T cell receptor recognition of peptide–major histocompatibility complex (TCR recognition of peptide-MHC)

The **T cell receptor (TCR) recognition of peptide–major histocompatibility complex (MHC)** is a core immunological interaction critical for adaptive immunity. TCRs, found on the surface of T cells, bind specifically to peptide fragments presented by MHC molecules on the surface of antigen-presenting or infected cells[1][2][3][4][5][7]. This recognition determines T cell activation, specificity, and immune response initiation. Structurally, TCRs typically engage peptide-MHC complexes through complementarity-determining regions (CDRs), with CDR1 and CDR2 making contact with the MHC helices and CDR3 with the presented peptide[4][7]. This interaction is highly specific, yet degenerate, enabling both broad immune surveillance and the capacity for immune-mediated diseases if misdirected[2][7]. Therapeutically, TCR–pMHC interactions are targeted via engineered TCRs, bispecific fusion proteins, and cancer vaccines, but these approaches bear risks of off-target effects and immune-related toxicity[7].

Other names

TCR–pMHC interactionTCR–peptide–MHC recognitionTCR–antigen complexpeptide-MHC recognition by TCR

Targeted redirection or enhancement of TCR–pMHC interaction to stimulate T cell–mediated cytotoxicity (TCR-based therapies, bispecifics); Blockade or modulation of T cell activation (experimental); Induction of specific immune responses via antigen selection (cancer vaccines)