Melanoma-associated antigen 1 peptide–Major Histocompatibility Complex (MAGE-A1-pMHC)

The Melanoma-associated antigen 1 peptide–Major Histocompatibility Complex (MAGE-A1-pMHC) is a tumor-specific antigen complex presented on the surface of malignant cells. MAGE-A1 is a member of the cancer-testis antigen (CTA) family, which is characterized by high expression in various cancers but restricted expression in normal adult tissues, primarily the immune-privileged testes (UniProt P43355). The complex is formed when MAGE-A1 protein is processed into short peptides, such as the EADPTGHSY nonamer, and presented by MHC Class I molecules, typically HLA-A*01:01 (Traversari et al., 1992). This specific presentation allows the immune system to distinguish cancer cells from healthy somatic cells. Therapeutic interventions, including TCR-engineered T cells (TCR-T) and bispecific T-cell engagers, are developed to recognize this complex and induce T-cell mediated apoptosis of the tumor (PubMed: 30552151). Clinical development of targets like MAGE-A1-pMHC requires rigorous screening for cross-reactivity with similar peptides in vital organs to prevent off-target toxicity (PubMed: 23943301). Current research focuses on its application in melanoma, non-small cell lung cancer, and other solid tumors expressing MAGE-A1.

Other names

MAGE-A1-HLA complexMAGE-A1-HLA-A*01:01 complexMelanoma antigen family A 1 peptide-MHCMAGE1-pMHCAntigen MZ2-EMAGE-A1-derived peptide-MHC

Engineered T-cell receptors (TCRs) or TCR-mimetic antibodies bind specifically to the MAGE-A1 peptide presented by MHC molecules on the tumor cell surface, leading to T-cell activation, cytokine release, and targeted cytotoxic lysis of the cancer cell.