TLRs对流产衣原体感染的牦牛胎盘滋养层细胞Th1/Th2型细胞因子表达的调控

Chlamydia abortus, which mainly parasites in placental trophoblast cells, can induce a variety of cytokines such as TNF-α, causing chronic placentitis, leading to abortion in animals. It has been shown that the imbalance of Th1/Th2 type cytokines during pregnancy is the key process of fetal loss caused by many factors. Recent years, the infection and incidence of a yak chlamydiosis caused by Chlamydia abortus has been increasing in the Qinghai-Tibet plateau region, and huge economic losses have been caused. In this program, pregnant yak cows and cultured trophoblast cells will be infected with Chlamydia abortus. By using the second generation sequencing technology and molecular biological methods, the expression of Th1/Th2 type cytokines will be detected and the involvement of pathways such as Toll-like receptors, NF-κB and MAPK will also be investigated. The results will reveal the role of the cytokines and relative signaling pathway in response to the infection and pathogenesis of Chlamydia abortus. In the previous study, the Chlamydia abortus isolates from aborted yaks have been isolated and characterized, inactivated vaccine against Chlamydia abortus has also been prepared. The experiment of vaccination and evaluation of the immune prevention effect of the inactivated vaccine has also been carried out. We hope that the results obtained from this program will further disclose the mechanisms of abortion caused by Chlamydia abortus, and provide theoretical support for the control of this disease.

流产衣原体（Chlamydia abortus）主要寄生于动物的胎盘滋养层细胞中，诱导TNF-α等细胞因子表达，引起慢性胎盘炎导致流产。研究表明，破坏妊娠期Th1/Th2型细胞因子的平衡状态是许多因素导致流产的关键。近年来，我国青藏高原地区牦牛流产衣原体病的感染和发病率呈上升趋势，造成巨大的经济损失。本项目拟以流产衣原体感染妊娠期牦牛和体外培养的牦牛胎盘滋养层细胞，结合第二代测序技术和分子生物学方法，在体内和体外研究胎盘滋养层细胞表达Th1/Th2型细胞因子的变化规律；研究参与调控细胞因子表达的TLRs及下游NF-κB、MAPKs信号转导通路活化情况，阐明其在应答流产衣原体感染和致病过程中的作用及机制。本项目前期研究已完成牦牛流产衣原体毒株的分离鉴定、疫苗制备，并开展了牦牛流产衣原体病的免疫防制工作。希望通过本项目研究，进一步揭示流产衣原体致流产的分子机制，为防制流产衣原体病提供理论依据。

流产衣原体（Chlamydia abortus）主要寄生于动物的胎盘滋养层细胞中，诱导TNF-α等细胞因子表达，引起慢性胎盘炎导致流产。近年来，我国青藏高原地区牦牛流产衣原体病的感染和发病率呈上升趋势，造成巨大的经济损失。本项目探讨了TLRs及下游信号转导通路对流产衣原体感染诱导牦牛胎盘滋养层细胞表达炎性细胞因子过程中的调控作用，以期揭示流产衣原体感染诱发胎盘炎症的分子机制。本项目从妊娠牦牛胎盘组织中成功分离培养了胎盘滋养层细胞，其可表达TLR2和TLR4，且对流产衣原体易感。用流产衣原体GN6菌株感染胎盘滋养层细胞可上调TLR2和TLR4的表达水平，并且活化NF-κB、ERK1/2和p38 MAPK信号通路，表达包括炎性细胞TNF-α、IL-1β和 IL-8等多种细胞因子；敲低TLR2或TLR4均可影响NF-κB、ERK1/2和p38 MAPK信号通路的活化和炎性细胞因子的表达；抑制NF-κB的通路可几乎完全阻断流产衣原体诱导的TNF-α和IL-8的表达，而对IL-1β表达影响不显著；抑制ERK1/2信号通路和p38 MAPK信号通路均可显著抑制TNF-α，IL-1β，IL-8的表达水平，表明流产衣原体感染经TLR2和TLR4及其下游NF-κB、MAPK信号通路对调控牦牛胎盘滋养层细胞表达炎性细胞因子。这些结果为揭示流产衣原体感染导致妊娠牦牛流产的机制奠定了理论基础。