EGCG治疗实验性自身免疫性脑脊髓炎免疫学作用机制研究  

Mechanism of epigallocatechin-3-gallate on amelioration of experimental autoimmune encephalomyelitis

作　　者：孙权业[1] 张霞[1] 郑英霞[1] 胡晓娟[1] 陈鸣[1] 聂红[1] 

机构地区：[1]上海交通大学医学院上海市免疫学研究所,上海200025

出　　处：《现代免疫学》2010年第3期190-194,共5页Current Immunology

基　　金：上海市教委重点学科(J50207);上海市教委科研项目(06BZ022);上海交通大学医学院基金资助项目(2008XJ005);上海市免疫学研究所基金资助项目(08-A09)

摘　　要：为了探讨表没食子儿茶素没食子酸酯（（-）-epigallocatechin-3-gallate,EGCG）治疗实验性自身免疫性脑脊髓炎（experimentalautoimmune encephalomyelitis,EAE）小鼠的免疫学作用机制。通过用MOG_（35-55）肽段免疫小鼠建立EAE疾病模型,分别获取EGCG治疗组及对照组小鼠体内MOG_（35-55）特异性T细胞,~3H掺入法检测EGCG对其增殖的影响;ELISA方法检测培养上清中IFN-γ、IL-4及TNF-α的含量;Western blot方法检测NF-κB信号通路中IKK和IκB蛋白表达水平;定量PCR技术检测Th1和Th2细胞转录因子T-bet及GATA-3基因表达水平。结果显示：EGCG治疗明显抑制MOG特异性T细胞的增殖;抑制炎性细胞因子IFN-γ及TNF-α的表达,并增加IL-4的表达水平;抑制NF-κB信号通路中IKK蛋白的表达;调节Th1/Th2细胞分化过程中特异性转录因子T-bet及GATA-3基因表达水平。研究结果表明,EGCG通过抑制MOG特异性T细胞增殖,抑制IKK蛋白表达,促使Th1型细胞向Th2型细胞转化等途径治疗EAE,为今后临床研究治疗多发性硬化症药物提供实验基础。To investigate the mechanism of epigallocatechin-3-gallate（EGCG） for the treatment of experimental autoimmune encephalomyelitis（EAE）,the EAE mouse model was established by immunization of mice with MOG_（35-55） peptide.The proliferation of MOG-specific T cells in EGCG-treated and control mice was investigated by ~3H-TdR mcorporation.ELISA assay was used to detect the contents of IFN-γ,TNF-αand IL-4 proteins in the culture supernatants and Western blot assay was applied to investigate the IKK and IκB protein expressions in NF-κB signal pathway.Meanwhile,the mRNA expression level of T-bet and GATA-3 gene was determined by real-time PCR.The experimental results showed that in vivo treatment of EAE mice with EGCG had great therapeutical benefit at clinical levels.Disease suppression was found to be associated with inhibition of MOGspecific T cell proliferation with down-regulation of the expression of inflammatory cytokines including IFN-γand TNF-αas well as with the up-regulation of the expression of anti-inflammatory cytokine IL-4.In vivo treatment of EAE mice with EGCG resulted in intracellular accumulation of IκB through decreasing IKK phosphorylation and subsequent inhibition of NF-κB activation and induced the gene expression shift of the specific transcription factor（T-bet and GATA-3） in Th1 and Th2 cell differentiation. In conclusion,our study provides experimental evidence that EGCG had great therapeutic effect on EAE by its inhibition action on pathogenic T cells,through a specific effect on the Th1/Th2 shift and induction of IκB expression to inhibit nuclear translocation of NF-κB.These results suggest that EGCG may be of potential therapeutic value for the treatment of autoimmune disorders.

关 键 词：EGCG EAE TH1 TH2 

分 类 号：R392.12[医药卫生—免疫学]