The Study On Mouse Immature Dendritic Cell Which Induce Immunologic Tolerance Of Diabetic Mouse After Heterogenic Islet Transplantation

BackgroundDiabetes mellitus is a global common disease.Insulin replacement therapy can not prevent the complication.Islet 8 cell replacement therapy,which including pancreatic transplantation and islet cell transplantation,can regulate insulin secretion and keep blood glucose with normal level.But graft rejective reaction may affect the outcome of transplantation.Immature dendritic cells express low level of costimulatory molecules.When immigrated into peripheral lymphoid tissue with autoantigen,immature dendritic cells could not activate T cell.We injectied intravenously recipient-type immature bone marrow-derived dendritic cells(iBMDCs)which loaded with antigen of donor the day before heterologous islet cell transplantation,induced recipient immunologic tolerancein in order to induce a significant prolongation of allograft survival.Methods36 male BALB/c mice were divided into 4 groups in random,9 per group. Group G₁ was control group,group G₂,G₃ and G₄ were injected with STZ 80mg/kg,200mg/ kg and 240mg/ kg to construct model of diabetes mellitus respectively.Dendritic cells were derived from 20 BABL/c mice bone marrow precursors. Briefly,bone marrow cells were cultured in Roswell Park Memorial Institute 1640 complete medium:20%endotoxin-free fetal calf serum,supplemented with rmlL-44 ng/mL and rmGM-CSF 1.5ng/mL.Cultures were fed with GM-CSF and IL-4 at day 1,day 3 and day 5.At day 7,adherent iBMDCs were collected. iBMDCs were stained using the monoclonal antibodies.We monitored and identificated cell population and imDC by flow cytometry.Pancreases,which were obtained from 30 female wistar rats,digested with collagenaseâ…¤.Purified islet cells were evaluated after dithizone and AO-PI staining.40 male BALB/c mice were divided into 4 groups in random,10 mice per group.Using STZ to construct model of diabetes mellitus,and group T₂ were transplanted heterogenic islet cells under mice renal capsules.Group T₃ and T₄ were injected intravenously recipient-type immature bone marrow-derived dendritic cells the day before heterogenic islet cells transplantation.ResultsThe achievement ratio of different doses of STZ induced diabetes mellitus were 0%,77.78%and 71.43%respectively;Survival rate of group G2 and group G3 were 85.71%and 40%respectively.533.33 islet cells could obtain from per wistar rat.Purity and survival rate were 80%and 95%respectively.Blood glucose of diabetes mellitus mice decreased after heterogenic islet cells transplantation.Graft survival rate of group T₃ and T₄ were more than that of group T₁ and group T₂,and the normal level of blood glucose of group T₃ and group T₄ were longer than the other groups.Conclusion200mg/kg STZ could gain best achievement ratio and survival rate. Additional injection of donor bone marrow-derived immature DCs can improve tolerogenic capacity of heterogenic islet cells transplantation,and degrade graft rejection obviously.Mice bone marrow and human spleen can achieve sufficient dendritic cells for experiment.The lasting time of normal level of blood glucose can increase by injecting immature bone marrow-derived dendritic cells before islet transplantion.