Silencing Spleen ROR?t Gene Improves The Function Of Islet Allograft In STZ-induced Diabetic Mice

BACKGROUND:Islet transplantation is an effective means to eradicate T1DM,but the shortage of donor and postoperative immune inflammation reaction and are still the main problems.Th17 cells are a subset of T cells characterized by the secretion of IL-17.In the acute rejection of organ transplantation,IL-17 mRNA and protein showed a high expression trend.ROR?t is a specific transcription factor for Th17 cells.Unsensitized T cells can differentiate into Th17 by fully express transcription factor ROR?t while the differentiation of Tregs which characterized by expressing Foxp3 can be inhibited.The T cells cannot differentiate into Th17 when the ROR?t was absence,and autoimmune diseases and rejection after organ transplantation were reduced.Adeno-associated virus?AAV?is a non-pathogenic single-stranded DNA virus and also an ideal expression vector for long-term gene therapy.In this experiment,the recombinant adeno-associated virus expression vector-mediated RNAi technology was used to silence the transcription factor ROR?t in vivo,and the differentiation of Th17cells and its effect on islet transplantation were observed.GROUPING:In this experiment,the recipient C57BL/6 mice were divided into the following three groups?n=10?:1)ROR?t-silencing group:inject 100 ul?1×10¹11 v.g.?rAVV9-ROR?t-siRNA into the spleen.2)GFP control group:inject 100 ul(1×10¹¹v.g.)rAVV9-GFP into the spleen.3)Control group:inject 100 ul normal saline into the spleen.Diabetes induction and islet allograft under the kidney capsule were performed in each group of recipients.RESULTS:The survival time of the islet grafts after transplantation in the experimental group was significantly longer than that of the control group?ROR?t:31.3 days,NS:12.7 days,GFP:13.2?.The AUC of the experimental group was slightly smaller than that of the two control groups?P<0.05?and Insulin secretion is better than the two control groups.Compared with the two control groups,the expression of ROR?t mRNA in the spleen of the experimental group was significantly decreased,and the expression of Foxp3 mRNA was increased?P<0.001?.The expression of ROR?t mRNA in the transplantation site of experimental group was significantly lower than that in the two control groups?P<0.001?,but the expression of Foxp3 mRNA has no statistically significant.The differentiation of Th17 cells in the spleen lymphocytes of the experimental group was significantly lower than that of the control group?ROR?t:1.23,GFP:6.82,NS:7.76?while the differentiation of Treg cells was significantly higher than that of the control group?ROR?t:8.17,GFP:2.90,NS:2.83?.CONCLUSION:Silencing the spleen ROR?t gene which inhibits Th17 cell differentiation and induces Treg cell differentiation,prolongs the survival time of islets allograft in vivo and improves the function of the islets allograft.