Allogeneic bone marrow derived mesenchymal stem cells transplantation leads to stable chimerism and induces donor specific tolerance

Objective To investigate the possibility of immune tole rance induced by bone marrow-derived mesenchymal stem cells in allogeneic organ transplantation. Methods Allogeneic bone marrow-derived mesenchymal stem cells and syngeneic bone marrow cells were cotransplanted to lethally irradiated female C57BL/6 recipient mice. FACS was used to analyze the chimerism 150 days later. Mixed lymphocyte reaction and ConA induced proliferation test were performed to evaluate proliferative activity of mice spleen cells in cell-transplanted group. Skin transplantation test was done to observe immune response of cell-transplanted group mice against organ graft from donor mice. Results About 5 97% donor T cells were detected in splenocytes of cell-transplanted group mice. MLR showed that mean SI of cell-transplanted group mice was 1.79, and that of untreated group mice was 7 28. ConA induced proliferation test showed that mean SI of cell-transplanted group mice was 31 92; and that of untreated group mice was 34 99. Mean survival time of donor-derived skin graft in cell-transplanted group mice was more than 90 days; and that in untreated group mice was 8 days. Conclusion Our results showed for the first time that induction of stable mixed hematopoietic chimerism after allogeneic bone marrow derived mesenchymal stem cells transplantation lead to stable donor-specific tolerance in allogeneic host and skin graft survival from donor mice.