HA-2 peptide–HLA-A*02:01 complex

The **HA-2 peptide–HLA-A*02:01 complex** is a molecular target formed by presentation of the minor histocompatibility antigen HA-2 peptide (typically the nonamer YIGEVLVSV) in the peptide binding cleft of the HLA-A*02:01 class I major histocompatibility molecule. This complex acts as an immunological target for CD8+ cytotoxic T cells, primarily in the context of allogeneic hematopoietic stem cell transplantation, where it can mediate beneficial graft-versus-leukemia effects by enabling immune recognition and lysis of recipient leukemia cells presenting HA-2. Recognition requires the T-cell receptor (TCR) to engage the specific conformation formed by this peptide within the HLA-A*02:01 binding cleft. The presence and presentation of the HA-2 peptide are highly dependent on the HLA-A*02:01 allele and are part of MHC class I–restricted antigen processing and presentation. This molecular complex is widely studied as a model for minor histocompatibility antigen–driven T-cell responses and immunotherapy research[1][4][7].

Other names

HA-2 antigen–HLA-A*02:01 complexHA-2 peptide presented on HLA-A*02:01Peptide–HLA-A*02:01 complex (when contextually specified as HA-2 peptide)

Presentation of HA-2 peptide in the groove of HLA-A*02:01 enables recognition by HA-2–specific cytotoxic (CD8+) T cells, leading to targeted killing of HA-2–expressing cells (e.g., in graft-versus-leukemia responses)[1][7].