Minor histocompatibility protein HB-1 (HMHB1)

More generally, minor histocomplatibility antigens (mHags) refer to immunogenic peptide that, when complexed with MHC, can generate an immune response after recognition by particular T-cells. The peptides are derived from polymorphic intracellular proteins, which can be cleaved by ordinary pathways of antigen processing.

The binding of the peptides to MHC class I or class II molecules and its expression on the cell surface can stimulate T-cell responses and thereby trigger graft rejection or graft-versus-host disease (GVHD) after hematopoietic stem cell transplantation from HLA- identical sibling donor. GVHD is a frequent complication after bone marrow transplantation (BMT), due to mismatch of minor histocomplatibility antigen in HLA-matched sibling marrow transplants.