Graft-versus-host disease (GVHD) is a major complication after allogeneic stem cell transplantation (SCT). Patients with GVHD suffer from prolonged immunodeficiency, which is usually attributed to the required immunosuppressive therapy. Using appropriate mouse models, we now aim to examine whether GVHD itself contributes to the delayed immune reconstitution. For this purpose, we examine the B cell compartment, as a coordinated interaction of all components of the adaptive immune system (T cells, B cells and antigenpresenting cells) is required for its quantitative and functional recovery. Thus, examining the reconstitution of humoral immunity permits the evaluation of the entire adoptive immune system in drug-free transplantation models. The final goal of this project is the identification of crucial cellular and molecular mechanisms causing immunodeficiency in GVHD and the development of new strategies fostering tolerance and immunity after transplantation.
