0056). On the other hand, CT of anti-PD-L1 did not affect TIL frequencies over GD2-EATs, but ST of anti-PD-L1 increased TIL frequencies over GD2- EATs alone (P=0.0018), and SCT regimen resulted in the highest TIL frequency among groups (P=0.0005). Among the TIL subsets, tumors treated with SCT regimen (irrespective of anti-PD-1 or anti-PD-L1) had significantly greater frequencies of CD8(+) T cells when compared to GD2-EATs alone (P<00001) The difference in TIL frequencies by treatment was confirmed by IHC staining using anti-CD3 antibody (FIG.27G). Anti-PD-L1 combinations consistently had greater frequencies of TILs providing a rationale for combining EATs with anti-PD-L1 for synergy with BsAb-based T cell immunotherapy. Example 17: Dual Antigens Targeting Strategies using EAT [00303] 2 target antigens GD2 (disialogangliosides) and HER2 were chosen to test the efficacy of dual-antigens targeting strategies including pooled EATs (co-administering GD2- EATs and HER2-EATs), dual-EATs (T cells simultaneously armed with GD2-BsAb and HER2-BsAb), alternate EATs (GD2-EATs alternating with HER2-EATs), and TriAb-EATs (T cells armed with trispecific antibody (HER2×GD2×CD3 TriAb)] (FIG.34A). [00304] First, in vitro tumor cell killing by EATs was tested at fixed BsAb arming dose (0.5μg of each BsAb/1×10 6 T cells) with increasing ET ratios (FIG.34B). Pooled-EATs and dual-EATs showed comparable tumor cell killing against GD2(+) and/or HER2(+) tumor cell lines (FIG.47) when compared with mono-EATs (GD2-EATs or HER2-EATs). While pooled EATs presented an intermediate potency and efficacy between mono-EATs, dual- EATs showed similar potency when compared to individual mono-EATs. In vivo anti-tumor effect of multi-EATs was also evaluated using GD2(+) and HER2(+) osteosarcoma PDXs (FIG.34C). While pooled-EATs showed an intermediate potency between mono-EATs, dual-EATs were equally effective as HER2-EATs; all 5 mice in the dual-EATs or HER2- EATs remained progression-free during follow-up period (up to 150 days post treatment), while none in the GD2-EATs group and only 2 of 5 in the pooled-EATs group showed a long-term remission. In vivo efficacy of dual-EATs compared to alternate-EATs was also tested using the osteosarcoma 143B CDX model (FIG.41A). In alternate-EATs, GD2-EATs administration was alternated with HER2-EATs. These double antigen targeting approaches did not compromise the anti-tumor activities of mono-EATs or increase toxicities. However, there was no substantial improvement of dual-EATs over mono-EATs or over alternate EATs in this CDX model (FIG.41B). [00305] Next, the anti-tumor efficacy of dual-EATs was compared with TriAb-EATs. A novel GD2×HER2×CD3 trispecific antibody (TriAb) built on the IgG-[L]-scFv platform was developed using a heterodimeric approach (FIG.35A) as previously described in Santich et al., Sci Transl Med 12, eaax1315 (2020), which is incorporated by reference herein. HER2×GD2×CD3 TriAb’s cytotoxicity against multiple cancer cell lines was tested in vitro at fixed BsAb arming dose (0.5μg of each BsAb/1×10 6 T cells) with increasing ET ratios (FIG.35B). While TriAb-EATs (0.5µg of TriAb/1×10 6 cells) were more effective than GD2-EATs (0.5μg of GD2-BsAb/1×10 6 cells) but less potent than HER2-EATs against HER2(+) cancer cell lines, dual-EATs exerted consistently potent cytotoxicity against a variety of cancer cell lines. In vivo anti-tumor efficacy of TriAb-EATs was also tested against two different osteosarcoma PDXs. Three doses of TriAb-EATs successfully ablated PDX tumors, prolonging survival without obvious toxicity in TEOSC1 PDX model (FIG. 35C). TriAb-EATs were also effective in HGSOC1 PDX model which was more sensitive to GD2-EATs than HER2-EATs, presenting a compelling anti-tumor effect to GD2-EATs (FIGs.42A-42B). Example 18: Optimizing BsAb Densities on Multi-EATs [00306] T cells were simultaneously armed with multiple T-BsAbs specific for GD2, HER2, CD33, STEAP-1, or PSMA, all built on the IgG-[L]-scFv platform. Given the finite CD3 density on human T cells, the range and the optimal BsAb surface density as a function of arming dose was set out to be identified. Surface BsAb density on EAT was analyzed using anti-human IgG Fc-specific antibody. Precise quantification of BsAb density was measured as antibody-binding capacity (ABC) by flow cytometry referenced to anti-rat quantum beads (FIG.36A). As the BsAb dose and number have increased, BsAb surface density also has increased. Arming with 5 BsAbs at high arming dose (25µg of each BsAb/10 6 cells), surface density of BsAbs plateaued at approximately 50,000 molecules per T cell. [00307] To identify the range of optimal surface density of BsAb for multi-EATs, in vitro cytotoxicity against CD33(+) leukemia cell line (MOLM13) was studied over a range of E:T ratios and BsAb arming doses (FIG.36B). Multi-EATs (armed with 5 BsAbs each targeting GD2, HER2, CD33, STEAP-1, and PSMA, respectively) showed the best cytotoxicity at the arming dose for each BsAb between 0.05μg/1×10 6 T cells and 1μg/1×10 6 T cells, corresponding to the BsAb densities between 5,000 and 20,000 molecules per T cell. When referenced to the BsAb density on CD33-EATs which showed the best efficacy between 0.5μg and 5μg of BsAb/1×10 6 T cells, EATs appear to show the best tumoricidal activity between 5,000 and 20,000 BsAb molecules per T cell. [00308] In vitro anti-tumor activity of multi-EATs targeting 5 antigens (GD2, HER2, CD33, PSMA, and STEAP1) was evaluated against varieties of tumor target (FIG.47) over a range of BsAb arming doses and compared with the cytotoxicity of mono-EATs (FIG.36C). Despite the presence of multiple BsAbs on the same EAT, multi-EATs exerted consistently potent anti-tumor activities against each tumor target, comparable to those of mono-EATs, although the maximal cytotoxicity (Emax) did vary depending on the specific targets studied. Example 19: Ex vivo Arming of T cells Attenuated Cytokine Surge from Multiple BsAbs [00309] Because simultaneous administration of multiple BsAbs may precipitate a cytokine storm, cytokine release was compared between multi-EATs and multiple BsAbs plus T cells at increasing doses of BsAb. Multi-EATs or multiple BsAb plus T cells were incubated with target cells at 37℃ for 4 hours. Cytokine release by multiple BsAbs plus T cells and multi-EATs increased by BsAb dose, but reached plateaus at 1µg of each BsAb/1×10 6 cells. However, the cytokine levels of multi-EATs were significantly lower than those of multiple-BsAbs plus T cells over a range of BsAb doses (FIG.37A). When the levels of cytokines released by mono-EATs (HER2-EATs), dual-EATs (HER2/GD2-EATs), triple-EATs (HER2/GD2/CD33-EATs), quadruple-EATs (HER2/GD2/CD33/PSMA-EATs), and quintuple-EATs (HER2/GD2/CD33/PSMA/STEAP1-EATs) were compared, the differences were not significant among groups (FIG.37B). Although IL-2, IL-10, IFN-γ, and TNF-α levels increased with BsAb arming dose, there was no excessive cytokine release with additional BsAbs for multi-EATs. In vivo cytokine levels by multi-EATs were also analyzed post treatment and compared among groups (FIG.37C). Multi-EATs (50μg of total BsAb/2×10 7 cells, G2) released significantly less IL-2, IL-6, IFN-γ, and TNF-α than administering GD2-BsAb (10μg) plus unarmed T cells (2×10 7 cells)(G1); there was no significant difference in cytokine release among mono-EATs (G3, GD2-EATs; G4, HER2- EATs) and multi-EATs (G2). Example 20: Multi-EATs were Efficient Multi-specific Cytotoxic Lymphocytes [00310] In vivo anti-tumor properties against diverse cancer types [00311] In vivo anti-tumor effect of multi-EATs was tested against xenografts representing diverse cancer diagnoses (FIG.38A). Multi-EATs (2μg of each BsAb × 5 BsAbs/2×10 7 T cells per injection) significantly suppressed tumor growth and consistently showed competitive anti-tumor effect to mono-EATs against a panel of target appropriate cancer xenografts, including HER2(+) M37 breast cancer PDX, PSMA(+) LNCaP-AR prostate cancer CDX, GD2(+) IMR32Luc neuroblastoma CDX, and STEAP1(+) ES3a Ewing sarcoma PDXs (FIG.38B), without clinical toxicities. For IMR32Luc CDXs, multi-EATs exerted a robust anti-tumor effect surpassing the efficacy of GD2-EATs and significantly prolonging survival. [00312] Multi-EATs were highly effective against tumor models with antigen heterogeneity [00313] The ability of multi-EATs to overcome tumor heterogeneity was studied by creating a mixed lineage, i.e., GD2(+) HER low IMR32Luc mixed with GD2 low HER2(+) HCC1954 (1:1 ratio) (FIG.6C). Dual-EATs (T cells armed with GD2-BsAb and HER2- BsAb) and multi-EATs (EATs armed with 5 BsAbs targeting GD2, HER2, CD33, PSMA, and STEAP1, respectively) mediated stronger cytotoxicity against this mixed lineage than GD2-EATs or HER2-EATs (FIG.39A). This enhanced in vitro cytotoxicity of dual- or multi-EATs was next tested for their in vivo anti-tumor response. A mixture of the two cell lines was xenografted subcutaneously and treated with dual- or multi- EATs when compared to mono-EATs (FIG.39B). EATs were armed at 10µg of each BsAb/2×10 7 T cells for each injection. No clinical toxicities were observed and there was no weight loss throughout the follow-up period (FIG.39C). While GD2-EATs or HER2-EATs failed to produce durable responses against this mixed lineage CDX, dual-, alternate-, or multi-EATs successfully achieved tumor regressions, producing long-term survival (FIGs.39D-39E). Dual-EATs and multi-EATs both surpassed the efficacy of each mono-EATs significantly improved tumor- free survival (vs. HER2-EATs, P=0.0033; vs. GD2-EATs, P<0.0001). [00314] The efficacy of TriAb-EATs against this mixed lineage was also tested. While TriAb-EATs showed enhanced in vitro cytotoxicity compared to GD2-EATs or HER2-EATs, it was not as effective when compared to dual- or multi-EATs (FIG.43A). In vivo anti- tumor activity of TriAb-EATs was also tested against this mixed lineage CDXs (FIG.43B). Tumors regressed following TriAb-EATs but the response was not durable: all 5 mice recurred in contrast to dual- or multi-EATs where long-term disease-free survival extended past 140 days in 3 out of 5 and 4 out of 5 mice, respectively. Example 21: Multi-EATs Overcame Tumoral Heterogeneity: Histologic Response of Mixed Lineage CDX to Multi-EATs [00315] The mixed lineage CDXs were harvested after treatment and analyzed their antigen expression. Gross examination of these tumors presented distinct differences between GD2(+) IMR32Luc and HER2(+) HCC1954 lineages (FIG.40A). Following treatment with GD2-EATs (b) or TriAb-EATs (d) tumors grossly resembled HCC1954 CDXs, while those following treatment with HER2-EATs (c) resembled IMR32Luc CDXs (FIGs.44A-44D). Following treatment with alternate-EATs (e), dual-EATs (f), or multi- EATs (g) tumors acquired the appearance of a cross between IMR32Luc and HCC1954 xenografts, while untreated tumors or those treated with unarmed T cells (a) more resembled HCC1954 CDXs, consistent with rapid outgrowth of HCC1954 overtaking IMR32Luc. H&E staining results were consistent with their gross phenotypes (FIG.40B). While following treatment with GD2-EATs or TriAb-EATs histology revealed poorly-differentiated invasive ductal breast carcinoma, following treatment with HER2-EATs, histology revealed immature, undifferentiated, small round neuroblasts accompanied by Homer-Wright pseudo-rosettes, typical characteristics of neuroblastoma. With no treatment or treatment with unarmed T cells, or with recurrence after initial response to alternate-, dual- or multi-EATs, tumor histology showed mixed lineage with a slight prominence of breast cancer features. Fresh frozen tumor staining with anti-GD2 antibody and FFPE tumor sections stained with anti- human HER2 also showed contrasting results following treatment (FIGs.40C-40D). While the tumors without treatment or treated with unarmed T cells showed heterogenous GD2(+) and HER2(+) staining patterns, those following treatment with GD2-EATs or TriAb-EATs became GD2 negative while retaining strong HER2 positivity; vice versa, those tumors following HER2-EATs became strongly GD2 positive while losing HER2 staining. These results demonstrated that mono-EATs could ablate tumors in an exquisitely antigen specific manner, but unexpectedly were unable to control antigen negative clones in the mix. Escape tumors had antigen loss. On the other hand, treatment with dual-, alternate-, or multi-EATs could overcome tumor heterogeneity and the escape tumors were either GD2 or HER2 weakly positive, and total antigen loss was uncommon, permitting repeat response to multi- EATs (FIGs.45A-45B). EQUIVALENTS [00316] The present technology is not to be limited in terms of the particular embodiments described in this application, which are intended as single illustrations of individual aspects of the present technology. Many modifications and variations of this present technology can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the present technology, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the present technology. It is to be understood that this present technology is not limited to particular methods, reagents, compounds compositions or biological systems, which can, 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. [00317] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. [00318] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. [00319] All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.