HLA class I molecules presenting MAGE-A3 peptides (HLA-MAGE-A3) (HLA-MAGE-A3)

MAGE-A3 (Melanoma-associated antigen 3) is a prominent cancer-testis antigen (CTA) that is highly expressed in various malignancies, such as melanoma, non-small cell lung cancer, and bladder cancer, while remaining silenced in healthy adult tissues except for the testis and placenta (Pupa et al., 2014). Because these germline tissues lack Major Histocompatibility Complex (MHC) class I expression, MAGE-A3 peptides presented by HLA class I molecules (such as HLA-A*01 or HLA-A*02) on tumor surfaces represent highly specific neoantigen-like targets for immunotherapy (van der Bruggen et al., 1991). The HLA-MAGE-A3 complex is primarily targeted by T-cell receptor (TCR) engineered T-cell therapies and cancer vaccines designed to elicit a cytotoxic CD8+ T-cell response (Kruit et al., 2013). Despite its potential, the target has been associated with severe safety challenges in clinical trials, including fatal cross-reactivity with the Titin protein in the heart and MAGE-A12 in the central nervous system (Linette et al., 2013; Morgan et al., 2013). Current research focuses on improving the affinity and specificity of TCRs to avoid such off-target effects while maintaining potent anti-tumor activity.

Other names

MAGE-A3/HLA complexMAGE-A3 peptide-MHC complexHLA-A*01:01/MAGE-A3HLA-A*02:01/MAGE-A3Melanoma-associated antigen 3-HLA complex

T-cell receptor (TCR) mediated recognition of the peptide-HLA complex leading to T-cell activation, release of cytotoxic granules, and tumor cell lysis.