T cell receptor–peptide-MHC complex (TCR–pMHC complex)

The **T cell receptor–peptide-MHC complex** is a multisubunit structure central to adaptive immunity, consisting of a clonotypic T cell receptor (usually an αβ heterodimer) on the T cell surface that recognizes specific peptide antigens presented by major histocompatibility complex (MHC) molecules on antigen-presenting cells. The recognition of the peptide-MHC (pMHC) complex by the TCR, typically in conjunction with CD3 signaling subunits and CD4 or CD8 coreceptors, triggers T cell activation and initiates cellular immune responses[1][2][3][4][5][6][7]. The TCR–pMHC interaction is highly specific and underlies immune discrimination between self and non-self, playing a fundamental role in the defense against infection and in immune surveillance of cancer[7]. Aberrant TCR–pMHC recognition is implicated in autoimmunity, infection, and tumor immunity. Current immunotherapeutic approaches exploit this specificity through engineered TCRs or TCR-mimetic antibodies, although the diversity and selectivity challenges remain significant[7].

Other names

T cell receptor:peptide-major histocompatibility complexTCR:pMHCT cell receptor–MHC complexTCR–peptide–MHC complex

Immune recognition (drugs aim to modulate, mimic, or block TCR–pMHC binding) Immunotherapy (engineered TCRs or TCR-mimetic antibodies recognizing tumor- or pathogen-specific pMHCs)