双氢青蒿素调节Tfh/Th17分化治疗系统性红斑狼疮的机制研究

Systemic lupus erythematosus is one of most common autoimmune diseases indued by T cell .So far there is no effective radical treatment as the etiology remains obscure. Natural compound from plant is regard as popular new drug for its high effectiveness but low toxicity.DHA appears immunoregulation function potency, however the exact mechanism remains unclear. We previously showed that DHA can suppress Th17 differentiation in vitro and provides significant improvement of LCMV –induced macrosplania and lymphadenovarix,following down-regulate Tfh,which suggests DHA can suppress Tfh/Th17 induction.It is regarded that both Tfh and Th17 are the key facts in SLE pathogenisis , and Tfh/Th17 appear to be a new target of SLE treatment. As STAT3 signal pathway is most important signal of Tfh/Th17 induction ,and it is proved in carcinoma cells that DHA has obvious effects on STAT3 signal pathway, we suppose that DHA works as Tfh/Th17 downregulator via STAT3 signal pathway to treat SLE. We expect to induce Tfh/Th17 in vitro using SLE patients’s blood ,study the effect of DHA on Tfh/Th17 differentiation by FACS,detect related transcription factor expression by real time PCR, compare activation of STAT3 signal pathway and associated protein’s expression with or without DHA treatment.in order to illuminate its relationship with with DHA’s effect, Besides,we plan to future to discuss DHA’s rule in lupus mouse’s Urea protein ,autoantibody,improvement of lupus nephritis as well as T cell subtype. Hopefully to find a new treatment for SLE and provide theoretical for artemisinin-based drugs for autoimmune disease’s treatment.

SLE是T细胞介导的自身免疫性疾病，病因不明，治疗无突破。植物来源的药物因其低毒高效成为SLE治疗的研究热点。我们前期发现双氢青蒿素DHA能显著抑制Th17分化；缓解LCMV感染所致脾淋巴结增大并下调Tfh，提示Tfh/Th17是DHA新的作用靶细胞。Tfh/Th17失衡是SLE致病的关键环节，STAT3是影响Tfh和Th17产生最重要的信号通路，且癌株研究显示DHA能调控STAT3信号，因此我们推测DHA通过STAT3通路下调Tfh/Th17来治疗SLE。拟用SLE病人外周血诱导Tfh/Th17，流式分析DHA对其分化的作用，PCR测转录因子表达，WB测干预前后STAT3活化及相关蛋白的表达差异，研究DHA对Tfh/Th17分化的作用及与该通路的相关性；并用体内实验证实DHA对狼疮鼠自身抗体、肾炎的治疗作用及对T细胞群的影响。本课题将为青蒿素类药物应用于狼疮等自身免疫病治疗提供理论依据。

系统性红斑狼疮是常见的自身免疫性皮肤病。目前学术界普遍认为SLE发病的关键环节是T、B细胞淋巴过度活化，SLE患者中活化的自身反应性T细胞刺激自身反应性B细胞增殖。临床上的治疗主要以糖皮质激素为主联合使用霉酚酸酯等免疫抑制剂来抑制机体的异常免疫反应，但是有很多地方不尽如人意。寻求相对创伤小、简便、安全、有效，易于临床应用的治疗方法已成为目前国内外研究热点。青蒿素是一种从中国植物青蒿素分离的倍半萜烯内酯，其萃取物具有抗疟抑制迟发型过敏反应、胶原诱导的关节炎、影响肿瘤细胞生长、血管生成以及免疫调节。青蒿素或其衍生物如DHA影响SLE T细胞功能的免疫调节功能的分子机制尚有待发现。Tfh/Th17失衡是SLE致病的关键环节，STAT3是影响Tfh和Th17产生最重要的信号通路，且癌株研究显示DHA能调控STAT3信号，因此我们推测DHA通过STAT3通路下调Tfh/Th17来治疗SLE。本研究（1）体内实验证实DHA治疗狼疮鼠的有效性。经DHA干预治疗的狼疮鼠，其临床表现比对照组轻，dsDNA、ANA及尿蛋白水平明显低于对照组； DHA干预组的狼疮鼠淋巴结及脾脏中的Th17、Tfh比例远低于对照组，提示Th17/Tfh是DHA有效治疗狼疮的治疗靶点。（2）证实DHA可以体外抑制Th17/Tfh分化。0.4μg/ml DHA 能显著抑制正常小鼠niave T 细胞向Th17 、Tfh的分化，促进niave T 细胞向Treg 的分化，而对Th1及Th2分化的影响不大。（3）Western blotting实验证实DHA选择性抑制Tfh分化过程中STAT3信号通路的活化；DHA抑制Th17分化过程中的cHMGCs蛋白表达。本研究为青蒿素类药物应用于狼疮等自身免疫病治疗提供理论依据。