联合应用CTLA-4Ig及抗ICOS单克隆抗体延长小鼠移植胰岛存活时间

Costimulatory blockade with anti-inducible costimulator antibody in combination with CTLA4Ig on prevention of islet allograft rejection

目的探讨共刺激信号阻断剂细胞毒T淋巴细胞相关抗原4免疫球蛋白(CTLA-4Ig)及抗共同刺激分子ICOS单克隆抗体(ICOSmAb)对移植胰岛功能的影响。方法以BALB/c小鼠为供者,C57BL/6糖尿病小鼠为受者,进行同种胰岛细胞移植。将移植后的小鼠随机分成4组,每组10只。ICOS组:移植后1、3、5d腹腔内注射ICOSmAb 100μg/kg;CTLA4组:移植后0、2、4d腹腔内注射CTLA-4Ig 50μg/kg;联合阻断组:移植后腹腔注射CTLA-4Ig和ICOSmAb,用法同CTLA4组和ICOS组;对照组:单纯胰岛移植,不注射CTLA-4Ig和ICOSmAb。观察术后移植物存活时间和移植胰岛的病理改变;逆转录聚合酶链法(RT-PCR)检测移植胰岛组织中白细胞介素2(IL-2)、白细胞介素10(IL-10)mRNA的表达情况;应用流式细胞仪检测CD4^+、CD8^+ T淋巴细胞表达情况。结果联合阻断组的小鼠移植胰岛存活时间较其它3组明显延长,移植胰岛的细胞形态经光镜检查接近正常。联合阻断组与其它3组比较,IL-2 mRNA表达减少,差异有统计学意义(P<0.05),IL-10 mRNA的表达差异无统计学意义(P>0.05);移植术后21d,CD4^+、CD8^+T淋巴细胞表达上调不明显。结论应用CTLA-4Ig和ICOSmAb联合阻断CD28和共同刺激分子ICOS,可以明显的抑制排斥反应,延长移植胰岛的存活时间及存活率。

Objective To study the effects of costimulatory blockade with anti-inducible costimulator antibody （ICOS mAb） in combination with CTLA4Ig on prevention of islet allograft rejection. Methods Experimental animals were randomly divided into 4 groups （10 rats in each group）. CT- LA4Ig ＋ ICOS mAb group （group A）： intraperitoneal injection of CTLA4Ig on day 0, 2, 4 and ICOS mAb on day 1, 3, 5 after islet transplantation; ICOSmAb group （group B） .. intraperitoneal injection of ICOS mAb on day 1, 3, 5 after islet transplantation; CTLA4Ig group （group C） .. intraperitoneal injection of CTLA4Ig on day 0, 2, 4 after islet transplantation; control group （group D） .. simple islet transplantation. The islet allograft survival and pathological changes in the transplanted islets after transplantation were observed. By using RT-PCR, the expression of IL-2 and IL-10 mRNA in the transplanted islets was detected. The expression of CD4^＋ and CD8^＋ T cell was detected by flow cytometry. Results In group A, the survival time was obviously prolonged as compared with other three groups and the transplanted islets were near normal under a light microscope. As compared with other three groups, the expression of IL-2 mRNA was significantly decreased in group A （P〈0. 01）, but there was no significant difference in the IL-10 mRNA expression between group A and other three groups （P〉0. 05）. The expression of CD4^＋ and CD8^＋ T cell was not obviously up-regulated on the day 21 after transplantation. Conclusion The blockade of costimulatory signals with ICOS mAb in combination with CTLA4Ig has a favorable effects to restrain the rejection of islet transplantation.