Minor histocompatibility antigen on malignant hematopoietic cell (representative example: "Minor histocompatibility antigen HA-1") (mHA (representative example: HA-1))

Alloreactive host antigens on malignant hematopoietic cells refers to a group of genetically variable cell-surface peptides—primarily minor histocompatibility antigens (mHAs)—that are present on the malignant blood and bone marrow cells of a transplant recipient. These antigens differ between individuals due to polymorphisms and are recognized as "foreign" by T cells of an allogeneic donor after transplantation. This interaction can result in a graft-versus-leukemia effect (desirable, leading to tumor control), but may also provoke graft-versus-host disease (undesirable, damaging normal tissues) if the antigens are also expressed outside the hematopoietic system. Notable examples of these antigens include HA-1 and HA-2, which are selectively expressed in hematopoietic cells and are being explored as targets for T cell immunotherapy designed to reduce relapse after allogeneic transplantation with minimal toxicity

Other names

Minor histocompatibility antigenmHAalloantigenhematopoietic-restricted mHAHA-1HA-2LRH-1ACC-2

Recognition by cytotoxic T lymphocytes leading to targeted cell lysis Induction of anti-tumor immunity via allo-reactive donor T cells after transplantation