Signal Transduction and Pilus/Toxin Regulation by Vibrio cholerae

霍乱弧菌的信号转导和菌毛/毒素调节

• 批准号: 7778352
• 负责人: Kenneth Milan Peterson
• 金额: $ 18.13万
• 依托单位: LOUISIANA STATE UNIV HSC SHREVEPORT
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2012-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7778352
• 关键词: Acidosis; Acute; Address; Adherence; Affect; Agglutination; Amino Acids; Arabinose; Area; Attenuated; Attenuated Live Virus Vaccine; Bacteria; Biological Assay; Cessation of life; Chemotaxis; Child; Cholera; Cholera Toxin; Cholera Vaccine; Complex; Country; Cytoplasmic Tail; Data; Dehydration; Developing Countries; Development; Disease; Disease Outbreaks; Enteral; Epidemic; Escherichia coli; Family; Feces; Gene Expression; Genes; Genetic Transcription; Goals; Human; Hypoglycemia; Immunity; Individual; Infection; Intestinal Mucosa; Intestines; Kidney Failure; Lead; Life; Link; Membrane Proteins; Methods; Molecular; Morbidity - disease rate; Mutagenesis; Mutation; Nausea; Painless; Pathogenesis; Pathway interactions; Pattern; Pilum; Plasmids; Play; Prevention; Prevention strategy; Process; Production; Property; Proteins; Public Health; Regulation; Research Proposals; Residual state; Rice; Role; Series; Shock; Side; Signal Transduction; Signaling Protein; Site; South American; Structure; Testing; Time; Tissues; Toxin; Vaccine Research; Vaccines; Vibrio; Vibrio cholerae; Virulence; Virulence Factors; Vomiting; Water; base; cell motility; enteric pathogen; genetic regulatory protein; human disease; improved; methyl-accepting chemotaxis proteins; mortality; mutant; novel; pathogen; prevent; public health relevance; research study; response; therapeutic development; vaccination strategy

DESCRIPTION (provided by applicant): Understanding the mechanisms by which mucosal pathogens such as Vibrio cholerae colonize the human intestinal mucosa is key to the rational development of live-attenuated vaccine derivatives capable of inducing protective immunity against cholera and other enteric diarrheal diseases. Current parenteral vaccination strategies for these infections are largely ineffective. Although many V. cholerae genes required for intestinal colonization have been identified, the molecular mechanisms by which the proteins they encode promote vibrio adherence to host tissue are poorly understood. The studies described in this research proposal represent an approach to understand at the molecular level, the contribution of the V. cholerae TcpI "chemotaxis related" protein to the intestinal colonization properties of this important human pathogen. TcpI is a 75-kDa inner membrane protein that belongs to a large family of signal transducing proteins involved in bacterial chemotaxis. V. cholerae tcpI mutants display an altered pattern of toxin- coregulated pilus (TCP) and cholera toxin expression. Specifically, tcpI mutants produce the TCP colonization pilus and cholera toxin under environmental conditions normally associated with a lack of pilus/toxin production (media pH of 7.0-8.4). These data show that TcpI is a repressor of pilus/toxin production in Luria Broth at neutral to basic pH. This proposal outlines a series of experiments aimed at understanding the contributions of TcpI to vibrio pilus/toxin production. V. cholerae TCP and cholera toxin are critical virulence determinants. Since TcpI contributes to the production of these essential virulence factors, it is important to understand the structure and function of TcpI. Our long-term goal is to use the information regarding the properties of this protein in the development of improved methods for treating and preventing cholera enteric infections. There are two SPECIFIC AIMS in this proposal: (1) Define the features of TcpI that promote the synthesis of toxin/pilus using ELISA/vibrio agglutination assays; (2) Determine at what level TcpI acts within the ToxR/TcpP/ToxT regulatory cascade to influence virulence gene expression by over-expressing relevant regulators of toxin/pilus synthesis. PUBLIC HEALTH RELEVANCE: Vibrio cholerae is a major cause of morbidity and disease worldwide. This bacterium has a complex regulatory cascade that temporally and spatially controls virulence factor synthesis in response to intraintestinal signals. The proposed studies will determine the mechanism by which a V. cholerae chemotaxis protein regulates cholera toxin and toxin co-regulated pilus synthesis in response to pH. The may allow the development of strategies to control the spread of this dread human disease.

描述（由申请人提供）：了解粘膜病原体（例如圆锥形霍乱）定居的粘膜病原体是人类肠道粘膜，这是能够诱导促霍乱和其他肠胃疾病的生存衰减疫苗衍生物合理发展的关键。这些感染的当前肠胃外疫苗接种策略在很大程度上无效。尽管已经鉴定出了许多肠道定植所需的霍乱基因，但它们编码的蛋白质的分子机制促进了对宿主组织的纤维粘附性的促进。该研究建议中描述的研究代表了一种在分子水平上的理解方法，即霍乱链球菌TCPI“趋化性”蛋白与这种重要人类病原体的肠道定植特性的贡献。 TCPI是一种75 kDa内膜蛋白，属于参与细菌趋化性的大型信号转导蛋白。 V. Cholerae TCPI突变体显示出毒素核心菌毛（TCP）和霍乱毒素表达的改变模式。具体而言，TCPI突变体在通常与缺乏菌毛/毒素产生相关的环境条件下产生TCP定菌化菌毛和霍乱毒素（介质pH为7.0-8.4）。这些数据表明，TCPI是中性pH至碱性pH值的Luria肉汤中菌毛/毒素产生的阻遏物。该提案概述了一系列旨在了解TCPI对颤音/毒素生产的贡献的实验。 V.霍乱TCP和霍乱毒素是关键的毒力决定因素。由于TCPI有助于产生这些基本毒力因子，因此了解TCPI的结构和功能很重要。我们的长期目标是利用有关该蛋白质特性的信息，以开发改进的治疗和预防霍乱肠道感染的方法。该提案中有两个具体的目的：（1）定义TCPI的特征，这些特征使用ELISA/Vibrio凝集测定法促进毒素/菌毛的合成； （2）确定TCPI在TOXR/TCPP/TOXT调节级联反应中的作用，以通过过度表达毒素/pilus合成的相关调节剂来影响毒力基因的表达。公共卫生相关性：弧菌霍乱是全球发病率和疾病的主要原因。该细菌具有一个复杂的调节级联，该级联反应于时间和空间控制毒力因子的合成，以响应内部的遗传信号。拟议的研究将确定霍乱趋化趋化蛋白调节霍乱毒素和毒素响应pH的合成的机制。可能会制定策略来控制这种可怕的人类疾病的传播。