T-cell receptor and peptide-major histocompatibility complex (TCR–pMHC complex)

The T-cell receptor and peptide-major histocompatibility complex (TCR–pMHC) complex is a fundamental protein complex in the adaptive immune system. The T-cell receptor (TCR), a transmembrane heterodimer consisting mainly of alpha and beta chains, binds specifically to antigenic peptides presented by major histocompatibility complex (MHC) molecules on antigen-presenting cells. This interaction is required for T cell activation, initiating immune responses against pathogens, tumors, and other challenges. The TCR recognizes both the presented peptide (derived from self, pathogens, or tumor antigens) and the MHC, providing exquisite specificity to immune surveillance. The structural basis of TCR–pMHC interaction is critical for understanding adaptive immunity, autoimmunity, and the development of next-generation cancer immunotherapies and engineered T-cell therapeutics. Therapeutic targeting of TCR–pMHC complexes (e.g., with engineered TCRs, bispecific molecules, or TCR-mimic antibodies) enables redirection of the immune response against cancers or chronic infections but poses risks of toxicity through cross-reactivity and unintended immune effects.

Other names

TCR–pMHCTCR-peptide-MHCT-cell receptor:peptide-MHC complex

Redirected T-cell cytotoxicity (via engineered TCR or TCR-mimic therapeutics binding pMHC) Immune activation or blockade through modulation of TCR–pMHC interaction