HLA-A*01-restricted Melanoma-associated antigen 3 peptide epitope (HLA-A1/MAGE-A3)

The HLA-A1-presented MAGE-3 peptide epitope is a molecular complex consisting of a specific peptide fragment (typically the decamer EVDPIGHLY) derived from the Melanoma-associated antigen 3 (MAGE-A3) protein bound to the Human Leukocyte Antigen A*01 (HLA-A1) molecule (Gaugler et al., 1994). MAGE-A3 is a member of the cancer-testis antigen family, which is characterized by restricted expression in male germ cells but frequent reactivation in various malignancies, including melanoma and lung cancer (van der Bruggen et al., 1991). Because it is absent in normal adult somatic tissues, the MAGE-A3/HLA-A1 complex serves as a highly specific target for cancer immunotherapies, such as T-cell receptor (TCR) engineered T-cells and therapeutic vaccines like the MAGE-A3 ASCI (ClinicalTrials.gov, NCT00480025). Clinical development of therapies targeting this epitope has faced significant challenges due to potential cross-reactivity with similar peptides in healthy tissues. A notable clinical trial involving a MAGE-A3-specific TCR resulted in fatal cardiotoxicity because the TCR cross-reacted with a similar peptide in the cardiac protein Titin (Linette et al., 2013). This event underscored the critical importance of rigorous preclinical specificity screening for TCR-based therapies. Current research continues to investigate this target using improved engineering platforms to maximize tumor-specific cytotoxicity while minimizing off-target risks in HLA-A1 positive patients.

Other names

MAGE-A3/HLA-A*01:01 complexEVDPIGHLY-HLA-A1 complexMAGE-3.A1Melanoma-associated antigen 3 (168-176) epitopeMAGE-3 antigen

Targeted T-cell mediated cytotoxicity via T-cell receptor (TCR) recognition of the peptide-MHC complex.