Minor histocompatibility antigen HA-2 peptide presented by HLA-A*02:01 (HA-2/HLA-A*02:01)

The HA-2 peptide presented by HLA-A*02:01 is a well-characterized minor histocompatibility antigen (mHAg) derived from the MYO1G (Myosin IG) protein (Pierce et al., 2001, PubMed: 11485741). This specific peptide, with the sequence YIGEVLVSV, is presented on the cell surface by the HLA-A*02:01 MHC class I molecule. Because MYO1G expression is restricted to the hematopoietic system, the HA-2/HLA-A*02:01 complex serves as a highly specific target for immunotherapy in the context of allogeneic hematopoietic stem cell transplantation (HSCT). Targeting this complex allows for a potent graft-versus-leukemia (GVL) effect, where donor-derived T cells eliminate residual recipient leukemic cells (Goulmy et al., 1996, PubMed: 8599115). Since the antigen is not expressed on non-hematopoietic tissues, the risk of broad graft-versus-host disease (GVHD) is significantly reduced compared to other targets. Therapeutic approaches include the use of TCR-engineered T cells and peptide-based vaccines designed to stimulate a robust cytotoxic T lymphocyte response against HA-2-positive malignant cells (Kloosterboer et al., 2004, PubMed: 15201300).

Other names

HA-2 antigenMYO1G-derived peptideHLA-A2-restricted HA-2YIGEVLVSV peptidemHAg HA-2

Recognition of the specific peptide-MHC complex by the T-cell receptor (TCR) of cytotoxic T lymphocytes (CTLs), leading to the targeted lysis of cells expressing the HA-2 antigen.