需氧菌性阴道炎致病菌及TLR2/4信号通路在其发病机制中的研究

In 2002, Donders et al. proposed the term aerobic vaginitis (AV) for the first time, but neither its pathogen nor pathogenesis is clear. Our previous study showed that lactobacillus decreased and enterococcus faecalis increased(already published); and significantly higher vaginal IL-1β/6/8 in AV patients(to be published). However，some questions are still to be answered including which kind of lactobacillus decreased and which kind of aerobic bacteria increased. And pathogenesis about cytokines production and relationship between cytokines and AV are unknown. In addition, studies on infection have shown that toll-like receptors (TLR) play a key role in inducing cytokines production and leading to inflammation. Furthermore, TLR2/4 are expressed in vaginal epithelia. So the hypothesis is pathogen could increase the expression of inflammatory cytokines by activating the TLR2/4 signaling pathway to cause AV. This project is planned to investigate on the pathogens and pathogenesis of AV by two ways: ①Using cultivation-independent molecular-based techniques as well as cultivation-dependent techniques to study on the detail of the lactobacillus and aerobic bacteria which provide a theoretical basis for reasonable choice of antibiotics and treatment of specific lactobacillus supplement; ②Exploring the expression of key proteins expression in TLR2/4 signaling pathway in vivo and in vitro; analyzing the correlation between the key proteins in TLR2/4 signaling pathway and cytokines detected by liquid chip to investigate the mechanism of AV. Our study will provide the basis for the application of cytokine modulators to treat AV and prevent its complications.

需氧菌性阴道炎(AV)是近年提出的阴道炎，致病菌及发病机制不清。我们的研究显示AV患者阴道乳杆菌减少而需氧菌增多(已发表),分泌物中IL-1β/6/8升高(待发表)，但何种乳杆菌较少、何种需氧菌增多，且细胞因子变化的机制、与AV发生的关系不明。有关感染的研究发现，需氧菌激活Toll样受体(TLR)信号通路，引起细胞因子释放导致炎症。阴道上皮具有TLR2/4表达，且AV中需氧菌增加伴细胞因子改变，这些均提示AV的发生可能是阴道需氧菌激活TLR2/4信号通路所致。本课题拟从两方面研究：①采用非培养法研究AV患者阴道乳杆菌菌种及需氧菌菌种改变，发现AV致病菌，为合理选择抗生素及补充特异乳杆菌的微生态治疗提供理论依据；②体内、体外试验观察阴道上皮细胞TLR2/4信号通路关键蛋白的表达，并与液相芯片技术检测的细胞因子变化进行相关分析，探讨AV的发病机制，为应用细胞因子调节剂治疗AV及其并发症提供依据

需氧菌性阴道炎(aerobic vaginitis, AV)是近年提出的阴道炎，致病菌及发病机制不清。我们的研究显示AV患者阴道乳杆菌减少而需氧菌增多，但何种乳杆菌减少、何种需氧菌增多，且细胞因子变化的机制、与AV发生的关系不明。既往研究发现，Toll样受体（Toll like receptors, TLR）信号通路激活会引起细胞因子释放导致炎症。阴道上皮具有TLR2/4表达，且AV中需氧菌增加伴细胞因子改变，这些均提示AV的发生可能是阴道需氧菌激活TLR2/4信号通路所致。本课题从两方面研究：①采用高通量测序法研究AV患者阴道乳杆菌菌种及需氧菌菌种改变，发现AV患者阴道内的卷曲乳杆菌显著减少，无乳链球菌、咽颊炎链球菌、柯氏气球菌等多种需氧菌及兼性厌氧菌丰度增加，支原体携带率较健康女性高。为合理选择抗生素及补充特异乳杆菌的微生态治疗提供理论依据；AV发病时表现出阴道局部免疫失衡状态，促炎性细胞因子如IL-1β、IL-6、IL-8、IL-12p70、IL-17和TNF-α通过表达上调参与阴道炎症反应，且重度AV时促炎性细胞因子水平显著提高，表现出更为明显的阴道局部免疫失衡，从细胞因子水平解释了疾病严重程度个体差异的病理机制。②体内、体外试验证实阴道需氧菌感染时，上皮细胞有TLR2/4信号通路关键蛋白表达及NF-κB的活化。与液相芯片技术检测的细胞因子变化进行相关分析，结果发现：革兰阴性需氧菌及革兰阳性需氧菌菌株及主要刺激成分（脂多糖和肽聚糖）均能刺激人永生化阴道上皮内TLR2、TLR4及NF-κB的表达，并可促进下游促炎性细胞因子IL-1β、IL-6、IL-8、IFN-γ及TNF-α和抑炎性细胞因子TGF-β及IL-1Rα的表达，提示需氧菌可通过激活TLR2/4信号通路并上调通路关键因子表达，释放促炎性及抑炎性细胞因子，导致患者局部炎症反应，进而发生AV。本研究为进一步研究AV的发病机制提供理论基础，为应用细胞因子调节剂治疗AV及其并发症提供依据。