Melanoma-associated antigen 3 (MAGE-A3) presented by Human leukocyte antigen A1 (HLA-A1) (MAGE-A3/HLA-A1)

Melanoma-associated antigen 3 (MAGE-A3) is a prominent member of the cancer-testis antigen (CTA) family, which is typically expressed in various malignancies but absent in normal adult tissues except for the immune-privileged testes and placenta (UniProt P43357). When the MAGE-A3 protein is processed intracellularly, its peptide fragments, such as the decamer EVDPIGHLY, are presented on the cell surface by the Human Leukocyte Antigen A1 (HLA-A1) molecule (PubMed: 21460103). This specific peptide-MHC complex serves as a target for the immune system, particularly for cytotoxic T lymphocytes (CTLs) that can recognize the complex via their T-cell receptors (TCRs). In clinical oncology, MAGE-A3 expression is linked to increased tumor invasiveness and poor patient prognosis in diseases like melanoma and non-small cell lung cancer (PubMed: 27050173). Therapeutic efforts targeting MAGE-A3/HLA-A1 have included recombinant protein vaccines and adoptive cell therapies using TCR-engineered T cells (TCR-T). However, these therapies have encountered significant safety hurdles, most notably lethal off-target toxicities caused by TCR cross-reactivity with similar peptides in the brain (MAGE-A12) and heart (Titin) (PubMed: 23584318). For instance, early clinical trials of MAGE-A3-specific TCR-T cells resulted in severe neurological damage and cardiac failure due to these unexpected cross-reactivities. Despite these setbacks, MAGE-A3 remains a significant target in the field of precision immuno-oncology, with ongoing research focused on engineering TCRs with higher specificity to avoid healthy tissue damage while maintaining potent anti-tumor activity.

Other names

MAGE-3Melanoma antigen family A 3MAGEA3Antigen MZ2-DHLA-A*01:01/MAGE-A3 complexMAGE-A3 peptide EVDPIGHLY

T-cell receptor (TCR) mediated recognition and cytotoxic cell lysis