ALLORECOGNITION AND GRAFT-VERSUS-HOST DISEASE

The development of graft-versus-host disease (GVHD) after allogeneic b one marrow transplantation (BMT) is mediated by alloreactive donor T l ymphocytes infused with the bone marrow (BM) inoculum, Over the past f ew years, knowledge about the molecular basis of antigen (Ag) recognit ion, tolerance induction and activation of alloreactive T lymphocytes has increased remarkably, Recent observations also challenged the trad itional view of the role and significance of various alloreactive T ce ll subsets and their particular effector cell functions involved in th e generation of GVHD, New information which emerged from these studies has a major impact in understanding the immunobiology of GVHD, It als o has important practical consequences, such as the successful predict ion of GVHD before allogeneic BMT by the measurement of recipient-spec ific alloreactivity, The current concepts of the molecular basis of al lorecognition, tolerance induction and T cell activation could be impo rtant in developing strategies to avoid GVHD while preserving a graft- versus-leukemia response.