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Small RNAs regulating group A Streptococcus virulence

小RNA调节A组链球菌毒力

基本信息

批准号：
7688585
负责人：
Paul Sumby
金额：
$ 18.75万
依托单位：
METHODIST HOSPITAL RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-09-17 至 2010-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7688585
关键词：
Acute Area Attenuated Bioinformatics Canada Characteristics Communities Custom Data Set Disease Disease model Eastern Europe Enterococcus Functional RNA Gene Expression Gene Expression Regulation Genome Goals Growth Human In Vitro Infection Knowledge Label Laboratories Location Mediating Mediator of activation protein Modeling Monitor Necrotizing fasciitis Northern Blotting Pathogenesis Pathway interactions Pattern Pharyngitis Prevalence Process Property Public Health RNA Regulation Research Rheumatic Fever Role Saliva Selection Criteria Series Serotyping Signal Transduction Small RNA Stimulus Streptococcal Infections Streptococcus Streptococcus pyogenes Syndrome Testing Toxic Shock Syndrome Translating Translational Research Triage Upper Respiratory Infections Virulence Virulence Factors antimicrobial antimicrobial drug base density design genome wide association study genome-wide genome-wide analysis in vitro Assay in vivo insight mouse model mutant neutrophil novel pathogen public health relevance response

项目摘要

DESCRIPTION (provided by applicant): The human bacterial pathogen group A Streptococcus (GAS) causes a broad spectrum of diseases, including pharyngitis, necrotizing fasciitis, and a toxic-shock-like syndrome. The long-term aim of the proposed research is to advance our understanding of the global regulatory mechanisms controlling bacterial virulence. Newly identified virulence-related regulatory mechanisms would represent attractive targets for manipulation by novel antimicrobial agents, and thus enhance public health. Small regulatory RNAs (sRNAs) represent a poorly understood area of gene regulation in GAS and related pathogens. The specific hypothesis is that sRNAs represent a major constituent of the global regulatory networks coordinating GAS virulence. This hypothesis is based upon the following observations. First, sRNAs regulate virulence in some bacterial pathogens. Second, a bioinformatic analysis indicates that GAS encodes 56 putative sRNAs. Third, two sRNAs have been experimentally verified in GAS and both, through as-yet-unknown mechanisms, appear to regulate virulence factor expression. Our hypothesis will be tested by the following specific aims: 1. Test the hypothesis that sRNAs are prevalent in GAS and conserved across streptococcal species. Whether sRNAs represent a major mechanism of regulation in GAS will be investigated through use of a custom Affymetrix microarray to detect sRNAs transcribed under a series of experimental conditions mimicking human infections, including both ex vivo and in vivo disease models. Completion of this specific aim would represent the first genome-wide analysis of sRNAs within a pathogen from the order Lactobacillales, which includes the streptococci and enterococci, and stimulate sRNA research in a spectrum of human bacterial pathogens. 2. Test the hypothesis that sRNAs regulate GAS virulence. Candidate sRNAs will be triaged based upon sequence conservation across Lactobacillales pathogens, and also upon sRNA expression patterns during in vivo growth. Isogenic sRNA mutant strains will be constructed for 12 conserved sRNAs and assayed in vitro and ex vivo for altered virulence characteristics. Strains with altered virulence characteristics will subsequently be tested for attenuated virulence in two mouse models of invasive disease. Completion of this specific aim would identify sRNAs critical for normal progression of GAS infections, and provide impetus to delineate the pathways by which these regulators function, with the ultimate goal of inhibiting these pathways through use of novel antimicrobials. PUBLIC HEALTH RELEVANCE: Each year in the U.S. there are ~30 million cases of GAS pharyngitis. The proposed research would provide insight into a fundamental and yet understudied field of gene regulation in GAS and related pathogens, and provide the research community with a detailed blueprint of sRNA locations and expression patterns to stimulate further study. Public health may be enhanced through the long-term goal of translating knowledge of sRNA virulence-regulating pathways into new treatment and/or preventative regimes based upon the inhibition of these pathways by novel antimicrobial agents.

描述（申请人提供）：人类细菌病原体A组链球菌（GAS）可引起多种疾病，包括咽炎、坏死性筋膜炎和中毒性休克样综合征。拟议研究的长期目标是促进我们对控制细菌毒力的全球调控机制的理解。新发现的毒力相关的调节机制将成为新型抗菌药物操纵的有吸引力的靶点，从而提高公众健康。小调控RNA（sRNA）代表了GAS和相关病原体中基因调控的一个知之甚少的领域。具体的假设是，sRNA代表了协调GAS毒力的全球调控网络的主要组成部分。这一假设基于以下观察。首先，sRNA调节某些细菌病原体的毒力。其次，生物信息学分析表明，GAS编码56个推定的sRNA。第三，两种sRNA已在GAS中得到实验验证，并且两者都通过迄今未知的机制调节毒力因子的表达。我们的假设将通过以下具体目标进行检验： 1.检验sRNA在GAS中普遍存在并在链球菌物种中保守的假设。sRNA是否代表GAS中的主要调节机制将通过使用定制的Affyellow微阵列来研究，以检测在一系列模拟人类感染的实验条件下转录的sRNA，包括离体和体内疾病模型。这一特定目标的完成将代表对乳杆菌目病原体（包括链球菌和肠球菌）内sRNA的首次全基因组分析，并刺激对人类细菌病原体谱的sRNA研究。 2.检验sRNA调节GAS毒力的假设。候选sRNA将基于乳杆菌目病原体之间的序列保守性以及体内生长期间的sRNA表达模式进行分类。将针对12种保守sRNA构建同基因sRNA突变株，并在体外和离体测定毒力特征的改变。随后将在两种侵袭性疾病小鼠模型中检测毒力特征改变的菌株的减毒力。这一特定目标的完成将确定对GAS感染的正常进展至关重要的sRNA，并提供动力来描绘这些调节剂发挥作用的途径，最终目标是通过使用新型抗菌剂来抑制这些途径。公共卫生相关性：美国每年约有3000万例GAS咽炎病例。拟议的研究将深入了解GAS和相关病原体中基因调控的基本但尚未充分研究的领域，并为研究界提供sRNA位置和表达模式的详细蓝图，以刺激进一步的研究。通过将sRNA毒力调节途径的知识转化为基于新型抗菌剂抑制这些途径的新治疗和/或预防方案的长期目标，可以增强公共卫生。