A quorum-sensing-controlled aggregative community formation program in Vibrio cholerae

霍乱弧菌中群体感应控制的聚合群落形成程序

• 批准号: 10038440
• 负责人: Matthew L Jemielita
• 金额: $ 5.11万
• 依托单位: PRINCETON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2021-03-12
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10038440
• 关键词: Acute Diarrhea; Back; Bacteria; Behavior; Bile fluid; Biochemistry; Biological Assay; Biology; Biophysics; Cell Communication; Cell Signaling Process; Cell division; Cells; Characteristics; Cholera; Communities; Coupled; Detection; Developing Countries; Development; Diarrhea; Disease; Environment; Epithelial; Epithelium; Etiology; Extracellular Matrix; Extracellular Structure; Face; Fluorescence Microscopy; Genes; Genetic; Genetic Screening; Goals; Human; Image Analysis; Individual; Infection; Ingestion; Intestines; Lead; Liquid substance; Measures; Methods; Microbial Biofilms; Microscopy; Modeling; Molecular Biology; Mucous Membrane; Mutagenesis; Pattern; Peptide Hydrolases; Physiological; Pilot Projects; Play; Population Density; Preparation; Privatization; Process; Production; Proteins; Proteolysis; Proteomics; Regulation; Research; Resistance; Role; Signaling Molecule; Small Intestines; Stress; Structure; Surface; Swimming; Testing; Time; Toxic effect; Training; Universities; Vibrio cholerae; Virulence; Western Blotting; Work; bacterial community; bacterial genetics; base; cell growth; combat; community building; confocal imaging; diarrheal disease; extracellular; global health; human pathogen; insight; member; mouse model; mutant; nutrient deprivation; pandemic disease; pathogenic bacteria; programs; protective effect; quorum sensing; skills; stressor; time use; tool; transcription factor; transmission process

PROJECT SUMMARY Vibrio cholerae is the etiological agent of the disease cholera. Cholera is an acute diarrheal disease prevalent in developing countries and is a major global health burden. The V. cholerae lifecycle is defined by repeated transitions between the marine environment and the human host. With respect to the disease, ingested planktonic V. cholerae cells migrate through the mucosal layer to colonize the epithelium of the small intestine. Infections are self-limiting: At the end of the infection cycle, V. cholerae disperses back into the environment as a result of the severe diarrhea characteristic of the disease cholera. This lifecycle requires that V. cholerae repeatedly make the key decision to switch between a free-living planktonic state or to join with others to form multicellular communities. This decision is controlled by quorum sensing (QS), the process of bacterial cell-cell communication that relies on the production, release, and group-wide detection of extracellular signal molecules called autoinducers. QS allows bacteria to collectively alter their behavior based on local population density. Multicellular community formation in bacteria, including V. cholerae, is commonly studied in the context of biofilms: surface-bound communities held together by an extracellular matrix. I have discovered an alternative multicellular community formation program in V. cholerae. This rapid, aggregative community formation program occurs in the absence of cell-division (<30 min to completion), does not require components essential for V. cholerae surface-biofilm formation, and occurs in liquid instead of on a surface. Like the surface-biofilm program this aggregative community formation program requires QS, although the pattern of regulation is different. I have determined the mechanism underlying how QS controls this new program and I conducted a genetic screen to identify genes required for aggregative community formation. My screen revealed genes involved in flagellar synthesis, encoding transcription factors for nutrient deprivation/stress, and a gene unique to the current pandemic strain of V. cholerae. Many of these genes are required for V. cholerae virulence in a murine model of cholera. My results suggest that this new multicellular community formation program facilitates transmission from the human host lumen back to the marine environment, promotes long-term environmental persistence by privatizing public goods production by the collective, and provides selectivity in community formation. My long- term goal is to develop a mechanistic and biophysical understanding of this new program of multicellularity in V. cholerae. I will use the tools of bacterial genetics, microscopy, proteomics, and biochemistry to (1) Determine how extracellular proteases regulate the timing of aggregative community formation; (2) Identify the structural components required for aggregative community formation; (3) Explore whether the aggregative community formation program protects participating cells from the toxic effects of bile, a stressor that V. cholerae must face during human infection. This work will deliver insight into the V. cholerae lifecycle and may lead to new strategies for combatting this important human pathogen.

项目摘要 霍乱弧菌是霍乱的病原体。霍乱是一种急性霍乱， 发展中国家，是全球健康的主要负担。霍乱弧菌的生命周期是由重复的 海洋环境和人类宿主之间的过渡。关于疾病，摄入 强直性霍乱弧菌细胞通过粘膜层迁移到小肠的上皮上。 感染是自限性的：在感染周期结束时，霍乱弧菌分散回到环境中， 这是霍乱所特有的严重腹泻的结果。这种生命周期要求霍乱弧菌 反复做出关键的决定，在自由生活的非紧张状态之间切换，或者与其他人一起形成 多细胞群落。这一决定是由群体感应（QS）控制的， 依赖于细胞外信号分子的产生、释放和群体范围的检测的通信 称为自体诱导物。QS允许细菌根据当地人口密度集体改变它们的行为。 细菌（包括霍乱弧菌）中的多细胞群落形成通常在以下背景下进行研究： 生物膜：通过细胞外基质结合在一起的表面结合群落。我发现了另一种选择 多细胞群落形成计划。这个快速的、聚合性的社区形成项目 发生在细胞分裂的情况下（<30分钟完成），不需要V必需的成分。 霍乱表面-生物膜形成，并且发生在液体中而不是表面上。比如表面生物膜项目 这种聚集性的社区形成计划需要QS，尽管监管模式不同。我有 我确定了QS如何控制这个新程序的机制，并进行了基因筛选， 鉴定聚集群落形成所需的基因。我的筛选显示鞭毛基因 合成，编码营养剥夺/压力的转录因子，以及目前唯一的基因 霍乱弧菌大流行株这些基因中的许多是霍乱弧菌在小鼠模型中的毒力所必需的。 霍乱。我的研究结果表明，这种新的多细胞群落形成程序有助于从 人类宿主腔回到海洋环境，促进长期的环境持久性， 公共产品生产由集体私有化，并在社区形成中提供选择性。我的长- 本学期目标是发展一个机制和生物物理的理解，这一新的程序，多细胞在V。 胆汁。我将使用细菌遗传学、显微镜、蛋白质组学和生物化学的工具来（1）确定 细胞外蛋白酶如何调节聚集群落形成的时间;（2）确定结构 （3）探讨聚集群落形成所需的组成成分; 形成程序保护参与细胞免受胆汁的毒性作用，胆汁是霍乱弧菌必须面对的应激源 在人类感染期间。这项工作将深入了解霍乱弧菌的生命周期，并可能导致新的战略 来对抗这种重要的人类病原体