联合阻断共刺激信号对兔新生血管化角膜移植术后免疫排斥反应的影响

目的　通过阻断新生血管化角膜兔模型穿透性角膜移植术后共刺激信号配体和受体的结合，探讨联合阻断共刺激信号对兔高风险角膜移植术后免疫排斥反应的影响。方法　缝线法制作新生血管化角膜兔动物模型，随机数字表法将其分组:对照组、ＭＲ１组、抗Ｂ７-１组、联合处理组，每组１２只。术后裂隙灯显微镜下观察角膜排斥反应排斥情况，并记录各组角膜植片存活时间、制作植片生存曲线，比较其差异；术后４周或免疫排斥反应发生时各组随机选取５只兔模型摘取术眼角膜，对植片行组织病理学检查角膜组织结构改变及炎性细胞浸润情况，通过免疫组织化学方法检测肿瘤坏死因子-α（ｔｕｍｏｒｎｅｃｒｏｓｉｓｆａｃｔｏｒ-α，ＴＮＦ-α）在角膜植片中的表达。结果　与对照组比较，ＭＲ１组、抗Ｂ７-１组和联合处理组角膜植片均获得了较长的存活时间，差异有统计学意义（Ｐ＜０．０５）。联合处理组分别与ＭＲ１组和抗Ｂ７-１组比较，生存时间更长，差异均有统计学意义（均为Ｐ＜０．０５）；ＭＲ１组和抗Ｂ７-１组角膜植片生存时间比较，差异无统计学意义（Ｐ＞０．０５）。联合处理组兔角膜植片炎性细胞浸润较其他三组明显减少，ＴＮＦ-α表达平均光密度值显著降低，差异有统计学意义（Ｐ＜０．０５）；而ＭＲ１组与抗Ｂ７-１组比较，差异无统计学意义（Ｐ＞０．０５）。结论　联合应用ＣＤ４０Ｌ和抗Ｂ７-１单克隆抗体阻断共刺激通路受体和配体的结合，比单独应用其中一种抗体能更有效地降低新生血管化角膜兔模型穿透性角膜移植术后植片排斥反应的发生率，延长植片的生存时间，提高植片的存活率。

Effects of combined block of co-stimulating signal on rabbit anti-rejection after neovascularization corneal transplantation

Objective Through making new blood vessels of corneal model in rabbit eyes and penetrating keratoplasty, postoperative blocking the combination of stimulus signal ligand and receptor , to explore the effects of joint block stimulus signal on postoperative rejection in high-risk corneal penetrating keratoplasty. Methods The arumal neovascularization models were established with suture method. The experimental rabbits were divided into four groups with random number table method : Control goup , MRI ~oup ,resistance against B7-I group and combined treatment goup ,12 cases in each group. The postoperative corneal immune rejection was observed under slit-lamp , the corneal graft survival time was recorded in each group , the survival curve of graft was made , and the difference was compared. At postoperative 4 weeks (28 days) or corneal immune rejection occurs. the cornea of experimental eyes was enucleated in 5 rabbits of each group ,the structure changes and inflammatory cell infiltration were observed by tissue pathology examination. Immunohistochemical method was used to detect expression of tumor necrosis factor-e/ ( TNF-e/) in corneal graft. Results Compared with the control group , the survival time in other three groups were obvious long ( P < 0. 05 ) , the combined treatment group was longer than MRI group and resistance against B7-I group ( aU P < 0. 05 ) .and there was no sigruficant difference between MRI group and resistance against B7-I group (P > 0. 05 ). The inflammatory cell infiltration in combined treatment group was less than those in other three groups,the average optical density value of TNF-a was obviously decreased (P < 0. 05 ) , but there was no statistical difference between MRI group and resistance against B7-I group ( P > 0. 05 ) . ConcIHsion The joint CD40L monoclonal antibodies and resistance to B7-I antibodies to block the receptor and the ligand binding of stimulus pathway can achieve lower incidence of postoperative rejection after corneal penetrating keratoplasty than separate application of anyone antibody, can prolong the survival time and improve the survival rate of graft tissue.