Major histocompatibility complex, class I, A (HLA-A) (HLA-A*02:01)

**Major histocompatibility complex, class I, A*02:01 (HLA-A*02:01)** is a subtype (allele) of the HLA-A gene, encoding a class I MHC cell surface glycoprotein in humans. It is part of the highly polymorphic MHC class I family, which functions to present short peptide fragments (usually 8–10 amino acids) from intracellular proteins to **cytotoxic CD8+ T cells** and also interacts with natural killer (NK) cell receptors. The HLA-A*02:01 molecule consists of a transmembrane alpha chain (with three extracellular domains) noncovalently associated with beta-2 microglobulin. The displayed antigenic peptide is loaded in the endoplasmic reticulum and the complex is then expressed on the cell surface. Recognition of foreign or aberrant peptides by cytotoxic T cells through this molecule can trigger targeted cell lysis, making HLA-A*02:01 a critical player in **antiviral, anticancer, and immune regulatory pathways**[1][2][3][4][5]. **HLA-A*02:01** is a well-studied allele due to its high frequency in populations and its importance as a restriction element for T cell-based immunotherapies and cancer vaccines. Its polymorphism and peptide-binding specificity influence individual immune responses to pathogens and malignancies[1][3].

Other names

HLA-A2HLA-A*02:01Human leukocyte antigen A2MHC class I A*0201

Presentation of intracellular peptide antigens on the cell surface to cytotoxic T lymphocytes, enabling immune recognition and destruction of infected or malignant cells