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

Melanoma-associated antigen 3 (MAGE-A3) is a prominent member of the cancer-testis antigen family, characterized by high expression in various malignant tumors and restricted expression in normal tissues, primarily the testes and placenta (Van der Bruggen et al., 1991, Science). The MAGE-A3 peptide presented by HLA-A*02 (specifically the A*02:01 allele) serves as a critical target for cellular immunotherapies, such as T-cell receptor (TCR) engineered T-cells, which recognize intracellular proteins processed into peptides and displayed on the cell surface. This complex is highly relevant in the treatment of melanoma and non-small cell lung cancer, where MAGE-A3 is frequently overexpressed (Gure et al., 2005, Clinical Cancer Research). Clinical development of drugs targeting this complex has faced significant hurdles, most notably lethal off-target cross-reactivity. For example, early TCR-T trials were halted after patients experienced fatal cardiotoxicity because the engineered TCRs cross-reacted with a similar peptide from the muscle protein Titin (Linette et al., 2013, Blood). Current research focuses on improving the specificity of TCRs to distinguish the MAGE-A3/HLA-A2 complex from similar self-peptides to ensure safety while maintaining anti-tumor efficacy.

Other names

MAGE-A3 peptide presented by HLA-A*02:01MAGE-A3/HLA-A2 complexMelanoma-associated antigen 3/HLA-A2MAGE-A3:112-120/HLA-A2MAGE-A3:271-279/HLA-A2

Targeting of the specific peptide-MHC complex by engineered T-cell receptors (TCRs) or TCR-mimetic antibodies to induce T-cell mediated lysis of tumor cells.