HLA-A*01-restricted melanoma-associated peptide (HLA-A1 melanoma peptide) (HLA-A1 melanoma peptide)

HLA-A*01-restricted melanoma-associated peptides are specific protein fragments, such as those derived from MAGE-A1, MAGE-A3, or tyrosinase, that are presented on the surface of melanoma cells by the Human Leukocyte Antigen A*01 (HLA-A1) molecule (van der Bruggen et al., 1991, Science). These peptide-MHC complexes serve as critical targets for the immune system, specifically for CD8+ cytotoxic T lymphocytes that recognize them via specialized T-cell receptors (TCRs) (Gaugler et al., 1994, J Exp Med). Because many of these antigens belong to the cancer-testis antigen family, they are typically expressed in tumors but not in healthy adult tissues, providing a basis for therapeutic selectivity. Therapeutic strategies targeting these peptides include cancer vaccines, such as the MAGE-A3 vaccine (GSK1572932A), and adoptive T-cell therapies using TCR-engineered T-cells (Vansteenkiste et al., 2016, Lancet Oncol). Bispecific T-cell engagers and TCR-T cells are designed to enhance the recognition and destruction of cells presenting these specific epitopes. However, clinical development has faced significant challenges, including fatal off-target toxicity. For instance, a TCR-T therapy targeting a MAGE-A3 HLA-A1 epitope caused lethal cardiotoxicity due to unexpected cross-reactivity with the Titin protein in heart tissue (Linette et al., 2013, Blood). Additionally, tumors can evade these therapies by downregulating HLA expression or through the loss of antigen expression. Patient eligibility for these treatments is strictly dependent on the presence of the HLA-A*01 allele and the confirmed expression of the target antigen within the tumor.

Other names

HLA-A1-restricted melanoma antigensMAGE-A1/A3 HLA-A1 epitopesMelanoma-associated peptide-MHC complexesHLA-A*01:01 restricted peptidesMAGE-A3 peptide EVDPIGHLY

Activation of CD8+ T-cells through specific TCR recognition of the peptide-MHC complex, leading to the release of perforins and granzymes and subsequent tumor cell apoptosis (Gaugler et al., 1994, J Exp Med).