CD40LIg基因修饰骨髓间充质干细胞对异种胰岛移植排斥反应的抑制作用

 目的 探讨T细胞分化群40补体免疫球蛋白（CD40LIg）基因修饰骨髓间充质干细胞（MSCs）对异种胰岛移植排斥反应的抑制作用。方法 建立Wistar-SD大鼠异种胰岛移植模型，用携带CD40LIg基因的重组腺病毒感染的MSCs进行干预治疗，观察糖尿病大鼠胰岛移植后生存情况、血糖变化和移植物病理形态学改变,检测移植物CD40LIg和胰岛素的表达以及移植大鼠白细胞介素2（IL-2）和肿瘤坏死因子（TNF-α）的水平变化。结果 (1)糖尿病大鼠血糖平均在移植后2天恢复正常，对照组血糖平均在移植后7天升高，单纯MSCs组和转染MSCs组血糖分别在20天和47天升高。(2)对照组、单纯MSCs组和转染MSCs组，移植物存活时间分别为（9±3.2）d、(25±5.3)d和(53±7.5) d，各组间比较具有显著差异(F =5.362, P < 0.05)；移植糖尿病大鼠生存时间分别为（24±6.8）d、(51±7.9)d、(95±12.7)d，各组间比较差异具有显著性(F =6.821, P < 0.05)。(3)对照组在胰岛移植后7d内，IL-2和TNF-α的水平均急剧上升，显著高于移植前水平(P < 0.01)。(4) 两个治疗组移植物内均可见成片的胰岛细胞团，未见淋巴细胞浸润，转染MSCs组移植物内可见CD40LIg和胰岛素的表达。结论 CD40LIg基因修饰骨髓间充质干细胞可以延长胰岛移植物的存活时间，抑制大鼠异种胰岛移植的排斥反应。

Effects of CD40LIg Modified Bone Marrow Mesenchymal Stem Cells on Rejection of Rat Islet Xenografts

【Objective】 To investigate the effects of cluster of differentiation 40 ligand immunoglobulin(CD40LIg) modified bone marrow mesenchymal stem cells(MSC) on the rejection of rat islet xenografts.【Methods】 The islet xenografts model was established with islet cells of Wistar rat transplant under the left kidney capsule of diabetic SD rat.MSC were infected with the recombinant adenoviruses containing CD40LIg gene as intervention treatment.Forty-five modeled diabetic rats were randomly divided into three groups with 15 in each: only islet cells were transplanted to rats in control group(A),islet cells and MSC were transplanted to rats in MSC group(B) and islet cells and MSC infected with CD40LIg gene were transplanted to rats in transfected MSC group(C).The blood sugar and the survival of transplantation rats and grafts were observed after transplantation.The morphological changes of grafts were observed.Expression of CD40LIg and insulin were detected by immunohistochemical staining and cytokines were quantified by ELISA.【Results】(1) The blood sugar of transplantation rats decreased to normal level on day 2 after transplantation.The average level blood glucose of control group(A),MSC group(B),transfected MSC group(C) increased on day 7,20,47,after transplantation respectively.(2) The grafts of group A,B,and C survived for(9.5 ± 3.2),(25.2 ± 5.3),and(53.6 ± 7.5) days,respectively.There are significant deviation of the grafts survival among group A,B and C(F=6.821,P < 0.05).The survival of transplantation rats were(24.1 ± 6.8),(51.7 ± 7.9),and(95.2 ± 12.7) days in group A,B,and C,respectively.The survival of transplantation rats compared each other were same as the survival of grafts(F=6.821,P < 0.05).(3)In group A,Serum IL-2 and TNF-α concentration were elevated to a high level within seven days post-transplantation and significantly increased compared with that pre-transplantation(P<0.01).Serum IL-4 and IL-10 concentration were significantly decreased compared with that pre-transplantation(P<0.01).(4) Hematoxylin-eosin staining of grafts showed islets bolus under the kidney capsule of transplantation rats,no inflammatory cell infiltrate and expression of insulin protein at islets in group B and C.The grafts positively stained for CD40LIg in group C.【Conclusion】 CD40LIg gene modified bone marrow mesenchymal stem cells could prolong the survival time of islet xenografts and inhibit the rejection of islet xenografts.