Small RNAs regulating group A Streptococcus virulence

小RNA调节A组链球菌毒力

• 批准号: 7450474
• 负责人: Paul Sumby
• 金额: $ 22.5万
• 依托单位: METHODIST HOSPITAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 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/7450474
• 关键词: Acute; Area; Attenuated; Bioinformatics; Canada; Characteristics; Communities; Condition; Custom; Data Set; Disease; Disease model; Eastern Europe; Enterococcus; Functional RNA; Gene Expression; Gene Expression Regulation; Genome; Goals; Growth; Human; In Vitro; Infection; Invasive; 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; Thinking; Toxic Shock Syndrome; Translating; Translational Research; Triage; Upper Respiratory Infections; Virulence; Virulence Factors; antimicrobial; antimicrobial drug; base; density; design; genome-wide analysis; in vitro Assay; in vivo; insight; mouse model; mutant; neutrophil; novel; pathogen; response

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（由申请人提供）：人类细菌病原体A组链球菌（GAS）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增进我们对控制细菌毒力的全球监管机制的理解。新发现的毒力相关监管机制将成为新型抗菌药物操纵的有吸引力的目标，从而增强公众健康。小调控 RNA (sRNA) 代表了 GAS 和相关病原体中基因调控的一个鲜为人知的领域。具体假设是 sRNA 代表协调 GAS 毒力的全球监管网络的主要组成部分。该假设基于以下观察。首先，sRNA 调节一些细菌病原体的毒力。其次，生物信息学分析表明 GAS 编码 56 个假定的 sRNA。第三，两种 sRNA 已在 GAS 中得到实验验证，并且两种 sRNA 似乎都通过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 中普遍存在并且在链球菌物种中保守的假设。 sRNA 是否代表 GAS 的主要调节机制将通过使用定制的 Affymetrix 微阵列来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）来研究。这一具体目标的完成将代表首次对乳杆菌目的病原体（包括链球菌和肠球菌）内的 sRNA 进行全基因组分析，并刺激一系列人类细菌病原体的 sRNA 研究。 2. 检验 sRNA 调节 GAS 毒力的假设。将根据乳杆菌病原体的序列保守性以及体内生长期间的 sRNA 表达模式对候选 sRNA 进行分类。将构建 12 种保守 sRNA 的同基因 sRNA 突变株，并在体外和离体体内检测改变的毒力特征。随后将在两种侵袭性疾病小鼠模型中测试毒力特征改变的菌株的减弱毒力。完成这一具体目标将确定对 GAS 感染正常进展至关重要的 sRNA，并为描绘这些调节因子发挥作用的途径提供动力，最终目标是通过使用新型抗菌药物抑制这些途径。 公共卫生相关性：美国每年约有 3000 万例气性咽炎病例。拟议的研究将深入了解 GAS 和相关病原体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，以激发进一步的研究。通过将 sRNA 毒力调节途径的知识转化为基于新型抗菌剂对这些途径的抑制的新治疗和/或预防方案的长期目标，可以增强公共卫生。