目的研究IL-17阳性细胞在实验性自身免疫性葡萄膜炎(EAU)大鼠模型眼部的表达。方法用光感受器间维生素A类结合蛋白(IRBP)和氟氏完全佐剂等量混合注射于20只Lewis大鼠的右后足底部为实验组,于建模后第7、10、11、12、13、14、21、28天用裂隙灯显微镜进行眼前节检查,并根据de Smet的标准对炎症进行分级。用0.3 mL肝素(5 000 U/mL)注射至左心室以抗凝血,然后取眼球制作冰冻切片。免疫组织化学染色观察IL-17多克隆抗体在眼组织中的表达,5只正常Lewis大鼠作为对照。结果用IRBP免疫Lewis鼠后第10天,裂隙灯显微镜下可见眼前节炎症表现,免疫后第7、14、21、28天各组大鼠眼部炎症平均得分为0.4、3.2、1.6和0.2。实验组大鼠眼组织切片的苏木精-伊红染色可见炎性细胞浸润和光感受器细胞破坏。免疫组织化学染色发现,实验组虹膜、睫状体和视网膜部位可见IL-17蛋白表达,而正常组未见IL-17蛋白表达。第7、14、21、28天各组大鼠眼部组织切片染色的平均得分分别为0.6、4、2、0.4。EAU大鼠眼部炎症表现的严重程度与IL-17的表达量呈正相关(r=0.968,P〈0.01)。结论IL-17蛋白在Lewis大鼠EAU模型中呈高表达,表明IL-17阳性表达细胞在EAU的发病过程中起一定作用。
Background Experimental autoimmune uveoretinitis(EAU) animal model is characterized by the similar pathological features and therefore is an useful researching tool in the study on uvetitis.Research also found that interleukin-17(IL-17) is overexpressed in many autoimmune diseases.ObjectiveThe aim of this study is to investigate the expression of IL-17 positive cells involved in EAU.MethodsThe EAU animal models were established by injecting the interphotoreceptor retinoid-binding protein(IRBP,100μg)+Freund complete adjuvant(1∶1) into the right pelma of 20 general Lewis rats.The another 5 normal Lewis rats served as the control group.The clinical examination of ocular anterior segment of the rats was performed in 7,10,11,12,13,14,21,28 days under the slim lamp after establishment of models and the inflammation response was scored as the standard of de Smet.0.3mL of heparin was perfused into left ventricle and then the frozen ocular tissue section was prepared.Immunohistochemistry was performed using polyclonal antibodies to detect the expression of IL-17 in ocular sections.ResultsThe inflammatory response of the ocular anterior segment was found from 10 days through 28 days after injection with the inflammatory score 0.4,3.2,1.6 and 0.2 in 7 days,14 days,21 days and 28 days respectively.The infiltration of inflammatory cells and destroy of retinal structure were seen in the rats with EAU.IL-17 was positively expressed in iris,ciliary and retina in 7,14,21 and 28 days after injection with the score 0.6,4.0,2.0 and 0.4 respectively.Absent staining for IL-17 was seen in the normal sample and negative control sample.The intensity of IL-17 expression was significantly positively correlated with EAU findings(r=0.968,P0.01).ConclusionIL-17 is overexpressed in ocular tissue of Lewis rats with EAU,indicating that IL-17 positive cells may be contributed to the inflammatory responses of the eye in EAU.