Human leukocyte antigen A-2 (HLA-A2) (HLA-A2)

HLA-A2 is a human class I major histocompatibility complex (MHC-I) molecule composed of a polymorphic heavy chain encoded by HLA-A*02 alleles and the invariant light chain beta-2 microglobulin; it forms a peptide-binding groove (α1–α2 domains) above an eight–strand β-sheet platform that binds predominantly 9-mer peptides derived from intracellular proteins and presents them on the cell surface for recognition by CD8+ T cells; peptide loading occurs in the endoplasmic reticulum within the peptide-loading complex that includes TAP1/2, tapasin, calreticulin, and ERp57, and stable surface expression depends on high-affinity peptide binding.[3][1][6]

Other names

HLA-A*02HLA-A2 antigenHuman class I histocompatibility antigen HLA-A2HLA-A 2A*02

For HLA-A2–restricted TCR-based or TCR-mimic agents: bind HLA-A*02:01–peptide complexes on target cells and redirect or activate T cells. For vaccines/epitopes: exploit HLA-A2 peptide-binding motif to elicit CD8+ T cell responses. HLA-A2 itself presents 8–11mer peptides (often 9-mers) generated in the cytosol and loaded in the ER via the peptide-loading complex.