Recipient-type specific CD4+CD25+ regulatory T cells favor immune reconstitution and control graft-versus-host disease while maintaining graft-versus-leukemia

CD4+CD25+ regulatory T cells (Treg's) play a pivotal role in preventing organ-specific autoimmune diseases and in inducing tolerance to allogeneic organ transplants. We and others recently demonstrated that high numbers of Treg's can also modulate graft-versus-host disease (GVHD) if administered in conjunction with allogeneic hematopoietic stem cell transplantation in mice. In a clinical setting, it would be impossible to obtain enough freshly...