Cotransplantation of Mesenchymal Stem Cells and Immature Dendritic Cells Potentiates the Blood Glucose Control of Islet Allografts

Background. Transplantation of islets is a promising alternative to treat type 1 diabetes (T1D), but graft rejection is themajor obstacle to its application in clinical practice. We evaluated the effects of mesenchymal stem cells (MSCs) and immature dendritic cells (imDCs) on islet transplantation in diabetic model. Methods. The streptozotocin T1D model was established in BABL/c mice. Rat islets were isolated and identified with dithizone (DTZ) staining. MSCs and imDCs were isolated from bone marrow of syngenic mice. Islets, alone or along with MSCs and/or imDCs, were transplanted to the left kidney capsule of diabetic mice. The blood glucose levels and glycosylated hemoglobin levels after transplantation were monitored. Results. Cotransplantation significantly decreased blood glucose and glycosylated hemoglobin levels in the diabetes mice. Transplantation of 200 islets + 2 x 10(5) MSCs + 2 x 10(5) imDCs could not only restore normal blood glucose levels, but also significantly prolong graft survival for 12.6 +/- 3.48 days. Conclusions. Cotransplantation of allogenic islets with imDCs and/or MSCs can significantly promote graft survival, reverse hyperglycemia, and effectively control the glycosylated hemoglobin levels.