Minor histocompatibility antigen (mHAg) (mHAg)

Minor histocompatibility antigens (mHAgs) are polymorphic peptides derived from intracellular proteins that differ between individuals due to genetic variations, primarily single nucleotide polymorphisms (SNPs) [1]. These peptides are presented by Major Histocompatibility Complex (MHC) molecules on the cell surface and can trigger a potent T-cell response in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT) [2]. When mHAgs are expressed on malignant cells, they become the primary targets for the graft-versus-leukemia (GvL) effect, which is responsible for the curative potential of allo-HSCT in hematologic malignancies [3]. Therapeutic approaches aim to harness this effect by using mHAg-specific T cells or vaccines to selectively target cancer cells while avoiding healthy tissues to prevent graft-versus-host disease (GvHD). The clinical utility of mHAgs depends on their restricted expression pattern and the presence of the appropriate HLA restriction element in the patient [4]. Engineered T-cell therapies, such as those targeting the HA-1 antigen, are currently under investigation to provide a more targeted and safer alternative to traditional donor lymphocyte infusions [4].

Other names

mHAgMinor H antigenPolymorphic self-antigenMinor histocompatibility locus antigen

T-cell mediated cytotoxicity following recognition of polymorphic peptides presented by MHC molecules on the surface of target cells.