Peptide–Major Histocompatibility Complex complex (Peptide-MHC complex (pMHC))

Peptide–MHC complexes are membrane-associated protein–peptide assemblies formed by the binding of short peptide antigens within the groove of MHC class I or II molecules, presenting them to T cell receptors on lymphocytes for immune recognition[1][2][4][6][7]. In humans, MHC molecules are encoded by highly polymorphic human leukocyte antigen (HLA) genes; Class I MHC binds peptides from cytosolic proteins and presents to CD8+ T cells, while Class II MHC binds peptides from extracellular proteins presented to CD4+ T cells[2][4][5][6][7]. Peptide–MHC complexes govern essential immune processes, including tolerance, infection defense, recognition of cancer-associated antigens, and are directly targeted by various immunotherapies, vaccines, and engineered cell therapies in clinical practice[1][6]. Their specificity, polymorphism, and centrality to T cell activation make them critical targets for disease modulation, biomarker development, and personalized medicine.

Other names

Peptide–MHC complexpMHC complexMHC-peptide complexHLA-peptide complex (in humans)

Blocking or modulating antigen presentation (e.g., altered peptide ligands inhibit T cell activation); Enhancing antigen presentation for immune recognition; Targeting pMHC for engineered T cell elimination of specific cell types (e.g., cancer).