The main complication following an allogeneic hematopoietic stem cell transplantation is acute graft-versus-host-disease (aGvHD). The conventional treatment methods can be associated with little long-term success and toxicities. This necessitates the development of less debilitating treatment options. A new approach involves the use of a specific anti-human CD4 antibody. The antibody specifically reduces adverse immune reactions, thus minimizing the chances of GvHD development following stem cell transplantation. The influence of this anti-human CD4 antibody is currently investigated with regard to both, the prevention of GvHD and preservation of the graft-versus-leukemia (GvL) effect in a clinically relevant, humanized leukemia model. For this purpose, models are used which are particularly qualified for the transplantation of human hematopoietic stem cells and human leukemia cells. The findings obtained from these studies are essential in applying the antibody and other new drugs in the clinics. Existing leukemia models will be constantly improved and the anti-human CD4 antibody and other drugs will be evaluated.
By using humanized models, it is possible to gain new insights into immunological processes occuring during GvHD development and the GvL effect. The models and findings are not only extremely valuable for hematopoietic stem cell transplantation and leukemia treatment, but also for stem cell transplantation in other indications (e.g. autoimmune diseases).