Phage resistance and mobile genetic elements in Vibrio cholerae

霍乱弧菌的噬菌体抗性和移动遗传元件

基本信息

批准号：
10682489
负责人：
Kimberley Diane Seed
金额：
$ 47.65万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-27 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10682489
关键词：
Area Bacterial Chromosomes Bacteriophages Biochemical Biological Models Capsid Cells Cholera Chromosomes Clustered Regularly Interspaced Short Palindromic Repeats Complex Cryoelectron Microscopy DNA biosynthesis Data Defense Mechanisms Disease Disease Outbreaks Disease Outcome Ecosystem Electron Microscopy Elements Environment Epidemic Evolution Excision Gene Expression Genes Genetic Genetic Materials Genome Genomics Goals Human Infection Infection Control Infrastructure Island Life Cycle Stages Lytic Measures Mediating Mobile Genetic Elements Modification Molecular Nature Open Reading Frames Outcome Parasites Predatory Behavior Process Production Proteomics Receptor Cell Regulation Resistance Role Sanitation Small RNA System Tail Techniques Transcript Untranslated RNA Vibrio cholerae Virion Water Work clinically relevant driving force gene product global health improved inhibitor microbial novel pathogen pathogenic bacteria response targeted nucleases transmission process waterborne pathogen

项目摘要

Waterborne pathogens like Vibrio cholerae pose significant threats to global health. V. cholerae can persist in the aquatic environment, and it can emerge to cause devastating cholera outbreaks in endemic regions and vulnerable areas lacking adequate water and sanitation infrastructure. The host-pathogen interactions that dictate disease outcome and cholera transmission dynamics occur in the context of a complex microbial ecosystem that includes predatory bacterial viruses (phages). Phages profoundly impact the evolution of their bacterial hosts, both through predation, which selects for hosts with defenses that overcome phage killing and through mobilization and dissemination of genetic material. Certain mobile elements called the phage satellites have evolved sophisticated mechanisms to exploit phages for their own selfish spread. Such elements interfere with the replication of the phages they parasitize, and as such, provide their cellular hosts with a means to limit phage predation. Our lab discovered PLEs (for phage-inducible chromosomal island-like elements) in V. cholerae that provide specific and robust defense against ICP1, the dominant lytic phage co-circulating with V. cholerae in cholera endemic regions. Upon infection by ICP1, PLEs excise from the V. cholerae chromosome, replicate to high copy and are assembled into virions to spread the PLE genome to new cells while concurrently abolishing phage production. PLEs are uniquely potent, highly specific, anti-phage barriers that act through multiple mechanisms to ensure that ICP1 does not propagate and spread to neighboring V. cholerae cells. However, few mechanisms of direct interference with ICP1 are known, and none are essential for PLE activity, indicating that additional mechanisms await discovery in this system. This proposal builds on our prior work defining the PLE lifecycle in response to phage infection to gain a mechanistic understanding of how PLEs execute their unusually potent anti-phage activity. Our data indicate that PLE’s most potent anti- phage inhibitors are focused on blocking virion assembly. To understand PLE activity in mechanistic detail, we will pursue the following specific aims: 1) We will define the structural composition of virions and capsid assembly intermediates for ICP1 and PLE 2) We will Interrogate the functions of three PLE-encoded ORFs that are each sufficient to inhibit phage 3) We will determine how a PLE-encoded small RNA perturbs phage gene expression. The proposed studies are expected to reveal novel mechanistic paradigms not previously documented in phage satellites or other anti-phage defense systems. The long-term coevolution of V. cholerae PLE and ICP1 serves as a powerful model system to understand clinically relevant phage defense mechanisms to inform phage therapy efforts and understand the forces driving the evolution of bacterial pathogens.

水传播病原体，例如弧菌霍乱，对全球健康构成了重大威胁。 V.霍乱可以持续水生环境，它可能出现在地方性地区造成毁灭性的霍乱疫情和缺乏足够的水和卫生基础设施的脆弱地区。宿主病原体相互作用决定疾病结果和霍乱传播动力学发生在复杂的微生物的背景下包括掠食性细菌病毒（噬菌体）的生态系统。噬菌体深刻影响他们的演变细菌宿主，既通过捕食，它都会选择具有克服噬菌体杀戮和的防御能力的宿主通过动员和遗传物质的传播。某些称为噬菌体卫星的移动元素已经发展出了复杂的机制，以利用噬菌体自我传播。这样的元素干扰随着它们寄生的噬菌体的复制噬菌体捕食。我们的实验室发现了V。霍乱提供了针对ICP1的特定和强大防御的霍乱。霍乱霍乱区域。 ICP1感染后，PLES经历了霍乱葡萄球菌的经验，复制到高拷贝并组装成病毒，将PLE基因组传播到新细胞，而同时废除噬菌体生产。 PLE具有独特的潜力，高度特异性的抗流量障碍通过多种机制采取行动，以确保ICP1不会传播并传播到相邻V。霍乱细胞。但是，很少有直接干扰ICP1的机制已知，也不是必不可少的对于PLE活动，表明该系统中的其他机制正在等待。该提议建立在我们先前定义PLE生命周期以响应噬菌体感染的工作，以获得对机械的理解 PLES如何执行其异常潜在的抗流量活动。我们的数据表明，PLE最可能的反 - 噬菌体抑制剂的重点是阻断病毒座组件。要了解机械细节的PLE活动，我们将追求以下特定目标：1）我们将定义病毒和capsid的结构组成 ICP1和PLE 2）的组装中间体我们将询问三个PLE编码ORF的功能每个都足以抑制噬菌体3）我们将确定PLE编码的小RNA如何渗透噬菌体基因表达。拟议的研究预计将揭示新的机械范例，而不是以前记录在噬菌体卫星或其他防水防御系统中。 V.霍乱的长期共同进化 PLE和ICP1是一个强大的模型系统，可以了解临床上相关的噬菌体防御为噬菌体疗法工作的机制，并了解推动细菌进化的力病原体。