Genetically engineered T cells bearing chimeric nanoconstructed receptors harboring TAG-72-specific camelid single domain antibodies as targeting agents.
Despite the preclinical success of adoptive therapy with T cells bearing chimeric nanoconstructed antigen receptors (CARs), certain limitations of this therapeutic approach such as the immunogenicity of the antigen binding domain, the emergence of tumor cell escape variants and the blocking capacity of soluble antigen still remain. Here, we address these issues using a novel CAR binding moiety based on the oligoclonal camelid single domain antibodies. A unique set of 13 single domain antibodies were selected from an immunized camel phage library based on their target specificity and binding affinity. A combination of these single domain antibodies was used to generate four tumor associated glycoprotein (TAG-72)-specific CARs harboring an identical antigen binding site, but with different signaling and spacer domains. Although all four CARs were functionally active against the TAG-72 expressing tumor cells, the combination of CD3ζ, OX40, CD28 as well as the CH3-CH2-hinge-hinge domains most efficiently triggered T cell activation. Importantly, CAR mediated functions were not blocked by the soluble TAG-72 antigen at a supraphysiological concentration. Our approach may have the potential to reverse multiple tumor immune evasion mechanisms, avoid CAR immunogenicity, and overcome problems in cancer gene therapy with engineered nanoconstructs.
National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran.
Zahra
Z
Sharifzadeh
Fatemeh
F
Rahbarizadeh
Mohammad A
MA
Shokrgozar
Davoud
D
Ahmadvand
Fereidoun
F
Mahboudi
Fatemeh Rahimi
FR
Jamnani
S Moein
SM
Moghimi
D000818:Animals; D000918:Antibody Specificity; D000951:Antigens, Neoplasm / Q000235:genetics / Q000276:immunology*; D002161:Camelids, New World; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000628:therapy; D003110:Colonic Neoplasms / Q000276:immunology / Q000628:therapy; D005818:Genetic Engineering / Q000379:methods*; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology*; D019073:HT29 Cells; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology; D016219:Immunotherapy, Adoptive / Q000379:methods*; D015458:Leukemia, T-Cell / Q000276:immunology / Q000628:therapy; D008213:Lymphocyte Activation; D019151:Peptide Library; D011946:Receptors, Antigen / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology*; D015398:Signal Transduction; D061905:Single-Domain Antibodies / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000502:physiology; D014162:Transfection
D000951:Antigens, Neoplasm; D006023:Glycoproteins; D007074:Immunoglobulin G; D019151:Peptide Library; D011946:Receptors, Antigen; D011993:Recombinant Fusion Proteins; D061905:Single-Domain Antibodies; C047052:tumor-associated antigen 72