Pathogenic mechanisms of non-01/non-0139 V. cholerae

非01/非0139霍乱弧菌的致病机制

• 批准号: 7525518
• 负责人: MICHELLE DZIEJMAN
• 金额: $ 36.83万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-15 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7525518
• 关键词: Actins; Africa; Animal Model; Area; Asia; Attenuated; Biological Assay; Biological Models; Bioterrorism; Categories; Cell Communication; Cell physiology; Cells; Centers for Disease Control and Prevention (U.S.); Cholera; Cholera Toxin; Condition; Country; Cyclic Nucleotides; Cytoskeletal Modeling; Cytosol; Data; Developed Countries; Developing Countries; Disease; Disruption; Epidemic; Eukaryotic Cell; Experimental Designs; Filopodia; Food; Gene Expression; Genes; Genetic; Genomics; Goals; Growth; Health; In Vitro; Individual; Infant; Infection; Intestines; Investigation; Island; Localized; Mammalian Cell; Mediating; Molecular; Mus; Names; Open Reading Frames; Oryctolagus cuniculus; PAWR protein; Pathogenesis; Pathogenicity Island; Phenotype; Pilum; Production; Proteins; Research Infrastructure; Ribotypes; Ribotyping; Role; Saccharomyces cerevisiae; Sanitation; Signal Pathway; South America; Structure; Structure-Activity Relationship; System; Today; Toxin; Transcription Regulatory Protein; Travel; United States; Vibrio cholerae; Vibrio cholerae O139; Vibrio parahaemolyticus; Virulence; Virulence Factors; War; Water; Yeasts; Yersinia; cellular targeting; comparative; cytotoxicity; experience; genome sequencing; in vivo; in vivo Model; mouse model; mutant; novel; pandemic disease; pathogenic bacteria; protein expression; research study; rho

DESCRIPTION (provided by applicant): Vibrio cholerae is the causative agent of the severe diarrheal disease, cholera, that is endemic in much of Asia, Africa, and South America. The species is quite diverse, although only strains of the O1 or O139 serogroup cause epidemic disease. However, a significant amount of disease occurs globally in sporadic episodes and is caused by strains belonging to non-O1/non-O139 serogroups. Unlike pathogenic O1 and O139 strains, the vast majority of pathogenic non-O1/non-O139 strains do not carry the well characterized virulence factors for colonization (TCP) and toxin production (CT), and presumably cause disease by an unknown mechanism(s). Whole genome sequencing of a clinically isolated non-O1/non-O139 strain, AM-19226, has revealed the presence of open reading frames (ORFs) having significant similarity to genes encoding a Type Three Secretion System (TTSS). These ORFs appear to be conserved among a subset of non-O1/non-O139 strains, as well as pandemic strains of V. parahaemolyticus. Many pathogenic bacteria use TTSSs to translocate virulence factors into the cytosol of host cells, and we hypothesize that the presence of similar ORFs in V. cholerae represents a newly identified mechanism for host cell interaction and virulence acquired by these strains. Experiments suggest that the TTSS is indeed functional and has a role in pathogenesis. Deletion of a critical component of the TTSS severely attenuates the ability of strain AM-19226 to colonize the infant mouse model. Furthermore, an effector protein (whose secretion is TTSS dependent) has been identified, and it appears to have a role in the reorganization of host cell actin. We propose to use three complimentary in vitro approaches to begin to understand TTSS mediated pathogenesis in V. cholerae. The first approach is to identify additional effector proteins that promote virulence, using complimentary in vitro and in vivo model systems. The second approach is to dissect how effector proteins interact with host cells at the molecular level to cause disease, and the third is to use genomic approaches to begin to understand the regulatory network governing expression of the genes encoding effector proteins and the TTSS structural apparatus. Project Narrative: Today cholera is considered a health threat mainly in developing nations, regions lacking modern sanitation facilities, and in countries experiencing disrupted civil infrastructure due to war or environmental crises. The disease poses a threat to individuals traveling to endemic areas, and the United States CDC considers some strains a Category B level BioTerrorism threat because of the potential for spread via contaminated food or water. While O1 and O139 epidemic causing strains are well studied, this proposal seeks to understand the virulence mechanisms employed by strains of other serogroups that represent an emerging threat.

描述（由申请人提供）：Vibrio Cholerae是严重腹泻病的病因，霍乱，在亚洲，非洲和南美大部分地区是特有的。该物种非常多样化，尽管只有O1或O139血清群的菌株会引起流行病。然而，在零星发作中，全球大量疾病发生，是由属于非O1/非O139血清群的菌株引起的。与致病性O1和O139菌株不同，绝大多数致病性非O1/non-O139菌株不会带有良好的定植毒力因子（TCP）（TCP）和毒素产生（CT），也可能会导致疾病，而疾病是不知名的机制。临床分离的非O1/非O139菌株AM-19226的整个基因组测序揭示了与编码三型分泌系统（TTSS）基因具有显着相似性的开放式阅读框（ORF）的存在。这些ORF似乎是在非O1/非O139菌株的一部分中保守的，以及副溶血杆菌的大流行菌株。许多致病细菌使用TTSS将毒力因子转移到宿主细胞的细胞质中，我们假设V. Cholerae中相似的ORF的存在代表了这些菌株获得的宿主细胞相互作用和毒力的新机制。实验表明TTSS确实具有功能性，并且在发病机理中起作用。 TTSS的关键成分的删除严重削弱了AM-19226菌株定居婴儿模型的能力。此外，已经确定了效应蛋白（其分泌是TTSS的分泌），并且似乎在宿主细胞肌动蛋白的重组中起作用。我们建议使用三种免费的体外方法开始了解霍乱弧菌中TTSS介导的发病机理。第一种方法是使用免费的体外和体内模型系统鉴定促进毒力的其他效应蛋白。第二种方法是剖析效应蛋白如何在分子水平与宿主细胞相互作用以引起疾病，第三种是使用基因组方法开始理解编码效应蛋白和TTSS结构性的基因表达的调节网络。项目叙述：如今，霍乱被认为是健康的威胁，主要是发展中国家，缺乏现代卫生设施的地区以及由于战争或环境危机而造成的民事基础设施中断的国家。该疾病对前往流行地区的个人构成威胁，美国疾病预防控制中心认为某些菌株是B类水平生物恐怖主义威胁，因为有可能通过受污染的食物或水传播。虽然对O1和O139的流行病进行了充分的研究，但该提案试图了解代表新兴威胁的其他血清群菌株所采用的毒力机制。