Major histocompatibility complex, class I, A3 (HLA-A3)

Major histocompatibility complex, class I, A3 (HLA-A3) is a specific serotype of the Human Leukocyte Antigen A (HLA-A) gene, belonging to the MHC class I family. It is expressed on the surface of nearly all nucleated cells and functions by presenting endogenous peptides to CD8+ cytotoxic T lymphocytes, a process essential for the detection and elimination of virally infected or malignant cells (Wikipedia, NIH). HLA-A3 is particularly prevalent in populations of European descent and is a key component of the ancestral A3-B7-DR15-DQ6 haplotype (Wikipedia, NIH). In oncology, HLA-A3 serves as a critical restriction element for the development of TCR-T cell therapies and cancer vaccines targeting antigens such as PRAME, MAGE-A3, and HER-2/neu (AACR, NIH). Conversely, recent clinical evidence suggests that HLA-A3 carriage is a biomarker for poor response to immune checkpoint inhibitors, such as nivolumab and avelumab, across multiple cancer types (NIH). Beyond its role in cancer, HLA-A3 is strongly associated with hereditary hemochromatosis and serves as a genetic risk factor for autoimmune conditions like multiple sclerosis (ResearchGate, NIH).

Other names

HLA-A*03MHC class I antigen A*03Human leukocyte antigen A3HL-A3

Recognition of specific peptide-MHC complexes by engineered or endogenous T-cell receptors, leading to the activation of cytotoxic T lymphocytes and targeted cell lysis.