Rat Bone Marrow Mesenchymal Stem Cells Cotransplanted with BM Improve Hematopietic Reconstitution and Immunoreconstitution with Alleviating Graft-versus-Host Disease

Prolonged immunodeficiency after allogeneic bone marrow transplantation (BMT) causes significant morbidity and mortality from infection, while graft versus host disease (GVHD) after allogeneic BMT and immunosuppression therapies against GVHD further deteriorate this process. Adult bone marrow mesenchymal stem cells (MSC) have recently been shown to inhibit T-cell proliferation and reduce GVHD after allo-BMT. In this study, we characterized the effect of MSC on immunoreconstitution and hematopoietic-reconstitution after bone marrow transplantation. BMT model from Fischer344 rats (RT-1Al) to WF rats (RT-1Au) was established for this experiment. Effects of MSCs on hematopoietic reconstitution, immunoreconstitution and GVHD were studied by survival rate, peripheral blood counts, histological analysis and FACS at day +30 after transplantation. Immune function recovery were assessed by lymphocyte proliferation reaction stimulated with ConA and LPS and allogeneic mixed-lymphocyte reaction. At day 30 postransplant, compared with BMT groups, we observed that cotransplantation of MSC and bone marrow promoted the recovery of peripheral blood white blood cells (5.47±1.11x109/L vs7.12±1.70x109/L, p