Human leukocyte antigen A2–T-cell receptor complex (HLA-A2/TCR complex)

The "HLA-A2/T-cell receptor complex" consists of the human leukocyte antigen A2 (HLA-A2), a class I major histocompatibility complex (MHC) molecule, bound to an antigenic peptide, and the T-cell receptor (TCR) on the surface of CD8+ cytotoxic T lymphocytes. This complex mediates antigen-specific recognition; the TCR binds diagonally across the HLA-A2/peptide-binding groove, burying much of the peptide and contacting a broad surface area of HLA-A2. The interaction enables T cells to distinguish infected, malignant, or foreign cells by recognizing intracellular peptides presented by HLA-A2[2][3][4][5]. The structural features of this complex are central to cellular immunity and form the basis for immune specificity, selection, and therapeutic targeting—especially in cancer, viral infection, autoimmunity, and transplantation biology[2][3][4]. - The HLA-A2 allele (most commonly HLA-A*0201) is frequent in many populations, making it a preferred target for patient stratification in clinical immunotherapy trials[4]. - The T-cell receptor exhibits a germline bias for MHC molecules, but its adaptability allows discrimination between subtly different peptide antigens[2]. - The complex is also modulated by coreceptors such as CD8, which enhances binding and signal transmission through the TCR/CD3 complex[6].

Other names

HLA-A*0201/T-cell receptor complexHLA-A2/peptide/TCRClass I pMHC/TCR complexHLA-A2/antigen/TCR complex

Drugs and biologics that target the complex typically act by: - Enhancing antigen presentation on HLA-A2 (peptide vaccines)[4]. - Redirecting TCR specificity to HLA-A2–presented tumor antigens (engineered TCRs)[4]. - Blocking or modulating TCR triggering or coreceptor engagement (immune checkpoint modulators)[6]. - Inducing tolerance or promoting immune activation depending on context[2].