Melanoma-associated antigen 3 (MAGE-A3) peptide-HLA-A*02:01 complex (MAGE-A3/HLA-A2)

Melanoma-associated antigen 3 (MAGE-A3) is a prominent member of the cancer-testis antigen (CTA) family, which is characterized by restricted expression in male germ cells and aberrant overexpression in various malignancies such as melanoma and non-small cell lung cancer (Source: UniProt P43357). The specific antigenic epitope, often the nonamer peptide FLWGPRALV, is processed intracellularly and presented on the cell surface by the Human Leukocyte Antigen A2 (HLA-A2) molecule (Source: PubMed PMID 8144964). This peptide-MHC (pMHC) complex serves as a critical target for T-cell-based immunotherapies, including TCR-engineered T cells (TCR-T) and cancer vaccines, designed to exploit the high tumor-specificity of MAGE-A3 (Source: PubMed PMID 23908459). However, clinical development has been complicated by severe safety issues; for example, early TCR-T trials resulted in lethal neurotoxicity due to unexpected cross-reactivity with MAGE-A12 in the brain and cardiotoxicity due to cross-reactivity with the muscle protein Titin (Source: PubMed PMID 23580834, 23776243). Despite these challenges, the MAGE-A3/HLA-A2 complex remains a high-priority target in oncology, with ongoing efforts focused on engineering TCRs with improved specificity to avoid off-target effects.

Other names

MAGE-3/HLA-A2MAGE-A3:271-279/HLA-A*02:01FLWGPRALV-HLA-A2 complexMAGE-A3-derived antigenic epitopeMAGE-A3/HLA-A*02:01

T-cell receptor (TCR) binding and activation of cytotoxic T-lymphocytes leading to tumor cell lysis