Rewiring networks for a pathogenic lifestyle

重新连接网络以适应致病的生活方式

• 批准号: 10893669
• 负责人: MICHELLE DZIEJMAN
• 金额: $ 60.99万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10893669
• 关键词: Address; Africa; Asia; Attenuated; Bacteria; Bile fluid; Binding; Biochemical; Cholera; Cholera Toxin; Chromosomes; Clinical; Country; Crowding; Cues; DNA; DNA Binding Domain; Data; Developed Countries; Developing Countries; Diarrhea; Disasters; Disease; Environment; Epidemic; Event; Evolution; Family; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Genome; Genomics; Genotype; Global Warming; Goals; Haiti; Horizontal Gene Transfer; In Vitro; Infection; Infrastructure; Integral Membrane Protein; Laboratories; Life Style; Mediating; Membrane; Microbial Biofilms; Modeling; Modernization; Molecular; Morbidity - disease rate; Oceans; Organism; Pathogenesis; Pathogenicity; Pathogenicity Island; Phenotype; Physiological; Pilum; Process; Production; Property; Proteins; Public Health; Regulation; Regulon; Reporting; Role; Signal Transduction; South America; Southeastern Asia; Specificity; Stimulus; Surface; Syria; System; Testing; Tissues; Toxin; Trans-Activators; Transcription Coactivator; Type III Secretion System Pathway; Ukraine; United States; Vibrio cholerae; Virulence; Virulence Factors; War; Water; burden of illness; cell motility; cis acting element; clinical sequencing; clinically relevant; diarrheal disease; drinking water; experience; experimental study; gene repression; genetic regulatory protein; gut colonization; in vivo; pathogen; pathogenic bacteria; programs; protein protein interaction; response; trait; transcriptome; virulence gene; waterborne pathogen

Project Summary Vibrio cholerae causes the severe diarrheal disease cholera that is endemic in much of Asia, Africa, and South America, and has recently reemerged in Haiti, Syria, and Ukraine. The species is highly diverse, although only O1 or O139 serogroup strains cause epidemic disease. However, increasing sporadic disease has been reported globally, and is caused by strains belonging to non-O1/non-O139 serogroups that present a public health threat both in developed and industrialized nations, including the United States. 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 the virulence mechanisms used by these strains are not well understood. Our study of pathogenic non-O1/non-O139 serogroup strains began with genomic sequencing of the clinically isolated O39 serogroup strain, AM-19226, which revealed a Type Three Secretion System (T3SS) that is conserved among other V. cholerae isolates. Like TCP and CT, the T3SS is acquired by horizontal gene transfer (HGT), and integrated into the ancestral chromosome. Our subsequent experiments identified two membrane localized transcriptional activators (MLTAs) encoded within the T3SS genomic pathogenicity island (PAI), which are essential for T3SS function in vivo and in vitro. We also found that ToxR, an ancestral MLTA required for TCP and CT expression, is important for T3SS regulation. ToxR is encoded by all strains of V. cholerae where it regulates core chromosomal functions, and is well-studied as an MLTA that cross-regulates PAI and ancestral gene expression. Interestingly, we found that the T3SS encoded MLTAs influence ancestral gene expression and phenotypes such as motility and biofilm formation. We hypothesize that in order to survive in aquatic environments and also cause disease, T3SS-positive V. cholerae must integrate virulence gene regulation with transcriptional circuits outside of the PAI, leveraging the activities of both ancestral and newly acquired, PAI encoded transcriptional regulatory factors. We propose to use complementary genetic and biochemical approaches to identify and characterize the mechanisms used by T3SS PAIs to coordinate motility, biofilm formation, and T3SS gene expression in response to environmental cues. Initial studies will define the regulons for T3SS MLTAs, and the conditions promoting regulation. We will investigate protein-protein interactions and MLTA transcriptional domain sequence specificity. Initial studies will focus on VttRA as the protein at the top of the regulatory hierarchy. Our overall goal is to discover how PAI encoded MLTA activity regulates virulence phenotypes and ancestral physiological traits that are necessary to maintain dual lifestyles of newly evolved pathogens.

项目摘要 霍乱弧菌导致严重的腹泻疾病霍乱，霍乱在亚洲、非洲和南部的大部分地区流行 美国，最近又在海地、叙利亚和乌克兰重新出现。该物种高度多样化，尽管只有 O1或O139血清群菌株可引起流行病。然而，越来越多的散发性疾病 全球报告，由属于非O1/非O139血清组的菌株引起，这些血清群呈现公共 在发达国家和工业化国家，包括美国，都存在健康威胁。与致病O1不同 和O139菌株，绝大多数致病的非O1/非O139菌株没有很好的携带特性 侵染毒力因子(TCP)和毒素产生(CT)，以及它们使用的毒力机制 菌株还没有被很好地理解。我们对致病性非O1/非O139血清群菌株的研究始于 临床分离的O39血清群毒株AM-19226的基因组序列分析 在其他霍乱弧菌分离株中保守的分泌系统(T3SS)。与TCP和CT一样，T3SS是 通过水平基因转移(HGT)获得，并整合到祖先染色体中。我们的后续行动 实验确定了编码在T3SS内的两个膜定位转录激活因子(MLTA) 基因组致病岛(PAI)，它们在体内和体外对T3SS的功能是必不可少的。我们还发现 ToxR是一种祖代性MLTA，在T3SS调控中起重要作用。ToxR是 霍乱弧菌由所有菌株编码，在那里它调节核心染色体功能，并被广泛研究为 交叉调节PAI和祖先基因表达的MLTA。有趣的是，我们发现T3SS编码 MLTA影响祖先的基因表达和表型，如运动性和生物膜的形成。我们 假设为了在水生环境中生存并引起疾病，T3SS阳性霍乱弧菌 必须将毒力基因调控与PAI外的转录电路结合起来，利用这些活动 对于祖先和新获得的，PAI编码转录调节因子。我们建议使用 互补的遗传和生化方法来识别和表征T3SS所使用的机制 PAI协调运动性、生物膜的形成和T3SS基因的表达以响应环境提示。 初步研究将确定T3SS MLTA的规则，以及促进规则的条件。我们会 研究蛋白质-蛋白质相互作用和MLTA转录结构域序列的特异性。初步研究将 重点关注VttRA作为监管层次结构顶端的蛋白质。我们的总体目标是了解PAI如何 编码的MLTA活性调节毒力表型和祖先的生理特性，这是 维持新进化的病原体的双重生活方式。