Chimeric antigen receptor protein (CAR)

A chimeric antigen receptor (CAR) is an engineered protein expressed on immune cells, most commonly T lymphocytes, designed to combine antigen recognition and T cell activation in a single molecule. A typical CAR consists of an extracellular antigen-binding domain (usually derived from a monoclonal antibody’s variable fragment), a hinge/spacer, a transmembrane region, and intracellular signaling domains (commonly CD3ζ and costimulatory domains)[1][3][5][8]. CARs enable T cells to recognize specific cell surface antigens on tumor cells independent of the major histocompatibility complex (MHC), redirecting immune function and permitting targeted cell killing[6][7][8]. CARs form the basis for adoptive T cell therapies (CAR-T cells) currently used to treat certain hematologic cancers.\nThere is something incorrect about the phrasing “Chimeric antigen receptor target protein” as a listed “target.” A chimeric antigen receptor is a synthetic construct and not itself a natural disease target (such as a receptor or enzyme implicated in pathology). Instead, it functions as the engineered receptor used to target other molecules (such as CD19, BCMA, etc.) present on disease cells[5][8]. The correct target entry for annotation purposes would be a specific protein recognized by the CAR (e.g., CD19). This entry is thus best characterized as a description of a molecular therapeutic tool, not a drug target.

Other names

chimeric immunoreceptorchimeric T cell receptorartificial T cell receptor

Redirect T cell specificity to recognize specific cell surface antigens on tumor cells in an MHC-independent fashion\n- Mediate tumor cell killing through:\n - Cytokine secretion (e.g., IL-2, IFN-γ, TNF-α)\n - Cytolytic mechanisms (perforin, granzymes)\n - Induction of apoptosis (via TRAIL, FasL pathways)