鹦鹉热嗜衣原体HtrA的结构及与功能研究

Chlamydophila psittaci (C. psittaci) is an obligate intracellular bacterial pathogen and multiply in a wide range of eukaryotic hosts including animals and humans. However, molecular mechanism of persistent C. psittaci infection haven't been best-studied yet. With available results of completed C. psittac genome sequencing and annotated its whole genome and frequent occurrence of zoonosis, Zoonotic pathogens became of great interest. chlamydial high temperature requirement protein A (cHtrA) have been localized inthe cytosol of the infected cells either by direct immunofluorescence visualization or functional，It have been found to play important roles in C. trachomatis interactions with host cells, a Herein, this project will construct in vitro cell modelings of persistent C. psittac infection, The three-dimensional structure of cHtrA receptors will be analyzed by crystal X-ray、Cryo-EM and NMR diffraction. We have uncovered a roleof :protease interface in oligomer formation specifically for chaperone substrates of Chlamydia trachomatis HtrA. We have demonstrated that cHtrA proteolysis could be activated by allosteric binding and oligomer formation. a potential in vivo chaperone substrate. screen related genes resulting in sustained C. psittac infection through Bioinformatics methods, ffinity proteomics and the split-ubiquitin membrane based using the genetic mutation technique and Co-Immunoprecipitation technique. will be used in this study to screen and identificate the cHtrA receptors that may exist on the membrane of HeLa cells and. The aims of this study are to understand the molecular mechanisms of the interaction between C. psittaci and host cells, elucidate the possible pathogenic mechanism of C. psittaci, reveal the structure and function of cHtrA, and provide new ideas for the development of novel targeted drugs and gene engineering vaccines.

鹦鹉热嗜衣原体（Chlamydophila psittaci,Cps）是一种严格细胞内寄生、多宿主性的人兽共患病病原体，通过分泌大量效应蛋白，从而维持其在宿主细胞包涵体内的正常生长，引起宿主细胞病理改变，导致多种疾病。衣原体高温依赖性蛋白（chlamydial high temperature requirement protein A,cHtrA）就是衣原体分泌在宿主细胞胞浆的三种具有酶活性的蛋白之一，在Cps与宿主细胞相互作用的过程中的作用至关重要，目前国内外对cHtrA的研究尚不深入，本项目将整合X-ray、Cryo-EM及NMR方法，配合细胞生物学、分子生物学、生物化学和生物物理学等多学科技术手段，揭示cHtrA的结构与功能，从结构生物学的角度探索cHtrA蛋白结构与功能的关系；以期了解cHtrA与宿主细胞相互作用的分子机制，阐明Cps可能的致病机理，为Cps感染的防治奠定基础。

感鹦鹉热衣原体(Chlamydia psittaci,Cps）是一种严格胞内寄生原核细胞型微生物，可引起禽鸟类的呼吸道疾病如鹦鹉热（psittacosis），偶然可通过密切接触传播给人类，发病严重，病死率高，通过分泌大量效应蛋白，从而维持其在宿主细胞包涵体内的正常生长，引起宿主细胞病理改变，导致多种疾病。衣原体高温依赖性蛋白（chlamydial high temperature requirement protein A,cHtrA）就是衣原体分泌在宿主细胞胞浆的三种具有酶活性的蛋白之一，在Cps与宿主细胞相互作用的过程中的作用至关重要，目前国内外对cHtrA的研究尚不深入。本项目克隆、表达，与纯化了cHtrA蛋白，并制备出高效价的cHtrA融合蛋白多克隆抗体，且初步证实cHtrA融合蛋白应用于血清学诊断的价值和其对THP-1细胞诱导产生的IL-1β、IL-6和TNF-α的作用。阐明了Cps可能的致病机理，为Cps感染的防治奠定了基础。