donor hematopoietic stem cells + recipient regulatory T cells

This therapy is a combination cellular immunotherapy involving the transplantation of donor-derived hematopoietic stem cells (HSCs) together with the adoptive transfer or in vivo expansion of regulatory T cells (Tregs) derived from the recipient. The primary aim is to achieve successful engraftment and immune reconstitution while minimizing graft-versus-host disease (GVHD), a major complication of allogeneic hematopoietic stem cell transplantation. Donor HSCs repopulate the recipient’s bone marrow, restoring hematopoiesis and immune function, while recipient Tregs act to suppress excessive immune responses, particularly those that could lead to GVHD. This approach leverages the immunomodulatory properties of Tregs—specifically their ability to maintain self-tolerance and regulate alloimmune reactions—without compromising beneficial graft-versus-leukemia effects[1][2][3]. Clinical studies have demonstrated feasibility and safety for this strategy, though efficacy outcomes are still under investigation.