共刺激分子Tim-1在角膜移植排斥反应中的作用

背景 角膜移植是目前临床上治疗角膜盲可靠且有效的复明手段,角膜移植术后的免疫排斥反应是角膜移植失败的主要原因. 目的 研究共刺激分子Tim-1在大鼠角膜组织中的表达及其在角膜移植排斥反应发生和发展过程中的作用.方法 40只清洁级成年雌性Wistar大鼠随机分为正常对照组、自体角膜移植组和同种异体角膜移植组.正常对照组大鼠未行任何手术,自体角膜移植组分别以Wistar大鼠作为供体和受体施行穿透角膜移植术,而同种异体角膜移植组以SD大鼠角膜作为供体,Wistar大鼠作为受体行穿透角膜移植术,各组供体角膜植片均为3.5mm,植床直径为3.0 mm.分别于术后7d、14d在裂隙灯显微镜下观察术眼角膜炎症反应情况,按照Larkin的标准进行排斥反应评分,计算排斥反应指数（RI）,观察各组角膜植片的平均存活时间和植片存活率.术后7d、14d,3个组各取3只大鼠眼球制备角膜组织切片,分别行组织病理学检查和免疫组织化学检测,观察角膜组织的炎症反应和共刺激分子Tim-1蛋白在角膜组织中的表达;此外分别于术后7d、14d各组取5只大鼠角膜制备组织匀浆,采用实时荧光定量PCR法检测共刺激分子Tim-1 mRNA在大鼠角膜植片中表达量（吸光度,A）的变化.结果 术后7d,自体角膜移植组和同种异体角膜移植组大鼠角膜植片均出现轻度水肿;术后14 d,自体角膜移植组角膜植片水肿消失,植片透明,而同种异体角膜移植组大鼠角膜植片水肿增厚,呈灰白色混浊,可见新生血管形成.自体角膜移植组植片的存活率为100％,同种异体角膜移植组植片存活率为0,平均生存时间为（9.8±1.2）d.组织病理学检查表明,术后7d自体角膜移植组植片基质层可见炎性细胞浸润,但术后14d炎性细胞明显减少;同种异体角膜移植组术后7d植片水肿,基质层可见炎性细胞浸润,术后14 d阳性细胞大量增加,可见新生血管.免疫?

Role of costimulatory molecule Tim-1 in the immune reaction of corneal transplantation in rats

Background Corneal transplantation is the most reliable and effective means to treat the corneal blindness in the clinical,immune rejection is a major cause of corneal graft failure after the keratoplasty.Objective This study aimed to investigate the role of Tim-1 in the immune reaction following corneal transplantation in rats.Methods Forty clean female Wistar rats were randomized into normal control group,autologous corneal transplantation group and allogeneic corneal transplantation group.Penetrating corneal transplantation was performed with the Wistar rat donors and Wistar rat receipts in the autologous corneal transplantation group,while with the SD rat donors and Wistar rat receipts in the allogeneic corneal transplantation group.The corneal graft diameter was 3.5 mm and the plant bed diameter was 3.0 mm.The inflammatory response of the grafts was examined under the slit lamp microscope 7 days and 14 days after operation and scored based on the criteria of Larkin.Rejection index （RI）,mean survival time and survival rate were calculated.The histopathological examination was performed 7 days and 14 days after surgery to evaluate the inflammatory manifestation,and the expressions of Tim-1 protein and mRNA were assayed by immnunochemistry and real-time fluorescence quantitative PCR （RT-qPCR）in the time points mentioned above.Results Mild edema of the grafts were found 7 days after operation in both the autologous corneal transplantation group and the allogeneic corneal transplantation group.In postoperative 14 days,the grafts were clear in the autologous corneal transplantation group,but the thickening,neovacularization and cloudy of the grafts were exhibited in the allogeneic corneal transplantation group.The survival rate of the grafts was 100％ in the autologous corneal transplantation group and that of the allogeneic corneal transplantation group was 0 with the survival time of （9.8±1.2） days.Histopathological examination revealed the stromal infiltration of inflammatory cells in both the aut