Human leukocyte antigen class II presenting melanoma-associated antigen 3 peptides (HLA-II/MAGE-A3)

HLA class II molecules presenting MAGE-A3 peptides constitute a specific peptide-major histocompatibility complex (pMHC) that serves as a critical target for cancer immunotherapy. MAGE-A3 (Melanoma-associated antigen 3) is a cancer-testis antigen typically expressed in various tumors, such as melanoma and non-small cell lung cancer, but restricted in normal tissues to the immune-privileged testes (PMID: 24695118). These intracellular antigens are processed and presented on the cell surface by HLA class II molecules, most notably HLA-DPB1*04:01, where they are recognized by CD4+ T-helper cells (PMID: 15604397). This recognition is vital for orchestrating a robust anti-tumor immune response, including the recruitment and activation of cytotoxic CD8+ T cells. Therapeutic interventions targeting this complex include recombinant protein vaccines and adoptive T-cell therapies using T-cell receptors (TCRs) engineered to recognize the MAGE-A3 peptide in the context of specific HLA alleles (PMID: 32433938). Clinical development has faced challenges, such as the failure of the MAGRIT trial for the MAGE-A3 vaccine, highlighting the complexity of achieving clinical efficacy (PMID: 27068175). Current research focuses on TCR-T cell therapies that offer higher affinity and specificity to overcome these hurdles while monitoring for potential off-target toxicities.

Other names

MAGE-A3/HLA class II complexMAGE-A3 peptide-MHC class II complexHLA-DPB1*04:01/MAGE-A3MAGE-A3/HLA-DP4Melanoma-associated antigen 3 presented by HLA class II

Recognition of the peptide-MHC complex by T-cell receptors (TCRs) on CD4+ T cells, leading to immune activation and anti-tumor activity.