狼疮肾炎是系统红斑狼疮常见并发症，10-20%狼疮肾炎病人最终发展成肾衰竭，需血液透析或肾脏移植维持生命。微粒（MPs）是细胞活化或凋亡时脱落的直径为0.2-10μm的小颗粒物质，形成的球型空间结构中包含多种自身抗原如DNA和RNA。研究表明MPs具有免疫刺激活性，可打破免疫耐受触发自身免疫应答，但MPs在狼疮肾炎发病中的作用还未见报道。本课题在狼疮肾炎小鼠模型及体外培养淋巴细胞的平台上综合利用ELISA、免疫荧光及流式细胞术等方法探讨MPs在狼疮肾炎发病中的作用。进一步我们将考察TLR7/9信号通路在MPs发挥免疫刺激活性中的作用。通过特异性封闭TLR7/9，比较封闭前后免疫细胞活化情况、MPs与TLR7/9结合量及TLR7/9通路中关键信号蛋白的变化论证MPs是否依赖TLR7/9发挥免疫激活作用。本研究将首次论证MPs在狼疮肾炎发病中的作用及其潜在信号通路，为治疗狼疮肾炎提供新思路。

Lupus nephritis (LN) is one of the most serious manifestations of systemic lupus erythematosus (SLE). Ten-20% patients with LN finally develop renal failure and need hemodialysis or kidney transplantation. Up to now, the underlying mechanisms in the pathogenesis of LN are still poorly understood. Recently, microparticles（MPs）become a renewed interest in pathogenesis of LN. MPs, released by activated or apoptotic cells are membrane-bound vesicles ranging from 200 to 1,000 nm in diameter. Internally, MPs, carrying a broad variety of DNA and RNA are immunoactivate. It was reported that MPs were sufficient to break immune tolerance and trigger autoimmune response. The concentration and composition of MPs in LN patients differed markedly from those in healthy subjects. However, the role of MPs in the pathogenesis of LN is still poorly defined. In this study, we mainly illustrate the pathogenic role of MPs in the development of LN in mice by using ELISA, immunofluorescence staining and flow cytometry analysis. Furthermore, the immunoactivity of MPs is testified on the cultured splenocytes of mice. The proliferation and activation of immune cells are detected by MTT and flow cytometry analysis, respectively. After defining the immune activity of MPs, we want to clarify the potential signaling pathways of MPs, especially the TLR7/9 signaling pathway. To implicate the role of TLR7/9 on the activity of MPs,the specific antagonists of TLR7/9 are used to block TLR7/9. The binding capability of MPs to TLR7/9, the activity of B cells and pDC, and the expression and activity of key proteins of TLR7/9 signaling pathway are detected by Western-blot and Real-time PCR. The results will firstly demonstrate the role of MPs in the pathogenesis of lupus nephritis and its potential signaling pathway. The data will provide new ideas for the treatment of lupus nephritis.