鞭毛蛋白在梅毒螺旋体感染所致皮肤黏膜免疫炎症病理损伤中的作用机制研究

Syphilis is a multistage sexually transmitted disease caused by the invasive spirochete Treponema pallidum subsp. pallidum (T. pallidum) and the pathogenesis is still unclear. It is probable that inflammatory response is a crucial event during all the stages of syphilis and responsible for tissue damage. Flagellin plays an important role in promoting pathogen invasion and inducing inflammatory response. Previous studies have shown that T. pallidum flagellin can induce the expression of inflammatory cytokines and MMPs in host cells. Combined with the literature, we proposed that T. pallidum flagellin activates the host skin immune-related cells through TLR5, induces the expression of proinflammatory cytokines, chemokines, adhesion molecules and so on, and promotes the inflammatory and pathological damage of skin and mucosa. In this study, we used gene cloning and expression, Western Blot, Real Time-PCR, flow cytometry, RNA interference and gene knockout and other methods, , to explore T. pallidum flagellin in syphilis infection process at the molecular, cellular and animal different levels, And to clarify the key factors and signal pathways leading to the inflammatory reaction of T. pallidum flagellin, and finally clarify the role and mechanism of T. pallidum flagellin in the pathogenesis of skin and mucosa. This study will provide a novel insight and evidence for the the pathogenesis, prevention and vaccine development of T. pallidum infection.

梅毒是由梅毒螺旋体（Treponema pallidum,Tp）引起的一类严重危害人类健康的性传播疾病,但致病机制仍不明确。炎症反应是Tp感染引起免疫病理损伤的关键因素。鞭毛蛋白在促进病原体侵袭和诱导宿主炎症反应中发挥重要作用,前期研究发现Tp鞭毛蛋白能够激活宿主细胞诱导炎症因子、MMPs的表达。我们推测:Tp鞭毛蛋白通过TLR5激活宿主皮肤免疫相关细胞,诱导促炎细胞因子、趋化因子、粘附分子的表达，促进炎症反应导致皮肤黏膜免疫病理损伤。本研究拟采用基因克隆与表达、WesternBlot、Real Time-PCR、流式细胞术、RNA干扰和基因敲除等方法,从分子、细胞及动物不同层面,探索鞭毛蛋白在梅毒感染过程中的致炎作用,明确鞭毛蛋白诱导炎症反应过程中的关键因子及信号通路,最终阐明Tp鞭毛蛋白在皮肤黏膜免疫病理损伤中的作用机制,为Tp致病机制、预防与治疗以及疫苗研发提供新的思路与依据。

梅毒是由梅毒螺旋体（Treponema pallidum,Tp）引起的一类严重危害人类健康的性传播疾病,但致病机制仍不明确。炎症反应是Tp感染引起免疫病理损伤的关键因素。鞭毛蛋白在促进病原体侵袭和诱导宿主炎症反应中发挥重要作用。本研究通过基因克隆与表达Tp鞭毛蛋白FlaA2、FlaB2和FlaB3，采用WesternBlot、Real Time-PCR、流式细胞术、RNA干扰和基因敲除等方法，探索鞭毛蛋白在梅毒感染过程中的致炎作用。研究结果显示：Tp鞭毛蛋白 FlaB1、FlaB2 和 FlaB3 具有较强免疫活性，能够诱导机体产生特异性免疫应答，可做为梅毒血清诊断候选抗原；Tp鞭毛蛋白 FlaB1、FlaB2 和 FlaB3 经 TLR5/MyD88 依赖途径激活皮肤角质形成细胞表达 MMP-9 和 MMP-13；MAPK 和 NF-κB 信号通路参与调控梅毒螺旋体鞭毛蛋白 FlaB1、FlaB2 和 FlaB3 诱导皮肤角质形成细胞表达 MMP-9 和 MMP-13。本研究的开展初步阐明了Tp鞭毛蛋白在梅毒炎症反应及皮肤黏膜免疫病理损伤中的作用机制，为梅毒的致病机制，防控及疫苗研发提供新的思路与依据。