Peptide-Major Histocompatibility Complex (pMHC)

Peptide-Major Histocompatibility Complex (pMHC) complexes are fundamental immunological units consisting of a short peptide fragment non-covalently bound within the groove of a Major Histocompatibility Complex (MHC) molecule on the cell surface. These complexes act as a molecular window into the intracellular environment, presenting fragments of endogenous or exogenous proteins for surveillance by T-cell receptors (TCRs). In oncology, pMHCs present tumor-associated antigens, neoantigens, or viral peptides, making them highly specific targets for immunotherapy. Therapeutic modalities such as TCR-engineered T-cells (TCR-T), bispecific T-cell engagers (ImmTACs), and TCR-mimic (TCRm) antibodies are designed to recognize these specific peptide-MHC combinations. This approach allows for the targeting of intracellular oncogenic drivers that are otherwise inaccessible to conventional antibody-based therapies. However, the effectiveness of these treatments is often restricted by the patient's specific HLA genotype and the risk of cross-reactivity with similar peptides expressed in healthy tissues.

Other names

pHLAPeptide-HLA complexAntigen-MHC complexMHC-peptide complexpMHCIpMHCIIPeptide-Major Histocompatibility Complex

Therapeutic agents target pMHC complexes through T-cell receptor (TCR) recognition or TCR-mimic antibody binding, facilitating the recruitment and activation of cytotoxic T-cells to eliminate cells presenting specific intracellularly-derived antigens.