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

• 批准号: 10366735
• 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
• 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/10366735
• 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; Ensure; Environment; Epidemic; Evolution; Excision; Gene Expression; Genes; Genetic; Genetic Materials; Genome; Genomics; Goals; Human; Infection; Infection Control; Infrastructure; Island; 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; Structure; System; Tail; Techniques; Transcript; Untranslated RNA; Vibrio cholerae; Virion; Water; Work; base; clinically relevant; driving force; gene product; global health; improved; inhibitor/antagonist; microbial; novel; pathogen; pathogenic bacteria; response; targeted nucleases; transmission process; waterborne pathogen

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.

霍乱弧菌等水生病原体对全球健康构成重大威胁。霍乱弧菌可持续存在于 它的出现可能在流行地区造成毁灭性的霍乱暴发， 缺乏足够的水和卫生基础设施的脆弱地区。宿主与病原体的相互作用 决定疾病的结果和霍乱传播动力学发生在一个复杂的微生物环境中， 生态系统，包括捕食性细菌病毒（peptidal bacterial viruses，peptidal bacterial viruses）。噬菌体深刻地影响着它们的进化 细菌宿主，既通过捕食，选择具有克服噬菌体杀伤的防御的宿主， 通过动员和传播遗传物质。某些移动的元素称为噬菌体卫星 已经进化出了复杂的机制来利用病毒进行自私的传播。这些元素干扰 它们寄生的寄生虫的复制，因此，为它们的细胞宿主提供了一种限制 噬菌体捕食我们的实验室在V. 霍乱弧菌，提供特异性和强大的防御ICP 1，占主导地位的裂解噬菌体共循环与V。 霍乱流行地区的霍乱。在被ICP 1感染后，PLEs从霍乱弧菌染色体上切除， 复制到高拷贝，并组装成病毒体，以将PLE基因组传播到新细胞， 同时消除噬菌体产生。PLEs是唯一有效的、高度特异性的抗噬菌体屏障， 通过多种机制来确保ICP 1不会传播和扩散到相邻的V。 胆管细胞然而，很少有直接干扰ICP 1的机制是已知的，没有一个是必要的 对于PLE活动，指示在该系统中等待发现的附加机制。该提案基于 我们先前的工作定义了PLE生命周期对噬菌体感染的反应，以获得对 PLEs如何执行其异常有效的抗噬菌体活性。我们的数据表明PLE最有效的抗- 噬菌体抑制剂集中于阻断病毒体装配。为了详细了解PLE活动的机制，我们 我们将致力于以下具体目标：1）我们将确定病毒粒子和衣壳的结构组成 ICP 1和PLE的组装中间体2）我们将询问三个PLE编码的ORF的功能， 3）我们将确定PL编码的小RNA如何干扰噬菌体基因 表情预计拟议的研究将揭示以前没有的新机制范式 记录在噬菌体卫星或其他抗噬菌体防御系统中。霍乱弧菌的长期协同进化 PLE和ICP 1作为一个强大的模型系统，以了解临床相关的噬菌体防御 了解噬菌体治疗工作和理解驱动细菌进化的力量的机制 病原体