Major histocompatibility complex class I A*02 (HLA-A*02)

Major histocompatibility complex class I A*02 (HLA-A*02) is a highly polymorphic cell surface glycoprotein belonging to the class I major histocompatibility complex family. It consists of a polymorphic heavy α chain and a non-polymorphic β2-microglobulin light chain, forming a platform for peptide binding. HLA-A*02 presents intracellularly derived peptides—most commonly from viruses or abnormal proteins—to cytotoxic CD8+ T lymphocytes, thereby enabling immune recognition and destruction of infected or malignant cells. This molecule is critical for adaptive immunity, transplantation compatibility, and serves as a common restriction element for T-cell therapeutic targeting, especially in cancer immunotherapy and vaccine development. In clinical therapeutics, its prevalence and peptide specificity make it a cornerstone in patient selection for T-cell receptor-directed therapies and peptide vaccines. Dysfunction or loss of HLA-A*02 expression can underlie immune evasion in tumors, while mismatch or inappropriate activation can present risks in autoimmunity and transplant rejection contexts.

Other names

HLA-A*02Human leukocyte antigen A*02HLA-A2 (historical/less precise)MHC class I A*02

Facilitation of cytotoxic T-cell recognition of presented peptides, leading to targeted cell death Presentation of intracellular (viral or tumor) peptides on the cell surface for immune detection Interactions with CD8 co-receptor to activate T-cell effector function