HLA class I histocompatibility antigen, A-2 alpha chain (HLA-A2)

HLA-A2 is a specific serotype within the human leukocyte antigen (HLA)-A group, which belongs to the Major Histocompatibility Complex (MHC) class I molecules (UniProt P01892). It is one of the most prevalent HLA alleles in human populations, particularly among Caucasians, making it a cornerstone for the development of HLA-restricted immunotherapies (PubMed: 31434684). The primary biological function of HLA-A2 is to present short, intracellularly derived peptides—typically 8 to 10 amino acids in length—on the cell surface for surveillance by CD8+ cytotoxic T cells (NCBI Gene: 3105). In oncology, HLA-A2 is critical because it presents tumor-associated antigens, such as gp100 or MAGE-A4, which can be targeted by engineered T-cell receptors (TCRs) or bispecific T-cell engagers (StatPearls: MHC). Drugs like Tebentafusp are specifically designed to bind the HLA-A*02:01 complex, redirecting T cells to attack uveal melanoma cells (FDA: Kimmtrak). Because HLA-A2 is highly polymorphic, therapeutic success depends on precise patient genotyping and the avoidance of cross-reactivity with similar peptides presented on healthy tissues (PubMed: 29109433). Consequently, HLA-A2 serves as both a vital therapeutic scaffold and a mandatory biomarker for patient selection in modern precision TCR-based medicine.

Other names

HLA-A*02MHC class I antigen A*2Human leukocyte antigen A2Major histocompatibility complex, class I, A2

Presentation of specific intracellularly derived peptides to the T-cell receptor (TCR) of CD8+ cytotoxic T lymphocytes, enabling the immune system to recognize and eliminate infected or malignant cells.