炎性复合体-细胞焦亡通路介导钩端螺旋体免疫逃避的分子机制

钩端螺旋体（钩体）病是由致病性钩体引起的一种全球性自然疫源性人兽共患传染病。针对钩体逃避宿主免疫系统，长期定殖于动物肾脏，并不断从尿液排出钩体污染环境，造成敏感动物和人类钩体病多发难控。为了明确钩体免疫逃避，依据细胞焦亡是清除胞内菌保护机体关键环节的理论，基于本课题组发现肾脏钩体的定殖与抑制NLRP3炎性体表达有关的研究基础，推论钩体免疫逃避与其抑制炎性复合体-细胞焦亡通路激活有关。本研究拟从钩体与炎性复合体的互作入手，探讨其在钩体免疫逃避中的作用及调控机制。首先明确钩体对宿主细胞焦亡和炎性复合体表达的影响；再利用基因缺陷细胞和小鼠，验证炎性复合体在钩体感染中的作用及机能；最后通过钩体PAMPs分子及基因敲除株刺激细胞和小鼠，经免疫共沉和蛋白质组学等方法，揭示PAMPs与炎性复合体通路互作的分子机制。这不仅有助于阐明钩体在肾脏中的免疫逃避机制，也为控制该病源头提供了新的研究思路和理论指导。

Leptospirosis, a zoonosis of worldwide distribution and recognized as an emerging natural focus infectious diseases, is caused by pathogenic bacteria of the genus Leptospira. Leptospires evade the host innate immune response and colonization in kidneys in resistant animals and chronically excrete the leptospiruria into the environment. Humans or animals become infected directly through exposure to urine and/or indirectly through fresh water contaminated with urine. To clarify the obscure mechanism of immune evasion in leptospirosis, we focus on pyroptosis which is contribute to bacterial clearance, and our previous studies showed that the expression of NLRP3 has been proved suppression by the survival of leptospires. Base on these data, we propose a scientific hypothesis that the immune evasion in leptospirosis is correction with the inhibition of inflammasome-pyroptosis pathway. In this study, we will focus on the interaction between leptospires and inflammasome, and explore the role and the control mechanism of inflammasome in immune evasion of leptospires. Specifically, we will figure out the impacts of leptospires on inflammasome-pyroptosis pathway; and validate the role of inflammasome in leptospirosis by using the gene deficient cells and mouse; and further reveal the molecular mechanism of the interaction between PAMPs and inflammasome through stimulating mice and cells with leptospiral PAMPs or knockout strains and detect by Co-IP and shotgun proteomics assay. The results will not only help to elucidate the mechanism of immune evasion in leptospires, also provide basis for the effective control, prevention and treatment of the disease.