联合阻断CD28和可诱导共刺激分子对小鼠同种异体胰岛移植物急性排斥反应的影响

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

目的在小鼠同种异体胰岛移植模型上,通过联合阻断CD28和可诱导共刺激分子(ICOS),观察CTLA-4Ig及ICOS单克隆抗体(ICOSmAb)对胰岛移植物功能的影响。方法将小鼠随机分成4组,每组10只。联合阻断组:分别于移植后0、2、4 d和1、3、5 d腹腔内注射CTLA-4Ig 50μg/ kg和ICOSmAb 100μg/kg体重组。ICOS组:移植后1、3、5 d腹腔内注射ICOSmAb 100μg/kg体重组。CTLA4组:移植后0、2,4d腹腔内注射CTLA-4Ig 50μg/kg体重组。对照组:单纯胰岛移植,不做CT- LA-4Ig和ICOSmAb处理组。观察术后移植物存活时间和病理改变,RT-PCR检测移植组织中IL-2、IL-10mRNA表达,流式细胞仪检测CD4^+、CD8^+T淋巴细胞表达。结果联合阻断组小鼠移植物存活时间平均为(31.00±6.57)d,较其他3组延长,差异有统计学意义(P<0.05);IL-2和IL-10 mRNA表达水平分别为(44.23±6.24)和(65.23±11.02),与其他3组比较,IL-2 mRNA表达差异有统计学意义(P<0.05),而IL-10mRNA表达差异无统计学意义(P>0.05);CD4^+、CD8^+T淋巴细胞荧光阳性百分率分别为(13.73±0.49)%和(14.56±0.31)%,表达上调均不明显;移植胰岛光镜检查接近正常。结论应用CTLA-4Ig和ICOSmAb联合阻断CD28和ICOS,可以明显抑制胰岛移植物排斥反应。

Objective To study the effects of costimulatory blockade with anti-inducible costimulator antibody in conjunction with CTLA4Ig on prevention of islet allograft rejection. Methods Experimental animals were divided into 4 groups in random, 10 rats in each group： The CTLA4Ig and ICOS mAb -treated group： intraperitoneal injection of CTLA4Ig 50μg/kg on day 0,2,4 and ICOS mAb 100μg/kg on day 1,3 and 5 after islet transplantation;The ICOS mAbtreated group： intraperitoneal injection of ICOS mAb 100μg/kg on day 1,3 and 5 after islet transplantation ;The CTLA4Ig -treated group： intraperitoneal injection of CTLA4Ig 50 μg/kg on day 0,2 and 4 after islet transplantation;Control group： simple islet transplantation, not subject to CTLA4Ig and ICOS mAb. HE stain for kidney was used to evaluate the histology,and immunohistochemical stain of insulin-Ab used to determine the expression of insulin. The expression of CD4^＋ and CD8^4 T cells was detected by flow cytometry. The expression of IL-2 and IL-10 mRNA was detected by RT- PCR. Results The mean survival time in CTLA4Ig and ICOS mAb - treated group was （31.00 ± 6.57 ） days ,which was significanntly different from that in other three groups （P 〈 0.05）. The expression level of IL-2 mRNA in CTLA4Ig and ICOS mAb -treated group was （44.23 ± 6.24）, which was obviously different from other three groups （P 〈 0.05）, but there was no significant difference in the expression level of IL-10 mRNA between among the groups （ P 〉 0.05）. The number of CD4^＋ and CD8^＋ T cells in CTLA4Ig and ICOS mAb - treated group was （ 13.73 ± 0.49） % and （ 14.56 ± 0.31 ） % respectively, showing no obvious up - regulation on the day 21 after transplantation. Uner light microscopy,the morphology of islets was close to the normal. Conclusion The blockade of costimulatory signals with ICOS mAb in conjunction with CT- LA4Ig has a favorable effect to restrain the rejection of islet transplantation.