HLA class I histocompatibility antigen, A-2 alpha chain presenting PR1 peptide (HLA-A2–PR1)

HLA class I histocompatibility antigen, A-2 alpha chain presenting PR1 peptide describes a peptide–MHC complex consisting of the PR1 peptide (a nine-amino acid epitope derived from proteinase 3 or neutrophil elastase) bound to the HLA-A*02:01 molecule (the A-2 alpha chain). This complex is presented on the surface of antigen-presenting cells and some leukemia cells, where it is specifically recognized by CD8+ cytotoxic T lymphocytes. Recognition of PR1/HLA-A2 by T cells or T cell–like therapeutic antibodies leads to selective killing of leukemia cells overexpressing PR1, making this complex an important immunotherapeutic target in hematologic malignancies[4][6][8]. The complex is also a useful biomarker for monitoring leukemia-specific immune responses and for selecting patients who may benefit from peptide-MHC–targeted therapies[6][8].

Other names

HLA-A*02:01/PR1PR1/HLA-A2 complexHLA-A2 presenting PR1PR1 peptide–MHC class I (HLA-A2) complex

Antibody-mediated binding to PR1/HLA-A2 complex, resulting in antibody-dependent cellular cytotoxicity (ADCC); Bispecific antibody recruitment of T cells via CD3 to PR1/HLA-A2-positive leukemia cells, leading to targeted cell lysis; T cell receptor (TCR) recognition, activation, and cytolytic response against cells expressing PR1/HLA-A2.