辅助性T细胞亚群在小鼠EAE模型视神经中的变化

Alteration of T helper cell subsets in the optic nerve of experimental autoimmune encephalomyelitis

目的:探讨辅助性T细胞亚群Th1、Th2、Th17及Treg在小鼠EAE模型视神经炎发病机制中的意义。方法:C57BL/6小鼠随机分为佐剂对照组(n=16)、EAE模型组(n=48),免疫后第11、15、19天分批处死小鼠,观察视神经组织的病理改变。ELISA方法检测视神经IFN-γ、IL-4、IL-17的蛋白含量;Real-timePCR方法检测视神经组织IFN-γ、IL-4、IL-17和Foxp3的基因表达。结果:免疫后第11天IL-17的蛋白及mRNA的表达比正常对照组明显增高(14.255±0.790vs10.615±0.664;0.798±0.137vs0.083±0.013,均P<0.05),免疫后第19天IFN-γ的蛋白及mRNA的表达比对照组明显增高(21.060±1.821vs12.845±0.970;0.617±0.070vs0.089±0.014,均P<0.05),IL-4的蛋白及mRNA的表达与对照组比较减少(10.227±0.767vs14.258±0.885;0.089±0.014vs0.250±0.047,均P<0.05)。Foxp3mRNA的表达由免疫后11天、15天至19天与对照组比较均明显减少(1.068±0.121,0.495±0.064,0.605±0.021vs3.087±0.194,P<0.01)。结论:EAE小鼠视神经Foxp3和Treg表达减少可能为视神经炎发生发展的重要因素;IL-17在EAE小鼠视神经炎的早期阶段介导炎症损伤,IFN-γ在发病的高峰期加重了EAE小鼠视神经的炎症损伤。

Objective：To detect protein and gene expression of interleukin-17（IL-17）,interferon-gamma（IFN-γ）,interleukin-4（IL-4）and forkhead/winged helix transcription factor p3（Foxp3）in optic nerve and further to explore the role of T helper cell subsets such as Th1,Th2,Th17,Treg in the pathogenesis of optic neuritis of experimental autoimmune encephalomyelitis（EAE）.Methods：Mice in C57BL/6 background were randomly divided into control group and EAE group,at the day 11,15 and 19 post-immunization,optic nerves were dissected for morphological study,to detect IL-17,IFN-γ,IL-4.Protein analysis was done by Enzyme-linked immunosorbent assay（ELISA）.Quantitative real-time polymerase chain reaction（PCR）was used for measuring the gene expression of IL-17,IFN-γ,IL-4 and Foxp3.Results：The concentrations of IL-17 protein in the optic nerve were significant up-regulated at 11 days post-immunization,and so were IFN-γ protein concentrations in 19 days.Concentrations of IL-4 protein in the optic nerve declines slightly in 19 days（P0.05,respectively）.The mRNA expression of IL-17,IFN-γ and IL-4 was consistent with their protein expression（P0.05,respectively）.Foxp3 mRNA transcription was down-regulated from 11 days to 19 days post-immunization（P0.01,respectively）.Conclusion：Decreased expression of Foxp3 mRNA and Treg in optic nerve may play a key role in development of optic neuritis.IL-17 may mediate inflammatory pathogenicity at the early stage of optic neuritis,and IFN-γ may aggravate inflammatory injury during the peak stage of optic neuritis.