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: 7638210
• 负责人: Kenneth Milan Peterson
• 金额: $ 21万
• 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 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7638210
• 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; Developed Countries; 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）：了解霍乱弧菌等粘膜病原体定植于人类肠粘膜的机制是合理开发能够诱导针对霍乱和其他肠道腹泻疾病的保护性免疫的减毒活疫苗衍生物的关键。目前针对这些感染的肠外疫苗接种策略基本上无效。尽管已鉴定出肠道定植所需的许多霍乱弧菌基因，但人们对它们编码的蛋白质促进弧菌粘附宿主组织的分子机制知之甚少。本研究提案中描述的研究代表了一种在分子水平上了解霍乱弧菌 TcpI“趋化性相关”蛋白对该重要人类病原体的肠道定植特性的贡献的方法。 TcpI 是一种 75 kDa 的内膜蛋白，属于参与细菌趋化性的信号转导蛋白大家族。霍乱弧菌 tcpI 突变体表现出毒素共调节菌毛 (TCP) 和霍乱毒素表达模式的改变。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（培养基 pH 为 7.0-8.4）产生 TCP 定植菌毛和霍乱毒素。这些数据表明，在中性至碱性 pH 值下，TcpI 是 Luria 肉汤中菌毛/毒素产生的抑制剂。该提案概述了一系列旨在了解 TcpI 对弧菌菌毛/毒素产生的贡献的实验。霍乱弧菌 TCP 和霍乱毒素是关键的毒力决定因素。由于 TcpI 有助于产生这些必需毒力因子，因此了解 TcpI 的结构和功能非常重要。我们的长期目标是利用有关这种蛋白质特性的信息来开发治疗和预防霍乱肠道感染的改进方法。该提案有两个具体目标：（1）使用 ELISA/弧菌凝集测定确定 TcpI 促进毒素/菌毛合成的特征； (2) 确定 TcpI 在 ToxR/TcpP/ToxT 调控级联中的作用水平，通过过表达毒素/菌毛合成的相关调控因子来影响毒力基因表达。公共卫生相关性：霍乱弧菌是全世界发病和疾病的主要原因。这种细菌具有复杂的调控级联，可以响应肠内信号在时间和空间上控制毒力因子的合成。拟议的研究将确定霍乱弧菌趋化蛋白调节霍乱毒素和毒素共同调节菌毛合成以响应 pH 值的机制。这可能有助于制定控制这种可怕的人类疾病传播的策略。