(一)一表没食子儿茶素没食子酸酯对胶原诱导性关节炎小鼠免疫调节机制研究

目的 采用鸡Ⅱ型胶原诱导性关节炎(CIA)小鼠模型,观察(-)-表没食子儿茶素没食子酸酯(EGCG)的治疗作用,并探讨其作用机制.方法 给予CIA小鼠EGCG治疗,以磷酸盐缓冲液(PBS)作为阴性对照,观察各组小鼠发病情况.通过对CIA小鼠关节评分和关节病灶病理学检测[苏木素-伊红(HE)染色] 判断EGCG的疗效;通过,3H-胸腺嘧啶核苷(TdR)掺入实验、流式细胞术及Western-blot方法阐明EGCG的免疫学作用机制.结果 ①EGCG能够改善CIA的关节评分、减少病变关节组织炎性细胞浸润;② EGCG能抑制CIA小鼠C Ⅱ反应性脾细胞的增殖[EGCG组每分钟脉冲数(cpm)值3366±199;PBS组cpm值5342+112,P<0.05]和细胞因子白细胞介素(IL)-17的分泌(EGCG组IL-17阳性细胞数占CD4+T细胞0.41%;PBS组占4.05%);③EGCG能提高CIA小鼠淋巴结细胞中IKB的表达,降低磷酸化IKB蛋白水平的表达.结论 EGCG能显著减轻CIA严重程度.EGCG通过抑制CIA小鼠C Ⅱ反应性脾细胞的增殖和炎症因子IL-17的分泌;以及通过抑制CⅡ反应性淋巴结细胞中IKB的磷酸化,增强IKB的表达从而抑制核因子(NF)-κB的活性来治疗CIA.

Immunological regulation mechanism of epigallocatechin-3-gallate on collagen-induced arthritis

Objective The therapeutic effect of epigallocatechin-3-gallate (EGCG) on the collageninduced arthritis model (CIA) was observed and its immunological mechanism was analyzed. Methods EGCG was administered to CIA mice and PBS was admitted as negative control. The severity of CIA was evaluated by clinical scores and histopathological assessment (H-E staining). Immunological mechanisms inv-suppressive effect on IL-17 secretion of CD4+T cells (EGCG group: 0.41%; PBS group: 4.05% ) and inhibitive activity of C Ⅱ -reactive splenocytes proliferation. There was statistical significant difference between IKB expression and down-regulate phosphorylated IKB expression in lymph node cells of CIA mice.Conclusion EGCG can significantly ameliorate the severity of CIA. The therapeutic mechanisms may be related to inhibition of C Ⅱ -reactive splenocyte proliferation and IL-17 secretion and via inhibiting the activity of NF-κB by inducing the expression of IKB and by suppressing the expression of phosphorylated IKB in CIA mice.