Melanoma-associated antigen 1 (MAGE-A1) peptide presented by HLA-A1 (MAGE-A1/HLA-A1)

The MAGE-A1 peptide presented by HLA-A1 is a specific peptide-major histocompatibility complex (pMHC) found on the surface of various cancer cells. MAGE-A1 (Melanoma-associated antigen 1) is a member of the cancer-testis antigen family, meaning it is typically expressed only in male germ cells (which lack HLA expression) and in various malignancies, making it a highly specific target for immunotherapy (UniProt P43355; van der Bruggen et al., Science, 1991). The specific nonamer peptide EADPTGHSY is processed from the MAGE-A1 protein and loaded onto HLA-A1 molecules for presentation to the immune system (Traversari et al., J Exp Med, 1992). Therapeutic strategies targeting this complex include T-cell receptor-engineered T-cell (TCR-T) therapies and TCR-mimetic antibodies, which aim to selectively destroy tumor cells while sparing healthy tissue (ClinicalTrials.gov). Because MAGE-A1 is not expressed in normal somatic tissues, it offers a wide therapeutic window, although careful screening for TCR cross-reactivity is essential to avoid off-target effects (PubMed: 16431647). Clinical development of agents targeting this pMHC complex, such as TK-8001, involves rigorous patient selection based on both HLA type and antigen expression. This target represents a cornerstone of modern precision oncology, leveraging the specificity of the cellular immune response against tumor-restricted antigens.

Other names

MAGE-1MAGEA1Antigen MZ2-ECancer/testis antigen 1.1HLA-A*01:01-MAGE-A1EADPTGHSY peptide

The target complex is recognized by specific T-cell receptors (TCRs) on cytotoxic T lymphocytes, which triggers a signaling cascade leading to the release of perforins and granzymes, resulting in the selective apoptosis of tumor cells presenting the MAGE-A1/HLA-A1 complex (van der Bruggen et al., 1991; Traversari et al., 1992).