TceSR和TcfSR在布鲁氏菌致病过程中的分子调控机制研究

Brucellosis is a serious hazard to public health and safety of zoonotic infectious disease. Ochrobactrum anthropi (O. anthropi) is a weak pathogenicity conditioned pathogen, which phylogenetic relationship is very close to Brucella. But the pathogenicity between them is very different. Comparative genomics found that O. anthropi lacks orthologs of the Brucella TCSs TceSR and TcfSR, which roles and virulence are still unclear. In this study, the two-component regulatory system (TCS) TceSR and TcfSR were studied, the virulence phenontypes of TCS TceSR and TcfSR mutants were analyze, virulence genes and proteins of Brucella regulated by TCS TceSR and TcfSR were verificated and identified. We found that O. anthropi lacks orthologs of the Brucella TCSs TceSR and TcfSR through comparative genomics analysis. This project will expound the molecular regulatory mechanism of pathogenic gene of Brucella regulated by TCS TceSR and TcfSR. The results of this project will provide the scientific foundation for Brucella pathogenic mechanism clarification, researching and developing the effective therapeutic drug targets and novel vaccine. The sRNA and mRNA regulated by TCS TceSR and TcfSR were verificated through RNA-Seq. The target genes of regulated sRNA were predicted and identified through bioinformatics and the regulatory pathway of TCS TceSR and TcfSR was intensive studied.

布鲁氏菌病是一种严重危害公共卫生安全的人兽共患传染病。苍白杆菌是一种致病力很弱的条件性致病菌，与布鲁氏菌的亲缘关系很近，但其致病性却差异很大。 比较基因组学发现，在苍白杆菌中缺少布鲁氏菌中的二元调控系统TceSR和TcfSR，且其功能及其毒力尚不清楚。本研究以二元调控系统TceSR和TcfSR为切入点，系统分析二元调控系统TceSR和TcfSR缺失株毒力表型，筛选验证受其调控的布鲁氏菌致病基因与蛋白。通过RNA-Seq技术筛选受TceSR和TcfSR调控的sRNA和mRNA分子；生物信息学预测调控sRNA的靶基因并进行验证，深入研究TceSR和TcfSR的调控通路，全面阐述二元调控系统TceSR和TcfSR调控布鲁氏菌致病性基因的分子机制，为深入阐明布鲁氏菌的致病机制和研发有效的治疗药物的靶点和新型疫苗提供科学依据。

布鲁氏菌作为一种重要的胞内致病菌，与条件性致病菌苍白杆菌具有较高的亲缘关系，但其致病性却差异较大。本项目以布鲁氏菌和苍白杆菌的差异蛋白-二元调控系统TceSR和TcfSR为切入点，系统分析布鲁氏菌二元调控系统TceSR和TcfSR缺失株的毒力表型，筛选受其调控的布鲁氏菌致病基因/蛋白，并深入探索其调控作用和调控通路。因此，本项目构建了具有良好遗传稳定性的布鲁氏菌二元调控系统TceSR和TcfSR基因突变株，通过建立细胞侵染模型和小鼠感染模型证实二元调控系统TceSR和TcfS是布鲁氏菌的重要毒力因子，其参与布鲁氏菌的持续性感染以及细胞自噬、溶酶体融合等生物学过程。为了明确二元调控系统TceSR和TcfSR对布鲁氏菌的调控过程，项目组通过转录组学技术筛选获得了331个TceSR调控基因和342个TcfSR调控基因；通过蛋白质组学技术筛选获得了465个TceSR调控蛋白和137个TcfSR调控蛋白；通过对其进行生物信息学解析，结果显示：TceSR 和 TcfSR 的调控基因/蛋白涉及脂多糖、自身代谢、外膜蛋白合成、T4SS分泌系统和毒力因子等生物学过程；同时本项目对受二元调控系统 TceSR 和 TcfSR 调控的布鲁氏菌外膜蛋白和T4SS分泌系统进行了生物学功能研究，阐明了与被调控蛋白互作的宿主蛋白及其互作结构域，从而为系统阐述布鲁氏菌二元调控系统TceSR和TcfSR的持续性感染的分子机制奠定理论依据，也为布鲁氏菌病的防控、疫苗的研发等提供科学依据。