Bacteriophage interactions with enteric pathogens

项目摘要 对于绝大多数人来说，真菌和病毒如何识别其特异性宿主细胞受体尚不清楚。 物种长期目标是了解结构和机制背后的一般原则， 控制噬菌体进入宿主细胞。本提案的目的是确定结构， 肠道病原体如何利用外膜和内膜蛋白进行感染的机制 如志贺氏菌、大肠杆菌和沙门氏菌。核心假设是存在保守的蛋白质结构 以及控制大多数噬菌体：宿主对的噬菌体进入的相应机制。我们预测 存在噬菌体进入通常所需的通用细胞表面特征， 这些特征可以是对单个噬菌体：宿主对特异性的。拟议工作的基本原理是， 我们将确定肠道病原体中介导噬菌体感染的关键受体蛋白， 对这些相互作用的理解将为识别新疗法或 改善现有的。我们将结合概念和技术来进行这项研究。 涉及遗传学、生物化学和生物物理学的创新。其中包括最近开发的创新， 我的实验室，以及更成熟的微生物技术。拟议的研究意义重大， 因为它将提供结构和机制的见解，了解它们如何与特定的宿主对接， 生产性感染的必要步骤。这项工作还将开发供其他机构使用的资源。 研究人员例如，拟议的工作将开发广泛适用的复杂转座子和单一转座子。 基因缺失文库，这将大大推动志贺氏菌的研究，因为目前还没有这样的基因缺失文库， 工具包存在。这项工作的预期成果将提供一个基本的理解， 宿主包括哪些蛋白质和相互作用是普遍需要的，哪些是个体特异性的 噬菌体：宿主对。此外，我们将获得蛋白质的原子水平的理解：蛋白质结合 相互作用和控制感染的瞬时感染中间状态。原子级细节，例如如何 与宿主的结合对于设计新的治疗方法或增强现有的治疗方法至关重要。

Project Summary How phages and viruses recognize their specific host cell receptors is not known for the vast majority of species. The long-term goal is to understand the general principles behind the structures and mechanisms that control host cell entry for bacteriophages. The objective of this proposal is to determine the structures, and mechanisms of how phages use both outer and inner membrane proteins for infection in enteric pathogens such as Shigella, E.coli and Salmonella. The central hypothesis is that there are conserved protein structures and corresponding mechanisms that govern phage entry for the majority of phage:host pairs. We predict that there are universal cell surface features that are generally required for phage entry, and also other cell surface features that may be specific to individual phage:host pairs. The rationale underlying the proposed work is that we will identify key receptor proteins in enteric pathogens that mediate phage infection, and that a better understanding of these interactions will provide physical targets for either identifying new therapies or improving existing ones. We will pursue this research using a combination of conceptual and technological innovations involving genetics, biochemistry and biophysics. These include innovations recently developed in my laboratory, as well as more established microbiological techniques. The proposed research is significant, as it will provide both structural and mechanistic insights into how phages dock to their specific hosts, a necessary step for productive infection. This work will also develop resources that will be used by other researchers. For example, the proposed work will develop widely-applicable complex transposon and single gene deletion libraries, which will greatly propel research forward in Shigella, as currently no such genetic toolkit exists. The expected outcome of this work will provide a basic understanding of how phages attach to hosts including which proteins and interactions are universally required, and which are specific to individual phage:host pairs. Additionally, we will gain an atomic level understanding of the protein:protein binding interactions and transient infection intermediate states that control infection. Atomic level details, such as how phages bind to their hosts are critical for engineering new therapeutics or enhancing existing ones.