中文摘要：

背景 角膜移植术后的免疫排斥反应仍然是导致角膜移植失败的首要原因,其免疫机制非常复杂.研究证实,辅助性T细胞17（Th17）及其主要效应分子之一白细胞介素-22（IL-22）对心脏、肝脏及骨髓等器官移植方面产生影响,但其在角膜移植排斥反应中的作用尚不确定.目的 探讨IL-22在大鼠角膜移植术后免疫排斥反应中的作用.方法 SPF级雌性SD大鼠24只,SPF级雌性Wistar大鼠76只,体质量180 ～220 g.按照随机数字表法将受体大鼠随机分为自体角膜移植组、同种异体角膜移植组和同种异体角膜移植抗排斥组,另取4只健康Wistar大鼠作为正常对照组.24只SD大鼠作为供体,48只Wistar大鼠作为受体,行同种异体角膜移植术;24只Wistar大鼠行自体角膜移植术.同种异体角膜移植抗排斥组大鼠术后用妥布霉素地塞米松滴眼液点眼2周.术后每日裂隙灯显微镜下观察大鼠角膜植片情况,参照Larkin等的排斥反应评分标准判断角膜植片的存活情况,采用Kaplan-Meier生存分析法比较各组角膜植片的累积生存率.分别于术后第5天、第14天任意取3只大鼠角膜行组织病理学检查,并于相应时间点任意取各组5只大鼠角膜植片行实时荧光定量PCR检测,计算并比较各组大鼠角膜组织中IL-22 mRNA和配体激活转录因子芳香烃受体（AhR） mRNA的相对表达量.结果 同种异体角膜移植组角膜植片的平均存活时间为10 d,同种异体角膜移植抗排斥组为17d,差异有统计学意义（x2=16.442,P=0.000）.术后不同时间点正常对照组、自体角膜移植组、同种异体角膜移植组和同种异体角膜移植抗排斥组大鼠角膜中IL-22 mRNA的相对表达量总体比较差异均有统计学意义（术后5 d：F=2.44,P=0.00;术后14 d：F=267.92,P=0.00）,其中术后5d和14 d同种异体角膜移植组角膜中IL-22 mRNA的相对表达量均明显高于同种异体角膜移植抗排斥组（术后5 d：9.70±0.35比0.46±0.21;?

英文摘要：

Background The rejection following keratoplasty still is a leading cause of corneal transplantation failure.Studies showed that the interleukin-22 （IL-22） ,one of the effector molecules of T helper cell 17 （Th17） participated on the rejection after heart,liver and bone marrow transplantation.However,the effect of IL-22 on corneal graft rejection is not well understood.Objective This study was to investigate the expression of IL-22 mRNA in the corneal grafts and the role of IL-22 in the immune rejection after corneal transplantation in rats.Methods Seventy-two Wistar rats were randomized into autologous keratoplasty group,allograft keratoplasty group and anti-rejection group,and other 4 normal Wistar rats served as normal control group.Autologous keratoplasty was operated on the Wistar rats of the autologous keratoplasty group,and allograft keratoplasty were carried out with the 24 SD rats as donors and 48 Wistar rats as recipients.Tobramycin and dexamethasone eye drops were topically administrated after autologous keratoplasty for 2 weeks in the anti-rejection group.The experimental eyes were examined by slit lamp microscope after surgery and graft survival was evaluated based on the rejection scoring criteria of Larkin.Intergroup accumulated survival rates of grafts were compared using Kaplan-Meier analysis.Histopathological examination of grafts was carried out in 5 and 14 days after operation respectively,and the related expression levels of IL-22 mRNA and aryl hydrocar-bon receptor （AhR） mRNA were carried out by real-time fluorescence quantitative PCR.The feeding and use of the experimental animals followed the Guangdong provincial regulations on the management of experimental animals.The experimental design was approved by the ethics committee of Southern Medical University.Results The median survival time of grafts in the allograft keratoplasty group was 10 days,and that in the anti-rejection group was 17 days,showing a significant survival extention in the anti-rejection group （x2=16.442,P =0