Peptide–Major Histocompatibility Complex class II (pMHCII) (pMHCII)

Peptide–Major Histocompatibility Complex class II (pMHCII) complexes are essential components of the adaptive immune system, formed by the association of an antigenic peptide with an MHC class II heterodimer (PubMed: 19038218). These complexes are primarily expressed on the surface of professional antigen-presenting cells, such as dendritic cells and B cells, where they present processed exogenous antigens to CD4+ T cells (UniProt: P01903). The recognition of pMHCII by the T-cell receptor (TCR) is a critical step in T-cell activation, governing the nature and magnitude of the immune response (PubMed: 29103130). In autoimmune diseases, pMHCII complexes presenting self-peptides can trigger aberrant immune attacks, making them prime targets for antigen-specific therapies (PubMed: 29103130). Conversely, in oncology, the presentation of tumor-derived neoantigens via MHCII is vital for effective anti-tumor immunity (PubMed: 30559448). Therapeutic interventions targeting pMHCII include TCR-like antibodies and peptide-based vaccines designed to either block pathogenic interactions or enhance protective immune responses (PubMed: 30559448). Drugs like Glatiramer acetate interact with these complexes to modulate immune activity in conditions like Multiple Sclerosis (PubMed: 10614774).

Other names

pMHCIIMHC class II-peptide complexHLA class II-peptide complexAntigen-MHC II complexPeptide-HLA class II complex

Competitive inhibition of T-cell receptor (TCR) binding to the pMHCII complex, induction of antigen-specific T-cell anergy or tolerance, and targeted delivery of cytotoxic or modulatory agents to specific antigen-presenting cells (PubMed: 30559448, PubMed: 10614774).