title: PD-1- and CTLA-4-based inhibitory chimeric antigen receptors (iCARs) divert off-target immunotherapy responses.
abstract: T cell therapies have demonstrated long-term efficacy and curative potential for the treatment of some cancers. However, their use is limited by damage to bystander tissues, as seen in graft-versus-host disease after donor lymphocyte infusion, or "on-target, off-tumor" toxicities incurred in some engineered T cell therapies. Nonspecific immunosuppression and irreversible T cell elimination are currently the only means to control such deleterious responses, but at the cost of abrogating therapeutic benefits or causing secondary complications. On the basis of the physiological paradigm of immune inhibitory receptors, we designed antigen-specific inhibitory chimeric antigen receptors (iCARs) to preemptively constrain T cell responses. We demonstrate that CTLA-4- or PD-1-based iCARs can selectively limit cytokine secretion, cytotoxicity, and proliferation induced through the endogenous T cell receptor or an activating chimeric receptor. The initial effect of the iCAR is temporary, thus enabling T cells to function upon a subsequent encounter with the antigen recognized by their activating receptor. iCARs thus provide a dynamic, self-regulating safety switch to prevent, rather than treat, the consequences of inadequate T cell specificity.
authors: Center for Cell Engineering, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY 10065, USA.
authors: Victor D
authors: VD
authors: Fedorov
authors: Maria
authors: M
authors: Themeli
authors: Michel
authors: M
authors: Sadelain
mesh_terms: D000818:Animals; D060908:CTLA-4 Antigen / Q000737:chemistry*; D002460:Cell Line; D049109:Cell Proliferation; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007165:Immunosuppression Therapy; D007167:Immunotherapy / Q000379:methods*; D049449:Luminescence; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D041681:NIH 3T3 Cells; D061026:Programmed Cell Death 1 Receptor / Q000737:chemistry*; D040901:Proteomics / Q000379:methods; D011946:Receptors, Antigen / Q000737:chemistry*; D013601:T-Lymphocytes / Q000166:cytology
chemical_list: D060908:CTLA-4 Antigen; D016207:Cytokines; C105992:PDCD1 protein, human; C491383:Pdcd1 protein, mouse; D061026:Programmed Cell Death 1 Receptor; D011946:Receptors, Antigen