HLA class I histocompatibility antigen, A alpha chain (HLA-A*02:03) (HLA-A*02:03)

HLA-A*02:03 is a specific allele of the Human Leukocyte Antigen (HLA) class I A gene, which encodes the alpha chain of the Major Histocompatibility Complex (MHC) class I molecule. This protein is essential for the adaptive immune system, as it binds and presents intracellularly derived peptides to CD8+ cytotoxic T cells, thereby facilitating the recognition and elimination of infected or malignant cells (1.2.3, 1.2.4). HLA-A*02:03 is notably prevalent in Southeast Asian populations, distinguishing it from the more globally common HLA-A*02:01 allele by specific amino acid substitutions that alter its peptide-binding pocket and specificity (1.2.2, 1.4.5). In clinical practice, it serves as a critical therapeutic target and biomarker for HLA-restricted immunotherapies, including TCR-engineered T-cell therapies like afamitresgene autoleucel and various cancer vaccines (1.4.2). Furthermore, it is associated with disease susceptibility or protection in conditions such as Hepatitis B, HIV, and certain autoimmune disorders like Graves' ophthalmopathy (1.1.4, 1.2.2, 1.3.1).

Other names

MHC class I antigen A*02:03HLA-A2A203HLA-A*0203Human leukocyte antigen A*02:03

Presentation of intracellularly derived antigenic peptides to CD8+ cytotoxic T lymphocytes to trigger an adaptive immune response.