Reconstitution of CD52-Negative CD4 T Cells after Alemtuzumab-Based T Cell Depleted Allogeneic Hematopoietic Stem Cell Transplantation

Abstract The human CD52 molecule is the target of the monoclonal antibody Alemtuzumab, which is used for treating patients with chemo-refractory chronic lymphocytic leukemia as well as for T cell depletion (TCD) in the context of allogeneic hematopoietic stem cell transplantation (HSCT). The molecule is expressed on the surface of lymphocytes, dendritic cells and to a lesser extent on blood-derived monocytes. Previously, investigators have demonstrated that the surface expression of CD52 on T cells is down-regulated after in vitro incubation with Alemtuzumab. By treating purified human CD4 T cells over 4 hours with 10 μg/mL Alemtuzumab in medium supplemented with 10% human AB serum in vitro…