Graft-versus-host disease (GVHD) has been the primary limitation to the wider application of
allogeneic bone marrow transplantation (BMT). The immunobiology of acute GVHD is
complex and can be conceptualized to be a three-step process. In step 1, the conditioning
regimen (irradiation and/or chemotherapy) leads to the damage and activation of host
tissues and induces the secretion of inflammatory cytokines TNF-α and IL-1. As a
consequence expression of MHC antigens and adhesion molecules is increased, thus …