T-cell receptor recognizing CAIX epitope (No universal abbreviation; sometimes "TCR-CAIX" may be used contextually, but this is not standardized.)

The T-cell receptor recognizing CAIX epitope is a membrane-bound heterodimeric protein (primarily α- and β-chains) expressed on the surface of cytotoxic T lymphocytes. This receptor mediates antigen-specific recognition by binding to a complex of CAIX-derived peptide presented by major histocompatibility complex (MHC) molecules on the surface of tumor cells. CAIX (carbonic anhydrase IX) is a transmembrane enzyme overexpressed in many hypoxic tumors, including clear cell renal cell carcinoma, breast, and lung cancers. Recognition of the CAIX epitope by the T-cell receptor triggers T-cell activation, proliferation, and cytolytic response against the tumor cell. Engineered T-cell receptors or CAR-T cell constructs targeting the CAIX epitope have been developed for cancer immunotherapy, with studies showing efficacy and highlighting the importance of epitope selection and affinity tuning for minimizing off-tumor toxicity. This receptor is considered a promising therapeutic target in cancers expressing CAIX, but safety and patient selection are major concerns. CAIX itself is commonly used as a biomarker for tumor hypoxia and therapeutic response. The underlying mechanism of action is peptide-MHC recognition leading to immune activation and tumor destruction.

Other names

CAIX-specific T-cell receptorCarbonic anhydrase IX-directed TCRTCR recognizing CAIX (context-dependent, not standardized)

Recognition of CAIX peptide-MHC complex presented on tumor cell surface, leading to: Activation of T-cell cytotoxic function; Induction of tumor cell apoptosis via immune mechanisms; CAR-T cells (chimeric antigen receptor T cells) may utilize a scFv targeting CAIX epitope to redirect T-cell specificity