Characterization of a novel family of Small Regulatory Proteins modulating virulence in Enterobacteriaceae

项目总结/摘要 在美国，疾病控制和预防中心（CDC）估计， 每年发生100万次急性胃肠炎，导致近100万次住院治疗， 5000人死亡没有针对肠道病原体的疫苗，部分原因是对肠道病原体的了解有限。 肠道病原菌进化出许多毒力机制来定殖、繁殖和逃避宿主 的防御合作.我们最近发现了ANR（AraC负调节因子）家族，包括一个大的 多种临床上重要的肠道病原体（包括弧菌）产生的许多小调节蛋白 spp.，沙门氏菌属，志贺氏菌属，耶尔森氏菌属，柠檬酸杆菌属，肠致病性（ETEC） EPEC、肠出血性（EHEC）和肠聚集性E.大肠杆菌（EAEC）。ANR家族成员 调节毒力因子如菌毛、毒素、3型和6型分泌系统的表达， 与代谢、应激反应和适应性相关的基因，通过蛋白质-蛋白质相互作用， AraC/XylS家族的正转录调节子和HNS家族的负调节子。 此外，这种调节系统的缺乏影响了天然的细菌模型中的细菌发病机制。 感染我们的总体假设是，ANR家族在协调调节适应性中起着关键作用 通过同时控制AraC和HNS， 全球监管机构。在这里，我们建议获得ANR分子相互作用（AIM-1）的机制见解， 利用EAEC、EPEC和C.啮齿动物作为病原体模型， 人类干细胞技术和疾病的自然动物模型，再加上遗传、生物化学和 分子方法，如表面等离子体共振（SPR），延时荧光显微镜 （TLFM）和ChIP-seq.我们提出的研究将推进我们对全球基因调控的认识， 控制致病菌的适应性和毒力的机制，并可能开辟新的途径， 治疗干预

PROJECT SUMMARY/ABSTRACT In the United States, the Center for Disease Control and Prevention (CDC) has estimated that more than 200 million episodes of acute gastroenteritis occur annually, resulting in nearly 1 million hospitalizations and over 5000 deceases. Vaccines against enteric pathogens are not available due, in part, to limited knowledge of the many virulence mechanisms that enteropathogens have evolved to colonize, multiply and escape host defenses. We have recently discovered the ANR (AraC Negative Regulators) family, comprising a large number of small regulatory proteins produced by diverse clinically important enteric pathogens including Vibrio spp., Salmonella spp., Shigella spp., Yersinia spp., Citrobacter spp., enterotoxigenic (ETEC), enteropathogenic EPEC, enterohaemorragic (EHEC) and enteroaggregative E. coli (EAEC). Members of the ANR family modulate the expression of virulence factors such as fimbriae, toxins, type-3 and type-6 secretion systems, and genes associated with metabolism, stress-response and fitness, by protein-protein interactions with positive transcriptional regulators of the AraC/XylS family and negative regulators of the HNS family. Furthermore, the absence of this regulatory system affects bacterial pathogenesis in a natural model of infection. Our overall hypothesis is that the ANR family plays a critical role in the concerted regulation of fitness and virulence in pathogens of the Enterobacteriaceae family by taking concomitant control of AraC and HNS global regulators. Here, we propose to obtain mechanistic insights into ANR molecular interactions (AIM-1), regulation (AIM 2) and pathogenesis (AIM-3) using EAEC, EPEC and C. rodentium as pathogen models, human stem cell technology and a natural animal model of disease, coupled with genetic, biochemical and molecular approaches such as Surface Plasmon Resonance (SPR), Time-lapse fluorescence microscopy (TLFM) and ChIP-seq. Our proposed studies will advance our knowledge of global gene regulatory mechanisms that govern fitness and virulence in pathogenic bacteria, and will likely open new avenues for therapeutic intervention.