实验性自身免疫性葡萄膜视网膜炎中可诱导的共刺激分子的表达及意义

目的探讨可诱导的共刺激分子（ICOS）在实验性自身免疫性葡萄膜视网膜炎(EAU)中的表达及意义。方法Lewis大鼠28只，用视网膜S抗原（50 μg）和福完全佐剂免疫24只大鼠以诱导EAU模型（免疫组），另外4只作为正常对照。裂隙灯显微镜每日观察大鼠眼部变化。免疫组大鼠分别于免疫后第7、12、15、21天被处死，摘除其脾脏后制作冰冻连续切片并提取组织蛋白。使用多克隆抗ICOS抗体，用免疫组织化学细菌蛋白过氧化物酶（SP）法在上述组织切片上进行免疫组织化学染色，并对提取的蛋白进行Western blotting检测。对照组大鼠在相应各时间点做同样处理。结果正常脾组织中可见少量ICOS阳性细胞；分别在免疫后第7、12 d，脾脏中ICOS阳性细胞数量明显增加，免疫后第15天时阳性细胞数量最多，21 d时阳性细胞数量减少，但仍显著高于正常组；Western blotting检测结果显示，ICOS蛋白的动态变化与免疫组织化学显示的阳性细胞数量变化一致。结论脾脏ICOS表达升高出现于EAU发生之前，随炎症的出现和加重而升高，在EAU消退期其表达有所降低，提示ICOS参与EAU的形成、发展和消退，在EAU发病中有重要意义。(中华眼底病杂志,2005,21:114-117)

Expression and significance of inducible co-stimulator in experimental autoimmune uveoretinitis

ObjectiveTo investigate the expression and significance of inducible co-stimulator (ICOS) in experimental autoimmune uveoretinitis (EAU). MethodsEAU was induced in 24 Lewis rats (immune group) by immunization with retinal S-antigen (50 μg) and complete Freund′s adjuvant, and another 4 rats were in the control group. Anterior segment of the rats′ eyes were observed by split microscope every day. Immunohistochemical staining was performed using polyclonal antibodies to ICOS on the sections of the spleen which were obtained from the rats in immune group at the 7th, 12th, 15th and 21st days after immunisation respectively. Western blotting was performed to investigate the dynamic expression of ICOS protein in the spleen. The same procedures were made at the corresponding time points in the rats in control group.ResultsA few ICOS positive cells were observed in the normal spleen. The number of ICOS positive cells in immune group increased obviously at the 7th and 12th days after immunization, reached the peak at the 15th day, and decreased at the 21st day which was still higher than that in the control group. The result of Western blotting showed that the dynamic changes of ICOS protein was identical with the changes of positive-cell number detected by immunohistochemistry.ConclusionsThe enhanced expression of ICOS happens before EAU occurs, which increases when the inflammation occurs and deteriorates, and decreases at the alleviative stage of EAU. It suggests that ICOS participates in the formation, development and disappearance of EAU and plays an important role in the incidence of EAU. (Chin J Ocul Fundus Dis, 2005,21:114-117)