IL-17及RORγt在实验性自身免疫性脑脊髓炎小鼠脑及脊髓组织中的动态表达

Study on the dynamic expression of IL-17 and RORγt in the experimental autoimmune encephalomyelitis mice

目的:探讨IL-17及RORγt在实验性自身免疫性脑脊髓炎(EAE)小鼠脑及脊髓组织中的动态表达。方法:以MOG35-55免疫建立小鼠EAE模型。免疫后,每日观察小鼠的发病情况、体重变化并进行神经功能评分。于免疫后13、20、30天3个时间点分别取脑、脊髓组织进行HE染色、免疫组织化学染色及Real-time PCR,观察炎症细胞浸润和IL-17及RORγt表达情况。结果:EAE组免疫后第13天IL-17及RORγt水平即出现明显上调,早于临床症状的发生(P<0.05);免疫后第20天EAE组IL-17及RORγt水平与对照组及EAE 13天组比较明显升高(P<0.05);免疫后30天,IL-17表达较EAE 20天组有所下降(P<0.05),但较正常对照组仍有升高(P<0.05),而此期RORγt mRNA较对照组虽有数值上的升高但升高趋势不明显(P>0.05)。EAE小鼠中炎症细胞浸润数及IL-17水平与小鼠神经功能评分呈显著正相关。结论:随免疫后时间的延长及EAE小鼠病程的进展,IL-17及其重要的调控因子RORγt水平呈逐渐增高后缓慢下降的变化趋势。IL-17及RORγt与EAE的发生、发展及缓解存在重要联系。

Objective：To study the dynamic expression of IL-17 and RORγt in the experimental autoimmune encephalomyelitis mice and to explore the correlation between the dynamic expression of IL-17 or RORγt and the progression of EAE.Methods： C57BL/6 mice were randomly divided into control group and EAE group,the latter immunized with MOG35-55.Furthermore,the EAE group was divided into premorbid group,fastigium group and paracmastic group.The morbidity of disease,weight and clinical signs were observed.The pathological changes in brain and spinal cord tissue sections were observed after HE staining.The expression of IL-17 was observed by immunohistochemistry staining.Additionally,the level of IL-17 mRNA and RORγt mRNA in the spinal cord of the groups above were measured by Real-time PCR.Results： Compared with the control group,the mean clinical score of EAE group increased significantly.There was an obvious increase in the number of inflammatory cells in the brain and spinal cord in three stages of EAE group,compared to the control group mice.The number of IL-17 positive cells in the brain and spinal cord in three stages of EAE group mice increased obviously compared with that in control group and there was statistical difference between the two groups（P〈0.05）.The number of IL-17 positive cells increased significantly in fastigium group in comparison with that in premorbid and paracmastic groups（P〈0.05）.The levels of IL-17 and RORγt mRNA in spinal cord of EAE group mice were significantly higher than those of control group（P〈0.05）.Conclusion： The dynamic expression of IL-17 and RORγt,the important regulatory factor of Th17 cells differentiation,are correlated with the progression of EAE.