Major histocompatibility complex class I molecules presenting melanoma-associated antigen 3 peptides (MHC-I/MAGE-A3)

MHC class I molecules presenting melanoma-associated antigen 3 (MAGE-A3) peptides are a critical target in cancer immunotherapy, particularly for T-cell-based interventions. MAGE-A3 is a cancer-testis antigen that is highly expressed in various tumors but absent in normal adult tissues, except for the testis and placenta, which do not express MHC class I molecules (PMID: 24711571). This expression pattern makes the MAGE-A3 peptide-MHC complex an ideal tumor-specific target for CD8+ cytotoxic T cells. Therapeutic approaches have included cancer vaccines designed to elicit an immune response and T-cell receptor (TCR) engineered T-cell therapies that directly recognize the complex (PMID: 27083334). However, the clinical development of MAGE-A3-targeted therapies has faced significant hurdles, including the failure of large-scale vaccine trials and severe safety issues. Specifically, early TCR-T trials resulted in fatal neurotoxicity and cardiotoxicity due to unexpected cross-reactivity with MAGE-A12 in the brain and the muscle protein Titin in the heart, respectively (PMID: 23550147, PMID: 23765128).

Other names

MAGE-A3/HLA complexMAGE-A3 peptide-MHC complexHLA-A*01:01/MAGE-A3HLA-A*02:01/MAGE-A3Melanoma-associated antigen 3 presented by MHC class I

Recognition of the peptide-MHC complex by engineered or endogenous T-cell receptors (TCRs) to trigger T-cell activation and tumor cell lysis; induction of MAGE-A3-specific immune responses via vaccination.