Abstract

Regeneration of Normal Hematopoiesis: Prevention of Immunological Complications with Preserved Anti-tumor Effect Following Hematopoietic Stem Cell Transplantation

Stephan Fricke, Investigator, Fraunhofer Institute for Cell Therapy and Immunology IZI

Allogeneic hematopoietic stem cell transplantation (aHSCT) is the only curative therapy for many hematological patients. Despite significant improvements in recent decades, it still can be associated with life-threatening complications. Graft-versus-host-disease (GvHD) is the main complication that often minimizes treatment success and the application of aHSCT for other indications (e.g. autoimmune diseases). The results presented here deal with new preventive strategies for GvHD without the use of conventional immunosuppressive drugs using monoclonal anti-human CD4 antibodies. For the first time, the ex vivo incubation of an allograft by epitope-specific anti-human CD4 antibodies allowed the Graft-versus-leukemia (GvL)-effect and the permanent suppression of GvHD simultaneously. Thus, the separation of GvL effect from GvHD as the most important requirement for aHSCT and the induction of immune tolerance (freedom of GvHD) as one of the most important requirements for transplantation immunology were experimentally achieved.