Patent Publication Number: US-2019194617-A1

Title: Single- and multi-chain chimeric antigen receptors

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. patent application Ser. No. 62/609,895, filed Dec. 22, 2017, and U.S. Provisional Patent Application Ser. No. 62/767,212, filed Nov. 14, 2018, the entire contents of these two applications are herein incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the field of biotechnology, and more specifically, to single-chain and multi-chain chimeric antigen receptors. 
     BACKGROUND 
     Chimeric antigen receptors (CARs) are a subclass of single-chain and multi-chain polypeptides. Chimeric antigen receptors typically include, e.g., an antigen-binding domain, a transmembrane domain, and one or more signaling domains. CARs have been investigated for use in the clinical treatment of different cancers, e.g., hematological cancers, in mammals. 
     SUMMARY 
     The present disclosure is based, at least in part, on the discovery that chimeric antigen-receptors that have a specific combination of intracellular signaling domains, when expressed in a T-cell, demonstrated improved T-cell activation, improved target cell killing, and improved cytokine secretion including IL-2, interferon-gamma, and TNFa, as compared to a T-cell that expresses a chimeric antigen receptor that includes only includes the intracellular signaling domains from CD3 and CD3ζ. 
     Provided herein are single-chain chimeric antigen receptors that include: an extracellular antigen-binding domain; a transmembrane domain; a first intracellular signaling domain from DAP-10 or DAP12; a second intracellular signaling domain from a protein selected from the group of: 4-1BB, CD27, OX40, CD40, CD28, GITR, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an immunoreceptor tyrosine-based activation motif (ITAM). In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain is selected from the group of: a scFv, a (scFv) 2 , a V H H domain, and a V NAR  domain. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain is a scFv. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain binds specifically to a single antigen. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the single antigen is a tumor antigen. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the tumor antigen is selected from the group of: MAGE, MUC16, CD19, WT-1, CD22, LI-CAM, ROR-1, CEA, 4-1BB, ETA, 5T4, adenocarcinoma antigen, alpha-fetoprotein (AFP), BAFF, B-lymphoma cell, C242 antigen, CA-125, carbonic anhydrase 9 (CA-IX), C-MET, CCR4, CD152, CD20, CD125 CD200, CD221, CD23 (IgE receptor), CD28, CD30 (TNFRSF8), CD33, CD4, CD40, CD44 v6, CD51, CD52, CD56, CD74, CD80, CEA, CNT0888, CTLA-4, DRS, EGFR, EpCAM, CD3, FAP, fibronectin extra domain-B, folate receptor 1, GD2, GD3 ganglioside, glycoprotein 75, GPNMB, HER2/neu, HGF, human scatter factor receptor kinase, IGF-1 receptor, IGF-I, IgGl, IL-13, IL-6, insulin-like growth factor I receptor, integrin α5β1, integrin αvβ3, MORAb-009, MS4A1, MUC1, mucin CanAg, N-glycolylneuraminic acid, NPC-1C, PDGF-R a, PDL192, phosphatidylserine, prostatic carcinoma cells, RANKL, RON, SCH 900105, SDC1, SLAMF7, TAG-72, tenascin C, TGF beta 2, TGF-β, TRAIL-R1, TRAIL-R2, tumor antigen CTAA16.88, VEGF-A, VEGFR-1, VEGFR2, and vimentin. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the tumor antigen is CD19. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain binds specifically to two different antigens. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, the transmembrane domain is a transmembrane domain from: a chain of α T cell receptor, β chain of the T cell receptor, ζ chain of the T cell receptor, CD28, CD3ε, CD3δ, CD3γ, CD33, CD37, CD64, CD80, CD45, CD4, CD5, CD8α, CD9, CD16, CD22, CD86, or CD154. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the ITAM comprises a cytoplasmic signaling sequence from CD3ζ. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor includes the extracellular antigen-binding domain, the transmembrane domain, the first intracellular signaling domain, the second intracellular signaling domain, and the ITAM. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the transmembrane domain and the first intracellular signaling domain directly abut each other. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the transmembrane domain and the first intracellular signaling domain are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). In some embodiments of any of the single-chain chimeric antigen receptors described herein, the first intracellular signaling domain and the second intracellular signaling domain directly abut each other. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the first intracellular signaling domain and the second intracellular signaling domain are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). In some embodiments of any of the single-chain chimeric antigen receptors described herein, the second intracellular signaling domain and the ITAM directly abut each other. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the second intracellular signaling domain and the ITAM are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor includes the extracellular antigen-binding domain, the transmembrane domain, the second intracellular signaling domain, the first intracellular signaling domain, and the ITAM. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor includes the extracellular antigen-binding domain, the transmembrane domain, the first intracellular signaling domain, the ITAM, and the second intracellular signaling domain. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor includes the extracellular antigen-binding domain, the transmembrane domain, the second intracellular signaling domain, the ITAM, and the first intracellular signaling domain. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, when going to the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor includes the extracellular antigen-binding domain, the transmembrane domain, the ITAM, the first intracellular signaling domain, and the second intracellular signaling domain. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, when going to the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor includes the extracellular antigen-binding domain, the transmembrane domain, the ITAM, the second intracellular signaling domain, and the first intracellular signaling domain. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain and the transmembrane domain directly abut each other. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain and the transmembrane domain are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, the first intracellular signaling domain is from DAP-10. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the first intracellular signaling domain is from DAP-12. 
     Also provided herein are nucleic acis that include a nucleotide sequence encoding any of the single-chain chimeric antigen receptors described herein. Also provided herein are vectors that include any of the nucleic acids described herein that include a nucleotide sequence encoding any of the single-chain chimeric antigen receptors described herein. 
     Also provided herein are mammalian cells that include any of the vectors described herein. In some embodiments of any of the mammalian cells described herein, the mammalian cell is a T cell. In some embodiments of any of the mammalian cells described herein, the mammalian cell is selected from the group of: a CD8 +  T cell, a CD4 +  T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a macrophage/monocyte. In some embodiments of any of the mammalian cells described herein, the mammalian cell is a mammalian cell obtained from a subject. In some embodiments of any of the mammalian cells described herein, the subject is diagnosed or identified as having a cancer. In some embodiments of any of the mammalian cells described herein, the subject is human. 
     Also provided herein are pharmaceutical compositions that include any of the mammalian cells described herein and a pharmaceutically acceptable carrier. Also provided herein are kits that include any of the pharmaceutical compositions described herein. 
     Also provided herein are pharmaceutical compositions that include any of the nucleic acids described herein or any of the vectors described herein, and a pharmaceutically acceptable carrier. Also provided herein are kits that include any of the pharmaceutical compositions described herein. 
     Also provided herein are methods of generating a chimeric antigen receptor-expressing cell, the method comprising introducing into a mammalian cell any of the nucleic acids described herein or any of the vectors described herein. In some embodiments of any of the methods described herein, the mammalian cell is a human cell. In some embodiments of any of the methods described herein, the mammalian cell is a cell selected from the group of: a CD8+ T cell, a CD4+ T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a macrophage/monocyte. In some embodiments of any of the methods described herein, the mammalian cell is a mammalian cell obtained from a subject. In some embodiments of any of the methods described herein, the subject is diagnosed or identified as having a cancer. Some embodiments of any of the methods described herein further include, after the introducing step: culturing the cell in a liquid culture medium. Some embodiments of any of the methods described herein further include, before the introducing step: obtaining the mammalian cell from the subject. 
     Also provided herein are methods of treating a cancer in a subject that include administering a therapeutically effective amount of any of the mammalian cells described herein to the subject. Some embodiments of any of the methods described herein further include, prior to the administering step, obtaining an initial cell from the subject; and introducing any of the nucleic acids described herein or any of the vectors described herein into the initial cell, to yield the mammalian cell that is administered to the subject. Some embodiments of any of the methods described herein further include, between the introducing step and the administering step, a step of culturing the cell that is administered to the subject in a liquid culture medium. In some embodiments of any of the methods described herein, the subject is human. 
     Also provided herein are multi-chain chimeric antigen receptors that include at least one first polypeptide including: a transmembrane domain; a first intracellular signaling domain from DAP-10 or DAP-12; a second intracellular signaling domain from a protein selected from the group of: 4-1BB, CD27, OX40, CD40, CD28, GITR, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an immunoreceptor tyrosine-based activation motif (ITAM). In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the transmembrane domain is a transmembrane domain from: α chain of a T cell receptor, β chain of the T cell receptor, ζ chain of the T cell receptor, CD28, CD3ε, CD3δ, CD3γ, CD33, CD37, CD64, CD80, CD45, CD4, CD5, CD8α, CD9, CD16, CD22, CD86, or CD154. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the ITAM includes a cytoplasmic signaling sequence from CD3ζ. 
     In some embodiments of any of the multi-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the first intracellular signaling domain, the second intracellular signaling domain, and the ITAM. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the transmembrane domain and the first intracellular signaling domain directly abut each other. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the transmembrane domain and the first intracellular signaling domain are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the first intracellular signaling domain and the second intracellular signaling domain directly abut each other. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the first intracellular signaling domain and the second intracellular signaling domain are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the second intracellular signaling domain and the ITAM directly abut each other. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the second intracellular signaling domain and the ITAM are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). 
     In some embodiments of any of the multi-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the second intracellular signaling domain, the first intracellular signaling domain, and the ITAM. 
     In some embodiments of any of the multi-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the first intracellular signaling domain, the ITAM, and the second intracellular signaling domain. 
     In some embodiments of any of the multi-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the second intracellular signaling domain, the ITAM, and the first intracellular signaling domain. 
     In some embodiments of any of the multi-chain chimeric antigen receptors described herein, when going to the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the ITAM, the first intracellular signaling domain, and the second intracellular signaling domain. 
     In some embodiments of any the multi-chain chimeric antigen receptors described herein, when going to the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the ITAM, the second intracellular signaling domain, and the first intracellular signaling domain. 
     In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the first intracellular signaling domain is from DAP-10. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the first intracellular signaling domain is from DAP-12. 
     Also provided herein are nucleic acids that encode any of the multi-chain chimeric antigen receptors described herein. Also provided herein are sets of nucleic acids that together encode any of the multi-chain chimeric antigen receptors described herein. 
     Also provided herein are mammalian cells that include any of the nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein. Also provided herein are mammalian cells that include any of the sets of nucleic acids described herein that together encode any of the multi-chain chimeric antigen receptors described herein. In some embodiments of any of the mammalian cells described herein, the mammalian cell is a T cell. In some embodiments of any of the mammalian cells described herein, the mammalian cell is selected from the group of: a CD8 +  T cell, a CD4 +  T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a macrophage/monocyte. In some embodiments of any of the mammalian cells described herein, the mammalian cell is a mammalian cell obtained from a subject. In some embodiments of any of the mammalian cells described herein, the subject is diagnosed or identified as having a cancer. In some embodiments of of any of the mammalian cells described herein, the subject is human. 
     Also provided herein are pharmaceutical compositions that include any of the mammalian cells described herein and a pharmaceutically acceptable carrier. Also provided herein are kits that include any of the pharmaceutical compositions described herein. 
     Also provided herein are pharmaceutical compositions that include any of the nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein, or any of the sets of nucleic acids described herein that together encode any of the multi-chain chimeric antigen receptors described herein, and a pharmaceutically acceptable carrier. Also provided herein are kits that include any of the pharmaceutical compositions described herein. 
     Also provided herein are methods of generating a multi-chain chimeric antigen receptor-expressing cell that include introducing into a mammalian cell any of the nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein, or any of the sets of nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein. In some embodiments of any of the methods described herein, the mammalian cell is a human cell. In some embodiments of any of the methods described herein, the mammalian cell is a cell selected from the group consisting of: a CD8+ T cell, a CD4+ T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a macrophage/monocyte. In some embodiments of any of the methods described herein, the mammalian cell is a mammalian cell obtained from a subject. In some embodiments of any of the methods described herein, the subject is diagnosed or identified as having a cancer. Some embodiments of any of the methods described herein further include, after the introducing step, culturing the cell in a liquid culture medium. Some embodiments of any of the methods described herein further include, before the introducing step, obtaining the mammalian cell from the subject. 
     Also provided herein are methods of treating cancer in a subject that include administering a therapeutically effective amount of any of the mammalian cell described herein to the subject. Some embodiments of any of the methods described herein further include, prior to the administering step, obtaining an initial cell from the subject; and 
     introducing any of the nucleic acids descried herein that encode any of the multi-chain chimeric antigen receptors described herein or any of the sets of nucleic acids described herein that together encode any of the multi-chain chimeric antigen receptors described herein into the initial cell, to yield the mammalian cell that is administered to the subject. Some embodiments of any of the methods described herein further include, between the introducing step and the administering step, a step of culturing the cell that is administered to the subject in a liquid culture medium. In some embodiments of any of the methods described herein, the subject is human. 
     Also provided herein are single-chain chimeric antigen receptors that include: an extracellular antigen-binding domain; a transmembrane domain; an intracellular signaling domain from a protein selected from the group of: 4-1BB, CD27, OX40, CD40, CD28, GITR, DAP-10, DAP-12, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an immunoreceptor tyrosine-based activation motif (ITAM). In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain is selected from the group consisting of: a scFv, a (scFv) 2 , a V H H domain, and a V NAR  domain. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain is a scFv. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain binds specifically to a single antigen. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the single antigen is a tumor antigen. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the tumor antigen is selected from the group of: MAGE, MUC16, CD19, WT-1, CD22, LI-CAM, ROR-1, CEA, 4-1BB, ETA, 5T4, adenocarcinoma antigen, alpha-fetoprotein (AFP), BAFF, B-lymphoma cell, C242 antigen, CA-125, carbonic anhydrase 9 (CA-IX), C-MET, CCR4, CD152, CD20, CD125 CD200, CD221, CD23 (IgE receptor), CD28, CD30 (TNFRSF8), CD33, CD4, CD40, CD44 v6, CD51, CD52, CD56, CD74, CD80, CEA, CNT0888, CTLA-4, DRS, EGFR, EpCAM, CD3, FAP, fibronectin extra domain-B, folate receptor 1, GD2, GD3 ganglioside, glycoprotein 75, GPNMB, HER2/neu, HGF, human scatter factor receptor kinase, IGF-1 receptor, IGF-I, IgGl, IL-13, IL-6, insulin-like growth factor I receptor, integrin α5β1, integrin αvβ3, MORAb-009, MS4A1, MUC1, mucin CanAg, N-glycolylneuraminic acid, NPC-1C, PDGF-R a, PDL192, phosphatidylserine, prostatic carcinoma cells, RANKL, RON, SCH 900105, SDC1, SLAMF7, TAG-72, tenascin C, TGF beta 2, TGF-β, TRAIL-R1, TRAIL-R2, tumor antigen CTAA16.88, VEGF-A, VEGFR-1, VEGFR2, and vimentin. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the tumor antigen is CD19. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain binds specifically to two different antigens. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, the transmembrane domain is a transmembrane domain from: a chain of a T cell receptor, β chain of the T cell receptor, ζ chain of the T cell receptor, CD28, CD3ε, CD3δ, CD3γ, CD33, CD37, CD64, CD80, CD45, CD4, CD5, CD8α, CD9, CD16, CD22, CD86, or CD154. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the ITAM includes a cytoplasmic signaling sequence from CD3ζ. 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor include the extracellular antigen-binding domain, the transmembrane domain, the intracellular signaling domain, and the ITAM. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the transmembrane domain and the intracellular signaling domain directly abut each other. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the transmembrane domain and the intracellular signaling domain are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). In some embodiments of any of the single-chain chimeric antigen receptors described herein, the intracellular signaling domain and the ITAM directly abut each other. In some embodiments of any of the single-cain chimeric antigen receptors described herein, the intracellular signaling domain and the ITAM are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). 
     In some embodiments of any of the single-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor includes the extracellular antigen-binding domain, the transmembrane domain, the ITAM, and the intracellular signaling domain. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain and the transmembrane domain directly abut each other. In some embodiments of any of the single-chain chimeric antigen receptors described herein, the extracellular antigen-binding domain and the transmembrane domain are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). 
     Also provided herein are nucleic acids the include a nucleotide sequence encoding any of the single-chain chimeric antigen receptors described herein. Also provided herein are vectors that include any of the nucleic acids described herein that encode any of the single-chain chimeric antigen receptors described herein. 
     Also provided herein are mammalian cells that include any of the vectors described herein. In some embodiments of any of the mammalian cells described herein, the mammalian cell is a T cell. In some embodiments of any of the mammalian cells described herein, the mammalian cell is selected from the group of: a CD8 +  T cell, a CD4 +  T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a macrophage/monocyte. In some embodiments of any of the mammalian cells described herein, the mammalian cell is a mammalian cell obtained from a subject. In some embodiments of any of the mammalian cells described herein, the subject is diagnosed or identified as having a cancer. In some embodiments of any of the mammalian cells described herein, the subject is human. 
     Also provided herein are pharmaceutical compositions that include any of the mammalian cells described herein and a pharmaceutically acceptable carrier. Also provided herein are kits that include any of the pharmaceutical compositions described herein. 
     Also provided herein are pharmaceutical compositions that include any of the nucleic acids described herein that encode any of the single-chain chimeric antigen receptors described herein, and a pharmaceutically acceptable carrier. Also provided herein are kits that include any of the pharmaceutical compositions described herein. 
     Also provided herein are methods of generating a chimeric antigen receptor-expressing cell that include introducing into a mammalian cell any of the nucleic acids described herein that encode any of the single-chain chimeric antigen receptors described herein or any of the vectors described herein. In some embodiments of any of the methods described herein, the mammalian cell is a human cell. In some embodiments of any of the methods described herein, the mammalian cell is a cell selected from the group of: a CD8+ T cell, a CD4+ T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a macrophage/monocyte. In some embodiments of any of the methods described herein, the mammalian cell is a mammalian cell obtained from a subject. In some embodiments of any of the methods described herein, the subject is diagnosed or identified as having a cancer. Some embodiments of any of the methods described herein further include, after the introducing step, culturing the cell in a liquid culture medium. Some embodiments of any of the methods described herein further include, before the introducing step, obtaining the mammalian cell from the subject. 
     Also provided herein are methods of treating a cancer in a subject that include administering a therapeutically effective amount of any of the mammalian cells described herein. Some embodiments of any of the methods described herein further include, prior to the administering step, obtaining an initial cell from the subject; and introducing any of the nucleic acids described herein that encode any of the single-chain chimeric antigen receptors described herein or any of the vectors described herein into the initial cell, to yield the mammalian cell that is administered to the subject. Some embodiments of any of the methods described herein further include, between the introducing step and the administering step, a step of culturing the cell that is administered to the subject in a liquid culture medium. In some embodiments of any of the methods described herein, the subject is human. 
     Also provided herein are multi-chain chimeric antigen receptors that include at least one first polypeptide including: a transmembrane domain; an intracellular signaling domain from a protein selected from the group of: 4-1BB, CD27, OX40, CD40, CD28, GITR, DAP-10, DAP-12, CD2, CD5, ICAM-1, CD1 la, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an immunoreceptor tyrosine-based activation motif (ITAM). In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the transmembrane domain is a transmembrane domain from: α chain of a T cell receptor, β chain of the T cell receptor, ζ chain of the T cell receptor, CD28, CD3ε, CD3δ, CD3γ, CD33, CD37, CD64, CD80, CD45, CD4, CD5, CD8α, CD9, CD16, CD22, CD86, or CD154. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the ITAM includes a cytoplasmic signaling sequence from CD3ζ. 
     In some embodiments of any of the multi-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the intracellular signaling domain, and the ITAM. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the transmembrane domain and the intracellular signaling domain directly abut each other. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the transmembrane domain and the intracellular signaling domain are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the intracellular signaling domain and the ITAM directly abut each other. In some embodiments of any of the multi-chain chimeric antigen receptors described herein, the intracellular signaling domain and the ITAM are separated by 1 to 500 amino acids (e.g., 1 to 250 amino acids, or 1 to 50 amino acids). 
     In some embodiments of any of the multi-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal direction or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the ITAM, and the intracellular signaling domain. 
     Also provided herein are nucleic acids that encode any of the multi-chain chimeric antigen receptors described herein. Also provided herein are sets of nucleic acids that together encode any of the multi-chain chimeric antigen receptors described herein. 
     Also provided herein are mammalian cells that include any of the nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein. Also provided herein are mammalian cells that include any of the sets of nucleic acids described herein that together encode any of the multi-chain chimeric antigen receptors described herein. In some embodiments of any of the mammalian cells described herein, the mammalian cell is a T cell. In some embodiments of any of the mammalian cells described herein, the mammalian cell is selected from the group of: a CD8 +  T cell, a CD4 +  T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a macrophage/monocyte. In some embodiments of any of the mammalian cells described herein, the mammalian cell is a mammalian cell obtained from a subject. In some embodiments of any of the mammalian cells described herein, the subject is diagnosed or identified as having a cancer. In some embodiments of any of the mammalian cells described herein, the subject is human. 
     Also provided herein are pharmaceutical compositions that include any of the mammalian cells described herein and a pharmaceutically acceptable carrier. Also provided herein are kits that include any of the pharmaceutical compositions described herein. 
     Also provided herein are pharmaceutical compositions that include any of the nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein or any of the sets of nucleic acids described herein that together encode any of the multi-chain chimeric antigen receptors described herein, and a pharmaceutically acceptable carrier. Also provided are kits that include any of the pharmaceutical compositions described herein. 
     Also provided herein are methods of generating a chimeric antigen receptor-expressing cell that include introducing into a mammalian cell any of the nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein or any of the sets of nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein. In some embodiments of any of the methods described herein, the mammalian cell is a human cell. In some embodiments of any of the methods described herein, the mammalian cell is a cell selected from the group consisting of: a CD8+ T cell, a CD4+ T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a macrophage/monocyte. In some embodiments of any of the methods described herein, the mammalian cell is a mammalian cell obtained from a subject. In some embodiments of any of the methods described herein, the subject is diagnosed or identified as having a cancer. Some embodiments of any of the methods described herein further include, after the introducing step, culturing the cell in a liquid culture medium. Some embodiments of any of the methods described herein further include, before the introducing step, obtaining the mammalian cell from the subject. 
     Also provided herein are methods of treating a cancer in a subject that include administering a therapeutically effective amount of any of the mammalian cells described herein. Some embodiments of any of the methods described herein further include, prior to the administering step, obtaining an initial cell from the subject; and introducing any of the nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein, of any of the sets of nucleic acids described herein that encode any of the multi-chain chimeric antigen receptors described herein into the initial cell, to yield the mammalian cell that is administered to the subject. Some embodiments of any of the methods described herein further include, between the introducing step and the administering step, a step of culturing the cell that is administered to the subject in a liquid culture medium. In some embodiments of any of the methods described herein, the subject is human. 
     The use of the term “a” before a noun is meant “one or more” of the particular noun. For example, the phrase “a mammalian cell” means “one or more mammalian cell.” 
     The terms “chimeric antigen receptor” and “CAR” are used interchangeably herein, and refer to artificial multi-module molecules capable of triggering or inhibiting the activation of an immune cell which generally but not exclusively comprise an extracellular domain (e.g., a ligand/antigen binding domain), a transmembrane domain and one or more intracellular signaling domains. CAR molecules and derivatives thereof (e.g., CAR variants) are described, e.g., in PCT Application No. US2014/016527; Fedorov et al.  Sci Transl Med  (2013);5(215):215ra172; Glienke et al.  Front Pharmacol  (2015) 6:21; Kakarla &amp; Gottschalk 52  Cancer J  (2014) 20(2):151-5; Riddell et al.  Cancer J  (2014) 20(2):141-4; Pegram et al.  Cancer J  (2014) 20(2):127-33; Cheadle et al.  Immunol Rev  (2014) 257(1):91-106; Barrett et al.  Annu Rev Med  (2014) 65:333-47; Sadelain et al.  Cancer Discov  (2013) 3(4):388-98; Cartellieri et al.,  J Biomed Biotechnol  (2010) 956304; the disclosures of which are incorporated herein by reference in their entirety. A CAR can be a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor. 
     The term “single-chain chimeric antigen receptor” means a chimeric antigen receptor that is a single-chain polypeptide. 
     The term “multi-chain chimeric antigen receptor” means a chimeric antigen receptor including two or more single-chain polypeptides. 
     The term “transmembrane domain” means a domain of a polypeptide that includes at least one contiguous amino acid sequence that traverses a lipid bilayer when present in the corresponding endogenous polypeptide when expressed in a mammalian cell. For example, a transmembrane domain can include one, two, three, four, five, six, seven, eight, nine, or ten contiguous amino acid sequences that each traverse a lipid bilayer when present in the corresponding endogenous polypeptide when expressed in a mammalian cell. As is known in the art, a transmembrane domain can, e.g., include at least one (e.g., two, three, four, five, six, seven, eight, nine, or ten) contiguous amino acid sequence (that traverses a lipid bilayer when present in the corresponding endogenous polypeptide when expressed in a mammalian cell) that has α-helical secondary structure in the lipid bilayer. In some embodiments, a transmembrane domain can include two or more contiguous amino acid sequences (that each traverse a lipid bilayer when present in the corresponding endogenous polypeptide when expressed in a mammalian cell) that form a β-barrel secondary structure in the lipid bilayer. Non-limiting examples of transmembrane domains are described herein. Additional examples of transmembrane domains are known in the art. 
     The term “antigen-binding domain” means a domain that binds specifically to a target antigen. In some examples, an antigen-binding domain can be formed from the amino acids present within a single-chain polypeptide. In other examples, an antigen-binding domain can be formed from amino acids present within a first single-chain polypeptide and the amino acids present in one or more additional single-chain polypeptides (e.g., a second single-chain polypeptide). Non-limiting examples of antigen-binding domains are described herein, including, without limitation, scFvs, or LBDs of growth factors. Additional examples of antigen-binding domains are known in the art. 
     As used herein, the term “antigen” refers generally to a binding partner specifically recognized by an antigen-binding domain described herein. Exemplary antigens include different classes of molecules, such as, but not limited to, polypeptides and peptide fragments thereof, small molecules, lipids, carbohydrates, and nucleic acids. Non-limiting examples of antigen or antigens that can be specifically bound by any of the antigen-binding domains are described herein. Additional examples of antigen or antigens that can be specifically bound by any of the antigen-binding domains are known in the art. 
     The term “intracellular signaling domain” means an intracellular signaling domain from an endogenous signaling transmembrane polypeptide expressed in an immune cell (e.g., a T lymphocyte) that promotes downstream immune cell signaling (e.g., T-cell receptor signaling) and/or immune cell activation (e.g., T cell activation). Non-limiting examples of intracellular signaling domains are described herein. Additional examples of intracellular signaling domains are known in the art. See, e.g., Chen et al.,  Nature Reviews Immunol.  13:227-242, 2013. 
     The term “immunoreceptor tyrosine-based activation motif” or “ITAM)” means an amino acid motif that includes a four amino-acid consensus sequence of a tyrosine separated from a leucine or an isoleucine by two other amino acids (YxxL/I). The tyrosine residue in the four-amino acid consensus sequence becomes phosphorylated following interaction of a signaling pathway kinase (e.g., a lymphocyte signaling pathway kinase). Non-limiting examples of ITAMs are described herein. Additional examples of ITAMs are known in the art. 
     The phrase “treatment of cancer” means a reduction in the number, frequency, or severity of one or more (e.g., two, three, four, or five) symptoms of a cancer in a subject having a cancer. Non-limiting symptoms of cancer are described herein. Additional symptoms of cancer are known in the art. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Methods and materials are described herein for use in the present invention; other, suitable methods and materials known in the art can also be used. The materials, methods, and examples are illustrative only and not intended to be limiting. All publications, patent applications, patents, sequences, database entries, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. 
     Other features and advantages of the invention will be apparent from the following detailed description and figures, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows the percent lysis of cell lines after co-culturing with CAR-T cells expressing various CAR constructs. The X axis shows the intracellular signaling domain(s) and ITAM in each tested construct. The Y axis shows the percentage of target cells that were lysed in the presence of the various CAR-T cells expressing the indicated CARs. The sequences of the various intracellular sequences of the CAR constructs are described in Example 1. UT=Untransduced. 
         FIG. 2  shows CD69 expression of CAR-T cells expressing various tested CAR constructs. The X axis shows the intracellular signaling domain(s) and ITAM in each tested construct. The Y axis shows the expression of CD69. MFI=median fluorescence intensity. The sequences of the various intracellular sequences of the CAR constructs are described in Example 1. UT=Untransduced. 
         FIGS. 3A-C  show cytokine production of CAR-T cells expressing various CAR constructs.  FIG. 3A  shows TNF-alpha production.  FIG. 3B  shows interferon gamma production.  FIG. 3C  shows interleukin 2 production. The X axes of  FIGS. 3  A-C show the intracellular signaling domain(s) and ITAM in each tested construct. The Y axes of  FIGS. 3  A-C show the expression in pg/ml of TNF-alpha, interferon gamma, and interleukin 2 cytokines, respectively. The sequences of the various intracellular sequences of the CAR constructs are described in Example 1. UT=Untransduced. 
     
    
    
     DETAILED DESCRIPTION 
     Provided herein are single-chain chimeric antigen receptors that include: an extracellular antigen-binding domain; a transmembrane domain; a first intracellular signaling domain from DAP-10 or DAP-12, a second intracellular signaling domain from a protein selected from the group of 4-1BB, CD27, OX40, CD40, CD28, GITR, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an immunoreceptor tyrosine-based activation motif (ITAM). 
     Also provided herein are multi-chain chimeric antigen receptors that comprise at least one first polypeptide including: a transmembrane domain; a first intracellular signaling domain from DAP-10 or DAP-12; a second intracellular signaling domain from a protein selected from the group of 4-1BB, CD27, OX40, CD40, CD28, GITR, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an ITAM. 
     Also provided herein are single-chain chimeric antigen receptors that include: an extracellular antigen-binding domain; a transmembrane domain; an intracellular signaling domain from a protein selected from the group of 4-1BB, CD27, 0X40, CD40, CD28, GITR, DAP-10, DAP-12, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an ITAM. Some embodiments of any of the single-chain chimeric antigen receptors described herein can include, in addition to the extracellular antigen-binding domain, the transmembrane domain, and the ITAM, one of the following combinations of intracellular signaling domains: (i) DAP12-OX40, (ii) DAP10-OX40, (iii) DAP12-CD40, (iv) DAP1O-CD28, (v) DAP12-CD28, (vi) DAP10-41BB, (vii) DAP1O-CD27, (viii) DAP1O-CD40, (ix) DAP1O-GITR, (x) DAP12-41BB, (xi) DAP12-CD27, (xii) DAP12-GITR, and (xiii) CD2-DAP12. 
     Also provided herein are multi-chain chimeric antigen receptors that comprise at least one first polypeptide including: an extracellular antigen-binding domain; a transmembrane domain; an intracellular signaling domain from a protein selected from the group of 4-1BB, CD27, OX40, CD40, CD28, GITR, DAP-10, DAP-12, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an ITAM. Some embodiments of any of the multi-chain chimeric antigen receptors described herein comprise at least one first polypeptide that include, in addition to the extracellular antigen-binding domain, the transmembrane domain, and the ITAM, one of the following combinations of intracellular signaling domains: (i) DAP12-OX40, (ii) DAP10-OX40, (iii) DAP12-CD40, (iv) DAP1O-CD28, (v) DAP12-CD28, (vi) DAP10-41BB, (vii) DAP1O-CD27, (viii) DAP1O-CD40, (ix) DAP10-GITR, (x) DAP12-41BB, (xi) DAP12-CD27, (xii) DAP12-GITR, and (xiii) CD2-DAP12. 
     Also provided herein are nucleic acids encoding any of the single-chain chimeric antigen receptors or any of the multi-chain chimeric antigen receptors described herein; vectors including any of these nucleic acids; mammalian cells including any of these vectors; and methods of treating a cancer in a subject by administering a mammalian cell (e.g., a T-cell) expressing any of the single-chain chimeric antigen receptors or any of the multi-chain chimeric antigen receptors described herein. 
     Non-limiting aspects of these single-chain chimeric antigen receptors, multi-chain chimeric antigen receptors, nucleic acids, vectors, mammalian cells, and methods are described below, and can be used in any combination without limitation. Additional aspects of these single-chain chimeric antigen receptors, multi-chain chimeric antigen receptors, nucleic acids, vectors, mammalian cells, and methods are known in the art. 
     In some embodiments, the compositions and/or methods disclosed herein can be used to selectively kill cancer cells in a subject. In some embodiments, a population of T-cells expressing any of the single-chain chimeric antigen receptors or any of the multi-chain chimeric antigen receptors described herein can have increased (e.g., a 1% to 300%, a 1% to 280%, a 1% to 260%, a 1% to 240%, a 1% to 220%, a 1% to 200%, a 1% to 190%, a 1% to 180%, a 1% to 170%, a 1% to 160%, a 1% to 150%, a 1% to 140%, a 1% to 130%, a 1% to 120%, a 1% to 110%, a 1% to 100%, a 1% to 95%, a 1% to 90%, a 1% to 85%, a 1% to 80%, a 1% to 75%, a 1% to 70%, a 1% to 65%, a 1% to 60%, a 1% to 55%, a 1% to 50%, a 1% to 45%, a 1% to 40%, a 1% to 35%, a 1% to 30%, a 1% to 25%, a 1% to 20%, a 1% to 15%, a 1% to 10%, a 1% to 5%, a 2% to 300%, a 2% to 280%, a 2% to 260%, a 2% to 240%, a 2% to 220%, a 2% to 200%, a 2% to 190%, a 2% to 180%, a 2% to 170%, a 2% to 160%, a 2% to 150%, a 2% to 140%, a 2% to 130%, a 2% to 120%, a 2% to 110%, a 2% to 100%, a 2% to 95%, a 2% to 90%, a 2% to 85%, a 2% to 80%, a 2% to 75%, a 2% to 70%, a 2% to 65%, a 2% to 60%, a 2% to 55%, a 2% to 50%, a 2% to 45%, a 2% to 40%, a 2% to 35%, a 2% to 30%, a 2% to 25%, a 2% to 20%, a 2% to 15%, a 2% to 10%, a 2% to 5%, a 3% to 300%, a 3% to 280%, a 3% to 260%, a 3% to 240%, a 3% to 220%, a 3% to 200%, a 3% to 190%, a 3% to 180%, a 3% to 170%, a 3% to 160%, a 3% to 150%, a 3% to 140%, a 3% to 130%, a 3% to 120%, a 3% to 110%, a 3% to 100%, a 3% to 95%, a 3% to 90%, a 3% to 85%, a 3% to 80%, a 3% to 75%, a 3% to 70%, a 3% to 65%, a 3% to 60%, a 3% to 55%, a 3% to 50%, a 3% to 45%, a 3% to 40%, a 3% to 35%, a 3% to 30%, a 3% to 25%, a 3% to 20%, a 3% to 15%, a 3% to 10%, a 3% to 5%, a 5% to 300%, a 5% to 280%, a 5% to 260%, a 5% to 240%, a 5% to 220%, a 5% to 200%, a 5% to 190%, a 5% to 180%, a 5% to 170%, a 5% to 160%, a 5% to 150%, a 5% to 140%, a 5% to 130%, a 5% to 120%, a 5% to 110%, a 5% to 100%, a 5% to 95%, a 5% to 90%, a 5% to 85%, a 5% to 80%, a 5% to 75%, a 5% to 70%, a 5% to 65%, a 5% to 60%, a 5% to 55%, a 5% to 50%, a 5% to 45%, a 5% to 40%, a 5% to 35%, a 5% to 30%, a 5% to 25%, a 5% to 20%, a 5% to 15%, a 5% to 10%, a 10% to 300%, a 10% to 280%, a 10% to 260%, a 10% to 240%, a 10% to 220%, a 10% to 200%, a 10% to 190%, a 10% to 180%, a 10% to 170%, a 10% to 160%, a 10% to 150%, a 10% to 140%, a 10% to 130%, a 10% to 120%, a 10% to 110%, a 10% to 100%, a 10% to 95%, a 10% to 90%, a 10% to 85%, a 10% to 80%, a 10% to 75%, a 10% to 70%, a 10% to 65%, a 10% to 60%, a 10% to 55%, a 10% to 50%, a 10% to 45%, a 10% to 40%, a 10% to 35%, a 10% to 30%, a 10% to 25%, a 10% to 20%, a 10% to 15%, a 15% to 300%, a 15% to 280%, a 15% to 260%, a 15% to 240%, a 15% to 220%, a 15% to 200%, a 15% to 190%, a 15% to 180%, a 15% to 170%, a 15% to 160%, a 15% to 150%, a 15% to 140%, a 15% to 130%, a 15% to 120%, a 15% to 110%, a 15% to 100%, a 15% to 95%, a 15% to 90%, a 15% to 85%, a 15% to 80%, a 15% to 75%, a 15% to 70%, a 15% to 65%, a 15% to 60%,a 15% to 55%,a 15% to 50%,a 15% to 45%, a 15% to 40%, a 15% to 35%, a 15% to 30%, a 15% to 25%, a 15% to 20%, a 20% to 300%, a 20% to 280%, a 20% to 260%, a 20% to 240%, a 20% to 220%, a 20% to 200%, a 20% to 190%, a 20% to 180%, a 20% to 170%, a 20% to 160%, a 20% to 150%, a 20% to 140%, a 20% to 130%, a 20% to 120%, a 20% to 110%, a 20% to 100%, a 20% to 95%, a 20% to 90%, a 20% to 85%, a 20% to 80%, a 20% to 75%, a 20% to 70%, a 20% to 65%, a 20% to 60%, a 20% to 55%, a 20% to 50%, a 20% to 45%, a 20% to 40%, a 20% to 35%, a 20% to 30%, a 20% to 25%, a 25% to 300%, a 25% to 280%, a 25% to 260%, a 25% to 240%, a 25% to 220%, a 25% to 200%, a 25% to 190%, a 25% to 180%, a 25% to 170%, a 25% to 160%, a 25% to 150%, a 25% to 140%, a 25% to 130%, a 25% to 120%, a 25% to 110%, a 25% to 100%, a 25% to 95%, a 25% to 90%, a 25% to 85%, a 25% to 80%, a 25% to 75%, a 25% to 70%, a 25% to 65%, a 25% to 60%, a 25% to 55%, a 25% to 50%, a 25% to 45%, a 25% to 40%, a 25% to 35%, a 25% to 30%, a 30% to 300%, a 30% to 280%, a 30% to 260%, a 30% to 240%, a 30% to 220%, a 30% to 200%, a 30% to 190%, a 30% to 180%, a 30% to 170%, a 30% to 160%, a 30% to 150%, a 30% to 140%, a 30% to 130%, a 30% to 120%, a 30% to 110%, a 30% to 100%, a 30% to 95%, a 30% to 90%, a 30% to 85%, a 30% to 80%, a 30% to 75%, a 30% to 70%, a 30% to 65%, a 30% to 60%, a 30% to 55%, a 30% to 50%, a 30% to 45%, a 30% to 40%, a 30% to 35%, a 35% to 300%, a 35% to 280%, a 35% to 260%, a 35% to 240%, a 35% to 220%, a 35% to 200%, a 35% to 190%, a 35% to 180%, a 35% to 170%, a 35% to 160%, a 35% to 150%, a 35% to 140%, a 35% to 130%, a 35% to 120%, a 35% to 110%, a 35% to 100%, a 35% to 95%, a 35% to 90%, a 35% to 85%, a 35% to 80%, a 35% to 75%, a 35% to 70%, a 35% to 65%, a 35% to 60%, a 35% to 55%, a 35% to 50%, a 35% to 45%, a 35% to 40%, a 40% to 300%, a 40% to 280%, a 40% to 260%, a 40% to 240%, a 40% to 220%, a 40% to 200%, a 40% to 190%, a 40% to 180%, a 40% to 170%, a 40% to 160%, a 40% to 150%, a 40% to 140%, a 40% to 130%, a 40% to 120%, a 40% to 110%, a 40% to 100%, a 40% to 95%, a 40% to 90%, a 40% to 85%, a 40% to 80%, a 40% to 75%, a 40% to 70%, a 40% to 65%, a 40% to 60%, a 40% to 55%, a 40% to 50%, a 40% to 45%, a 45% to 300%, a 45% to 280%, a 45% to 260%, a 45% to 240%, a 45% to 220%, a 45% to 200%, a 45% to 190%, a 45% to 180%, a 45% to 170%, a 45% to 160%, a 45% to 150%, a 45% to 140%, a 45% to 130%, a 45% to 120%, a 45% to 110%, a 45% to 100%, a 45% to 95%, a 45% to 90%, a 45% to 85%, a 45% to 80%, a 45% to 75%, a 45% to 70%, a 45% to 65%, a 45% to 60%, a 45% to 55%, a 45% to 50%, a 50% to 300%, a 50% to 280%, a 50% to 260%, a 50% to 240%, a 50% to 220%, a 50% to 200%, a 50% to 190%, a 50% to 180%, a 50% to 170%, a 50% to 160%, a 50% to 150%, a 50% to 140%, a 50% to 130%, a 50% to 120%, a 50% to 110%, a 50% to 100%, a 50% to 95%, a 50% to 90%, a 50% to 85%, a 50% to 80%, a 50% to 75%, a 50% to 70%, a 50% to 65%, a 50% to 60%, a 50% to 55%, a 55% to 300%, a 55% to 280%, a 55% to 260%, a 55% to 240%, a 55% to 220%, a 55% to 200%, a 55% to 190%, a 55% to 180%, a 55% to 170%, a 55% to 160%, a 55% to 150%, a 55% to 140%, a 55% to 130%, a 55% to 120%, a 55% to 110%, a 55% to 100%, a 55% to 95%, a 55% to 90%, a 55% to 85%, a 55% to 80%, a 55% to 75%, a 55% to 70%, a 55% to 65%, a 55% to 60%, a 60% to 300%, a 60% to 280%, a 60% to 260%, a 60% to 240%, a 60% to 220%, a 60% to 200%, a 60% to 190%, a 60% to 180%, a 60% to 170%, a 60% to 160%, a 60% to 150%, a 60% to 140%, a 60% to 130%, a 60% to 120%, a 60% to 110%, a 60% to 100%, a 60% to 95%, a 60% to 90%, a 60% to 85%, a 60% to 80%, a 60% to 75%, a 60% to 70%, a 60% to 65%, a 65% to 300%, a 65% to 280%, a 65% to 260%, a 65% to 240%, a 65% to 220%, a 65% to 200%, a 65% to 190%, a 65% to 180%, a 65% to 170%, a 65% to 160%, a 65% to 150%, a 65% to 140%, a 65% to 130%, a 65% to 120%, a 65% to 110%, a 65% to 100%, a 65% to 95%, a 65% to 90%, a 65% to 85%, a 65% to 80%, a 65% to 75%, a 65% to 70%, a 70% to 300%, a 70% to 280%, a 70% to 260%, a 70% to 240%, a 70% to 220%, a 70% to 200%, a 70% to 190%, a 70% to 180%, a 70% to 170%, a 70% to 160%, a 70% to 150%, a 70% to 140%, a 70% to 130%, a 70% to 120%, a 70% to 110%, a 70% to 100%, a 70% to 95%, a 70% to 90%, a 70% to 85%, a 70% to 80%, a 70% to 75%, a 75% to 300%, a 75% to 280%, a 75% to 260%, a 75% to 240%, a 75% to 220%, a 75% to 200%, a 75% to 190%, a 75% to 180%, a 75% to 170%, a 75% to 160%, a 75% to 150%, a 75% to 140%, a 75% to 130%, a 75% to 120%, a 75% to 110%, a 75% to 100%, a 75% to 95%, a 75% to 90%, a 75% to 85%, a 75% to 80%, a 80% to 300%, a 80% to 280%, a 80% to 260%, a 80% to 240%, a 80% to 220%, a 80% to 200%, a 80% to 190%, a 80% to 180%, a 80% to 170%, a 80% to 160%, a 80% to 150%, a 80% to 140%, a 80% to 130%, a 80% to 120%, a 80% to 110%, a 80% to 100%, a 80% to 95%, a 80% to 90%, a 80% to 85%, a 85% to 300%, a 85% to 280%, a 85% to 260%, a 85% to 240%, a 85% to 220%, a 85% to 200%, a 85% to 190%, a 85% to 180%, a 85% to 170%, a 85% to 160%, a 85% to 150%, a 85% to 140%, a 85% to 130%, a 85% to 120%, a 85% to 110%, a 85% to 100%, a 85% to 95%, a 85% to 90%, a 90% to 300%, a 90% to 280%, a 90% to 260%, a 90% to 240%, a 90% to 220%, a 90% to 200%, a 90% to 190%, a 90% to 180%, a 90% to 170%, a 90% to 160%, a 90% to 150%, a 90% to 140%, a 90% to 130%, a 90% to 120%, a 90% to 110%, a 90% to 100%, a 90% to 95%, a 95% to 300%, a 95% to 280%, a 95% to 260%, a 95% to 240%, a 95% to 220%, a 95% to 200%, a 95% to 190%, a 95% to 180%, a 95% to 170%, a 95% to 160%, a 95% to 150%, a 95% to 140%, a 95% to 130%, a 95% to 120%, a 95% to 110%, a 95% to 100%, a 100% to 300%, a 100% to 280%, a 100% to 260%, a 100% to 240%, a 100% to 220%, a 100% to 200%, a 100% to 190%, a 100% to 180%, a 100% to 170%, a 100% to 160%, a 100% to 150%, a 100% to 140%, a 100% to 130%, a 100% to 120%, a 100% to 110%, a 110% to 300%, a 110% to 280%, a 110% to 260%, a 110% to 240%, a 110% to 220%, a 110% to 200%, a 110% to 190%, a 110% to 180%, a 110% to 170%, a 110% to 160%, a 110% to 150%, a 110% to 140%, a 110% to 130%, a 110% to 120%, a 120% to 300%, a 120% to 280%, a 120% to 260%, a 120% to 240%, a 120% to 220%, a 120% to 200%, a 120% to 190%, a 120% to 180%, a 120% to 170%, a 120% to 160%, a 120% to 150%, a 120% to 140%, a 120% to 130%, a 130% to 300%, a 130% to 280%, a 130% to 260%, a 130% to 240%, a 130% to 220%, a 130% to 200%, a 130% to 190%, a 130% to 180%, a 130% to 170%, a 130% to 160%, a 130% to 150%, a 130% to 140%, a 140% to 300%, a 140% to 280%, a 140% to 260%, a 140% to 240%, a 140% to 220%, a 140% to 200%, a 140% to 190%, a 140% to 180%, a 140% to 170%, a 140% to 160%, a 140% to 150%, a 150% to 300%, a 150% to 280%, a 150% to 260%, a 150% to 240%, a 150% to 220%, a 150% to 200%, a 150% to 190%, a 150% to 180%, a 150% to 170%, a 150% to 160%, a 160% to 300%, a 160% to 280%, a 160% to 260%, a 160% to 240%, a 160% to 220%, a 160% to 200%, a 160% to 190%, a 160% to 180%, a 160% to 170%, a 170% to 300%, a 170% to 280%, a 170% to 260%, a 170% to 240%, a 170% to 220%, a 170% to 200%, a 170% to 190%, a 170% to 180%, a 180% to 300%, a 180% to 280%, a 180% to 260%, a 180% to 240%, a 180% to 220%, a 180% to 200%, a 180% to 190%, a 190% to 300%, a 190% to 280%, a 190% to 260%, a 190% to 240%, a 190% to 220%, a 190% to 200%, a 200% to 300%, a 200% to 280%, a 200% to 260%, a 200% to 240%, a 200% to 220%, a 220% to 300%, a 220% to 280%, a 220% to 260%, a 220% to 240%, a 240% to 300%, a 240% to 280%, a 240% to 260%, a 260% to 300%, a 260% to 280%, or a 280% to 300% increase) production of one or more cytokines (e.g., IL-2, interferon-gamma, and TNFαcompared to a control T-cell (e.g., a T-cell including a CD28 costimulatory domain and a CD3 signaling domain) (e.g., when assessed using the same in vitro assay or in similar subjects in vivo). 
     In some embodiments, a population of T-cells expressing any of the single-chain chimeric antigen receptors or any of the multi-chain chimeric antigen receptors described herein can have increased (e.g., a 1% to 300%, or any of the subranges of this range described herein, increase) activation as compared a control population of T-cells (e.g., a T-cell including a CD28 costimulatory domain and a CD3 signaling domain) (e.g., when assessed using the same in vitro assay or in similar subjects in vivo). 
     In some embodiments, a population of T-cells expressing any of the single-chain chimeric antigen receptors or any of the multi-chain chimeric antigen receptors described herein can have increased (e.g., a 1% to 300%, or any of the subranges of this range described herein, increase) target cell killing as compared a control population of T-cells (e.g., a T-cell including a CD28 costimulatory domain and a CD3 signaling domain) (e.g., when assessed using the same in vitro assay or in similar subjects in vivo). 
     Single-Chain Chimeric Antigen Receptors 
     Single-Chain Chimeric Antigen Receptors Including a First Intracellular Signaling Domain, a Second Intracellular Signaling Domain, and an ITAM 
     Provided herein are single-chain chimeric antigen receptors that include: an extracellular antigen-binding domain (e.g., any of the antigen-binding domains described herein or known in the art); a transmembrane domain (e.g., any of the transmembrane domains described herein or known in the art); a first intracellular signaling domain from DAP-10 or DAP-12, a second intracellular signaling domain from a protein selected from the group of 4-1BB, CD27, OX40, CD40, CD28, GITR, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an ITAM. The single-chain chimeric antigen receptors described herein can bind to any of the exemplary antigens described herein (e.g., any of MAGE, MUC16, CD19, WT-1, CD22, LI-CAM, ROR-1, CEA, 4-1BB, ETA, 5T4, adenocarcinoma antigen, alpha-fetoprotein (AFP), BAFF, B-lymphoma cell, C242 antigen, CA-125, carbonic anhydrase 9 (CA-IX), C-MET, CCR4, CD152, CD20, CD125 CD200, CD221, CD23 (IgE receptor), CD28, CD30 (TNFRSF8), CD33, CD4, CD40, CD44 v6, CD51, CD52, CD56, CD74, CD80, CEA, CNT0888, CTLA-4, DRS, EGFR, EpCAM, CD3, FAP, fibronectin extra domain-B, folate receptor 1, GD2, GD3 ganglioside, glycoprotein 75, GPNMB, HER2/neu, HGF, human scatter factor receptor kinase, IGF-1 receptor, IGF-I, IgGl, IL-13, IL-6, insulin-like growth factor I receptor, integrin α5β1, integrin αvβ3, MORAb-009, MS4A1, MUC1, mucin CanAg, N-glycolylneuraminic acid, NPC-1C, PDGF-R a, PDL192, phosphatidylserine, prostatic carcinoma cells, RANKL, RON, SCH 900105, SDC1, SLAMF7, TAG-72, tenascin C, TGF beta 2, TGF-β, TRAIL-R1, TRAIL-R2, tumor antigen CTAA16.88, VEGF-A, VEGFR-1, VEGFR2, and vimentin) or any other antigen known in the art. In some embodiments, the single-chain chimeric antigen receptor binds specifically to a single antigen (e.g., any of the exemplary antigens described herein). In some embodiments, the single-chain chimeric antigen receptor binds specifically to two different antigens (e.g., any combination of the exemplary antigens described herein). In some embodiments, the single-chain chimeric antigen receptor or the multi-chain chimeric antigen receptor can bind specifically to a tumor antigen. 
     Some embodiments of these single-chain chimeric antigen receptors can include one or more (e.g., two, three, four, or five) ITAMs (e.g., any of the ITAMs described herein or known in the art). In some embodiments of these single-chain chimeric antigen receptors, the ITAM includes a cytoplasmic signaling sequence from CD3 (e.g., human CD3ζ). 
     In some embodiments of any of these single-chain chimeric antigen receptors, any two neighboring domains can be separated by 1amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, about 20 amino acids, about 15 amino acids, about 10 amino acids, about 8 amino acids, about 6 amino acids, about 4 amino acid, or about 3 amino acids (inclusive); about 2 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, about 20 amino acids, about 15 amino acids, about 10 amino acids, about 8 amino acids, about 6 amino acids, or about 4 amino acid (inclusive); about 3 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, about 20 amino acids, about 15 amino acids, about 10 amino acids, about 8 amino acids, about 6 amino acids, or about 5 amino acids (inclusive); about 4 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, about 20 amino acids, about 15 amino acids, about 10 amino acids, about 8 amino acids, or about 6 amino acids (inclusive); about 5 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, about 20 amino acids, about 15 amino acids, about 10 amino acids, about 8 amino acids, or about 7 amino acids (inclusive); about 6 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, about 20 amino acids, about 15 amino acids, about 10 amino acids, or about 8 amino acids (inclusive); about 8 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, about 20 amino acids, about 15 amino acids, or about 10 amino acids (inclusive); about 10 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, about 20 amino acids, or about 15 amino acids (inclusive); about 15 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, about 25 amino acids, or about 20 amino acids (inclusive); about 20 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, about 30 amino acids, or about 25 amino acids (inclusive); about 25 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, about 35 amino acids, or about 30 amino acids (inclusive); about 30 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids, or about 35 amino acids (inclusive); about 35 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, about 45 amino acids, about 40 amino acids (inclusive); about 40 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, about 50 amino acids, or about 45 amino acids (inclusive); about 45 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, about 55 amino acids, or about 50 amino acids (inclusive); about 50 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, about 60 amino acids, or about 55 amino acids (inclusive); about 55 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, about 65 amino acids, or about 60 amino acids (inclusive); about 60 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, about 70 amino acids, or about 65 amino acids (inclusive); about 65 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, about 75 amino acids, or about 70 amino acids (inclusive); about 70 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, or about 75 amino acids (inclusive); about 75 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, about 80 amino acids, or about 75 amino acids (inclusive); about 75 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, about 90 amino acids, about 85 amino acids, or about 80 amino acids (inclusive); about 80 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, about 110 amino acids, about 100 amino acids, about 95 amino acids, or about 90 amino acids (inclusive); about 100 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, about 120 amino acids, or about 110 amino acids (inclusive); about 110 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, or about 120 amino acids (inclusive); about 120 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, about 130 amino acids, or about 120 amino acids (inclusive); about 120 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, about 140 amino acids, or about 130 amino acids (inclusive); about 130 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, about 150 amino acids, or about 140 amino acids (inclusive); about 140 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, about 160 amino acids, or about 150 amino acids (inclusive); about 150 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, about 170 amino acids, or about 160 amino acids (inclusive); about 160 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, about 180 amino acids, or about 170 amino acids (inclusive); about 170 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, about 190 amino acids, or about 180 amino acids (inclusive); about 180 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, about 200 amino acids, or about 190 amino acids (inclusive); about 190 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, about 220 amino acids, or about 200 amino acids (inclusive); about 200 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, about 240 amino acids, or about 220 amino acids (inclusive); about 220 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, about 260 amino acids, or about 240 amino acids (inclusive); about 240 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, about 280 amino acids, or about 260 amino acids (inclusive); about 260 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, about 300 amino acids, or about 280 amino acids (inclusive); about 280 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, about 320 amino acids, or about 300 amino acids (inclusive); about 300 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, about 340 amino acids, or about 320 amino acids (inclusive); about 320 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, about 360 amino acids, or about 340 amino acids (inclusive); about 340 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, about 380 amino acids, or about 360 amino acids (inclusive); about 360 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, about 400 amino acids, or about 380 amino acids (inclusive); about 380 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, about 420 amino acids, or about 400 amino acids (inclusive); about 400 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, about 440 amino acids, or about 420 amino acids (inclusive); about 420 amino acids to about 500 amino acids, about 480 amino acids, about 460 amino acids, or about 440 amino acids (inclusive); about 440 amino acids to about 500 amino acids, about 480 amino acids, or about 460 amino acids (inclusive); about 460 amino acids to about 500 amino acids or about 480 amino acids (inclusive); or about 480 amino acids to about 500 amino acids (inclusive). 
     In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain is a sequence from the same endogenous single-chain polypeptide from which the transmembrane domain is derived (e.g., a CD8a hinge region, e.g., SEQ ID NO: 1). In some embodiments, a sequence comprising SEQ ID NO: 1 or 3 is positioned between the extracellular antigen-binding domain and the transmembrane domain. In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain is or includes a hinge region sequence of an antibody such as, without limitation, a human antibody (e.g., IgG1, IgG2, IgG3, or IgG4). In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain is or comprises a linker peptide sequence (e.g., a non-naturally occurring linker sequence, e.g., GS or any of the other linker sequences described herein). 
     
       
         
           
               
            
               
                 (CD8 alpha hinge) 
               
               
                 SEQ ID NO: 1 
               
               
                 TTTPAPRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFAC 
               
               
                   
               
               
                 (DNA sequence encoding CD8 alpha hinge of SEQ ID 
               
               
                 NO: 1) 
               
               
                 SEQ ID NO: 2 
               
               
                 ACCACGACGCCAGCGCCGCGACCACCAACACCGGCGCCCACCATCGCGTC 
               
               
                 GCAGCCCCTGTCCCTGCGCCCAGAGGCGTGCCGGCCAGCGGCGGGGGGCG 
               
               
                 CAGTGCACACGAGGGGGCTGGACTTCGCCTGT 
               
               
                   
               
               
                 (Dap10 extracellular domain) 
               
               
                 SEQ ID NO: 3 
               
               
                 QTTPGERSSLPAFYPGTSGSCSGCGSLSLP 
               
               
                   
               
               
                 (Dap10 extracellular domain) 
               
               
                 SEQ ID NO: 4 
               
               
                 CAGACAACACCAGGCGAGAGATCTAGCCTGCCCGCCTTCTACCCTGGCAC 
               
               
                 CAGCGGCTCTTGTTCTGGCTGTGGCAGCCTGTCTCTGCCC 
               
            
           
         
       
     
     In some embodiments of the single-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, the single-chain chimeric antigen receptor includes the extracellular antigen-binding domain, the transmembrane domain, the first intracellular signaling domain, the second intracellular signaling domain, and the ITAM. In some of these embodiments, one or more amino acids between the transmembrane domain and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the first intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the first intracellular signaling domain and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first or second intracellular signaling domain is derived. In some embodiments, one or more amino acids between the first intracellular signaling domain and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the first intracellular signaling domain and the second intracellular signaling domain directly abut each other. In some of these embodiments, one or more amino acids separating the second intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the second intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the second intracellular signaling domain and the ITAM directly abut each other. 
     In some embodiments of any of the single-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, include the extracellular antigen-binding domain, the transmembrane domain, the second intracellular signaling domain, the first intracellular signaling domain, and the ITAM. In some of these embodiments, one or more amino acids between the transmembrane domain and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the second intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the second intracellular signaling domain and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second or first intracellular signaling domain is derived. In some embodiments, one or more amino acids between the second intracellular signaling domain and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the second intracellular signaling domain and the first intracellular signaling domain directly abut each other. In some of these embodiments, one or more amino acids separating the first intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the first intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the first intracellular signaling domain and the ITAM directly abut each other. 
     In some embodiments of any of the single-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, include the extracellular antigen-binding domain, the transmembrane domain, the first intracellular binding domain, the ITAM, and the second intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the first intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the first intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the first intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the first intracellular signaling domain and the ITAM directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the second intracellular signaling domain is derived. In some embodiments, one or more amino acids between the ITAM and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the second intracellular signaling domain directly abut each other. 
     In some embodiments of any of the single-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, include the extracellular antigen-binding domain, the transmembrane domain, the second intracellular binding domain, the ITAM, and the first intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the second intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the second intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the second intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the second intracellular signaling domain and the ITAM directly abut each other. 
     In some of these embodiments, one or more amino acids separating the ITAM and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the first intracellular signaling domain is derived. In some embodiments, one or more amino acids between the ITAM and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the first intracellular signaling domain directly abut each other. 
     In some embodiments of any of the single-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, include the extracellular antigen-binding domain, the transmembrane domain, the ITAM, the first intracellular signaling domain, and the second intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the ITAM can directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the ITAM and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the first intracellular signaling domain directly abut each other. In some of these embodiments, one or more amino acids separating the first intracellular signaling domain and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the second intracellular signaling domain is derived. In some embodiments, one or more amino acids between the first intracellular signaling domain and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the first intracellular signaling domain and the second intracellular signaling domain directly abut each other. 
     In some embodiments of any of the single-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, include the extracellular antigen-binding domain, the transmembrane domain, the ITAM, the second intracellular signaling domain, and the first intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the ITAM can directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the ITAM and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the second intracellular signaling domain directly abut each other. In some of these embodiments, one or more amino acids separating the second intracellular signaling domain and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the first intracellular signaling domain is derived. In some embodiments, one or more amino acids between the second intracellular signaling domain and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the second intracellular signaling domain and the first intracellular signaling domain directly abut each other. 
     Some embodiments of any of the single-chain chimeric antigen receptors described herein can further include a dimerization domain and/or a peptide tag. 
     Single-Chain Chimeric Antigen Receptor Including an Intracellular Signaling Domain and an ITAM 
     Also provided herein are single-chain chimeric antigen receptors that include: an extracellular antigen-binding domain (e.g., any of the antigen-binding domains described herein or known in the art); a transmembrane domain (e.g., any of the transmembrane domains described herein or known in the art); an intracellular signaling domain from a protein selected from the group of 4-1BB, CD27, OX40, CD40, CD28, GITR, DAP-10, DAP-12, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and ITAM. The single-chain chimeric antigen receptors described herein can bind to any of the exemplary antigens described herein (e.g., any of MAGE, MUC16, CD19, WT-1, CD22, LI-CAM, ROR-1, CEA, 4-1BB, ETA, 5T4, adenocarcinoma antigen, alpha-fetoprotein (AFP), BAFF, B-lymphoma cell, C242 antigen, CA-125, carbonic anhydrase 9 (CA-IX), C-MET, CCR4, CD152, CD20, CD125 CD200, CD221, CD23 (IgE receptor), CD28, CD30 (TNFRSF8), CD33, CD4, CD40, CD44 v6, CD51, CD52, CD56, CD74, CD80, CEA, CNT0888, CTLA-4, DRS, EGFR, EpCAM, CD3, FAP, fibronectin extra domain-B, folate receptor 1, GD2, GD3 ganglioside, glycoprotein 75, GPNMB, HER2/neu, HGF, human scatter factor receptor kinase, IGF-1 receptor, IGF-I, IgGl, IL-13, IL-6, insulin-like growth factor I receptor, integrin α5β1, integrin αvβ3, MORAb-009, MS4A1, MUC1, mucin CanAg, N-glycolylneuraminic acid, NPC-1C, PDGF-R a, PDL192, phosphatidylserine, prostatic carcinoma cells, RANKL, RON, SCH 900105, SDC1, SLAMF7, TAG-72, tenascin C, TGF beta 2, TGF-β, TRAIL-R1, TRAIL-R2, tumor antigen CTAA16.88, VEGF-A, VEGFR-1, VEGFR2, and vimentin) or any other antigen known in the art. In some embodiments, the single-chain chimeric antigen receptor binds specifically to a single antigen (e.g., any of the exemplary antigens described herein). In some embodiments, the single-chain chimeric antigen receptor binds specifically to two different antigens (e.g., any combination of the exemplary antigens described herein). In some embodiments, the single-chain chimeric antigen receptor or the multi-chain chimeric antigen receptor can bind specifically to a tumor antigen. 
     Some embodiments of these single-chain chimeric antigen receptors can include one or more (e.g., two, three, four, or five) ITAMs (e.g., any of the ITAMs described herein or known in the art). In some embodiments of these single-chain chimeric antigen receptors, the ITAM includes a cytoplasmic signaling sequence from CD3 (e.g., human CD3ζ). In some embodiments of any of these single-chain chimeric antigen receptors, any two neighboring domains can be separated by 1amino acids to about 500 amino acids (or any of the subranges of this range described herein). 
     In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain is a sequence from the same endogenous single-chain polypeptide from which the transmembrane domain is derived (e.g., a CD8a hinge region, e.g., SEQ ID NO: 1). In some embodiments, a sequence comprising SEQ ID NO: 1 or 3 is positioned between the extracellular antigen-binding domain and the transmembrane domain. In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain is or includes a hinge region sequence of an antibody such as, without limitation, a human antibody (e.g., IgG1, IgG2, IgG3, or IgG4). In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain is or comprises a linker peptide sequence (e.g., a non-naturally occurring linker sequence, e.g., GS or any of the other linker sequences described herein). 
     Some embodiments of the single-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal or in the C-termnal to the N-terminal direction, include the extracellular antigen-binding domain, the transmembrane domain, the intracellular signaling domain, and the ITAM. In some of these embodiments, one or more amino acids between the transmembrane domain and the intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the intracellular signaling domain and the ITAM directly abut each other. 
     Some embodiments of the single-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal or in the C-termnal to the N-terminal direction, include the extracellular antigen-binding domain, the transmembrane domain, the ITAM, and the intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the transmembrane domain or the ITAM is derived. In some embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the ITAM can directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the intracellular signaling domain is derived. In some embodiments, one or more amino acids between the ITAM and the intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the intracellular signaling domain directly abut each other. 
     Some embodiments of any of the single-chain chimeric antigen receptors described herein can further include a dimerization domain and/or a peptide tag. 
     Multi-Chain Chimeric Antigen Receptors 
     Multi-Chain Chimeric Antigen Receptors that Include at Least One First Polypeptide Including a First Intracellular Signaling Domain, a Second Intracellular Signaling Domain, and an ITAM 
     Also provided herein are multi-chain chimeric antigen receptors that include at least one first polypeptide including: a transmembrane domain (e.g., any of the transmembrane domains described herein or known in the art); a first intracellular binding domain from DAP-10 or DAP-12, a second intracellular signaling domain from a protein selected from the group of 4-1BB, CD27, OX40, CD40, CD28, GITR, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an ITAM. In some embodiments, the at least one first polypeptide can further include an antigen-binding domain (e.g., any of the antigen-binding domains described herein or known in the art). In some embodiments, the multi-chain chimeric antigen receptor further includes a second polypeptide including an antigen-binding domain (e.g., any of the antigen-binding domains described herein or known in the art) and a transmembrane domain (e.g., any of the transmembrane domains described herein). The antigen specifically bound by the antigen-binding domain in any of these multi-chain chimeric antigen receptors can be any of the antigens described herein or known in the art. In some embodiments, the multi-chain chimeric antigen receptor only binds specifically to a single antigen (e.g., any of the exemplary antigens described herein). In some embodiments, the multi-chain chimeric antigen receptor binds specifically to two different antigens (e.g., any combination of any of the exemplary antigens described herein). In some embodiments, the multi-chain chimeric antigen receptor binds to a tumor antigen. 
     In some embodiments of the multi-chain chimeric antigen receptors, the extracellular antigen-binding domain and the transmembrane domain in the at least one first polypeptide and/or the second polypeptide directly abut each other. In some embodiments of the multi-chain chimeric antigen receptors, 1 to about 500 amino acids (e.g., any of the subranges of this range described herein) are between the extracellular antigen-binding domain and the transmembrane domain in the at least one first polypeptide and/or the second polypeptide. In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain in the at least one first polypeptide and/or the second polypeptide is a sequence from the same endogenous single-chain polypeptide from which the transmembrane domain is derived. In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain of the at least one first polypeptide and/or the second polypeptide is or includes a hinge region sequence of human antibody (e.g., IgG1, IgG2, IgG3, or IgG4). In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain in the at least one first polypeptide and/or the second polypeptide is or includes a linker sequence (e.g., a non-naturally occurring linker sequence). 
     In some embodiments, any two neighboring domains (e.g., the transmembrane domain, the first intracellular signaling domain, the second intracellular signaling domain, and the ITAM) in the at least one first polypeptide can directly abut each other. In some embodiments, any two neighboring domains in the at least one first polypeptide (e.g., the transmembrane domain, the first intracellular signaling domain, the second intracellular signaling domain, and the ITAM) can be separated by 1 to 500 amino acids (or any subrange of this range described herein). 
     In some embodiments of the multi-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the first intracellular signaling domain, the second intracellular signaling domain, and the ITAM. In some of these embodiments, one or more amino acids between the transmembrane domain and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the first intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the first intracellular signaling domain and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first or second intracellular signaling domain is derived. In some embodiments, one or more amino acids between the first intracellular signaling domain and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the first intracellular signaling domain and the second intracellular signaling domain directly abut each other. In some of these embodiments, one or more amino acids separating the second intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the second intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the second intracellular signaling domain and the ITAM directly abut each other. 
     In some embodiments of any of the multi-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the second intracellular signaling domain, the first intracellular signaling domain, and the ITAM. In some of these embodiments, one or more amino acids between the transmembrane domain and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the second intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the second intracellular signaling domain and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second or first intracellular signaling domain is derived. In some embodiments, one or more amino acids between the second intracellular signaling domain and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the second intracellular signaling domain and the first intracellular signaling domain directly abut each other. In some of these embodiments, one or more amino acids separating the first intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the first intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the first intracellular signaling domain and the ITAM directly abut each other. 
     In some embodiments of any of the multi-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the first intracellular binding domain, the ITAM, and the second intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the first intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the first intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the first intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the first intracellular signaling domain and the ITAM directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the second intracellular signaling domain is derived. In some embodiments, one or more amino acids between the ITAM and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the second intracellular signaling domain directly abut each other. 
     In some embodiments of any of the multi-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the second intracellular binding domain, the ITAM, and the first intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the second intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the second intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the second intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the second intracellular signaling domain and the ITAM directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the first intracellular signaling domain is derived. In some embodiments, one or more amino acids between the ITAM and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the first intracellular signaling domain directly abut each other. 
     In some embodiments of any of the multi-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the ITAM, the first intracellular signaling domain, and the second intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the ITAM can directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the ITAM and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the first intracellular signaling domain directly abut each other. In some of these embodiments, one or more amino acids separating the first intracellular signaling domain and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the first intracellular signaling domain or the second intracellular signaling domain is derived. In some embodiments, one or more amino acids between the first intracellular signaling domain and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the first intracellular signaling domain and the second intracellular signaling domain directly abut each other. 
     In some embodiments of any of the multi-chain chimeric antigen receptors, when going in the N-terminal to the C-terminal direction, or in the C-terminal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the ITAM, the second intracellular signaling domain, and the first intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the ITAM can directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the second intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the ITAM and the second intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the second intracellular signaling domain directly abut each other. In some of these embodiments, one or more amino acids separating the second intracellular signaling domain and the first intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the second intracellular signaling domain or the first intracellular signaling domain is derived. In some embodiments, one or more amino acids between the second intracellular signaling domain and the first intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the second intracellular signaling domain and the first intracellular signaling domain directly abut each other. 
     In some embodiments of these multi-chain chimeric antigen receptors, the at least one first polypeptide can further include one or both of: a dimerizing domain (e.g., any dimerizing domain known in the art) and/or a peptide tag (e.g., any peptide tag known in the art). 
     The second polypeptide that can, e.g., include one or more (e.g., two, three, or four) of: an extracellular antigen-binding domain (e.g., any of the antigen-binding domains described herein), a transmembrane domain (e.g., any of the transmembrane domains described herein), a dimerizing domain (e.g., a dimerizing domain that can interact with a dimerizing domain in the at least one first polypeptide in a mammalian cell), one or more intracellular signaling domain (e.g., any of the intracellular signaling domains described herein), and one or more ITAM (e.g., any of the ITAMs described herein). As can be appreciated by those in the art, a pair or each pair of neighboring domains in the second polypeptide can abut each other or can be separated by 1 to about 500 amino acids (e.g., any of the subranges of this range described herein). The one or more amino acids between a pair of neighboring domains in the second polypeptide can be a sequence from an endogenous single-chain polypeptide from which a transmembrane, an intracellular signaling domain, or an ITAM present in the second polypeptide has been derived, or can be or include a linker peptide sequence. In some embodiments, any pair of neighboring domains in the second polypeptide can directly abut each other. 
     As can be appreciated in the art, the two or more polypeptides present in a multi-chain chimeric antigen receptor can associate via pair of domains that interact with each other (through dimerizing domains). In some embodiments, the interaction between dimerizing domains can be triggered by the addition of a small molecule. In some embodiments, the two or more polypeptides present in a multi-meric chimeric antigen receptor can associate through non-covalent interactions (e.g., between associations between dimerizing domains). In some embodiments, the two or more polypeptides present in a multi-meric chimeric antigen receptor can be through a covalent interaction (e.g., through a disulfide bond, through an ester bond, through an amide bond, through a thioester bond, or a combination thereof). 
     Multi-Chain Chimeric Antigen Receptors that Include at Least One First Polypeptide Including an Intracellular Signaling Domain and an ITAM 
     Also provided herein are multi-chain chimeric antigen receptors that include at least one first polypeptide including: a transmembrane domain (e.g., any of the transmembrane domains described herein or known in the art); an intracellular signaling domain from a protein selected from the group of 4-1BB, CD27, OX40, CD40, CD28, GITR, DAP-10, DAP-12, CD2, CD5, ICAM-1, CD11a, Lck, TNFR-I, TNFR-II, FasR, CD30, ICOS, LIGHT, NKG2C, and B7-H3; and an ITAM. In some embodiments, the at least one first polypeptide can further include an antigen-binding domain (e.g., any of the antigen-binding domains described herein or known in the art). In some embodiments, the multi-chain chimeric antigen receptor further includes a second polypeptide including an antigen-binding domain (e.g., any of the antigen-binding domains described herein or known in the art) and a transmembrane domain (e.g., any of the transmembrane domains described herein). The antigen specifically bound by the antigen-binding domain in any of these multi-chain chimeric antigen receptors can be any of the antigens described herein or known in the art. In some embodiments, the multi-chain chimeric antigen receptor only binds specifically to a single antigen (e.g., any of the exemplary antigens described herein). In some embodiments, the multi-chain chimeric antigen receptor binds specifically to two different antigens (e.g., any combination of any of the exemplary antigens described herein). In some embodiments, the multi-chain chimeric antigen receptor binds to a tumor antigen. 
     In some embodiments of the multi-chain chimeric antigen receptors, the extracellular antigen-binding domain and the transmembrane domain in the at least one first polypeptide and/or the second polypeptide directly abut each other. In some embodiments of the multi-chain chimeric antigen receptors, 1 to about 500 amino acids (e.g., any of the subranges of this range described herein) are between the extracellular antigen-binding domain and the transmembrane domain in the at least one first polypeptide and/or the second polypeptide. In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain in the at least one first polypeptide and/or the second polypeptide is a sequence from the same endogenous single-chain polypeptide from which the transmembrane domain is derived. In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain of the at least one first polypeptide and/or the second polypeptide is or includes a hinge region sequence of human antibody (e.g., IgG1, IgG2, IgG3, or IgG4). In some embodiments, one or more amino acids between the extracellular antigen-binding domain and the transmembrane domain in the at least one first polypeptide and/or the second polypeptide is or includes a linker sequence (e.g., a non-naturally occurring linker sequence). 
     In some embodiments, any two neighboring domains (e.g., the transmembrane domain, the intracellular signaling domain, and the ITAM) in the at least one first polypeptide can directly abut each other. In some embodiments, any two neighboring domains in the at least one first polypeptide (e.g., the transmembrane domain, the intracellular signaling domain, and the ITAM) can be separated by 1 to 500 amino acids (or any subrange of this range described herein). 
     Some embodiments of the multi-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal or in the C-termnal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the intracellular signaling domain, and the ITAM. In some of these embodiments, one or more amino acids between the transmembrane domain and the intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the intracellular signaling domain or the transmembrane domain is derived. In some embodiments, one or more amino acids between the transmembrane domain and the intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the intracellular signaling domain can directly abut each other. In some of these embodiments, one or more amino acids separating the intracellular signaling domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the intracellular signaling domain or the ITAM is derived. In some embodiments, one or more amino acids between the intracellular signaling domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the intracellular signaling domain and the ITAM directly abut each other. 
     Some embodiments of the multi-chain chimeric antigen receptors described herein, when going in the N-terminal to the C-terminal or in the C-termnal to the N-terminal direction, the at least one first polypeptide includes the transmembrane domain, the ITAM, and the intracellular signaling domain. In some of these embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a sequence from the same endogenous single chain polypeptide from which the transmembrane domain or the ITAM is derived. In some embodiments, one or more amino acids between the transmembrane domain and the ITAM is or includes a linker peptide sequence (e.g., any of the linker peptides sequences described herein or known in the art). In some of these embodiments, the transmembrane domain and the ITAM can directly abut each other. In some of these embodiments, one or more amino acids separating the ITAM and the intracellular signaling domain is or includes a sequence from the same endogenous single chain polypeptide from which the ITAM or the intracellular signaling domain is derived. In some embodiments, one or more amino acids between the ITAM and the intracellular signaling domain is or includes a linker peptide sequence (e.g., any of the linker peptide sequences described herein or known in the art). In some of these embodiments, the ITAM and the intracellular signaling domain directly abut each other. 
     In some embodiments of these multi-chain chimeric antigen receptors, the at least one first polypeptide can further include one or both of: a dimerizing domain (e.g., any dimerizing domain known in the art) and/or a peptide tag (e.g., any peptide tag known in the art). 
     The second polypeptide that can, e.g., include one or more (e.g., two, three, or four) of: an extracellular antigen-binding domain (e.g., any of the antigen-binding domains described herein), a transmembrane domain (e.g., any of the transmembrane domains described herein), a dimerizing domain (e.g., a dimerizing domain that can interact with a dimerizing domain in the at least one first polypeptide in a mammalian cell), one or more intracellular signaling domain (e.g., any of the intracellular signaling domains described herein), and one or more ITAM (e.g., any of the ITAMs described herein). As can be appreciated by those in the art, a pair or each pair of neighboring domains in the second polypeptide can abut each other or can be separated by 1 to about 500 amino acids (e.g., any of the subranges of this range described herein). The one or more amino acids between a pair of neighboring domains in the second polypeptide can be a sequence from an endogenous single-chain polypeptide from which a transmembrane, an intracellular signaling domain, or an ITAM present in the second polypeptide has been derived, or can be or include a linker peptide sequence. In some embodiments, any pair of neighboring domains in the second polypeptide can directly abut each other. 
     As can be appreciated in the art, the two or more polypeptides present in a multi-chain chimeric antigen receptor can associate via pair of domains that interact with each other (through dimerizing domains). In some embodiments, the interaction between dimerizing domains can be triggered by the addition of a small molecule. In some embodiments, the two or more polypeptides present in a multi-meric chimeric antigen receptor can associate through non-covalent interactions (e.g., between associations between dimerizing domains). In some embodiments, the two or more polypeptides present in a multi-meric chimeric antigen receptor can be through a covalent interaction (e.g., through a disulfide bond, through an ester bond, through an amide bond, through a thioester bond, or a combination thereof). 
     Transmembrane Domains 
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain, or portion thereof, from an endogenous polypeptide, where the endogenous polypeptide is selected from the group of: an a chain of a T cell receptor, a β chain of the T cell receptor, a ζ chain of the T cell receptor, CD28 (also known as Tp44), CD3ε, CD3δ, CD3γ, CD33, CD37 (also known as GP52-40 or TSPAN26), CD64 (also known as FCGR1A), CD80 (also known as B7, B7-1, B7.1, BB1, CD28LG, CD28LG1, and LAB7), CD45 (also known as PTPRC, B220, CD45R, GP180, L-CA, LCA, LYS, T200, and protein tyrosine phosphatase, receptor type C), CD4, CD5 (also known as LEU1and T1), CD8α (also known as Leu2, MAL, and p32), CD9 (also known as BTCC-1, DRAP-27, MIC3, MRP-1, TSPAN-29, and TSPAN29), CD16 (also known as FCGR3 andFCG3), CD22 (also known as SIGLEC-2 and SIGLEC2), CD86 (also known as B7-2, B7.2, B70, CD28LG2, and LAB72), CD134 (also known as TNFRSF4, ACT35, RP5-902P8.3, IMD16, OX40, TXGP1L, and tumor necrosis factor receptor superfamily member 4), CD137 (also known as TNFRSF9, 4-1BB, CDw137, ILA, and tumor necrosis factor receptor superfamily member 9), CD27 (also known as S152, S152.LPFS2, T14, TNFRSF7, and Tp55), CD152 (also known as CTLA4, ALPS5, CELIAC3, CTLA-4, GRD4, GSE, IDDM12, and cytotoxic T-lymphocyte associated protein 4), PD1 (also known as PDCD1, CD279, PD-1, SLEB2, hPD-1, hPD-1, hSLE1, and Programmed cell death 1), ICOS (also known as AILIM, CD278, and CVID1), CD272 (also known as BTLA and BTLA1), CD30 (also known as TNFRSF8, D1S166E, and Ki-1), GITR (also known as TNFRSF18, RP5-902P8.2, AITR, CD357, and GITR-D), HVEM (also known as TNFRSF14, RP3-395M20.6, ATAR, CD270, HVEA, HVEM, LIGHTR, and TR2), DAP10, and CD154 (also known as CD40LG, CD40L, HIGM1, IGM, IMD3, T-BAM, TNFSFS, TRAP, gp39, hCD40L, and CD40 ligand). The letters “CD” is the previous sentence stand for “Cluster of Differentiation.” E.g., CD3 stands for “Cluster of Differentiation 3.” In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain, or portion thereof, from an endogenous mammalian (e.g., human) polypeptide (e.g., a mammalian or human homolog of any of the polypeptides listed above). 
     Any transmembrane domain, or portion thereof, that serves to anchor an endogenous polypeptide in a lipid bilayer (e.g., plasma membrane) of a mammalian cell is suitable for use in accordance with compositions and methods disclosed herein. In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain, or portion thereof, from human CD28, e.g., Accession No. P01747, e.g., amino acids 153 to 179 of SEQ ID NO: 5. In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain that is at least 80% (e.g., at least 82%, at least 84%, at least 85%, at least 86%, at least 88%, at least 90%, at least 92%, at least 94%, at least 95%, at least 96%, at least 98%, or at least 99% identical) to amino acids 153 to 179 of SEQ ID NO: 5, or a portion thereof. 
     
       
         
           
               
            
               
                 (Transmembrane domain of human CD28) 
               
               
                 SEQ ID NO: 5 
               
               
                 MLRLLLALNLFPSIQVTGNKILVKQSPMLVAYDNAVNLSCKYSYNLFSRE 
               
               
                   
               
               
                 FRASLHKGLDSAVEVCVVYGNYSQQLQVYSKTGFNCDGKLGNESVTFYLQ 
               
               
                   
               
               
                 NLYVNQTDIYFCKIEVMYPPPYLDNEKSNGTIIHVKGKHLCPSPLFPGPS 
               
               
                   
               
               
                 KPFWVLVVVGGVLACYSLLVTVAFIIFWVRSKRSRLLHSDYMNMTPRRPG 
               
               
                   
               
               
                 PTRKHYQPYAPPRDFAAYRS 
               
            
           
         
       
     
     In some embodiments, transmembrane domain can comprise a sequence at least 80% (e.g., at least 82%, at least 84%, at least 86%, at least 88%, at least 90%, at least 92%, at least 94%, at least 96%, at least 98%, at least 99%, or 100% identical) to SEQ ID NO: 6 (or a portion thereof). 
     
       
         
           
               
            
               
                 (CD8 alpha transmembrane domain) 
               
               
                 SEQ ID NO: 6 
               
               
                 DIYIWAPLAGTCGVLLLSLVITLYC 
               
            
           
         
       
     
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain, or portion thereof, from human CD3, e.g., Accession No. P20963, e.g., amino acids 31 to 51 of SEQ ID NO: 7. In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain that is or includes a sequence that is at least 80% (e.g., at least 82%, at least 84%, at least 85%, at least 86%, at least 88%, at least 90%, at least 92%, at least 94%, at least 95%, at least 96%, at least 98%, or at least 99% identical) to amino acids 31 to 51 of SEQ ID NO: 7. 
     
       
         
           
               
            
               
                 (Transmembrane domain of human CD3) 
               
               
                 SEQ ID NO: 7 
               
               
                 MKWKALFTAAILQAQLPITEAQSFGLLDPKLCYLLDGILFIYGVILTALF 
               
               
                   
               
               
                 LRVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKP 
               
               
                   
               
               
                 QRRKNPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTATK 
               
               
                   
               
               
                 DTYDALHMQALPPR 
               
            
           
         
       
     
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain, or portion thereof, of any one of SEQ ID Nos. 8-14: 
     
       
         
           
               
            
               
                 (SEQ ID NO: 8) 
               
            
           
           
               
               
            
               
                   
                 LGLLVAGVLVLLVSLGVAIHLCC; 
               
               
                   
               
            
           
           
               
            
               
                 (SEQ ID NO: 9) 
               
            
           
           
               
               
            
               
                   
                 VAAILGLGLVLGLLGPLAILLALYLL; 
               
               
                   
               
            
           
           
               
            
               
                 (SEQ ID NO: 10) 
               
            
           
           
               
               
            
               
                   
                 ALIVLGGVAGLLLFIGLGIFFCVRC; 
               
               
                   
               
            
           
           
               
            
               
                 (SEQ ID NO: 11) 
               
            
           
           
               
               
            
               
                   
                 LCYLLDGILFIYGVILTALFLRV; 
               
               
                   
               
            
           
           
               
            
               
                 (SEQ ID NO: 12) 
               
            
           
           
               
               
            
               
                   
                 WVLVVVGGVLACYSLLVTVAFIIFWV; 
               
               
                   
               
            
           
           
               
            
               
                 (SEQ ID NO: 13) 
               
            
           
           
               
               
            
               
                   
                 IYIWAPLAGTCGVLLLSLVITLYC; 
               
               
                   
                 and 
               
               
                   
               
            
           
           
               
            
               
                 (SEQ ID NO: 14) 
               
            
           
           
               
               
            
               
                   
                 ALPAALAVISFLLGLGLGVACVLA. 
               
            
           
         
       
     
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain that is or includes a sequence that is at least 80% (e.g., at least 82%, at least 84%, at least 85%, at least 86%, at least 88%, at least 90%, at least 92%, at least 94%, at least 95%, at least 96%, at least 98%, or at least 99% identical) to any one of SEQ ID Nos. 8-14. 
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain that is or includes a sequence that is at least 80% (e.g., at least 82%, at least 84%, at least 85%, at least 86%, at least 88%, at least 90%, at least 92%, at least 94%, at least 95%, at least 96%, at least 98%, or at least 99% identical, or 100% identical) to SEQ ID NO: 13. 
     
       
         
           
               
            
               
                 (CD8 transmembrane domain) 
               
               
                 SEQ ID NO: 13 
               
               
                 IYIWAPLAGTCGVLLLSLVITLYC 
               
               
                   
               
               
                 (DNA sequence encoding CD8 transmembrane domain) 
               
               
                 SEQ ID NO: 15 
               
               
                 atctatatttgggcacccctggctggaacctgcggagtgctgctgctgtc 
               
               
                   
               
               
                 tctcgtgattacactgtattgc 
               
               
                   
               
               
                 (DNA sequence encoding CD8 alpha transmembrane  
               
               
                 domain) 
               
               
                 SEQ ID NO: 16 
               
               
                 gatatctacatctgggcgcccttggccgggacttgtggggtccttctcct 
               
               
                   
               
               
                 gtcactggttatcaccctttactgc 
               
            
           
         
       
     
     As will be appreciated by those of ordinary skill in the art, certain endogenous polypeptides have two or more isoforms that differ at least in their primary polypeptide sequence. A single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor disclosed herein can include a transmembrane domain that includes a sequence of amino acids from any isoform of an endogenous transmembrane protein (e.g., an endogenous mammalian, e.g., human, transmembrane protein) including, e.g., an isoform (e.g., a human isoform) of: an α chain of a T cell receptor, a β chain of the T cell receptor, a ζ chain of the T cell receptor, CD28, CD3ε, CD3δ, CD3γ, CD33, CD37, CD64, CD80, CD45, CD4, CD5, CD8α, CD9, CD16, CD22, CD86, CD27, CD152, PD1, or CD154. 
     In some embodiments, a transmembrane domain, or portion thereof, of a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to the transmembrane domains from one or more of the following endogenous mammalian (e.g., human) transmembrane proteins: an α chain of a T cell receptor, a β chain of the T cell receptor, a ζ chain of the T cell receptor, CD28, CD3ε, CD3δ, CD3γ, CD33, CD37, CD64, CD80, CD45, CD4, CD5, CD8α, CD9, CD16, CD22, CD86, CD27, CD152, PD1, or CD154. In some embodiments, a transmembrane domain, or portion thereof, of a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a sequence of amino acids having one or more amino acid substitutions, deletions, or additions as compared to the transmembrane domain of an endogenous mammalian (e.g., human) transmembrane protein: an α chain of a T cell receptor, a β chain of the T cell receptor, a ζ chain of the T cell receptor, CD28, CD3ε, CD3δ, CD3γ, CD33, CD37, CD64, CD80, CD45, CD4, CD5, CD8α, CD9, CD16, CD22, CD86, CD27, CD152, PD1, or CD154. 
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a synthetic transmembrane domain. In some cases, a synthetic transmembrane domain can include predominantly hydrophobic residues such as, without limitation, leucine and valine. In some embodiments, a synthetic transmembrane domain includes a triplet of phenylalanine, tryptophan, and valine at each end of the domain. 
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a transmembrane domain that is a chimeric transmembrane domain having portions of a transmembrane domain from two or more endogenous mammalian (e.g., human) transmembrane polypeptides such as, without limitation, an α chain of a T cell receptor, a β chain of the T cell receptor, a ζ chain of the T cell receptor, CD28, CD3ε, CD3δ, CD3γ, CD33, CD37, CD64, CD80, CD45, CD4, CD5, CD8α, CD9, CD16, CD22, CD86, CD27, CD152, PD1, and CD154, such that the two or more portions of transmembrane domains together constitute a functional transmembrane domain. In some embodiments, such a portion of a chimeric transmembrane domain can include one or more amino acid substitutions, deletions, or additions as compared to a corresponding portion of a wild type transmembrane domain. 
     A transmembrane domain can include one, two, three, four, five, six, seven, eight, nine, or ten contiguous amino acid sequences that each traverse a lipid bilayer when present in the corresponding endogenous polypeptide when expressed in a mammalian cell. As is known in the art, a transmembrane domain can, e.g., include at least one (e.g., two, three, four, five, six, seven, eight, nine, or ten) contiguous amino acid sequence (that traverses a lipid bilayer when present in the corresponding endogenous polypeptide when expressed in a mammalian cell) that has α-helical secondary structure in the lipid bilayer. In some embodiments, a transmembrane domain can include two or more contiguous amino acid sequences (that each traverse a lipid bilayer when present in the corresponding endogenous polypeptide when expressed in a mammalian cell) that form a (3-barrel secondary structure in the lipid bilayer. Additional examples and features of transmembrane domains are known in the art. 
     Antigen-Binding Domains 
     In some embodiments of the single-chain chimeric antigen receptors or the multi-chain chimeric antigen receptors, the antigen-binding domain can be selected from a scFv, a scFv-Fc, a VHH domain, a VNAR domain, a (scFv) 2 , and a BiTE. Additional examples of antigen-binding domains that can be used in a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor are known in the art. 
     A single-chain Fv or scFv fragment includes a V H  domain and a V L  domain in a single polypeptide chain. The V H  and V L  are generally linked by a peptide linker. In other examples, the linker can be a single amino acid. In some examples, the linker can be a chemical bond. See, e.g., Pluckthun, Antibodies from  E. coli . In Rosenberg M. &amp; Moore GP. (Eds.), The Pharmacology of Monoclonal Antibodies, Vol. 113, pp. 269-315, Spinger-Verlag, New York, 1994. An exemplary V L  and V H  sequences that can be used in a scFv are shown in SEQ ID NOs: 18 and 21. An exemplary linker that can be used between the V L  and V H  domains in an scFv can be any of the exemplary linkers described herein (e.g., a linker having the sequence of SEQ ID NO: 31). 
     Sc-Fv-Fc fragments include an scFv attached to an Fc domain. For example, an Fc domain can be attached, e.g., to the C-terminus of the scFv. The Fc domain can follow the V L  or V H , depending on the orientation of the variable domains in the scFv. The Fc domain can be any Fc domain known in the art. In some examples, the Fc domain is an IgG1, IgG2, IgG3, or IgG4 Fc domain (e.g., a human IgG1, IgG2, IgG3, or IgG4 Fc domain). 
     BiTEs are antigen-binding domains that include two V L  and two V H  in a single polypeptide that together form two scFvs, which can each bind to different epitopes on the same antigen or each bind to different antigens. See, e.g., Baeuerle et al.,  Curr. Opin. Mol. Ther.  11:22-30, 2009; Wolf et al.,  Drug Discovery Today  10:1237-1244, 2005; and Huehls et al.,  Immunol. Cell Biol.  93:290-296, 2015. 
     A V H H domain is a single monomeric variable antibody domain found in camelids, and a V NAR  domain is a single monomeric variable antibody domain found in cartilaginous fish. V H H domains and V NAR  domains are described in, e.g., Van Audenhove et al.,  EBioMedicine  8:40-48, 2016; Krah et al.,  Immunopharmacol. Immunotoxicol.  38:21-28, 2016; Cromie et al.,  Curr. Top. Med. Chem.  15:2543-2557, 2016; Kijanka et al.,  Nanomedicine  10:161-174, 2015; Kovaleva et al.,  Expert. Opin. Biol. Ther.  14:1527-1539, 2014; De Meyer et al.,  Trends Biotechnol.  32:263-270, 2014; Mujic-Delic et al.,  Trends Pharmacol. Sci.  35:247-255, 2014; Muyldermans,  Ann. Rev. Biochem.  82:775-797, 2013; Vincke et al.,  Methods Mol. Biol.  911:15-26, 2012; Rahbarizadeh et al.,  Immunol. Invest.  40:299-338, 2011; Van Bockstaele et al.,  Curr. Opin. Investig. Drugs  10:1212-1224, 2009; Wesolowski et al.,  Med. Microbiol. Immunol.  198:157-174, 2009; De Genst et al.,  Dev. Comp. Immunol.  30:187-198, 2006; Muyldermans,  J. Biotechnol.  74:277-302, 2001; and Muyldermans et al.,  Trends Biochem. Sci.  26:230-235, 2001. 
     In some embodiments of the multi-chain chimeric antigen receptors, at least two of the polypeptides that make up the multi-chain chimeric antigen receptor can interact together to form an antigen-binding domain. In such embodiments, the antigen-binding domain can be selected from the group of an antigen-binding antibody fragment, a dual-affinity re-targeting antibody (DART), Fab-scFv-Fc, a triomab, a crossmab, an ortho-Fab , IgG-scFv, scFv 2 -Fc, a bi-nanobody, tanden antibody, a DART-Fc, a scFv-HAS-scFv, DNL-Fab 3 , DAF (two-in-one or four-in-one), DutaMab, DT-IgGs knobs-in-holes common LC, knobs-in-holes assembly, Fab-arm exchange antibody, SEEDbody, Triomab, LUZ-Y, scDiabody-Fc, Fcab, la-body, orthogonal Fab, DVD-IgG; IgG(H)-scFv, scFv-(H)IgG; IgG(L)-scFv, scFv-(L)-IgG; IgG (L,H)-Fc, IgG(H)-V, V(H)-IgG; IgG(L)-V, V(L)-IgG; KIH IgG-scFab, 2seFv-IgG; IgG-2scFv, scFv4-Ig, Zybody, DVI-NG; nanobody, nanobody-HSA, a diabody, a TandAb, scDiabody, scDiabody-CH3, charge pair antibody, diabody-CH3, Cov-X-Bod, Triple Body, miniantibody, a DVD-Ig, minibody, a 2-in-1-IgG TriBi minibody, scFv-CH3 KIH, Fab-scFv, scFv-CH-CL-scFv, F(ab′) 2 -scFV 2 , scFv-KIH, tetravalent HCAb, diabody-Fc, tandem scFv-Fc, intrabody, dock and lock bispecific antibody, ImmTAC, HSAbody, scDiabody-HAS, tandem scFv, IgG-IgG; and seFv1-PEG-seFv 2 . 
     Non-limiting examples of an antigen-binding antibody fragments include an FAT fragment, a Fab fragment, a F(ab′) 2  fragment, and a Fab′ fragment. Additional examples of an antigen-binding antibody fragment is an antigen-binding fragment of an IgG (e.g., an antigen-binding fragment of IgG1, IgG2, IgG3, or IgG4) (e.g., an antigen-binding fragment of a human or humanized NG; e.g., human or humanized IgG1, IgG2, IgG3, or IgG4); an antigen-binding fragment of an IgA (e.g., an antigen-binding fragment of IgA1 or IgA2) (e.g., an antigen-binding fragment of a human or humanized IgA, e.g., a human or humanized IgA1 or IgA2); an antigen-binding fragment of an IgD (e.g., an antigen-binding fragment of a human or humanized IgD); an antigen-binding fragment of an IgE (e.g., an antigen-binding fragment of a human or humanized IgE); or an antigen-binding fragment of an IgM (e.g., an antigen-binding fragment of a human or humanized IgM). 
     Examples of DVD-Igs are described, e.g., in DiGiammarino et al.,  Methods Mol. Biol.  899:145-156, 2012; Jakob et al.,  MABs  5:358-363, 2013; and U.S. Pat. Nos. 7,612,181; 8,258,268; 8,586,714; 8,716,450; 8,722,855; 8,735,546; and 8,822,645. Examples of DARTs are described in, e.g., Garber,  Nature Reviews Drug Discovery  13:799-801, 2014. Examples of triomabs, kih IgG with a common LCs, crossmabs, ortho-Fab IgGs, 2-in-1-IgGs, IgG-ScFvs, scFv2-Fcs, bi-nanobodies, tanden antibodies, DART-Fes, scFv-HAS-scFvs, and DNL-Fab3s are described in, e.g., Kontermann et al.,  Drug Discovery Today  20:838-847, 2015. Examples of DAFs (two-in-one or four-in-one), DutaMabs, DT-IgGs, knobs-in-holes common LCs, knobs-in-holes assemblies, charge pair antibodies, Fab-arm exchange antibodies, SEEDbodies, Triomabs, LUZ-Ys, Fcabs, Ukλ,-bodies, orthogonal Fabs, DVD-IgGs, IgG(H)-scFvs, scFv-(H)IgGs, IgG(L)-scFvs, scFv-(L)-IgGs, IgG (L,H)-Fcs, IgG(H)-Vs, V(H)-IgGs, IgG(L)-Vs, V(L)-IgGs, KIH IgG-scFabs, 2scFv-IgGs, IgG-2scFvs, scFv4-Igs, Zybodies, DVI-IgGs, nanobodies, nanobody-HSAs, diabodies, TandAbs, scDiabodies, scDiabody-CH3s, Diabody-CH3s, Triple Bodies, miniantibodies, minibodies, TriBi minibodies, scFv-CH3 KIHs, Fab-scFvs, scFv-CH-CL-scFvs, F(ab′) 2 -scFV2s, scFv-KIHs, Fab-scFv-Fcs, tetravalent HCAbs, scDiabody-Fcs, diabody-Fcs, tandem scFv-Fcs, intrabodies, dock and lock bispecific antibodies, ImmTACs, HSAbodies, scDiabody-HASs, tandem scFvs, IgG-IgGs, Cov-X-Bodies, and scFv1-PEG-scFv2s are described in, e.g., Spiess et al.,  Mol. Immunol.  67:95-106, 2015. 
     Exemplary sequences that encode an anti-CD19 scFv are shown below. 
     
       
         
           
               
            
               
                 (FMC63 V L ) 
               
               
                 SEQ ID NO: 17 
               
               
                 gacatccagatgacccagaccaccagcagcctgagcgccagcctgggcga 
               
               
                   
               
               
                 tagagtgaccatcagctgcagagccagccaggacatcagcaagtacctga 
               
               
                   
               
               
                 actggtatcagcagaaacccgacggcaccgtgaagctgctgatctaccac 
               
               
                   
               
               
                 accagcagactgcacagcggcgtgcccagcagattttctggcagcggctc 
               
               
                   
               
               
                 cggcaccgactacagcctgaccatctccaacctggaacaggaagatatcg 
               
               
                   
               
               
                 ctacctacttctgtcagcaaggcaacaccctgccctacaccttcggcgga 
               
               
                   
               
               
                 ggcaccaagctggaaatcaca 
               
               
                   
               
               
                 (FMC63 V L ) 
               
               
                 SEQ ID NO: 18 
               
               
                 DIQMTQTTSSLSASLGDRVTISCRASQDISKYLNWYQQKPDGTVKLLIYH 
               
               
                   
               
               
                 TSRLHSGVPSRFSGSGSGTDYSLTISNLEQEDIATYFCQQGNTLPYTFGG 
               
               
                   
               
               
                 GTKLEIT 
               
               
                   
               
               
                 ((G 4 S) 3  linker between V L  and V H ) 
               
               
                 SEQ ID NO: 19 
               
               
                 ggcggcggaggatctggcggaggcggaagtggcggagggggatct 
               
               
                   
               
               
                 (FMC63 V H ) 
               
               
                 SEQ ID NO: 20 
               
               
                 gaagtgaaactgcaggaaagcggccctggcctggtggccccatctcagtc 
               
               
                   
               
               
                 tctgagcgtgacctgtaccgtgtccggcgtgtccctgcctgactatggcg 
               
               
                   
               
               
                 tgtcctggatcagacagccccccagaaagggcctggaatggctgggagtg 
               
               
                   
               
               
                 atctggggcagcgagacaacctactacaacagcgccctgaagtcccggct 
               
               
                   
               
               
                 gaccatcatcaaggacaactccaagagccaggtgttcctgaagatgaaca 
               
               
                   
               
               
                 gcctgcagaccgacgacaccgccatctactactgcgccaagcactactac 
               
               
                   
               
               
                 tacggcggcagctacgccatggactactggggccagggcacaagcgtgac 
               
               
                   
               
               
                 cgtgtctagc 
               
               
                   
               
               
                 (FMC63 V H ) 
               
               
                 SEQ ID NO: 21 
               
               
                 EVKLQESGPGLVAPSQSLSVTCTVSGVSLPDYGVSWIRQPPRKGLEWLGV 
               
               
                   
               
               
                 IWGSETTYYNSALKSRLTIIKDNSKSQVFLKMNSLQTDDTAIYYCAKHYY 
               
               
                   
               
               
                 YGGSYAMDYWGQGTSVTVSS 
               
            
           
         
       
     
     Any of the antigen-binding domains described herein can bind to an antigen with a dissociation equilibrium constant (K D ) of less than 1×10 −7  M, less than 1×10 −8 M, less than 1×10 −9  M, less than 1×10 −10 M, less than 1×10 −11  M, less than 1×10 12  M, or less than 1×10 −13  M. In some embodiments, the antigen-binding protein complexes provided herein can bind to a first and/or second antigen with a K D  of about 1×10 −4  M to about 1×10 −6  M, about 1×10 −5  M to about 1×10 −7 M, about 1×10 −6  M to about 1×10 −8 M, about 1×10 −7  M to about 1×10 −9  M, about 1×10 −8  M to about 1×10 −10  M, or about 1×10 −9  M to about 1×10 −11  M (inclusive). A variety of different methods known in the art can be used to determine the K D  value of an antigen-binding domain (e.g., an electrophoretic mobility shift assay, a filter binding assay, surface plasmon resonance, and a biomolecular binding kinetics assay, etc.). 
     Linker Peptide Sequences 
     In some embodiments, any two domains of single-chain chimeric antigen receptor, or any two neighboring domains within of a single-chain polypeptide that makes up a multi-chain chimeric antigen receptor (e.g., the at least one first polypeptide and second polypeptide) can be separated by a sequence that includes one or more (e.g., one, two, three, four, or five) linker peptide sequences. The length of a linker peptide sequence can be about 2 amino acids to about 100 amino acids, about 2 amino acids to about 95 amino acids, about 2 amino acids to about 90 amino acids, about 2 amino acids to about 85 amino acids, about 2 amino acids to about 80 amino acids, about 2 amino acids to about 75 amino acids, about 2 amino acids to about 70 amino acids, about 2 amino acids to about 65 amino acids, about 2 amino acids to about 60 amino acids, about 2 amino acids to about 55 amino acids, about 2 amino acids to about 50 amino acids, about 2 amino acids to about 45 amino acids, about 2 amino acids to about 40 amino acids, about 2 amino acids to about 35 amino acids, about 2 amino acids to about 30 amino acids, about 2 amino acids to about 25 amino acids, about 2 amino acids to about 20 amino acids, about 2 amino acids to about 15 amino acids, about 2 amino acids to about 14 amino acids, about 2 amino acids to about 12 amino acids, about 2 amino acids to about 10 amino acids, about 2 amino acids to about 8 amino acids, about 2 amino acids to about 6 amino acids, about 2 amino acids to about 4 amino acids, about 4 amino acids to about 100 amino acids, about 4 amino acids to about 95 amino acids, about 4 amino acids to about 90 amino acids, about 4 amino acids to about 85 amino acids, about 4 amino acids to about 80 amino acids, about 4 amino acids to about 75 amino acids, about 4 amino acids to about 70 amino acids, about 4 amino acids to about 65 amino acids, about 4 amino acids to about 60 amino acids, about 4 amino acids to about 55 amino acids, about 4 amino acids to about 50 amino acids, about 4 amino acids to about 45 amino acids, about 4 amino acids to about 40 amino acids, about 4 amino acids to about 35 amino acids, about 4 amino acids to about 30 amino acids, about 4 amino acids to about 25 amino acids, about 4 amino acids to about 20 amino acids, about 4 amino acids to about 15 amino acids, about 4 amino acids to about 14 amino acids, about 4 amino acids to about 12 amino acids, about 4 amino acids to about 10 amino acids, about 4 amino acids to about 8 amino acids, about 4 amino acids to about 6 amino acids, about 6 amino acids to about 100 amino acids, about 6 amino acids to about 95 amino acids, about 6 amino acids to about 90 amino acids, about 6 amino acids to about 85 amino acids, about 6 amino acids to about 80 amino acids, about 6 amino acids to about 75 amino acids, about 6 amino acids to about 70 amino acids, about 6 amino acids to about 65 amino acids, about 6 amino acids to about 60 amino acids, about 6 amino acids to about 55 amino acids, about 6 amino acids to about 50 amino acids, about 6 amino acids to about 45 amino acids, about 6 amino acids to about 40 amino acids, about 6 amino acids to about 35 amino acids, about 6 amino acids to about 30 amino acids, about 6 amino acids to about 25 amino acids, about 6 amino acids to about 20 amino acids, about 6 amino acids to about 15 amino acids, about 6 amino acids to about 14 amino acids, about 6 amino acids to about 12 amino acids, about 6 amino acids to about 10 amino acids, about 6 amino acids to about 8 amino acids, about 8 amino acids to about 100 amino acids, about 8 amino acids to about 95 amino acids, about 8 amino acids to about 90 amino acids, about 8 amino acids to about 85 amino acids, about 8 amino acids to about 80 amino acids, about 8 amino acids to about 75 amino acids, about 8 amino acids to about 70 amino acids, about 8 amino acids to about 65 amino acids, about 8 amino acids to about 60 amino acids, about 8 amino acids to about 55 amino acids, about 8 amino acids to about 50 amino acids, about 8 amino acids to about 45 amino acids, about 8 amino acids to about 40 amino acids, about 8 amino acids to about 35 amino acids, about 8 amino acids to about 30 amino acids, about 8 amino acids to about 25 amino acids, about 8 amino acids to about 20 amino acids, about 8 amino acids to about 15 amino acids, about 8 amino acids to about 14 amino acids, about 8 amino acids to about 12 amino acids, about 8 amino acids to about 10 amino acids, about 10 amino acids to about 100 amino acids, about 10 amino acids to about 95 amino acids, about 10 amino acids to about 90 amino acids, about 10 amino acids to about 85 amino acids, about 10 amino acids to about 80 amino acids, about 10 amino acids to about 75 amino acids, about 10 amino acids to about 70 amino acids, about 10 amino acids to about 65 amino acids, about 10 amino acids to about 60 amino acids, about 10 amino acids to about 55 amino acids, about 10 amino acids to about 50 amino acids, about 10 amino acids to about 45 amino acids, about 10 amino acids to about 40 amino acids, about 10 amino acids to about 35 amino acids, about 10 amino acids to about 30 amino acids, about 10 amino acids to about 25 amino acids, about 10 amino acids to about 20 amino acids, about 10 amino acids to about 15 amino acids, about 10 amino acids to about 14 amino acids, about 10 amino acids to about 12 amino acids, about 12 amino acids to about 100 amino acids, about 12 amino acids to about 95 amino acids, about 12 amino acids to about 90 amino acids, about 12 amino acids to about 85 amino acids, about 12 amino acids to about 80 amino acids, about 12 amino acids to about 75 amino acids, about 12 amino acids to about 70 amino acids, about 12 amino acids to about 65 amino acids, about 12 amino acids to about 60 amino acids, about 12 amino acids to about 55 amino acids, about 12 amino acids to about 50 amino acids, about 12 amino acids to about 45 amino acids, about 12 amino acids to about 40 amino acids, about 12 amino acids to about 35 amino acids, about 12 amino acids to about 30 amino acids, about 12 amino acids to about 25 amino acids, about 12 amino acids to about 20 amino acids, about 12 amino acids to about 15 amino acids, about 12 amino acids to about 14 amino acids, about 15 amino acids to about 100 amino acids, about 15 amino acids to about 95 amino acids, about 15 amino acids to about 90 amino acids, about 15 amino acids to about 85 amino acids, about 15 amino acids to about 80 amino acids, about 15 amino acids to about 75 amino acids, about 15 amino acids to about 70 amino acids, about 15 amino acids to about 65 amino acids, about 15 amino acids to about 60 amino acids, about 15 amino acids to about 55 amino acids, about 15 amino acids to about 50 amino acids, about 15 amino acids to about 45 amino acids, about 15 amino acids to about 40 amino acids, about 15 amino acids to about 35 amino acids, about 15 amino acids to about 30 amino acids, about 15 amino acids to about 25 amino acids, about 15 amino acids to about 20 amino acids, about 20 amino acids to about 100 amino acids, about 20 amino acids to about 95 amino acids, about 20 amino acids to about 90 amino acids, about 20 amino acids to about 85 amino acids, about 20 amino acids to about 80 amino acids, about 20 amino acids to about 75 amino acids, about 20 amino acids to about 70 amino acids, about 20 amino acids to about 65 amino acids, about 20 amino acids to about 60 amino acids, about 20 amino acids to about 55 amino acids, about 20 amino acids to about 50 amino acids, about 20 amino acids to about 45 amino acids, about 20 amino acids to about 40 amino acids, about 20 amino acids to about 35 amino acids, about 20 amino acids to about 30 amino acids, about 20 amino acids to about 25 amino acids, about 20 amino acids to about 100 amino acids, about 20 amino acids to about 95 amino acids, about 20 amino acids to about 90 amino acids, about 20 amino acids to about 85 amino acids, about 20 amino acids to about 80 amino acids, about 20 amino acids to about 75 amino acids, about 20 amino acids to about 70 amino acids, about 20 amino acids to about 65 amino acids, about 20 amino acids to about 60 amino acids, about 20 amino acids to about 55 amino acids, about 20 amino acids to about 50 amino acids, about 20 amino acids to about 45 amino acids, about 20 amino acids to about 40 amino acids, about 20 amino acids to about 35 amino acids, about 20 amino acids to about 30 amino acids, about 20 amino acids to about 25 amino acids, about 25 amino acids to about 100 amino acids, about 25 amino acids to about 95 amino acids, about 25 amino acids to about 90 amino acids, about 25 amino acids to about 85 amino acids, about 25 amino acids to about 80 amino acids, about 25 amino acids to about 75 amino acids, about 25 amino acids to about 70 amino acids, about 25 amino acids to about 65 amino acids, about 25 amino acids to about 60 amino acids, about 25 amino acids to about 55 amino acids, about 25 amino acids to about 50 amino acids, about 25 amino acids to about 45 amino acids, about 25 amino acids to about 40 amino acids, about 25 amino acids to about 35 amino acids, about 25 amino acids to about 30 amino acids, about 30 amino acids to about 100 amino acids, about 30 amino acids to about 95 amino acids, about 30 amino acids to about 90 amino acids, about 30 amino acids to about 85 amino acids, about 30 amino acids to about 80 amino acids, about 30 amino acids to about 75 amino acids, about 30 amino acids to about 70 amino acids, about 30 amino acids to about 65 amino acids, about 30 amino acids to about 60 amino acids, about 30 amino acids to about 55 amino acids, about 30 amino acids to about 50 amino acids, about 30 amino acids to about 45 amino acids, about 30 amino acids to about 40 amino acids, about 30 amino acids to about 35 amino acids, about 35 amino acids to about 100 amino acids, about 35 amino acids to about 95 amino acids, about 35 amino acids to about 90 amino acids, about 35 amino acids to about 85 amino acids, about 35 amino acids to about 80 amino acids, about 35 amino acids to about 75 amino acids, about 35 amino acids to about 70 amino acids, about 35 amino acids to about 65 amino acids, about 35 amino acids to about 60 amino acids, about 35 amino acids to about 55 amino acids, about 35 amino acids to about 50 amino acids, about 35 amino acids to about 45 amino acids, about 35 amino acids to about 40 amino acids, about 40 amino acids to about 100 amino acids, about 40 amino acids to about 95 amino acids, about 40 amino acids to about 90 amino acids, about 40 amino acids to about 85 amino acids, about 40 amino acids to about 80 amino acids, about 40 amino acids to about 75 amino acids, about 40 amino acids to about 70 amino acids, about 40 amino acids to about 65 amino acids, about 40 amino acids to about 60 amino acids, about 40 amino acids to about 55 amino acids, about 40 amino acids to about 50 amino acids, about 40 amino acids to about 45 amino acids, about 45 amino acids to about 100 amino acids, about 45 amino acids to about 95 amino acids, about 45 amino acids to about 90 amino acids, about 45 amino acids to about 85 amino acids, about 45 amino acids to about 80 amino acids, about 45 amino acids to about 75 amino acids, about 45 amino acids to about 70 amino acids, about 45 amino acids to about 65 amino acids, about 45 amino acids to about 60 amino acids, about 45 amino acids to about 55 amino acids, about 45 amino acids to about 50 amino acids, about 50 amino acids to about 100 amino acids, about 50 amino acids to about 95 amino acids, about 50 amino acids to about 90 amino acids, about 50 amino acids to about 85 amino acids, about 50 amino acids to about 80 amino acids, about 50 amino acids to about 75 amino acids, about 50 amino acids to about 70 amino acids, about 50 amino acids to about 65 amino acids, about 50 amino acids to about 60 amino acids, about 50 amino acids to about 55 amino acids, about 55 amino acids to about 100 amino acids, about 55 amino acids to about 95 amino acids, about 55 amino acids to about 90 amino acids, about 55 amino acids to about 85 amino acids, about 55 amino acids to about 80 amino acids, about 55 amino acids to about 75 amino acids, about 55 amino acids to about 70 amino acids, about 55 amino acids to about 65 amino acids, about 55 amino acids to about 60 amino acids, about 60 amino acids to about 100 amino acids, about 60 amino acids to about 95 amino acids, about 60 amino acids to about 90 amino acids, about 60 amino acids to about 85 amino acids, about 60 amino acids to about 80 amino acids, about 60 amino acids to about 75 amino acids, about 60 amino acids to about 70 amino acids, about 60 amino acids to about 65 amino acids, about 65 amino acids to about 100 amino acids, about 65 amino acids to about 95 amino acids, about 65 amino acids to about 90 amino acids, about 65 amino acids to about 85 amino acids, about 65 amino acids to about 80 amino acids, about 65 amino acids to about 75 amino acids, about 65 amino acids to about 70 amino acids, about 70 amino acids to about 100 amino acids, about 70 amino acids to about 95 amino acids, about 70 amino acids to about 90 amino acids, about 70 amino acids to about 85 amino acids, about 70 amino acids to about 80 amino acids, about 70 amino acids to about 75 amino acids, about 75 amino acids to about 100 amino acids, about 75 amino acids to about 95 amino acids, about 75 amino acids to about 90 amino acids, about 75 amino acids to about 85 amino acids, about 75 amino acids to about 80 amino acids, about 80 amino acids to about 100 amino acids, about 80 amino acids to about 95 amino acids, about 80 amino acids to about 90 amino acids, about 80 amino acids to about 85 amino acids, about 85 amino acids to about 100 amino acids, about 85 amino acids to about 95 amino acids, about 85 amino acids to about 90 amino acids, about 90 amino acids to about 100 amino acids, about 90 amino acids to about 95 amino acids, or about 95 amino acids to about 100 amino acids. 
     A linker peptide sequence can be or include a non-naturally occurring sequence (e.g., a synthetic sequence). In some embodiments, a linker peptide sequence can include a sequence from a naturally occurring polypeptide (e.g., a domain). In some embodiments of any of the linker peptide sequences described herein, the linker peptide sequence is a flexible sequence (e.g., does not form an alpha alpha-helix or a beta-strand). In some embodiments of any of the linker peptide sequences described herein, the linker peptide sequence (or a portion thereof) forms an alpha-helix. In some embodiments of any of the linker peptides sequences described herein, the linker peptide sequence (or a portion thereof) forms a beta-strand. 
     In some embodiments, a linker peptide sequence can include one or more of the following amino acid sequences: GSGSGSGSGS (SEQ ID NO: 22), GSGSGSGS (SEQ ID NO: 23), or RSGSGSGS (SEQ ID NO: 24). In some embodiments, linker peptide sequence can be encoded by one or more of the following nucleic acid sequences: 
                    (SEQ ID NO: 25)                         GGATCCGGCAGCGGATCTGGCAGTGGAAGC,                             (SEQ ID NO: 26)                         GGATCTGGCTCTGGAAGCGGCAGC,                             (SEQ ID NO: 27)                         AGATCCGGATCTGGAAGTGGCTCC,           or                             (SEQ ID NO: 28)                         GGAAGTGGATCTGGGAGCGGCTCT.            
In some embodiments, a linker peptide sequence can include one or more (e.g., two, three, or four) copies of any one of SEQ ID NOs: 22-24, e.g., in tandem.
 
     In some embodiments, a linker peptide sequence can be or can include one or more of SEQ ID NO: 23, 24, or 31. In some embodiments, a linker peptide sequence can be or include GS (which can, e.g., be encoded by the DNA sequence of ggatcc). 
     
       
         
           
               
               
            
               
                   
                 (DNA sequence encoding the exemplary linker 
               
               
                   
                 peptide sequence of SEQ ID NO: 23) 
               
            
           
           
               
            
               
                 SEQ ID NO: 29 
               
            
           
           
               
               
            
               
                   
                 ggatcaggcagtggctctggcagc 
               
               
                   
               
               
                   
                 (DNA sequence encoding the exemplary linker 
               
               
                   
                 peptide sequence of SEQ ID NO: 24) 
               
            
           
           
               
            
               
                 SEQ ID NO: 30 
               
            
           
           
               
               
            
               
                   
                 ggatctggaagtggctcc 
               
               
                   
               
               
                   
                 (DNA sequence encoding the exemplary linker 
               
               
                   
                 peptide sequence of SEQ ID NO: 23) 
               
            
           
           
               
            
               
                 SEQ ID NO: 28 
               
            
           
           
               
               
            
               
                   
                 ggaagtggatctgggagcggctct 
               
               
                   
               
               
                   
                 ((G4S) 3  linker peptide sequence) 
               
            
           
           
               
            
               
                 SEQ ID NO: 31 
               
            
           
           
               
               
            
               
                   
                 GGGGSGGGGSGGGGS 
               
            
           
         
       
     
     Additional examples of linker peptide sequences that can be used in the present single-chain chimeric antigen receptors and multi-chain chimeric antigen receptors are known in the art. 
     Antigens 
     In some embodiments, an antigen-binding domain described herein can bind to a single antigen (e.g., any of the exemplary antigens described herein or known in the art). In some embodiments, an antigen-binding domain described herein can bind to two or more different antigens (e.g., two or more of any of the exemplary antigens described herein or known in the lo art). Non-limiting examples of antigens include: HER2, A33 antigen, 9-0-acetyl-GD3, CA19-9 marker, BhCG CA-125 marker, carboanhydrase IX (MN/CA IX), calreticulin, CCR5, CCR8, CD2, CD3, CD5, CD16, CD19, CD20, CD22, CD24, CD25, CD27, CD28, CD30, CD33, CD38, CD40L, CD44, CD44V6, CD63, CD70, CD84, CD96, CD100, CC123, CD133, CD138, CD150, CD152 (CTLA-4), CD160, CRTAM, CS1 (CD319), DNAM-1 (CD226), CD229, CD244, CD272 (BTLA), CD274 (PDL-1, B7H1), CD279 (PD-1), CD319, CD352, CRTAM (CD355), CD358, DR3, GITR (TNFRSF 18), HVEM, ICOS, LIGHT, LTBR, OX40, activating forms of KIR, NKG2C, NKG2D, NKG2E, one or more natural cytotoxicity receptors, NTB-A, PEN-5, carcinoma embryonic antigen (CEA; CD66e), desmoglein 4, E-cadherin neoepitope, endosialin, ephrin A2 (EphA2), epidermal growth factor receptor (EGFR), epithelial cell adhesion molecule (EpCAM), fucosyl GM1, GD2, GD3, GM2, ganglioside GM3, Globo H, glycoprotein 100, HER2/neu, HER3, HER4, insulin-like growth factor receptor 1, Lewis-Y, LG S  Ly-6, melanoma-specific chondroitin-sulfate proteoglycan (MCSCP), mesothelin, MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5 b , MUC7, MUC16, Mullerian inhibitory substance (MIS) receptor type II, plasma cell antigen, poly SA, PSCA, PSMA, sonic hedgehog (SHH), SAS, STEAP, sTn antigen, TNF-α precursor, 2B4 (CD244), β2-integrins, KIR, KIR2DL1, KIR2DL2, KIR2DL3, KIR3DL2, KIR-L, KLRGI, LAIR-1, NKG2A, NKR-P IA, Siglec-3, Siglec-7, Siglec-9, TCRa, TCRB, TCR5y, TIM1, LAG3, LAIR1, PD-1H, TIGIT, TIM2, and TIM3. 
     In some embodiments, the antigen-binding domain described herein can specifically bind to antigen selected from the group of: MAGE, MUC16, CD19, WT-1, CD22, LI-CAM, ROR-1, CEA, 4-1BB, ETA, 5T4, adenocarcinoma antigen, alpha-fetoprotein (AFP), BAFF, B-lymphoma cell, C242 antigen, CA-125, carbonic anhydrase 9 (CA-IX), C-MET, CCR4, CD152, CD20, CD125 CD200, CD221, CD23 (IgE receptor), CD28, CD30 (TNFRSF8), CD33, CD4, CD40, CD44 v6, CD51, CD52, CD56, CD74, CD80, CEA, CNT0888, CTLA-4, DRS, EGFR, EpCAM, CD3, FAP, fibronectin extra domain-B, folate receptor 1, GD2, GD3 ganglioside, glycoprotein 75, GPNMB, HER2/neu, HGF, human scatter factor receptor kinase, IGF-1 receptor, IGF-I, IgG1, IL-13, IL-6, insulin-like growth factor I receptor, integrin α5β1, integrin αvβ3, MORAb-009, MS4A1, MUC1, mucin CanAg, N-glycolylneuraminic acid, NPC-1C, PDGF-R a, PDL192, phosphatidylserine, prostatic carcinoma cells, RANKL, RON, SCH 900105, SDC1, SLAMF7, TAG-72, tenascin C, TGF beta 2, TGF-β, TRAIL-R1, TRAIL-R2, tumor antigen CTAA16.88, VEGF-A, VEGFR-1, VEGFR2, and vimentin. 
     Additional examples of antigens are known in the art. 
     Intracellular Signaling Domains 
     An example of an intracellular signaling domain is the intracellular signaling domain of Lck (also variously known as lymphocyte-specific protein tyrosine kinase, LCK proto-oncogene, Src family tyrosine kinase, IMD22, LSK, YT16, p561ck, or pp581ck). Lck is a member of the Src family of tyrosine kinases that is found in lymphocytes. Lck phosphorylates tyrosine residues of various proteins involved in the intracellular signaling pathways of lymphocytes. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from human Lck polypeptide. An exemplary polypeptide sequence of a human Lck (e.g., UniProt Protein Accession: P06239, found at URL www.uniprot.org/uniprot/P06239) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 32. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 32, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 32. 
     
       
         
           
               
            
               
                 (Human Lck with an exemplary intracellular 
               
               
                 signaling domain underlined) 
               
               
                 SEQ ID NO: 32 
               
               
                 MGCGCSSHPEDDWMENIDVCENCHYPIVPLDGKGTLLIRNGSEVRDPLVT 
               
               
                   
               
               
                 YEGSNPPASPLQDNLVIALHSYEPSHDGDLGFEKGEQLRILEQSGEWWKA 
               
               
                   
               
               
                 QSLTTGQEGFIPFNFVAKANSLEPEPWFFKNLSRKDAERQLLAPGNTHGS 
               
               
                   
               
               
                 FLIRESESTAGSFSLSVRDFDQNQGEVVKHYKIRNLDNGGFYISPRITFP 
               
               
                   
               
               
                 GLHELVRHYTNASDGLCTRLSRPCQTQKPQKPWWEDEWEVPRET   LKLVER     
               
               
                   
               
               
                 
                   
                     LGAGQFGEVWMGYYNGHTKVAVKSLKQGSMSPDAFLAEANLMKQLQHQRL 
                   
                 
               
               
                   
               
               
                 
                   
                     VRLYAVVTQEPIYIITEYMENGSLVDFLKTPSGIKLTINKLLDMAAQIAE 
                   
                 
               
               
                   
               
               
                 
                   
                     GMAFIEERNYIHRDLRAANILVSDTLSCKIADFGLARLIEDNEYTAREGA 
                   
                 
               
               
                   
               
               
                 
                   
                     KFPIKWTAPEAINYGTFTIKSDVWSFGILLTEIVTHGRIPYPGMTNPEVI 
                   
                 
               
               
                   
               
               
                     QNLERGYRMVRPDNCPEELYQLMRLCWKERPEDRPTFDYLRSVLEDFF   TA 
               
               
                   
               
               
                 TEGQYQPQP 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from mouse Lck polypeptide. An exemplary polypeptide sequence of a mouse Lck (e.g., a polypeptide as shown in UniProt Protein Accession: P06240, found at URL www.uniprot.org/uniprot/P06240) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 33. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 33, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 33. 
     
       
         
           
               
            
               
                 (Mouse Lck polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
               
                 SEQ ID NO: 33 
               
               
                 MGCVCSSNPEDDWMENIDVCENCHYPIVPLDSKISLPIRNGSEVRDPLVT 
               
               
                   
               
               
                 YEGSLPPASPLQDNLVIALHSYEPSHDGDLGFEKGEQLRILEQSGEWWKA 
               
               
                   
               
               
                 QSLTTGQEGFIPFNFVAKANSLEPEPWFFKNLSRKDAERQLLAPGNTHGS 
               
               
                   
               
               
                 FLIRESESTAGSFSLSVRDFDQNQGEVVKHYKIRNLDNGGFYISPRITFP 
               
               
                   
               
               
                 GLHDLVRHYTNASDGLCTKLSRPCQTQKPQKPWWEDEWEVPRET   LKLVER     
               
               
                   
               
               
                 
                   
                     LGAGQFGEVWMGYYNGHTKVAVKSLKQGSMSPDAFLAEANLMKQLQHPRL 
                   
                 
               
               
                   
               
               
                 
                   
                     VRLYAVVTQEPIYIITEYMENGSLVDFLKTPSGIKLNVNKLLDMAAQIAE 
                   
                 
               
               
                   
               
               
                 
                   
                     GMAFIEEQNYIHRDLRAANILVSDTLSCKIADFGLARLIEDNEYTAREGA 
                   
                 
               
               
                   
               
               
                 
                   
                     KFPIKWTAPEAINYGTFTIKSDVWSFGILLTEIVTHGRIPYPGMTNPEVI 
                   
                 
               
               
                   
               
               
                     QNLERGYRMVRPDNCPEELYHLMMLCWKERPEDRPTFDYLRSVLDDFF   TA 
               
               
                   
               
               
                 TEGQYQPQP 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from FasR polypeptide (also variously known as Fas receptor, ALPS1A, APO-1, APT1, CD95, FAS1, FASTM, TNFRSF6, or Fas cell surface death receptor). The Fas receptor is encoded by the FasR gene, and is a death receptor on the surface of cells that leads to apoptosis. 
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from human FasR polypeptide. An exemplary polypeptide sequence of a human FasR (e.g., UniProt Protein Accession: P25445, found at URL www.uniprot.org/uniprot/P25445) with an exemplary cytoplasmic signaling domain underlined is SEQ ID NO: 34. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 34, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 34. 
     
       
         
           
               
            
               
                 (Human FasR polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
               
                 SEQ ID NO: 34 
               
               
                 MLGIWTLLPLVLTSVARLSSKSVNAQVTDINSKGLELRKTVTTVETQNLE 
               
               
                   
               
               
                 GLHHDGQFCHKPCPPGERKARDCTVNGDEPDCVPCQEGKEYTDKAHFSSK 
               
               
                   
               
               
                 CRRCRLCDEGHGLEVEINCTRTQNTKCRCKPNFFCNSTVCEHCDPCTKCE 
               
               
                   
               
               
                 HGIIKECTLTSNTKCKEEGSRSNLGWLCLLLLPIPLIVWV   KRKEVQKTCR     
               
               
                   
               
               
                 
                   
                     KHRKENQGSHESPTLNPETVAINLSDVDLSKYITTIAGVMTLSQVKGFVR 
                   
                 
               
               
                   
               
               
                 
                   
                     KNGVNEAKIDEIKNDNVQDTAEQKVQLLRNWHQLHGKKEAYDTLIKDLKK 
                   
                 
               
               
                   
               
               
                 
                   
                     ANLCTLAEKIQTIILKDITSDSENSNFRNEIQSLV 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain of mouse FasR polypeptide. An exemplary polypeptide sequence of a mouse FasR (e.g., a polypeptide as shown in UniProt Protein Accession: P25446, found at URL www.uniprot.org/uniprot/P25446) with an exemplary cytoplasmic signaling domain underlined is SEQ ID NO: 35. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 35, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 35. 
     
       
         
           
               
            
               
                 (Mouse FasR polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
               
                 SEQ ID NO: 35 
               
               
                 MLWIWAVLPLVLAGSQLRVHTQGTNSISESLKLRRRVRETDKNCSEGLYQ 
               
               
                   
               
               
                 GGPFCCQPCQPGKKKVEDCKMNGGTPTCAPCTEGKEYMDKNHYADKCRRC 
               
               
                   
               
               
                 TLCDEEHGLEVETNCTLTQNTKCKCKPDFYCDSPGCEHCVRCASCEHGTL 
               
               
                   
               
               
                 EPCTATSNTNCRKQSPRNRLWLLTILVLLIPLVFIYRKY   RKRKCWKRRQD     
               
               
                   
               
               
                 
                   
                     DPESRTSSRETIPMNASNLSLSKYIPRIAEDMTIQEAKKFARENNIKEGK 
                   
                 
               
               
                   
               
               
                 
                   
                     IDEIMHDSIQDTAEQKVQLLLCWYQSHGKSDAYQDLIKGLKKAECRRTLD 
                   
                 
               
               
                   
               
               
                 
                   
                     KFQDMVQKDLGKSTPDTGNENEGQCLE 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain that is a domain from TNFR-I (also variously known as tumor necrosis factor receptor 1, TNFRSF1A, CD120a, FPF, MS5, TBP1, TNF-R, TNF-R-I, TNF-R55, TNFAR, TNFR1, TNFR1-d2, TNFR55, TNFR60, p55, p55-R, p60, tumor necrosis factor receptor superfamily member 1A, or TNF receptor superfamily member 1A). TNFR-I is a membrane receptor that binds tumor necrosis factor-alpha (TNFa). In some embodiments, an intracellular signaling domain can be an intracellular signaling domain of human TNFR-I polypeptide. An exemplary polypeptide sequence of a human TNFR-I (e.g., UniProt Protein Accession: P19438, found at URL www.uniprot.org/uniprot/P19438) with an exemplary cytoplasmic signaling domain underlined is SEQ ID NO: 36. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 36, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 36. 
     
       
         
           
               
            
               
                 (Human TNFR-I polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
               
                 SEQ ID NO: 36 
               
               
                 MGLSTVPDLLLPLVLLELLVGIYPSGVIGLVPHLGDREKRDSVCPQGKYI 
               
               
                   
               
               
                 HPQNNSICCTKCHKGTYLYNDCPGPGQDTDCRECESGSFTASENHLRHCL 
               
               
                   
               
               
                 SCSKCRKEMGQVEISSCTVDRDTVCGCRKNQYRHYWSENLFQCFNCSLCL 
               
               
                   
               
               
                 NGTVHLSCQEKQNTVCTCHAGFFLRENECVSCSNCKKSLECTKLCLPQIE 
               
               
                   
               
               
                 NVKGTEDSGTTVLLPLVIFFGLCLLSLLFIGLMY   RYQRWKSKLYSIVCGK     
               
               
                   
               
               
                 
                   
                     STPEKEGELEGTTTKPLAPNPSFSPTPGFTPTLGFSPVPSSTFTSSSTYT 
                   
                 
               
               
                   
               
               
                 
                   
                     PGDCPNFAAPRREVAPPYQGADPILATALASDPIPNPLQKWEDSAHKPQS 
                   
                 
               
               
                   
               
               
                 
                   
                     LDTDDPATLYAVVENVPPLRWKEFVRRLGLSDHEIDRLELQNGRCLREAQ 
                   
                 
               
               
                   
               
               
                 
                   
                     YSMLATWRRRTPRREATLELLGRVLRDMDLLGCLEDIEEALCGPAALPPA 
                   
                 
               
               
                   
               
               
                 
                   
                     PSLLR 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular domain from a mouse TNFR-I polypeptide. An exemplary polypeptide sequence of a mouse TNFR-I (e.g., a polypeptide as shown in UniProt Protein Accession: P25118, found at URL www.uniprot.org/uniprot/P25118) with an exemplary cytoplasmic signaling domain underlined is SEQ ID NO: 37. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 37, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 37. 
     
       
         
           
               
            
               
                 (Mouse TNFR-I polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
               
                 SEQ ID NO: 37 
               
               
                 MGLPTVPGLLLSLVLLALLMGIHPSGVTGLVPSLGDREKRDSLCPQGKYV 
               
               
                   
               
               
                 HSKNNSICCTKCHKGTYLVSDCPSPGRDTVCRECEKGTFTASQNYLRQCL 
               
               
                   
               
               
                 SCKTCRKEMSQVEISPCQADKDTVCGCKENQFQRYLSETHFQCVDCSPCF 
               
               
                   
               
               
                 NGTVTIPCKETQNTVCNCHAGFFLRESECVPCSHCKKNEECMKLCLPPPL 
               
               
                   
               
               
                 ANVTNPQDSGTAVLLPLVILLGLCLLSFIFISLMC   RYPRWRPEVYSIICR     
               
               
                   
               
               
                 
                   
                     DPVPVKEEKAGKPLTPAPSPAFSPTSGFNPTLGFSTPGFSSPVSSTPISP 
                   
                 
               
               
                   
               
               
                 
                   
                     IFGPSNWHFMPPVSEVVPTQGADPLLYESLCSVPAPTSVQKWEDSAHPQR 
                   
                 
               
               
                   
               
               
                 
                   
                     PDNADLAILYAVVDGVPPARWKEFMRFMGLSEHEIERLEMQNGRCLREAQ 
                   
                 
               
               
                   
               
               
                 
                   
                     YSMLEAWRRRTPRHEDTLEVVGLVLSKMNLAGCLENILEALRNPAPSSTT 
                   
                 
               
               
                   
               
               
                 
                   
                     RLPR 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from TNFR-II (also variously known as tumor necrosis factor receptor 2, TNFRSF1B, CD120b, TBPII, TNF-R-II, TNF-R75, TNFBR, TNFR1B, TNFR2, TNFR80, p75, p75TNFR, tumor necrosis factor receptor superfamily member 1B, or TNF receptor superfamily member 1B). TNFR-II is a membrane receptor that binds tumor necrosis factor-alpha (TNFa). In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human TNFR-II polypeptide. An exemplary polypeptide sequence of a human TNFR-II (e.g., UniProt Protein Accession: P20333, found at URL www.uniprot.org/uniprot/P20333) with an exemplary cytoplasmic signaling domain underlined is SEQ ID NO: 38. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 38, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 38. 
     
       
         
           
               
            
               
                 (Human TNFR-II polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
               
                 SEQ ID NO: 38 
               
               
                 MAPVAVWAALAVGLELWAAAHALPAQVAFTPYAPEPGSTCRLREYYDQTA 
               
               
                   
               
               
                 QMCCSKCSPGQHAKVFCTKTSDTVCDSCEDSTYTQLWNWVPECLSCGSRC 
               
               
                   
               
               
                 SSDQVETQACTREQNRICTCRPGWYCALSKQEGCRLCAPLRKCRPGFGVA 
               
               
                   
               
               
                 RPGTETSDVVCKPCAPGTFSNTTSSTDICRPHQICNVVAIPGNASMDAVC 
               
               
                   
               
               
                 TSTSPTRSMAPGAVHLPQPVSTRSQHTQPTPEPSTAPSTSFLLPMGPSPP 
               
               
                   
               
               
                 AEGSTGDFALPVGLIVGVTALGLLIIGVVNCVIMTQV   KKKPLCLQREAKV     
               
               
                   
               
               
                 
                   
                     PHLPADKARGTQGPEQQHLLITAPSSSSSSLESSASALDRRAPTRNQPQA 
                   
                 
               
               
                   
               
               
                 
                   
                     PGVEASGAGEARASTGSSDSSPGGHGTQVNVTCIVNVCSSSDHSSQCSSQ 
                   
                 
               
               
                   
               
               
                 
                   
                     ASSTMGDTDSSPSESPKDEQVPFSKEECAFRSQLETPETLLGSTEEKPLP 
                   
                 
               
               
                   
               
               
                 
                   
                     LGVPDAGMKPS 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain is an intracellular signaling domain from a mouse TNFR-II polypeptide. An exemplary polypeptide sequence of a mouse TNFR-II (e.g., a polypeptide as shown in UniProt Protein Accession: P25119, found at URL www.uniprot.org/uniprot/P25119) with an exemplary cytoplasmic signaling domain underlined is SEQ ID NO: 39. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 39, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 39. 
     
       
         
           
               
            
               
                 (Mouse TNFR-II polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
               
                 SEQ ID NO: 39 
               
               
                 MAPAALWVALVFELQLWATGHTVPAQVVLTPYKPEPGYECQISQEYYDRK 
               
               
                   
               
               
                 AQMCCAKCPPGQYVKHFCNKTSDTVCADCEASMYTQVWNQFRTCLSCSSS 
               
               
                   
               
               
                 CTTDQVEIRACTKQQNRVCACEAGRYCALKTHSGSCRQCMRLSKCGPGFG 
               
               
                   
               
               
                 VASSRAPNGNVLCKACAPGTFSDTTSSTDVCRPHRICSILAIPGNASTDA 
               
               
                   
               
               
                 VCAPESPTLSAIPRTLYVSQPEPTRSQPLDQEPGPSQTPSILTSLGSTPI 
               
               
                   
               
               
                 IEQSTKGGISLPIGLIVGVTSLGLLMLGLVNCIILVQR   KKKPSCLQRDAK     
               
               
                   
               
               
                 
                   
                     VPHVPDEKSQDAVGLEQQHLLTTAPSSSSSSLESSASAGDRRAPPGGHPQ 
                   
                 
               
               
                   
               
               
                 
                   
                     ARVMAEAQGFQEARASSRISDSSHGSHGTHVNVTCIVNVCSSSDHSSQCS 
                   
                 
               
               
                   
               
               
                 
                   
                     SQASATVGDPDAKPSASPKDEQVPFSQEECPSQSPCETTETLQSHEKPLP 
                   
                 
               
               
                   
               
               
                 
                   
                     LGVPDMGMKPSQAGWFDQIAVKVA 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain is an intracellular signaling domain is from LIGHT (also variously known as tumor necrosis factor superfamily member 14, TNFSF14, CD258, HVEML, LIGHT, LTg, TR2, TNLG1D, tumor necrosis factor superfamily member 14, or TNF superfamily member 14). LIGHT is a secreted protein of the TNF superfamily, has been shown to stimulate the proliferation of T cells, and trigger apoptosis of various tumor cells, and has been shown to interact with TNFRSF14, TNFRSF6B, BIRC2, TRAF2, and TRAF3. In some embodiments, an intracellular signaling domain is an intracellular signaling domain from a human LIGHT polypeptide. An exemplary polypeptide sequence of a human LIGHT (e.g., UniProt Protein Accession: O43557, found at URL www.uniprot.org/uniprot/043557) with an exemplary cytoplasmic signaling domain underlined is SEQ ID NO: 40. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 40, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 40. 
     
       
         
           
               
            
               
                 (Human LIGHT polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 40 
               
            
           
           
               
            
               
                     MEESVVRPSVFVVDGQTDIPFTRLGRSHRRQSCSVAR   VGLGLLLLLMGAG 
               
               
                   
               
               
                 LAVQGWFLLQLHWRLGEMVTRLPDGPAGSWEQLIQERRSHEVNPAAHLTG 
               
               
                   
               
               
                 ANSSLTGSGGPLLWETQLGLAFLRGLSYHDGALVVTKAGYYYIYSKVQLG 
               
               
                   
               
               
                 GVGCPLGLASTITHGLYKRTPRYPEELELLVSQQSPCGRATSSSRVWWDS 
               
               
                   
               
               
                   
               
               
                 SFLGGVVHLEAGEKVVVRVLDERLVRLRDGTRSYFGAFMV 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain is an intracellular signaling domain from a mouse LIGHT polypeptide. An exemplary polypeptide sequence of a mouse LIGHT (e.g., a polypeptide as shown in UniProt Protein Accession: Q9QYH9, found at URL www.uniprot.org/uniprot/Q9QYH9) with an exemplary cytoplasmic signaling domain underlined is SEQ ID NO: 41. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 41, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 41. 
     
       
         
           
               
            
               
                 (Mouse LIGHT polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 41 
               
            
           
           
               
            
               
                     MESVVQPSVFVVDGQTDIPFRRLEQNHRRRRCGTVQV   SLALVLLLGAGLA 
               
               
                   
               
               
                 TQGWFLLRLHQRLGDIVAHLPDGGKGSWEKLIQDQRSHQANPAAHLTGAN 
               
               
                   
               
               
                 ASLIGIGGPLLWETRLGLAFLRGLTYHDGALVTMEPGYYYVYSKVQLSGV 
               
               
                   
               
               
                 GCPQGLANGLPITHGLYKRTSRYPKELELLVSRRSPCGRANSSRVWWDSS 
               
               
                   
               
               
                 FLGGVVHLEAGEEVVVRVPGNRLVRPRDGTRSYFGAFMV 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from ICOS (also variously known as CD278, AILIM, CVID1, inducible T-cell co-stimulator, or inducible T-cell costimulator). ICOS is an immune checkpoint protein that is a member of the CD28-superfamily costimulatory molecule and is expressed on activated T cells. In some embodiments, an intracellular signaling domain is an intracellular signaling domain from a human ICOS polypeptide. An exemplary polypeptide sequence of a human ICOS (e.g., UniProt Protein Accession: Q9Y6W8, found at URL www.uniprot.org/uniprot/Q9Y6W8) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 42. An intracellular to signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 42, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 42. 
     
       
         
           
               
            
               
                 (Human ICOS polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 42 
               
            
           
           
               
            
               
                 MKSGLWYFFLFCLRIKVLTGEINGSANYEMFIFHNGGVQILCKYPDIVQQ 
               
               
                   
               
               
                 FKMQLLKGGQILCDLTKTKGSGNTVSIKSLKFCHSQLSNNSVSFFLYNLD 
               
               
                   
               
               
                 HSHANYYFCNLSIFDPPPFKVTLTGGYLHIYESQLCCQLKFWLPIGCAAF 
               
               
                   
               
               
                   
               
               
                 VVVCILGCILI   CWLTKKKYSSSVHDPNGEYMFMRAVNTAKKSRLTDVTL     
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain is an intracellular signaling domain from a mouse ICOS polypeptide. An exemplary polypeptide sequence of a mouse ICOS (e.g., a polypeptide as shown in UniProt Protein Accession: Q9WVSO, found at URL www.uniprot.org/uniprot/Q9WVS0) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 43. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 43, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 43. 
     
       
         
           
               
            
               
                 (Mouse ICOS polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 43 
               
            
           
           
               
            
               
                 MKPYFCRVFVFCFLIRLLTGEINGSADHRMFSFHNGGVQISCKYPETVQQ 
               
               
                   
               
               
                 LKMRLFREREVLCELTKTKGSGNAVSIKNPMLCLYHLSNNSVSFFLNNPD 
               
               
                   
               
               
                 SSQGSYYFCSLSIFDPPPFQERNLSGGYLHIYESQLCCQLKLWLPVGCAA 
               
               
                   
               
               
                 FVVVLLFGCILIIWF   SKKKYGSSVHDPNSEYMFMAAVNTNKKSRLAGVTS     
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from 4-1BB (also variously known as TNFRSF9, CD137, CDw137, ILA, tumor necrosis factor receptor superfamily member 9, or TNF receptor superfamily member 9). 4-1BB is a member of the tumor necrosis factor (TNF) receptor family that contributes to costimulatory activity for activated T cells. In some embodiments, an intracellular signaling domain is an intracellular signaling domain from a human 4-1BB polypeptide. An exemplary polypeptide sequence of a human 4-1BB (e.g., UniProt Protein Accession: Q07011, found at URL www.uniprot.org/uniprot/Q07011) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 44. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 44, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 44. 
     
       
         
           
               
            
               
                 (Human 4-1BB polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 44 
               
            
           
           
               
            
               
                 MGNSCYNIVATLLLVLNFERTRSLQDPCSNCPAGTFCDNNRNQICSPCPP 
               
               
                   
               
               
                 NSFSSAGGQRTCDICRQCKGVFRTRKECSSTSNAECDCTPGFHCLGAGCS 
               
               
                   
               
               
                 MCEQDCKQGQELTKKGCKDCCFGTFNDQKRGICRPWTNCSLDGKSVLVNG 
               
               
                   
               
               
                 TKERDVVCGPSPADLSPGASSVTPPAPAREPGHSPQIISFFLALTSTALL 
               
               
                   
               
               
                 FLLFFLTLRFSVV   KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEE     
               
               
                   
               
               
                 GGCEL 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 50% (at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or 100%) identical to SEQ ID NO: 45. 
     
       
         
           
               
            
               
                 (4-1BB intracellular signaling domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 45 
               
            
           
           
               
            
               
                 KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL 
               
               
                   
               
               
                 (DNA sequence encoding the 4-1BB intracellular 
               
               
                 signaling domain of SEQ ID NO: 45) 
               
            
           
           
               
            
               
                 SEQ ID NO: 46 
               
            
           
           
               
            
               
                 AAAAGGGGCCGGAAAAAGCTGCTGTATATTTTCAAACAGCCTTTTATGAG 
               
               
                   
               
               
                 GCCTGTGCAGACAACACAGGAAGAGGACGGCTGTAGCTGTCGGTTCCCCG 
               
               
                   
               
               
                 AAGAGGAAGAGGGGGGCTGCGAACTG 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular domain from amino acids 214 to 255 of SEQ ID NO: 44 (human 4-1BB). In some embodiments, a costimulatory domain is or includes a sequence that is at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to amino acids 214 to 255 of SEQ ID NO: 44, or a portion thereof. 
     
       
         
           
               
            
               
                 (Human 4-1BB polypeptide) 
               
            
           
           
               
            
               
                 SEQ ID NO: 44 
               
            
           
           
               
            
               
                 MGNSCYNIVATLLLVLNFERTRSLQDPCSNCPAGTFCDNNRNQICSPCPP 
               
               
                   
               
               
                 NSFSSAGGQRTCDICRQCKGVFRTRKECSSTSNAECDCTPGFHCLGAGCS 
               
               
                   
               
               
                 MCEQDCKQGQELTKKGCKDCCFGTFNDQKRGICRPWTNCSLDGKSVLVNG 
               
               
                   
               
               
                 TKERDVVCGPSPADLSPGASSVTPPAPAREPGHSPQIISFFLALTSTALL 
               
               
                   
               
               
                 FLLFFLTLRFSVVKRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEE 
               
               
                   
               
               
                 GGCEL 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 50% (at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or 100%) identical to SEQ ID NO: 47. 
     
       
         
           
               
            
               
                 (Human 4-1BB intracellular signaling domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 47 
               
            
           
           
               
            
               
                 KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCE 
               
               
                   
               
               
                 (DNA encoding the 4-1BB intracellular signaling 
               
               
                 domain of SEQ ID NO: 47) 
               
            
           
           
               
            
               
                 SEQ ID NO: 48 
               
            
           
           
               
            
               
                 aaacggggcagaaagaaactcctgtatatattcaaacaaccatttatgag 
               
               
                   
               
               
                 accagtacaaactactcaagaggaagatggctgtagctgccgatttccag 
               
               
                   
               
               
                 aagaagaagaaggaggatgtgaa 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse 4-1BB polypeptide. An exemplary polypeptide sequence of a mouse 4-1BB (e.g., a polypeptide as shown in UniProt Protein Accession: P20334, found at URL www.uniprot.org/uniprot/P20334) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 49. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 49, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 49. 
     
       
         
           
               
            
               
                 (Mouse 4-1BB polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 49 
               
            
           
           
               
            
               
                 MGNNCYNVVVIVLLLVGCEKVGAVQNSCDNCQPGTFCRKYNPVCKSCPPS 
               
               
                   
               
               
                 TFSSIGGQPNCNICRVCAGYFRFKKFCSSTHNAECECIEGFHCLGPQCTR 
               
               
                   
               
               
                 CEKDCRPGQELTKQGCKTCSLGTFNDQNGTGVCRPWTNCSLDGRSVLKTG 
               
               
                   
               
               
                 TTEKDVVCGPPVVSFSPSTTISVTPEGGPGGHSLQVLTLFLALTSALLLA 
               
               
                   
               
               
                 LIFITLLF   SVLKWIRKKFPHIFKQPFKKTTGAAQEEDACSCRCPQEEEGG     
               
               
                   
               
               
                 
                   
                     GGGYEL 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be a domain from CD27 (also variously known as S152, S152. LPFS2, T14, TNFRSF7, Tp55, or CD27 molecule). CD27 is a member of the tumor necrosis factor (TNF) receptor superfamily and plays a role in the generation and long-term maintenance of T cell immunity. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human CD27 polypeptide. An exemplary polypeptide sequence of a human CD27 (e.g., UniProt Protein Accession: P26842, found at URL www.uniprot.org/uniprot/P26842) with an intracellular signaling domain underlined is SEQ ID NO: 50. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 50, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 50. 
     
       
         
           
               
            
               
                 (Human CD27 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 50 
               
            
           
           
               
            
               
                 MARPHPWWLCVLGTLVGLSATPAPKSCPERHYWAQGKLCCQMCEPGTFLV 
               
               
                   
               
               
                 KDCDQHRKAAQCDPCIPGVSFSPDHHTRPHCESCRHCNSGLLVRNCTITA 
               
               
                   
               
               
                 NAECACRNGWQCRDKECTECDPLPNPSLTARSSQALSPHPQPTHLPYVSE 
               
               
                   
               
               
                 MLEARTAGHMQTLADFRQLPARTLSTHWPPQRSLCSSDFIRILVIFSGMF 
               
               
                   
               
               
                 LVFTLAGALFLH   QRRKYRSNKGESPVEPAEPCHYSCPREEEGSTIPIQED     
               
               
                   
               
               
                 
                   
                     YRKPEPACSP 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 50% (at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or 100%) identical to SEQ ID NO: 51. 
     
       
         
           
               
            
               
                 (CD27 Intracellular Signaling Domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 51 
               
            
           
           
               
            
               
                 QRRKYRSNKGESPVEPAEPCHYSCPREEEGSTIPIQEDYRKPEPACSP 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse CD27 polypeptide. An exemplary polypeptide sequence of a mouse CD27 (e.g., a polypeptide as shown in UniProt Protein Accession: P41272, found at URL www.uniprot.org/uniprot/P41272) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 52. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 52, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 52. 
     
       
         
           
               
            
               
                 (Mouse CD27 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 52 
               
            
           
           
               
            
               
                 MAWPPPYWLCMLGTLVGLSATLAPNSCPDKHYWTGGGLCCRMCEPGTFFV 
               
               
                   
               
               
                 KDCEQDRTAAQCDPCIPGTSFSPDYHTRPHCESCRHCNSGFLIRNCTVTA 
               
               
                   
               
               
                 NAECSCSKNWQCRDQECTECDPPLNPALTRQPSETPSPQPPPTHLPHGTE 
               
               
                   
               
               
                 KPSWPLHRQLPNSTVYSQRSSHRPLCSSDCIRIFVTFSSMFLIFVLGAIL 
               
               
                   
               
               
                 FFH   QRRNHGPNEDRQAVPEEPCPYSCPREEEGSAIPIQEDYRKPEPAFYP     
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be a domain from OX40 (also variously known as CD134, TNFRSF4, ACT35, IMD16, OX40, TXGP1L, tumor necrosis factor receptor superfamily member 4, or TNF receptor superfamily member 4). OX40 is a member of the tumor necrosis factor (TNF) receptor superfamily and is a secondary co-stimulatory immune checkpoint molecule. OX40 binds to its ligand OX4OL. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human OX40 polypeptide. An exemplary polypeptide sequence of a human OX40 (e.g., UniProt Protein Accession: P43489, found at URL www.uniprot.org/uniprot/P43489) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 53. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 53, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 53. 
     
       
         
           
               
            
               
                 (Human OX40 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 53 
               
            
           
           
               
            
               
                 MCVGARRLGRGPCAALLLLGLGLSTVTGLHCVGDTYPSNDRCCHECRPGN 
               
               
                   
               
               
                 GMVSRCSRSQNTVCRPCGPGFYNDVVSSKPCKPCTWCNLRSGSERKQLCT 
               
               
                   
               
               
                 ATQDTVCRCRAGTQPLDSYKPGVDCAPCPPGHFSPGDNQACKPWTNCTLA 
               
               
                   
               
               
                 GKHTLQPASNSSDAICEDRDPPATQPQETQGPPARPITVQPTEAWPRTSQ 
               
               
                   
               
               
                 GPSTRPVEVPGGRAVAAILGLGLVLGLLGPLAILL   ALYLLRRDQRLPPDA     
               
               
                   
               
               
                 
                   
                     HKPPGGGSFRTPIQEEQADAHSTLAKI 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 50% (at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or 100%) identical to SEQ ID NO: 54. 
     
       
         
           
               
               
            
               
                   
                 (OX40 intracellular signaling domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 54 
               
            
           
           
               
               
            
               
                   
                 ALYLLRRDQRLPPDAHKPPGGGSFRTPIQEEQADAHSTLAKI 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse OX40 polypeptide. An exemplary polypeptide sequence of a mouse OX40 (e.g., a polypeptide as shown in UniProt Protein Accession: P47741, found at URL www.uniprot.org/uniprot/P47741) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 55. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 55, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 55. 
     
       
         
           
               
            
               
                 (Mouse OX40 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 55 
               
            
           
           
               
            
               
                 MYVWVQQPTALLLLALTLGVTARRLNCVKHTYPSGHKCCRECQPGHGMVS 
               
               
                   
               
               
                 RCDHTRDTLCHPCETGFYNEAVNYDTCKQCTQCNHRSGSELKQNCTPTQD 
               
               
                   
               
               
                 TVCRCRPGTQPRQDSGYKLGVDCVPCPPGHFSPGNNQACKPWTNCTLSGK 
               
               
                   
               
               
                 QTRHPASDSLDAVCEDRSLLATLLWETQRPTFRPTTVQSTTVWPRTSELP 
               
               
                   
               
               
                 SPPTLVTPEGPAFAVLLGLGLGLLAPLTVLLALYLL   RKAWRLPNTPKPCW     
               
               
                   
               
               
                 
                   
                     GNSFRTPIQEEHTDAHFTLAKI 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from CD2 (also variously known as cluster of differentiation 2, LFA-2, SRBC, T11, or CD2 molecule). CD2 is a cell adhesion molecule found on the surface of T cells and natural killer (NK) cells, and acts as a co-stimulatory molecule on these cells. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human CD2 polypeptide. An exemplary polypeptide sequence of a human CD2 (e.g., UniProt Protein Accession: P06729, found at URL www.uniprot.org/uniprot/P06729) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 56. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 56, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 56. 
     
       
         
           
               
            
               
                 (Human CD2 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 56 
               
            
           
           
               
            
               
                 MSFPCKFVASFLLIFNVSSKGAVSKEITNALETWGALGQDINLDIPSFQM 
               
               
                   
               
               
                 SDDIDDIKWEKTSDKKKIAQFRKEKETFKEKDTYKLFKNGTLKIKHLKTD 
               
               
                   
               
               
                 DQDIYKVSIYDTKGKNVLEKIFDLKIQERVSKPKISWTCINTTLTCEVMN 
               
               
                   
               
               
                 GTDPELNLYQDGKHLKLSQRVITHKWTTSLSAKFKCTAGNKVSKESSVEP 
               
               
                   
               
               
                 VSCPEKGLDIYLIIGICGGGSLLMVFVALLVFYIT   KRKKQRSRRNDEELE     
               
               
                   
               
               
                 
                   
                     TRAHRVATEERGRKPHQIPASTPQNPATSQHPPPPPGHRSQAPSHRPPPP 
                   
                 
               
               
                   
               
               
                 
                   
                     GHRVQHQPQKRPPAPSGTQVHQQKGPPLPRPRVQPKPPHGAAENSLSPSS 
                   
                 
               
               
                   
               
               
                 
                   
                     N 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse CD2 polypeptide. An exemplary polypeptide sequence of a mouse CD2 (e.g., a polypeptide as shown in UniProt Protein Accession: P08920, found at URL www.uniprot.org/uniprot/P08920) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 57. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 57, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 57. 
     
       
         
           
               
            
               
                 (Mouse CD2 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 57 
               
            
           
           
               
            
               
                 MKCKFLGSFFLLFSLSGKGADCRDNETIWGVLGHGITLNIPNFQMTDDID 
               
               
                   
               
               
                 EVRWVRRGTLVAEFKRKKPPFLISETYEVLANGSLKIKKPMMRNDSGTYN 
               
               
                   
               
               
                 VMVYGTNGMTRLEKDLDVRILERVSKPMIHWECPNTTLTCAVLQGTDFEL 
               
               
                   
               
               
                 KLYQGETLLNSLPQKNMSYQWTNLNAPFKCEAINPVSKESKMEVVNCPEK 
               
               
                   
               
               
                 GLSFYVTVGVGAGGLLLVLLVALFIFCIC   KRRKRNRRRKDEELEIKASRT     
               
               
                   
               
               
                 
                   
                     STVERGPKPHSTPAAAAQNSVALQAPPPPGHHLQTPGHRPLPPGHRTREH 
                   
                 
               
               
                   
               
               
                 
                   
                     QQKKRPPPSGTQIHQQKGPPLPRPRVQPKPPCGSGDGVSLPPPN 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from CD5 (also variously known as cluster of differentiation 5, LEU1, Ti, or CD5 molecule). CD5 is expressed on the surface of T cells and is upregulated on T cells upon strong activation. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human CD5 polypeptide. An exemplary polypeptide sequence of a human CD5 (e.g., UniProt Protein Accession: P06127, found at URL www.uniprot.org/uniprot/P06127) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 58. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 58, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 58. 
     
       
         
           
               
            
               
                 (Human CD5 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 58 
               
            
           
           
               
            
               
                 MPMGSLQPLATLYLLGMLVASCLGRLSWYDPDFQARLTRSNSKCQGQLEV 
               
               
                   
               
               
                 YLKDGWHMVCSQSWGRSSKQWEDPSQASKVCQRLNCGVPLSLGPFLVTYT 
               
               
                   
               
               
                 PQSSIICYGQLGSFSNCSHSRNDMCHSLGLTCLEPQKTTPPTTRPPPTTT 
               
               
                   
               
               
                 PEPTAPPRLQLVAQSGGQHCAGVVEFYSGSLGGTISYEAQDKTQDLENFL 
               
               
                   
               
               
                 CNNLQCGSFLKHLPETEAGRAQDPGEPREHQPLPIQWKIQNSSCTSLEHC 
               
               
                   
               
               
                 FRKIKPQKSGRVLALLCSGFQPKVQSRLVGGSSICEGTVEVRQGAQWAAL 
               
               
                   
               
               
                 CDSSSARSSLRWEEVCREQQCGSVNSYRVLDAGDPTSRGLFCPHQKLSQC 
               
               
                   
               
               
                 HELWERNSYCKKVFVTCQDPNPAGLAAGTVASIILALVLLVVLLVVCGPL 
               
               
                   
               
               
                 AY   KKLVKKFRQKKQRQWIGPTGMNQNMSFHRNHTATVRSHAENPTASHVD     
               
               
                   
               
               
                 
                   
                     NEYSQPPRNSHLSAYPALEGALHRSSMQPDNSSDSDYDLHGAQRL 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse CD5 polypeptide. An exemplary polypeptide sequence of a mouse CD5 (e.g., a polypeptide as shown in UniProt Protein Accession: P13379, found at URL sww.uniprot.org/uniprot/P13379) with an intracellular signaling domain underlined is SEQ ID NO: 59. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 59, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 59. 
     
       
         
           
               
            
               
                 (Mouse CD5 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 59 
               
            
           
           
               
            
               
                 MDSHEVLLAATYLLGTLAAFCLGQSGRGGLDIQVMLSGSNSKCQGQVEIQ 
               
               
                   
               
               
                 MENKWKTVCSSSWRLSQDHSKNAQQASAVCKQLRCGDPLALGPFPSLNRP 
               
               
                   
               
               
                 QNQVFCQGSPWSISNCNNTSSQDQCLPLSLICLEPQRTTPPPTTTPPTTV 
               
               
                   
               
               
                 PEPTAPPRLQLVPGHEGLRCTGVVEFYNGSWGGTILYKAKDRPLGLGNLI 
               
               
                   
               
               
                 CKSLQCGSFLTHLSGTEAAGTPAPAELRDPRPLPIRWEAPNGSCVSLQQC 
               
               
                   
               
               
                 FQKTTAQEGGQALTVICSDFQPKVQSRLVGGSSVCEGIAEVRQRSQWEAL 
               
               
                   
               
               
                 CDSSAARGRGRWEELCREQQCGDLISFHTVDADKTSPGFLCAQEKLSQCY 
               
               
                   
               
               
                 HLQKKKHCNKRVFVTCQDPNPAGLAPGTVASIILTLVLLVVLLAMCGPLV 
               
               
                   
               
               
                 Y   KKLVKKFRQKKQRQWIGPTGVNQNMSFHRSHTATVRSQVENPTASHVDN     
               
               
                   
               
               
                 
                   
                     EYSQPPRNSHLSAYPALEGALHRSSTQPDNSSDSDYDLQVAQRL 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from CD30 (also variously known as TNFRSF8, D1S166E, Ki-1, tumor necrosis factor receptor superfamily member 8, or TNF receptor superfamily member 8). CD30 is expressed by activated T and B cells and is involved with the activation of NF-kappaB. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human CD30 polypeptide. An exemplary polypeptide sequence of a human CD30 (e.g., UniProt Protein Accession: P28908, found at URL www.uniprot.org/uniprot/P28908) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 60. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 60, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 60. 
     
       
         
           
               
            
               
                 (Human CD30 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 60 
               
            
           
           
               
            
               
                 MRVLLAALGLLFLGALRAFPQDRPFEDTCHGNPSHYYDKAVRRCCYRCPM 
               
               
                   
               
               
                 GLFPTQQCPQRPTDCRKQCEPDYYLDEADRCTACVTCSRDDLVEKTPCAW 
               
               
                   
               
               
                 NSSRVCECRPGMFCSTSAVNSCARCFFHSVCPAGMIVKFPGTAQKNTVCE 
               
               
                   
               
               
                 PASPGVSPACASPENCKEPSSGTIPQAKPTPVSPATSSASTMPVRGGTRL 
               
               
                   
               
               
                 AQEAASKLTRAPDSPSSVGRPSSDPGLSPTQPCPEGSGDCRKQCEPDYYL 
               
               
                   
               
               
                 DEAGRCTACVSCSRDDLVEKTPCAWNSSRTCECRPGMICATSATNSCARC 
               
               
                   
               
               
                 VPYPICAAETVTKPQDMAEKDTTFEAPPLGTQPDCNPTPENGEAPASTSP 
               
               
                   
               
               
                 TQSLLVDSQASKTLPIPTSAPVALSSTGKPVLDAGPVLFWVILVLVVVVG 
               
               
                   
               
               
                 SSAFLLC   HRRACRKRIRQKLHLCYPVQTSQPKLELVDSRPRRSSTQLRSG     
               
               
                   
               
               
                 
                   
                     ASVTEPVAEERGLMSQPLMETCHSVGAAYLESLPLQDASPAGGPSSPRDL 
                   
                 
               
               
                   
               
               
                 
                   
                     PEPRVSTEHTNNKIEKIYIMKADTVIVGTVKAELPEGRGLAGPAEPELEE 
                   
                 
               
               
                   
               
               
                 
                   
                     ELEADHTPHYPEQETEPPLGSCSDVMLSVEEEGKEDPLPTAASGK 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse CD30 polypeptide. An exemplary polypeptide sequence of a mouse CD30 (e.g., a polypeptide as shown in UniProt Protein Accession: Q60846, found at URL www.uniprot.org/uniprot/Q60846) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 61. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 61, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 61. 
     
       
         
           
               
            
               
                 (Mouse CD30 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 61 
               
            
           
           
               
            
               
                 MSALLTAAGLLFLGMLQAFPTDRPLKTTCAGDLSHYPGEAARNCCYQCPS 
               
               
                   
               
               
                 GLSPTQPCPRGPAHCRKQCAPDYYVNEDGKCTACVTCLPGLVEKAPCSGN 
               
               
                   
               
               
                 SPRICECQPGMHCCTPAVNSCARCKLHCSGEEVVKSPGTAKKDTICELPS 
               
               
                   
               
               
                 SGSGPNCSNPGDRKTLTSHATPQAMPTLESPANDSARSLLPMRVTNLVQE 
               
               
                   
               
               
                 DATELVKVPESSSSKAREPSPDPGNAEKNMTLELPSPGTLPDISTSENSK 
               
               
                   
               
               
                 EPASTASTLSLVVDAWTSSRMQPTSPLST   GTPFLDPGPVLFWVAMVVLLV     
               
               
                   
               
               
                 
                   
                     GSGSFLLCYWKACRRRFQQKFHLDYLVQTFQPKMEQTDSCPTEKLTQPQR 
                   
                 
               
               
                   
               
               
                 
                   
                     SGSVTDPSTGHKLSPVSPPPAVETCASVGATYLENLPLLDDSPAGNPFSP 
                   
                 
               
               
                   
               
               
                 
                   
                     REPPEPRVSTEHTNNRIEKIYIMKADTVIVGSVKTEVPEGRAPAGSTESE 
                   
                 
               
               
                   
               
               
                 
                   
                     LEAELEVDHAPHYPEQETEPPLGSCTEVMFSVEEGGKEDHGPTTVSEK 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from CD40 (also variously known as Bp50, CDW40, TNFRSFS, p50, or CD40 molecule). CD40 is a costimulatory protein found on antigen presenting cells and plays a role in their activation. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human CD40 polypeptide. An exemplary polypeptide sequence of a human CD40 (e.g., UniProt Protein Accession: P25942, found at URL www.uniprot.org/uniprot/P25942) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 62. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 62, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 62. 
     
       
         
           
               
            
               
                 (Human CD40 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 62 
               
            
           
           
               
            
               
                 MVRLPLQCVLWGCLLTAVHPEPPTACREKQYLINSQCCSLCQPGQKLVSD 
               
               
                   
               
               
                 CTEFTETECLPCGESEFLDTWNRETHCHQHKYCDPNLGLRVQQKGTSETD 
               
               
                   
               
               
                 TICTCEEGWHCTSEACESCVLHRSCSPGFGVKQIATGVSDTICEPCPVGF 
               
               
                   
               
               
                 FSNVSSAFEKCHPWTSCETKDLVVQQAGTNKTDVVCGPQDRLRALVVIPI 
               
               
                   
               
               
                 IFGILFAILLVLVFI   KKVAKKPTNKAPHPKQEPQEINFPDDLPGSNTAAP     
               
               
                   
               
               
                 
                   
                     VQETLHGCQPVTQEDGKESRISVQERQ 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 50% (at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or 100%) identical to SEQ ID NO: 63.
     SEQ ID NO: 63 (CD40 Intracellular Signaling Sequence)   KKVAKKPTNKAPHPKQEPQEINFPDDLPGSNTAAPVQETLHGCQPVTQ(A) EDGKESRISVQERQ   

     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse CD40 polypeptide. An exemplary polypeptide sequence of a mouse CD40 (e.g., a polypeptide as shown in UniProt Protein Accession: P27512, found at URL www.uniprot.org/uniprot/P27512) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 64. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 64, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 64. 
     
       
         
           
               
            
               
                 (Mouse CD40 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 64 
               
            
           
           
               
            
               
                 MVSLPRLCALWGCLLTAVHLGQCVTCSDKQYLHDGQCCDLCQPGSRLTSH 
               
               
                   
               
               
                 CTALEKTQCHPCDSGEFSAQWNREIRCHQHRHCEPNQGLRVKKEGTAESD 
               
               
                   
               
               
                 TVCTCKEGQHCTSKDCEACAQHTPCIPGFGVMEMATETTDTVCHPCPVGF 
               
               
                   
               
               
                 FSNQSSLFEKCYPWTSCEDKNLEVLQKGTSQTNVICGLKSRMRALLVIPV 
               
               
                   
               
               
                 VMGILITIFGVFLYI   KKVVKKPKDNEILPPAARRQDPQEMEDYPGHNTAA     
               
               
                   
               
               
                 
                   
                     PVQETLHGCQPVTQEDGKESRISVQERQVTDSIALRPLV 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from CD28 (also variously known as cluster of differentiation 28, Tp44, or CD28 molecule). CD28 is a costimulatory protein expressed on T cells and provides co-stimulatory signals involved in T cell activation and survival. CD28 is the receptor for CD80 and CD86. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human CD28 polypeptide. An exemplary polypeptide sequence of a human CD28 (e.g., UniProt Protein Accession: P10747, found at URL www.uniprot.org/uniprot/P10747) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 5. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 5, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 5. 
     
       
         
           
               
            
               
                 (Human CD28 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 5 
               
            
           
           
               
            
               
                 MLRLLLALNLFPSIQVTGNKILVKQSPMLVAYDNAVNLSCKYSYNLFSRE 
               
               
                   
               
               
                 FRASLHKGLDSAVEVCVVYGNYSQQLQVYSKTGFNCDGKLGNESVTFYLQ 
               
               
                   
               
               
                 NLYVNQTDIYFCKIEVMYPPPYLDNEKSNGTIIHVKGKHLCPSPLFPGPS 
               
               
                   
               
               
                 KPFWVLVVVGGVLACYSLLVTVAFIIFWV   RSKRSRLLHSDYMNMTPRRPG     
               
               
                   
               
               
                 
                   
                     PTRKHYQPYAPPRDFAAYRS 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical (or is identical) to amino acids 180 to 220 of SEQ ID NO: 5, or a fragment thereof. 
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical (or is identical) to amino acids 180 to 220 of SEQ ID NO: 65, or a fragment thereof. 
     
       
         
           
               
               
            
               
                   
                 (CD28 Intracellular Signaling Domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 65 
               
            
           
           
               
               
            
               
                   
                 RSKRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAYRS 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse CD28 polypeptide. An exemplary polypeptide sequence of a mouse CD28 (e.g., a polypeptide as shown in UniProt Protein Accession: P31041, found at URL www.uniprot.org/uniprot/P31041) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 66. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 66, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 66. 
     
       
         
           
               
            
               
                 (Mouse CD28 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 66 
               
            
           
           
               
            
               
                 MTLRLLFLALNFFSVQVTENKILVKQSPLLVVDSNEVSLSCRYSYNLLAK 
               
               
                   
               
               
                 EFRASLYKGVNSDVEVCVGNGNFTYQPQFRSNAEFNCDGDFDNETVTFRL 
               
               
                   
               
               
                 WNLHVNHTDIYFCKIEFMYPPPYLDNERSNGTIIHIKEKHLCHTQSSPKL 
               
               
                   
               
               
                 FWALVVVAGVLFCYGLLVTVALCVIWT   NSRRNRLLQSDYMNMTPRRPGLT     
               
               
                   
               
               
                 
                   
                     RKPYQPYAPARDFAAYRP 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain that from CD11a . CD11a is found on T-cells, B-cells, macrophages, neutrophils, and NK cells, and binds to CD11a on antigen-presenting cells. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from human CD11a polypeptide. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human CD11a polypeptide. 
     An exemplary polypeptide sequence of a human CD11a with an exemplary intracellular signaling domain underlined is SEQ ID NO: 67. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 67, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 67. 
     
       
         
           
               
               
            
               
                   
                 (Human CD11a with exemplary intracellular 
               
               
                   
                 signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 67 
               
            
           
           
               
               
            
               
                   
                 mkdscitvma mallsgffff apassynldv rgarsfsppr 
               
               
                   
                   
               
               
                   
                 agrhfgyrvl qvgngvivga pgegnstgsl yqcqsgtghc 
               
               
                   
                   
               
               
                   
                 lpvtlrgsny tskylgmtla tdptdgsila cdpglsrtcd 
               
               
                   
                   
               
               
                   
                 qntylsglcy lfrqnlqgpm lqgrpgfqec ikgnvdlvfl 
               
               
                   
                   
               
               
                   
                 fdgsmslqpd efqkildfmk dvmkklsnts yqfaavqfst 
               
               
                   
                   
               
               
                   
                 syktefdfsd yvkrkdpdal lkhvkhmlll tntfgainyv 
               
               
                   
                   
               
               
                   
                 atevfreelg arpdatkvli iitdgeatds gnidaakdii 
               
               
                   
                   
               
               
                   
                 ryiigigkhf qtkesqetlh kfaskpasef vkildtfekl 
               
               
                   
                   
               
               
                   
                 kdlftelqkk iyviegtskq dltsfnmels ssgisadlsr 
               
               
                   
                   
               
               
                   
                 ghavvgavga kdwaggfldl kadlqddtfi gnepltpevr 
               
               
                   
                   
               
               
                   
                 agylgytvtw lpsrqktsll asgapryqhm grvllfqepq 
               
               
                   
                   
               
               
                   
                 ggghwsqvqt ihgtqigsyf ggelcgvdvd qdgetellli 
               
               
                   
                   
               
               
                   
                 gaplfygeqr ggrvfiyqrr qlgfeevsel qgdpgyplgr 
               
               
                   
                   
               
               
                   
                 fgeaitaltd ingdglvdva vgapleeqga vyifngrhgg 
               
               
                   
                   
               
               
                   
                 lspqpsqrie gtqvlsgiqw fgrsihgvkd legdgladva 
               
               
                   
                   
               
               
                   
                 vgaesqmivl ssrpvvdmvt lmsfspaeip vhevecsyst 
               
               
                   
                   
               
               
                   
                 snkmkegvni ticfqiksli pqfqgrlvan ltytlqldgh 
               
               
                   
                   
               
               
                   
                 rtrrrglfpg grhelrmia vttsmsctdf sfhfpvcvqd 
               
               
                   
                   
               
               
                   
                 lispinvsln fslweeegtp rdqraqgkdi ppilrpslhs 
               
               
                   
                   
               
               
                   
                 etweipfekn cgedkkcean lrvsfspars ralrltafas 
               
               
                   
                   
               
               
                   
                 lsvelslsnl eedaywvqld lhfppglsfr kvemlkphsq 
               
               
                   
                   
               
               
                   
                 ipvsceelpe esrllsrals cnvsspifka ghsvalqmmf 
               
               
                   
                   
               
               
                   
                 ntlvnsswgd svelhanvtc nnedsdlled nsattiipil 
               
               
                   
                   
               
               
                   
                 ypiniliqdq edstlyvsft pkgpkihqvk hmyqvriqps 
               
               
                   
                   
               
               
                   
                 ihdhniptle avvgvpqpps egpithqwsv qmeppvpchy 
               
               
                   
                   
               
               
                   
                 edlerlpdaa epclpgalfr cpvvfrqeil vqvigtlelv 
               
               
                   
                   
               
               
                   
                 geieassmfs lcsslsisfn sskhfhlygs naslaqvvmk 
               
               
                   
                   
               
               
                   
                 vdvvyekqml ylyvlsgigg llllllifiv l   ykvgffkrn     
               
               
                   
                   
               
               
                   
                 
                   
                     lkekmeagrg vpngipaeds eqlasgqeag dpgclkplhe 
                   
                 
               
               
                   
                   
               
               
                   
                 
                   
                     kdsesgggkd 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical (or is identical) to amino acids 180 to 220 of SEQ ID NO: 68, or a fragment thereof. 
     
       
         
           
               
            
               
                 (Exemplary CD11a intracellular signaling domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 68 
               
            
           
           
               
            
               
                 YKVGFFKRNLKEKMEAGRGVPNGIPAEDSEQLASGQEAGDPGCLKPLHEK 
               
               
                   
               
               
                 DSESGGGKD 
               
            
           
         
       
     
     An exemplary polypeptide sequence of a mouse CD11a with an exemplary intracellular signaling domain underlined is SEQ ID NO: 69. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 69, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 69. 
     
       
         
           
               
               
            
               
                   
                 (mouse CD11a with exemplary intracellular 
               
               
                   
                 signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 69 
               
            
           
           
               
               
            
               
                   
                 msfriagprl lllglqlfak awsynldtrp tqsflaqagr 
               
               
                   
                   
               
               
                   
                 hfgyqvlqie dgvvvgapge gdntgglyhc rtssefcqpv 
               
               
                   
                   
               
               
                   
                 slhgsnhtsk ylgmtlatda akgsllacdp glsrtcdqnt 
               
               
                   
                   
               
               
                   
                 ylsglcylfp qslegpmlqn rpayqecmkg kvdlvflfdg 
               
               
                   
                   
               
               
                   
                 sqsldrkdfe kilefmkdvm rklsntsyqf aavqfstdcr 
               
               
                   
                   
               
               
                   
                 teftfldyvk qnknpdvllg svqpmflltn tfrainyvva 
               
               
                   
                   
               
               
                   
                 hvfkeesgar pdatkvlvii tdgeasdkgn isaahditry 
               
               
                   
                   
               
               
                   
                 iigigkhfvs vqkqktlhif asepveefvk ildtfeklkd 
               
               
                   
                   
               
               
                   
                 lftdlqrriy aiegtnrqdl tsfnmelsss gisadlskgh 
               
               
                   
                   
               
               
                   
                 avvgavgakd waggfldlre dlqgatfvgq epltsdvrgg 
               
               
                   
                   
               
               
                   
                 ylgytvawmt srssrpllaa gapryqhvgq vllfqapeag 
               
               
                   
                   
               
               
                   
                 grwnqtqkie gtqigsyfgg elcsvdldqd geaellliga 
               
               
                   
                   
               
               
                   
                 plffgeqrgg rvftyqrrqs lfemvselqg dpgyplgrfg 
               
               
                   
                   
               
               
                   
                 aaitaltdin gdrltdvavg apleeqgavy ifngkpggls 
               
               
                   
                   
               
               
                   
                 pqpsqriqga qvfpgirwfg rsihgvkdlg gdrladvvvg 
               
               
                   
                   
               
               
                   
                 aegrvvvlss rpvvdvvtel sfspeeipvh evecsysare 
               
               
                   
                   
               
               
                   
                 eqkhgvklka cfrikpltpq fqgrllanls ytlqldghrm 
               
               
                   
                   
               
               
                   
                 rsrglfpdgs helsgntsit pdkscldfhf hfpiciqdli 
               
               
                   
                   
               
               
                   
                 spinvslnfs lleeegtprd qkvgramqpi lrpsihtvtk 
               
               
                   
                   
               
               
                   
                 eipfekncge dkkceanltl ssparsgplr lmssaslave 
               
               
                   
                   
               
               
                   
                 wtlsnsgeda ywvrldldfp rglsfrkvem lqphsrmpvs 
               
               
                   
                   
               
               
                   
                 ceeltegssl ltktlkcnvs spifkagqev slqvmfntll 
               
               
                   
                   
               
               
                   
                 nsswedfvel ngtvhcenen sslqednsaa thipvlypvn 
               
               
                   
                   
               
               
                   
                 iltkeqenst lyisftpkgp ktqqvqhvyq vriqpsaydh 
               
               
                   
                   
               
               
                   
                 nmptlealvg vpwphsedpi tytwsvqtdp lvtchsedl   k     
               
               
                   
                   
               
               
                   
                 
                   
                     rpsseaeqpc lpgvqfrcpi vfrreiliqv tgtvelskei 
                   
                 
               
               
                   
                   
               
               
                   
                 
                   
                     kasstlslcs slsvsfnssk hfhlygskas eaqvlvkvdl 
                   
                 
               
               
                   
                   
               
               
                   
                 
                   
                     ihekemlhvy vlsgigglvl lfliflalyk vgffkrnlke 
                   
                 
               
               
                   
                   
               
               
                   
                 
                   
                     kmeadggvpn gsppedtdpl avpgeetkdm gcleplresd 
                   
                 
               
               
                   
                   
               
               
                   
                 
                   
                     kd 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from ICAM-1 (also variously known as BB2, CD54, cluster of differentiation 54, P3.58, or intercellular adhesion molecule 1). ICAM-1 is a cell surface glycoprotein that is expressed on endothelial cells and cells of the immune system. It binds to integrins of type CD11a/CD18, or CD11b/CD18. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human ICAM-1 polypeptide. An exemplary polypeptide sequence of a human ICAM-1 (e.g., UniProt Protein Accession: P05362, found at URL www.uniprot.org/uniprot/P05362) with an intracellular signaling domain underlined is SEQ ID NO: 70. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 70, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 70. 
     
       
         
           
               
            
               
                 (Human ICAM-1 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 70 
               
            
           
           
               
            
               
                 MAPSSPRPALPALLVLLGALFPGPGNAQTSVSPSKVILPRGGSVLVTCST 
               
               
                   
               
               
                 SCDQPKLLGIETPLPKKELLLPGNNRKVYELSNVQEDSQPMCYSNCPDGQ 
               
               
                   
               
               
                 STAKTFLTVYWTPERVELAPLPSWQPVGKNLTLRCQVEGGAPRANLTVVL 
               
               
                   
               
               
                 LRGEKELKREPAVGEPAEVTTTVLVRRDHHGANFSCRTELDLRPQGLELF 
               
               
                   
               
               
                 ENTSAPYQLQTFVLPATPPQLVSPRVLEVDTQGTVVCSLDGLFPVSEAQV 
               
               
                   
               
               
                 HLALGDQRLNPTVTYGNDSFSAKASVSVTAEDEGTQRLTCAVILGNQSQE 
               
               
                   
               
               
                 TLQTVTIYSFPAPNVILTKPEVSEGTEVTVKCEAHPRAKVTLNGVPAQPL 
               
               
                   
               
               
                 GPRAQLLLKATPEDNGRSFSCSATLEVAGQLIHKNQTRELRVLYGPRLDE 
               
               
                   
               
               
                 RDCPGNWTWPENSQQTPMCQAWGNPLPELKCLKDGTFPLPIGESVTVTRD 
               
               
                   
               
               
                 LEGTYLCRARSTQGEVTRKVTVNVLSPRYEIVIITVVAAAVIMGTAGLST 
               
               
                   
               
               
                 YLY   NRQRKIKKYRLQQAQKGTPMKPNTQATPP     
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse ICAM-1 polypeptide. An exemplary polypeptide sequence of a mouse ICAM-1 (e.g., a polypeptide as shown in UniProt Protein Accession: P13597, found at URL www.uniprot.org/uniprot/P13597) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 71. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 71, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 71. 
     
       
         
           
               
            
               
                 (Mouse ICAM-1 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 71 
               
            
           
           
               
            
               
                 MASTRAKPTLPLLLALVTVVIPGPGDAQVSIHPREAFLPQGGSVQVNCSS 
               
               
                   
               
               
                 SCKEDLSLGLETQWLKDELESGPNWKLFELSEIGEDSSPLCFENCGTVQS 
               
               
                   
               
               
                 SASATITVYSFPESVELRPLPAWQQVGKDLTLRCHVDGGAPRTQLSAVLL 
               
               
                   
               
               
                 RGEEILSRQPVGGHPKDPKEITFTVLASRGDHGANFSCRTELDLRPQGLA 
               
               
                   
               
               
                 LFSNVSEARSLRTFDLPATIPKLDTPDLLEVGTQQKLFCSLEGLFPASEA 
               
               
                   
               
               
                 RIYLELGGQMPTQESTNSSDSVSATALVEVTEEFDRTLPLRCVLELADQI 
               
               
                   
               
               
                 LETQRTLTVYNFSAPVLTLSQLEVSEGSQVTVKCEAHSGSKVVLLSGVEP 
               
               
                   
               
               
                 RPPTPQVQFTLNASSEDHKRSFFCSAALEVAGKFLFKNQTLELHVLYGPR 
               
               
                   
               
               
                 LDETDCLGNWTWQEGSQQTLKCQAWGNPSPKMTCRRKADGALLPIGVVKS 
               
               
                   
               
               
                 VKQEMNGTYVCHAFSSHGNVTRNVYLTVLYHSQNNWTIIILVPVLLVIVG 
               
               
                   
               
               
                 LVMAASYVY   NRQRKIRIYKLQKAQEEAIKLKGQAPPP     
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from NKG2C (also variously known as CD159c, NKG2-C, NKG2C, or killer cell lectin like receptor C2). NKG2C is expressed primarily in natural killer (NK) cells and acts as a receptor for the recognition of MHC class I HLA-E molecules. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human NKG2C polypeptide. An exemplary polypeptide sequence of a human NKG2C (e.g., UniProt Protein Accession: P26717, found at URL www.uniprot.org/uniprot/P26717) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 72. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 72, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 72. 
     
       
         
           
               
            
               
                 (Human NKG2C polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 72 
               
            
           
           
               
            
               
                 
                   
                     MSKQRGTFSEVSLAQDPKRQQRKPKGNKSSISGTEQEIFQVELNLQNPSL 
                   
                 
               
               
                   
               
               
                     NHQGIDKIYDCQGLLPPPEK   LTAEVLGIICIVLMATVLKTIVLIPFLEQN 
               
               
                   
               
               
                 NSSPNTRTQKARHCGHCPEEWITYSNSCYYIGKERRTWEESLLACTSKNS 
               
               
                   
               
               
                 SLLSIDNEEEMKFLASILPSSWIGVFRNSSHHPWVTINGLAFKHKIKDSD 
               
               
                   
               
               
                 NAELNCAVLQVNRLKSAQCGSSMIYHCKHKL 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from GITR (also variously known as glucocorticoid-induced tumor necrosis factor receptor, tumor necrosis factor receptor superfamily member 18, TNFRSF18, activation-inducible TNFR family receptor, AITR, CD357, GITR-D, or TNF receptor superfamily member 18). GITR is a member of the tumor necrosis factor receptor (TNF-R) superfamily and is involved in inhibiting the suppressive activity of T-regulatory cells and extending the survival of T-effector cells. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human GITR polypeptide. An exemplary polypeptide sequence of a human GITR (e.g., UniProt Protein Accession: Q9Y5U5, found at URL www.uniprot.org/uniprot/Q9Y5U5) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 73. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 73, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 73. 
     
       
         
           
               
            
               
                 (Human GITR polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 73 
               
            
           
           
               
            
               
                 MAQHGAMGAFRALCGLALLCALSLGQRPTGGPGCGPGRLLLGTGTDARCC 
               
               
                   
               
               
                 RVHTTRCCRDYPGEECCSEWDCMCVQPEFHCGDPCCTTCRHHPCPPGQGV 
               
               
                   
               
               
                 QSQGKFSFGFQCIDCASGTFSGGHEGHCKPWTDCTQFGFLTVFPGNKTHN 
               
               
                   
               
               
                 AVCVPGSPPAEPLGWLTVVLLAVAACVLLLTSA   QLGLHIWQLRSQCMWPR     
               
               
                   
               
               
                 
                   
                     ETQLLLEVPPSTEDARSCQFPEEERGERSAEEKGRLGDLWV 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical (or is identical) to amino acids 180 to 220 of SEQ ID NO: 74, or a fragment thereof. 
     
       
         
           
               
            
               
                 (GITR intracellular signaling domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 74 
               
            
           
           
               
            
               
                 QLGLHIWQLRSQCMWPRETQLLLEVPPSTEDARSCQFPEEERGERSAEEK 
               
               
                   
               
               
                 GRLGDLWV 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse GITR polypeptide. An exemplary polypeptide sequence of a mouse GITR (e.g., a polypeptide as shown in UniProt Protein Accession: 035714, found at URL www.uniprot.org/uniprot/035714) with an intracellular signaling domain underlined is SEQ ID NO: 75. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 75, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 75. 
     
       
         
           
               
            
               
                 (Mouse GITR polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 75 
               
            
           
           
               
            
               
                 MGAWAMLYGVSMLCVLDLGQPSVVEEPGCGPGKVQNGSGNNTRCCSLYAP 
               
               
                   
               
               
                 GKEDCPKERCICVTPEYHCGDPQCKICKHYPCQPGQRVESQGDIVFGFRC 
               
               
                   
               
               
                 VACAMGTFSAGRDGHCRLWTNCSQFGFLTMFPGNKTHNAVCIPEPLPTEQ 
               
               
                   
               
               
                 YGHLTVIFLVMAACIFFLTTVQLG   LHIWQLRRQHMCPRETQPFAEVQLSA     
               
               
                   
               
               
                 
                   
                     EDACSFQFPEEERGEQTEEKCHLGGRWP 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain is from DAP-10 (also variously known as hematopoietic cell signal transducer, HCST, KAP10, DAP10, PIK3AP, or hematopoietic cell signal transducer). See e.g., Lanier, DAP10- and DAP12-associated receptors in innate immunity,  Immunol Rev. , January; 227(1):150-60. doi: 10.1111/j.1600-065X.2008.00720.x, 2009, incorporated by reference herein in its entirety. DAP-10 is a transmembrane signaling adaptor that contains a YxxM ITAM motif in its cytoplasmic domain. In some embodiments, an intracellular signaling domain is an intracellular signaling domain from a human DAP-10 polypeptide. An exemplary polypeptide sequence of a human DAP-10 (e.g., UniProt Protein Accession: Q9UBK5, found at URL www.uniprot.org/uniprot/Q9UBK5) an exemplary intracellular signaling domain underlined is SEQ ID NO: 76. An intracellular signaling domain can be a portion of the exemplary to intracellular signaling domain underlined in SEQ ID NO: 76, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 76. 
     
       
         
           
               
            
               
                 (Human DAP-10 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 76 
               
            
           
           
               
            
               
                 MIHLGHILFLLLLPVAAAQTTPGERSSLPAFYPGTSGSCSGCGSLSLPLL 
               
               
                   
               
               
                 AGLVAADAVASLLIVGAVF   LCARPRRSPAQEDGKVYINMPGRG     
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical (or is identical) to amino acids 180 to 220 of SEQ ID NO: 77, or a fragment thereof. 
     
       
         
           
               
               
            
               
                   
                 (DAP-10 intracellular signaling domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 77 
               
            
           
           
               
               
            
               
                   
                 LCARPRRSPAQEDGKVYINMPGRG 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain is an intracellular signaling domain from a mouse DAP-10 polypeptide. An exemplary polypeptide sequence of a mouse DAP-10 (e.g., a polypeptide as shown in UniProt Protein Accession: Q9QUJO, found at URL www.uniprot.org/uniprot/Q9QUJ0) with an intracellular signaling domain underlined is SEQ ID NO: 78. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 78, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 78. 
     
       
         
           
               
            
               
                 (Mouse DAP-10 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 78 
               
            
           
           
               
            
               
                 MDPPGYLLFLLLLPVAASQTSAGSCSGCGTLSLPLLAGLVAADAVMSLLI 
               
               
                   
               
               
                 VGVVFV   CMRPHGRPAQEDGRVYINMPGRG     
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from DAP-12 (also variously known as TYROBP, DAP12, KARAP, PLOSL, and TYRO protein tyrosine kinase binding protein). See e.g., Lanier,  Immunol Rev., Jan; 227(1):150-60. doi: 10.1111/j.1600-065X.2008.00720.x, 2009, incorporated by reference herein in its entirety. DAP-12 is a transmembrane signaling adaptor that contains a YxxM ITAM motif in its cytoplasmic domain. In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a human DAP-12 polypeptide. An exemplary polypeptide sequence of a human DAP-12 (e.g., UniProt Protein Accession: 043914, found at URL www.uniprot.org/uniprot/O43914) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 79. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 79, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 79. 
     
       
         
           
               
            
               
                 (Human DAP-12 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 79 
               
            
           
           
               
            
               
                 MGGLEPCSRLLLLPLLLAVSGLRPVQAQAQSDCSCSTVSPGVLAGIVMGD 
               
               
                   
               
               
                 LVLTVLIALAV   YFLGRLVPRGRGAAEAATRKQRITETESPYQELQGQRSD     
               
               
                   
               
               
                 
                   
                     VYSDLNTQRPYYK 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be or can include a sequence that is at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical (or is identical) to amino acids 180 to 220 of SEQ ID NO: 80, or a fragment thereof. 
     
       
         
           
               
            
               
                 (DAP-12 intracellular signaling domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 80 
               
            
           
           
               
            
               
                 YFLGRLVPRGRGAAEAATRKQRITETESPYQELQGQRSDVYSDLNTQRPY 
               
               
                   
               
               
                 YK 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain from a mouse DAP-12 polypeptide. An exemplary polypeptide sequence of a mouse DAP-12 (e.g., a polypeptide as shown in UniProt Protein Accession: 054885, found at URL www.uniprot.org/uniprot/054885) with an exemplary intracellular signaling domain underlined is SEQ ID NO: 81. An intracellular signaling domain can be a portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 81, or a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to the portion of the exemplary intracellular signaling domain underlined in SEQ ID NO: 81. 
     
       
         
           
               
            
               
                 (Mouse DAP-12 polypeptide with an exemplary 
               
               
                 intracellular signaling domain underlined) 
               
            
           
           
               
            
               
                 SEQ ID NO: 81 
               
            
           
           
               
            
               
                 MGALEPSWCLLFLPVLLTVGGLSPVQAQSDTFPRCDCSSVSPGVLAGIVL 
               
               
                   
               
               
                 GDLVLTLLIALAV   YSLGRLVSRGQGTAEGTRKQHIAETESPYQELQGQRP     
               
               
                   
               
               
                 
                   
                     EVYSDLNTQRQYYR 
                   
                 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain can be an intracellular signaling domain of B7-H3 (also called CD276). An exemplary sequence of human B7-H3 polypeptide is SEQ ID NO: 82. An exemplary intracellular signaling domain can be amino acids 488 to 534 of SEQ ID NO: 82. An intracellular signaling domain can be a sequence that is at least 50% identical (e.g., at least 55%, at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical) to amino acids 488 to 534 of SEQ ID NO: 82. 
     
       
         
           
               
               
            
               
                   
                 (Human B7-H3 polypeptide) 
               
            
           
           
               
            
               
                 SEQ ID NO: 82 
               
            
           
           
               
               
            
               
                   
                 mlrrrgspgm gvhvgaalga lwfcltgale vqvpedpvva 
               
               
                   
                   
               
               
                   
                 lvgtdatlcc sfspepgfsl aqlnliwqlt dtkqlvhsfa 
               
               
                   
                   
               
               
                   
                 egqdqgsaya nrtalfpdll aqgnaslrlq rvrvadegsf 
               
               
                   
                   
               
               
                   
                 tcfvsirdfg saavslqvaa pyskpsmtle pnkdlrpgdt 
               
               
                   
                   
               
               
                   
                 vtitcssyqg ypeaevfwqd gqgvpltgnv ttsqmaneqg 
               
               
                   
                   
               
               
                   
                 lfdvhsilrv vlgangtysc lvrnpvlqqd ahssvtitpq 
               
               
                   
                   
               
               
                   
                 rsptgavevq vpedpvvalv gtdatlrcsf spepgfslaq 
               
               
                   
                   
               
               
                   
                 lnliwqltdt kqlvhsfteg rdqgsayanr talfpdllaq 
               
               
                   
                   
               
               
                   
                 gnaslrlqrv rvadegsftc fvsirdfgsa avslqvaapy 
               
               
                   
                   
               
               
                   
                 skpsmtlepn kdlrpgdtvt itcssyrgyp eaevfwqdgq 
               
               
                   
                   
               
               
                   
                 gvpltgnvtt sqmaneqglf dvhsvlrvvl gangtysclv 
               
               
                   
                   
               
               
                   
                 rnpvlqqdah gsvtitgqpm tfppealwvt vglsvclial 
               
               
                   
                   
               
               
                   
                 lvalafvcwr kikqsceeen agaedqdgeg egsktalqpl 
               
               
                   
                   
               
               
                   
                 khsdskeddg qeia 
               
            
           
         
       
     
     In some embodiments, an intracellular signaling domain (e.g., one or more intracellular signaling domains) can be a variant polypeptide sequence that differs by at least one amino acid from an intracellular signaling domain of a wildtype protein selected from the group consisting of: Lck, FasR, TNFR-I, TNFR-II, LIGHT, ICOS, 4-1BB, CD27, OX40, CD2, CD5, CD30, CD40, CD27, CD28, CD11a, ICAM-1, B7-H3, NKG2C, GITR, DAP-10, and DAP-12. A variant polypeptide sequence, as used herein (e.g., in reference to an intracellular signaling domain) is an intracellular signaling domain having a polypeptide sequence that is at least about 80% (e.g., at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%) identical to the wild type polypeptide sequence of an intracellular signaling domain (e.g., of a protein selected from the group consisting of: Lck, FasR, TNFR-I, TNFR-II, LIGHT, ICOS, 4-1BB, CD27, OX40, CD2, CD5, CD30, CD40, CD27, CD28, CD11a, ICAM-1, B7-H3, NKG2C, GITR, DAP-10, and DAP-12). In some embodiments, a single-chain or a multi-chain CAR comprises two or more intracellular signaling domains, at least one of which comprises a wild type intracellular signaling domain polypeptide sequence, and at least one of which comprises a variant intracellular signaling domain polypeptide sequence. In some embodiments, a CAR comprises two or more variant intracellular signaling domains. In some embodiments, a CAR comprises a variant intracellular signaling domain comprising at least the amino acid residues that play a role in mediating signaling. For example, a CAR can comprise a variant intracellular signaling domain comprising at least the amino acid residues that play a role in interacting with various tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) proteins including, but not limited to, TRAF1, TRAF2, TRAF3, and/or TRAF 5. See, e.g., Xie, TRAF molecules in cell signaling and in human diseases,  J. Mol. Signal.,  8(1):7. doi: 10.1186/1750-2187-8-7, 2013. Those of ordinary skill in the art will be aware of known structural and functional features of individual intracellular signaling domains and their partners that play a role in mediating signaling, will be able to select appropriate amino acid residues of endogenous intracellular signaling domains for use in designing variant intracellular signaling domains for use in the single-chain and multi-chain CARs described herein. 
     Immunoreceptor Tyrosine-Based Activation Motifs (ITAMs) 
     ITAMs include a tyrosine separated from a leucine or isoleucine by any two other amino acids, and can thus be represented as, e.g., Tyr-X-X-Leu/Ile. ITAMs are typically repeated (e.g., two or more times) in the cytoplasmic tails of certain cell surface proteins of the immune system, and are typically separated by between six and eight amino acids. 
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes an ITAM, or portion thereof, from an endogenous mammalian (e.g., human) polypeptide, wherein endogenous mammalian (e.g., human) polypeptide is selected from the group of: CD3ζ (also referred to as CD3 zeta), CD3−(CD3 delta), CD3ε (CD3 epsilon), CD3γ (CD3 gamma), DAP12, FCεRlγ (Fc epsilon receptor I gamma chain), FcRy, FcRft, CD35, CD22, CD79A (antigen receptor complex-associated protein alpha chain), CD79B (antigen receptor complex-associated protein beta chain), and CD66d. The letters “CD” is the previous sentence stand for “Cluster of Differentiation.” For example, CD3 stands for “Cluster of Differentiation 3.” 
     Any ITAM, or portion thereof, that serves to mediate signaling in an endogenous mammalian (e.g., human) transmembrane protein suitable for use in accordance with compositions and methods disclosed herein. In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes an ITAM, or portion thereof, from human CD3 zeta (e.g. Accession No. P20963, e.g., an ITAM present in amino acids 52-164 of SEQ ID NO: 7, or a portion thereof; or SEQ ID NO: 83 or a portion thereof). In some embodiments, an ITAM comprises a sequence that is at least 80% (e.g., at least 82%, at least 84%, at least 86%, at least 88%, at least 90%, at least 92%, at least 94%, at least 96%, at least 98%, at least 99%, or 100% identical to: the sequence of amino acids 52-165 of SEQ ID NO: 7 (or a portion thereof), or the sequence of SEQ ID NO: 83 (or a portion thereof). 
     
       
         
           
               
            
               
                 SEQ ID NO: 7 
               
            
           
           
               
            
               
                 MKWKALFTAAILQAQLPITEAQSFGLLDPKLCYLLDGILFIYGVILTALF 
               
               
                   
               
               
                 LRVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKP 
               
               
                   
               
               
                 QRRKNPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTATK 
               
               
                   
               
               
                 DTYDALHMQALPPR 
               
               
                   
               
               
                 (Human CD3 zeta signaling domain) 
               
            
           
           
               
            
               
                 SEQ ID NO: 83 
               
            
           
           
               
            
               
                 LRVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKP 
               
               
                   
               
               
                 RRKNPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTATKD 
               
               
                   
               
               
                 TYDALHMQALPPR 
               
               
                   
               
               
                 (cDNA encoding human CD3 zeta signaling 
               
               
                 domain of SEQ ID NO: 83) 
               
            
           
           
               
            
               
                 SEQ ID NO: 84 
               
            
           
           
               
            
               
                 ctgagagtgaagttcagcaggagcgcagacgcccccgcgtaccagcaggg 
               
               
                   
               
               
                 ccagaaccagctctataacgagctcaatctaggacgaagagaggagtacg 
               
               
                   
               
               
                 atgttttggacaagagacgtggccgggaccctgagatggggggaaagccg 
               
               
                   
               
               
                 agaaggaagaaccctcaggaaggcctgtacaatgaactgcagaaagataa 
               
               
                   
               
               
                 gatggcggaggcctacagtgagattgggatgaaaggcgagcgccggaggg 
               
               
                   
               
               
                 gcaaggggcacgatggcctttaccagggtctcagtacagccaccaaggac 
               
               
                   
               
               
                 acctacgacgcccttcacatgcaggccctgccccctcgc 
               
            
           
         
       
     
     As will be appreciated by those of ordinary skill in the art, certain polypeptides have two or more isoforms that differ at least in their primary polypeptide sequence. For example, different isoforms can be generated as a result of alternative splicing. A single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor disclosed herein can include an ITAM that includes a sequence of amino acids from any isoform of an endogenous mammalian transmembrane polypeptide having an ITAM including, e.g., a mammalian (e.g., human) isoform of: CD3ζ, CD3D, CD3E, CD3G, DAP12, FCER1G, FcRy, FcRft, CD35, CD22, CD79A, CD79B, or CD66d. 
     In some embodiments, an ITAM, or portion thereof, of a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes a sequence of amino acids having one or more (e.g., two, three, four, or five) amino acid substitutions, deletions, or additions as compared to an ITAM of one or more of an ITAM in an endogenous mammalian (e.g., human) transmembrane protein, such as, CD3ζ, CD3D, CD3E, CD3G, DAP12, FCER1G, FcRy, FcRft, CD35, CD22, CD79A, CD79B, or CD66d. For example, the tyrosine and leucine or isoleucine of an ITAM could be retained, while the two amino acids separating them could be replaced with different amino acids. In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes an ITAM that is a chimeric ITAM having portions of an ITAM from two or more endogenous mammalian (e.g., human) transmembrane polypeptides including, without limitation, CD3ζ, CD3D, CD3E, CD3G, DAP12, FCER1G, FcRy, FcRft, CD35, CD22, CD79A, CD79B, or CD66d (including, without limitation, a mammalian or human homolog of any of these polypeptides), such that the two or more ITAM portions together constitute a functional ITAM. In some embodiments, such a portion of a chimeric ITAM can include one or more amino acid substitutions, deletions, or additions as compared to a corresponding portion of a wild type ITAM. 
     In some embodiments, a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor includes two or more ITAMs, e.g., two, three, four, or five, or more ITAMs. In some embodiments, the two or more ITAMs are identical (e.g., they have the same amino acid sequence). In some embodiments, the two or more ITAMs are not identical. For example, the ITAMs can be selected from different endogenous mammalian (e.g., human) transmembrane polypeptides including, without limitation, CD3, CD3D, CD3E, CD3G, DAP12, FCER1G, FcRy, FcRft, CD35, CD22, CD79A, CD79B (including, without limitation, a mammalian or human homolog of any of these polypeptides). In some embodiments, the two or more ITAMs can differ from each other by one or more amino acid substitutions, deletions, or additions. 
     Nucleic Acids 
     Also provided herein are nucleic acids that encode any of the single-chain chimeric antigen receptors and multi-chain chimeric antigen receptors described herein. Also provided herein are a set of nucleic acids that encode one or more single-chain polypeptides that make up a multi-chain chimeric antigen receptor described herein (e.g., where at least one single-chain polypeptide that makes up the multi-chain chimeric antigen receptor is encoded by each nucleic acid in the set). 
     Vectors 
     Provided herein are vectors that include any of the nucleic acids provided herein. A “vector” according to the present disclosure is a polynucleotide capable of inducing the expression of a recombinant protein (e.g., a single-chain chimeric antigen receptor or a multi-chain chimeric antigen receptor) in a mammalian cell. A vector provided herein can be, e.g., in circular or linearized form. Non-limiting examples of vectors include plasmids, SV40 vectors, adenoviral viral vectors, and adeno-associated virus (AAV) vectors. Non-limiting examples of vectors include lentiviral vectors or retroviral vectors, e.g., gamma-retroviral vectors. See, e.g., Carlens et al.,  Exp. Hematol.  28(10:1137-1146, 2000; Park et al.,  Trends Biotechnol.  29(11):550-557, 2011; and Alonso-Camino et al.,  Mol. Ther. Nucleic Acids  2:e93, 2013. Non-limiting examples of retroviral vectors include those derived from Moloney murine leukemia virus, myeloproliferative sarcoma virus, murine embryonic stem cell virus, murine stem cell virus, spleen focus forming virus, or adeno-associated virus. Non-limiting examples of retroviral vectors are described in, e.g., U.S. Pat. Nos. 5,219,740 and 6,207,453; Miller et al.,  BioTechniques  7:980-990, 1989; Miller,  Human Gene Therapy  1:5-14, 1990; Scarpa et al.,  Virology  180:849-852, 1991; Burns et al.,  Proc. Natl. Acad. Sci. U.S.A.  90:8033-8037, 1993; and Boris-Lawrie et al.,  Cur. Opin. Genet. Develop.  3:102-109, 1993. Exemplary lentiviral vectors are described in, e.g., Wang et al.,  J. Immunother.  35(9):689-701, 2003; Cooper et al.,  Blood  101:1637-1644, 2003; Verhoeyen et al.,  Methods Mol. Biol.  506:97-114, 2009; and Cavalieri et al.,  Blood  102(2):497-505, 2003. 
     Exemplary vectors, in which any of the nucleic acids provided herein can be inserted, are described in, e.g., Ausubel et al., Eds. “Current Protocols in Molecular Biology” Current Protocols, 1993; and Sambrook et al., Eds. “Molecular Cloning: A Laboratory Manual,” 2nd ed., Cold Spring Harbor Press, 1989. 
     In some embodiments, the vectors further include a promoter and/or enhancer operably linked to any of the nucleic acids described herein. Non-limiting examples of promoters include promoters from human cytomegalovirus (CMV), mouse phosphoglycerate kinase 1, polyoma adenovirus, thyroid stimulating hormone α, vimentin, simian virus 40 (SV40), tumor necrosis factor, β-globin, α-fetoprotein, γ-globin, β-interferon, γ-glutamyl transferase, human ubiquitin C (UBC), mouse mammary tumor virus (MMTV), Rous sarcoma virus, glyceraldehyde-3-phosphate dehydrogenase, (3-actin, metallothionein II (MT II), amylase, human EF1α, cathepsin, MI muscarinic receptor, retroviral LTR (e.g. human T-cell leukemia virus HTLV), AAV ITR, interleukin-2, collagenase, platelet-derived growth factor, adenovirus E2, stromelysin, murine MX, rat insulin, glucose regulated protein 78, human immunodeficiency virus, glucose regulated protein 94, α-2-macroglobulin, MHC class I, HSP70, proliferin, immunoglobulin light chain, T-cell receptor, HLA DQα, HLA DQβ, interleukin-2 receptor, MHC class II, prealbumin (transthyretin), elastase I, albumin, c-fos, neural cell adhesion molecule (NCAM), H2B histone, rat growth hormone, human serum amyloid (SAA), muscle creatinine kinase, troponin I (TN I), and Gibbon Ape Leukemia Virus (GALV). In some embodiments, the promoter may be an inducible promoter or a constitutive promoter. Additional examples of promoters are known in the art. 
     In some examples, the vectors provided herein further include a poly(A) sequence, which is operably linked and positioned 3′ to the sequence encoding the single-chain chimeric antigen receptor or any of the polypeptides that make up the multi-chain chimeric antigen receptor. Non-limiting examples of a poly(A) sequence include those derived from bovine growth hormone (Woychik et al.,  Proc. Natl. Acad. Sci. U.S.A.  81(13): 3944-3948, 1984, and U.S. Pat. No. 5,122, 458), mouse-β-globin, mouse-a-globin (Orkin et al.,  EMBO J.  4(2): 453-456, 1985), human collagen, polyoma virus (Batt et al.,  Mol. Cell Biol.  15(9):4783-4790, 1995), the Herpes simplex virus thymidine kinase gene (HSV TK), IgG heavy chain gene polyadenylation signal (U.S. Patent Application Publication No. 2006/0040354), human growth hormone (hGH) (Szymanski et al.,  Mol. Therapy  15(7):1340-1347, 2007), SV40 poly(A) site, e.g., SV40 late and early poly(A) site (Schek et al.,  Mol. Cell Biol.  12(12):5386-5393, 1992). In some embodiments, the poly(A) sequence includes a highly conserved upstream element (AATAAA). The this AATAAA sequence can, e.g., be substituted with other hexanucleotide sequences with homology to AATAAA which are capable of signaling polyadenylation, including, e.g., ATTAAA, AGTAAA, CATAAA, TATAAA, GATAAA, ACTAAA, AATATA, AAGAAA, AATAAT, AAAAAA, AATGAA, AATCAA, AACAAA, AATCAA, AATAAC, AATAGA, AATTAA, and AATAAG. See, e.g., WO 06012414 A2). 
     A poly(A) sequence can, e.g., be a synthetic polyadenylation site. See, e.g., Levitt el al,  Genes Dev.  3(7): 1019-1025, 1989). In some examples, a poly(A) sequence can be the polyadenylation signal of soluble neuropilin-1: AAATAAAATACGAAATG (SEQ ID NO: 85). Additional examples of poly(A) sequences are known in the art. Additional examples and aspects of vectors are also known in the art. 
     Methods of Introducing a Nucleic Acid or Vectors into a Mammalian Cell 
     A variety of different methods known in the art can be used to introduce any of the lo nucleic acids and vectors disclosed herein into a mammalian cell (e.g., any of the mammalian cells described herein, e.g., any of the T cells (e.g., human T cells) described herein). Non-limiting examples of methods that can be used to introduce a nucleic acid or vector into a mammalian cell include lipofection, transfection, electroporation, microinjection, calcium phosphate transfection, dendrimer-based transfection, cationic polymer transfection, cell squeezing, sonoporation, optical transfection, impalection, hydrodynamic delivery, magnetofection, viral transduction (e.g., adenoviral and lentiviral transduction), and nanoparticle transfection. Additional methods of introducing a nucleic acid or vector into a mammalian cell are known in the art. 
     Mammalian Cells 
     Also provided herein are mammalian cells that include any of the nucleic acids or vectors described herein. In some embodiments, the mammalian cell is previously obtained from a subject (e.g., a human subject, e.g., a human subject identified or diagnosed as having a cancer). 
     Non-limiting examples of mammalian cells include a T cell (e.g., a human T cell). Non limiting examples of T cells (e.g., human T cells) include, e.g., an immature thymocyte, a peripheral blood lymphocyte, a naïve T cell, a pluripotent T H  cell precursor, a lymphoid progenitor cell, a T reg  cell, a memory T cell, a T H 17 cell, a T H 22 cell, a T H 9 cell, a T H 2 cell, a T H 1 cell, a T H 3 cell, γδ T cell, an αβ T cell, a Treg cell, and a tumor-infiltrating T cell. Additional examples of a T cell (e.g., a human T cell) include a CD8 +  T cell, a CD4 +  T cell, a memory T cell, a Treg cell, natural killer T cell, B cell, and a monocyte. Additional examples of mammalian cells include a mast cell, a macrophage, a neutrophil, a dendritic cell, a basophil, an eosinophil, and a natural killer cell. 
     Compositions and Kits 
     Also provided herein are compositions (e.g., pharmaceutical compositions) that include any of the nucleic acids, vectors, sets of nucleic acids, sets of vectors, or mammalian cells described herein. For example, provided herein is a composition that includes any of the nucleic acids or sets of nucleic acids described herein, or any of the vectors or sets of vectors provided herein and a pharmaceutically acceptable solvent or carrier. 
     In some embodiments, a composition can be any of the mammalian cells described herein (e.g., any of the mammalian cells described herein previously obtained from a subject, e.g., a subject identified or diagnosed as having a cancer) comprising a nucleic acid encoding any of the single-chain chimeric antigen receptors or multi-chain chimeric antigen receptors described herein. In a composition including any of the mammalian cells described herein, the composition can further include a cell culture medium or a pharmaceutically acceptable buffer (e.g., phosphate-buffered saline). A composition that includes any of the mammalian cells described herein can be formulated for intravenous or intraarterial administration. 
     Also provided are kits that include one or more of any of the compositions described herein. In some embodiments, a kit can further include instructions for performing any of the methods described herein. 
     Methods of Treating a Cancer in a Subject 
     Also provided herein are methods of treating a cancer in a subject (e.g., a human, a mouse, a rabbit, a rat, a horse, a dog, a monkey, or an ape) that include administering a therapeutically effective amount of any of the mammalian cells including a nucleic acid encoding any of the single-chain chimeric antigen receptors described herein or any of the multi-chain chimeric antigen receptors described herein. In some examples of these methods, the mammalian cell is a T cell (e.g., a CD8+ T cell, a CD4+ T cell, a memory T cell, a Treg cell, and a natural killer T cell). In some examples, the mammalian cell (e.g., any of the mammalian cells described herein) is a mammalian cell previously obtained from a subject (e.g., a subject that has been identified or diagnosed as having a cancer, e.g., any of the cancers described herein). Some embodiments of these methods further include obtaining the mammalian cell from the subject. 
     Some embodiments of these methods further include introducing a nucleic acid encoding the the single-chain chimeric antigen receptor described herein or the multi-chain chimeric antigen receptor described into a mammalian cell (e.g., any of the mammalian cells described herein or known in the art) to generate the mammalian cell that is administered to the subject. 
     Non-limiting examples of cancer that can be treated using any of the methods provided herein include: acute lymphoblastic leukemia, acute myeloid leukemia, adrenocortical carcinoma, Kaposi sarcoma, lymphoma, anal cancer, appendix cancer, teratoid/rhabdoid tumor, basal cell carcinoma, bile duct cancer, bladder cancer, bone cancer, brain cancer, breast cancer, bronchial tumor, carcinoid tumor, cardiac tumor, cervical cancer, chordoma, chronic lymphocytic leukemia, chronic myeloproliferative neoplasm, colon cancer, colorectal cancer, craniopharyngioma, bile duct cancer, endometrial cancer, ependymoma, esophageal cancer, esthesioneuroblastoma, Ewing sarcoma, eye cancer, fallopian tube cancer, gallbladder cancer, gastric cancer, gastrointestinal carcinoid tumor, gastrointestinal stromal tumor, germ cell tumor, hairy cell leukemia, head and neck cancer, heart cancer, liver cancer, hypopharngeal cancer, pancreatic cancer, kidney cancer, laryngeal cancer, chronic myelogenous leukemia, lip and oral cavity cancer, lung cancer, melanoma, Merkel cell carcinoma, mesothelioma, mouth cancer, oral cancer, osteosarcoma, ovarian cancer, penile cancer, pharyngeal cancer, prostate cancer, rectal cancer, salivary gland cancer, skin cancer, small intestine cancer, soft tissue sarcoma, gastric cancer, testicular cancer, throat cancer, thyroid cancer, urethral cancer, uterine cancer, vaginal cancer, and vulvar cancer. 
     In some embodiments of any of these methods, the methods result in a decrease in the tumor burden (e.g., tumor mass and/or volume) in a subject. For example, any of the methods described herein can result in at least about 1% to about 99% (e.g., about 1% to about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, about 10%, or about 5% (inclusive); about 2% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, about 10%, or about 5% (inclusive); about 3% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, about 10%, or about 5% (inclusive); about 5% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, or about 10% (inclusive); about 10% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, or about 15% (inclusive); about 15% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, or about 20% (inclusive); about 20% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, or about 25% (inclusive); about 25% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, or about 30% (inclusive); about 30% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, or about 35% (inclusive); about 35% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, or about 40% (inclusive); about 40% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, or about 45% (inclusive); about 45% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, or about 50% (inclusive); about 50% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, or about 55% (inclusive); about 55% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, or about 60% (inclusive); about 60% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, or about 65% (inclusive); about 65% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, or about 70% (inclusive); about 70% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, or about 72% (inclusive); about 72% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, or about 74% (inclusive); about 74% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, or about 76% (inclusive); about 76% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, or about 78% (inclusive); about 78% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, or about 80% (inclusive); about 80% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, or about 82% (inclusive); about 82% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, or about 84% (inclusive); about 84% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, or about 86% (inclusive); about 86% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, or about 88% (inclusive); about 88% to about 99%, about 98%, about 96%, about 94%, about 92%, or about 90% (inclusive); about 90% to about 99%, about 98%, about 96%, about 94%, or about 92% (inclusive); about 92% to about 99%, about 98%, about 96%, or about 94% (inclusive); about 94% to about 99%, about 98%, or about 96% (inclusive); or about 96% to about 99% or about 98% (inclusive)) reduction in the tumor burden in a subject (e.g., as compared to the tumor burden in the subject prior to treatment). 
     In some embodiments, the methods result in a decrease in the rate of progression of a cancer in the subject. For example, any of the methods described herein can result in at least about 1% to about 99% (e.g., about 1% to about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, about 10%, or about 5% (inclusive); about 2% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, about 10%, or about 5% (inclusive); about 3% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, about 10%, or about 5% (inclusive); about 5% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, or about 10% (inclusive); about 10% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, or about 15% (inclusive); about 15% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, or about 20% (inclusive); about 20% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, about 30%, or about 25% (inclusive); about 25% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, about 35%, or about 30% (inclusive); about 30% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, about 40%, or about 35% (inclusive); about 35% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, about 45%, or about 40% (inclusive); about 40% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, about 50%, or about 45% (inclusive); about 45% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, about 55%, or about 50% (inclusive); about 50% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, about 60%, or about 55% (inclusive); about 55% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, about 65%, or about 60% (inclusive); about 60% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, about 70%, or about 65% (inclusive); about 65% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, about 72%, or about 70% (inclusive); about 70% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, about 74%, or about 72% (inclusive); about 72% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, about 76%, or about 74% (inclusive); about 74% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, about 78%, or about 76% (inclusive); about 76% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, about 80%, or about 78% (inclusive); about 78% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, about 82%, or about 80% (inclusive); about 80% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, about 84%, or about 82% (inclusive); about 82% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, about 86%, or about 84% (inclusive); about 84% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, about 88%, or about 86% (inclusive); about 86% to about 99%, about 98%, about 96%, about 94%, about 92%, about 90%, or about 88% (inclusive); about 88% to about 99%, about 98%, about 96%, about 94%, about 92%, or about 90% (inclusive); about 90% to about 99%, about 98%, about 96%, about 94%, or about 92% (inclusive); about 92% to about 99%, about 98%, about 96%, or about 94% (inclusive); about 94% to about 99%, about 98%, or about 96% (inclusive); or about 96% to about 99% or about 98% (inclusive)) reduction in the rate of progression of a cancer in a subject (e.g., as compared to the rate of progression of a cancer in the subject prior to treatment or in a control subject or a control population of subjects having the same cancer and administered no treatment or a different treatment). 
     In some embodiments of any of these methods, the methods result in an increase in the time of survival of a cancer in a subject. For example, any of the methods described herein can result in an about 1% to about 800% (e.g., about 1% to about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, about 200%, about 150%, about 100%, about 80%, about 60%, about 40%, about 20%, about 10%, or about 5% (inclusive); about 5% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, about 200%, about 150%, about 100%, about 80%, about 60%, about 40%, about 20%, or about 10% (inclusive); about 10% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, about 200%, about 150%, about 100%, about 80%, about 60%, about 40%, or about 20% (inclusive); about 20% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, about 200%, about 150%, about 100%, about 80%, about 60%, or about 40% (inclusive); about 40% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, about 200%, about 150%, about 100%, about 80%, or about 60% (inclusive); about 60% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, about 200%, about 150%, about 100%, about 80% (inclusive); about 80% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, about 200%, about 150%, or about 100% (inclusive); about 100% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, about 200%, or about 150% (inclusive); about 150% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, about 250%, or about 200% (inclusive); about 200% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, about 300%, or about 250% (inclusive); about 250% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, about 350%, or about 300% (inclusive); about 300% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, about 400%, or about 350% (inclusive); about 350% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, about 450%, or about 400% (inclusive); about 400% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, about 500%, or about 450% (inclusive); about 450% to about 800%, about 750%, about 700%, about 650%, about 600%, about 550%, or about 500% (inclusive); about 500% to about 800%, about 750%, about 700%, about 650%, about 600%, or about 550% (inclusive); about 550% to about 800%, about 750%, about 700%, about 650%, or about 600% (inclusive); about 600% to about 800%, about 750%, about 700%, or about 650% (inclusive); about 650% to about 800%, about 750%, or about 700% (inclusive); about 700% to about 800% or about 750% (inclusive); or about 750% to about 800% (inclusive)) increase in the time of survival of a cancer in a subject (e.g., as compared to the time of survival for a control subject or a population of control subjects having the same cancer and receiving no treatment or a different treatment). 
     EXAMPLES 
     The invention is further described in the following examples, which do not limit the scope of the invention described in the claims. 
     Example 1 
     Percent Lysis of Cell Lines After Co-culturing with CAR-T Cells Expressing Various CAR Constructs 
     CAR-T cells were generated to express CARs that include the anti-CD19 FMC63 ScFv, the CD8 hinge region, the CD8 transmembrane region, and various co-stimulatory domains. The X axis of  FIG. 1  shows the intracellular signaling domain(s) and immunoreceptor tyrosine-based activation motifs in each tested construct. The Y axis of  FIG. 1  shows the percentage of target cells that were lysed in the presence of the various CAR-T cells expressing the indicated CARs. 
     For the various CAR constructs tested and shown in  FIG. 1 , the following intracellular sequences were used: 
     
       
         
           
               
            
               
                 4-1BB 
               
            
           
           
               
            
               
                 (SEQ ID NO: 45) 
               
            
           
           
               
            
               
                 KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL 
               
               
                   
               
               
                 GITR 
               
            
           
           
               
            
               
                 (SEQ ID NO: 74) 
               
            
           
           
               
            
               
                 QLGLHIWQLRSQCMWPRETQLLLEVPPSTEDARSCQFPEEERGERSAEEK 
               
               
                   
               
               
                 GRLGDLWV 
               
               
                   
               
               
                 OX40 
               
            
           
           
               
            
               
                 (SEQ ID NO: 54) 
               
            
           
           
               
            
               
                 ALYLLRRDQRLPPDAHKPPGGGSFRTPIQEEQADAHSTLAKI 
               
               
                   
               
               
                 CD27 
               
            
           
           
               
            
               
                 (SEQ ID NO: 51) 
               
            
           
           
               
            
               
                 QRRKYRSNKGESPVEPAEPCHYSCPREEEGSTIPIQEDYRKPEPACSP 
               
               
                   
               
               
                 CD40 
               
            
           
           
               
            
               
                 (SEQ ID NO: 86) 
               
            
           
           
               
            
               
                 KKVAKKPTNKAPHPKQEPQEINFPDDLPGSNTAAPVQETLHGCQPVTQED 
               
               
                   
               
               
                 GKESRISVQERQ 
               
               
                   
               
               
                 CD28 
               
            
           
           
               
            
               
                 (SEQ ID NO: 65) 
               
            
           
           
               
            
               
                 RSKRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAYRS 
               
               
                   
               
               
                 DAP10 
               
            
           
           
               
            
               
                 (SEQ ID NO: 77) 
               
            
           
           
               
            
               
                 LCARPRRSPAQEDGKVYINMPGRG 
               
               
                   
               
               
                 DAP12 
               
            
           
           
               
            
               
                 (SEQ ID NO: 80) 
               
            
           
           
               
            
               
                 YFLGRLVPRGRGAAEAATRKQRITETESPYQELQGQRSDVYSDLNTQRPY 
               
               
                   
               
               
                 YK 
               
               
                   
               
               
                 CD3z 
               
            
           
           
               
            
               
                 (SEQ ID NO: 83) 
               
            
           
           
               
            
               
                 LRVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKP 
               
               
                   
               
               
                 RRKNPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTATKD 
               
               
                   
               
               
                 TYDALHMQALPPR 
               
            
           
         
       
     
     Constructs were expressed in primary T cells at roughly equivalent surface levels, cultured for fourteen days after CD3/CD28 activation and transduction, and 20,000 CAR T cells were plated at 10:1 target-to-effector cell ratios with the CD19+luciferase transduced NALM6_fluc cell line. Nalm-6 was obtained from the ATCC, and transduced in-house. 24 hours after co-culture, NALM6_fluc lysis was quantified using a luminimeter and the percent lysis was calculated by subtracting the observed luciferase activity for each CAR-T construct from that observed in untreated cells at each concentration of 20,000 CAR-T cells. UT=Untransduced. 
     Example 2 
     CD69 Expression of CAR-T Cells Expressing Various CAR Constructs 
     CAR-T cells were generated to express CARs that include the anti-CD19 FMC63 ScFv, the CD8 hinge region, the CD8 transmembrane region, and various co-stimulatory domains using standard molecular biology techniques. The X axis of  FIG. 2  shows the intracellular signaling domain(s) and immunoreceptor tyrosine-based activation motifs in each tested construct. The sequences of the various intracellular signaling domain(s) and immunoreceptor tyrosine-based activation motifs are as described in Example 1. The Y axis of  FIG. 2  shows the expression of CD69. MFI=median fluorescence intensity. 
     Constructs were expressed in primary T cells at roughly equivalent surface levels, cultured for fourteen days after CD3/CD28 activation and transduction, and plated at 1:1 ratios with the CD19+ cell line NALM6. 24 hours after co-culture, expression of activation marker CD69 was evaluated in the CAR-T cells by flow cytometry. UT=Untransduced 
     Example 3 
     Cytokine Production of CAR-T Cells Expressing Various CAR Constructs 
     CAR-T cells were generated to express CARs that include the anti-CD19 FMC63 ScFv, the CD8 hinge region, the CD8 transmembrane region, and various co-stimulatory domains using standard molecular biology techniques. The X axes of  FIGS. 3  A-C show the intracellular signaling domain(s) and immunoreceptor tyrosine-based activation motifs in each tested construct. The sequences of the various intracellular signaling domain(s) and immunoreceptor tyrosine-based activation motifs are as described in Example 1. The Y axes of  FIGS. 3  A-C show the expression of TNF-alpha, interferon gamma, and interleukin 2 cytokines, respectively. 
     Constructs were expressed in primary T cells at roughly equivalent surface levels, cultured for fourteen days after CD3/CD28 activation and transduction, and plated at 1:1 ratios with the CD19+cell line NALM6. 24 hours after co-culture, supernatant was collected from each sample and Luminex Assays Millipore/Sigma (Cat. Number HSTCMAG28SPMX21) were performed to quantitate the levels of TNF-alpha, interferon gamma, and interleukin 2 cytokines. The cytokine concentrations shown in  FIGS. 3A-C  are displayed in pg/mL. UT=Untransduced. 
     Other Embodiments 
     It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.