Secreted antimicrobial proteins of the intestinal Bacteriodales

项目摘要 肠道微生物群对人类健康和发育极为重要。在过去的十年里， 分析肠道微生物群的研究数量激增;然而， 仍然相对较少的机制研究，旨在了解这一生态系统的基本生物学特性， 其成员近年来，我们实验室一直在研究肠道类杆菌目的主要成员如何相互作用， 在有利和竞争/对抗关系中彼此。这些研究对于 了解这些细菌如何在哺乳动物肠道中形成稳定的健康状态， 促进社区。这一提议是我们对这些细菌之间拮抗作用研究的继续， 专门研究肠道类杆菌产生的分泌型抗菌分子。依据初始 项目，我们取得了意想不到的发现，关于分泌的抗菌分子的类型， 一系列分泌抗菌分子的拟杆菌目物种，以及耐药机制， 产生菌株。这个更新项目的目标是了解分泌的抗菌素的广度， 由肠道类杆菌产生的分子，它们在敏感细胞中的靶点和作用机制，以及 它们在介导哺乳动物肠道微生物群中的竞争、入侵和防御中的重要性。在目标1中， 我们将研究一大类蛋白质，这些蛋白质具有由不同的肠道产生的膜攻击/穿孔素结构域， 拟杆菌目使用预测数据来确定这些分子中哪些具有抗菌活性以及如何具有抗菌活性 它们针对敏感细胞。目的2：研究一种具有抗菌活性的真核生物类泛素分子， 活动，可能由B获得。fragilis通过界间转移，并确定其靶点和机制， 行动上目的3是分析肠道类杆菌产生的抗菌分子的宽度 通过研究不同的拟杆菌目物种，这些物种产生不同的有效分泌的抗菌分子， 班在目标4中，我们将使用分析的组合，包括计算建模，实验 在gnotobiotic小鼠的分析，并分析人类宏基因组数据集，以了解生态 肠道类杆菌分泌的抗菌分子的相关性及其对生态系统的贡献 入侵防御和稳定目前，我们是唯一一个研究分泌的抗菌蛋白的小组。 肠道拟杆菌及其生态学意义。将进行的综合分析 这一提议在该领域是前所未有的，我们发现的生态特性将作为指导 这些原则可以应用于许多人类健康应用，例如恢复健康的微生物群， 益生菌患者，以及改良益生菌的创造。

Project Summary The intestinal microbiota is extremely important to human health and development. Over the last decade, there has been a tremendous surge in the number of studies analyzing the gut microbiota; however, there are still relatively few mechanistic studies aimed at understanding basic biological properties of this ecosystem and its members. In recent years, our lab has been studying how predominant gut Bacteroidales members interact with each other in both beneficial and competitive/antagonistic relationships. These studies are essential to understanding how these bacteria become established in the mammalian intestine to form stable health- promoting communities. This proposal is a continuation of our studies of antagonism among these bacteria, specifically studying secreted antimicrobial molecules produced by the gut Bacteroidales. Under the initial project, we made unexpected findings regarding the types of secreted antimicrobial molecules produced, the range of Bacteroidales species that secrete antimicrobial molecules, and the mechanisms of resistance in producing strains. The goal of this renewal project is to understand the breadth of secreted antimicrobial molecules produced by the gut Bacteroidales, their targets and mechanisms of action in sensitive cells, and their importance in mediating competition, invasion and defense in the mammalian gut microbiota. In Aim 1, we will study a large class of proteins with membrane attack/perforin domains produced by diverse gut Bacteroidales using predictive data to determine which of these molecules have antimicrobial activity and how they target sensitive cells. In Aim 2, we will study a eukaryotic-like ubiquitin molecule with antimicrobial activity, likely acquired by B. fragilis by inter-kingdom transfer, and determine its target and mechanism of action. Aim 3 is designed to analyze the breadth of antimicrobial molecules produced by the gut Bacteroidales by studying diverse Bacteroidales species that produce potent secreted antimicrobial molecules of different classes. In Aim 4, we will use a combination of analyses, including computational modeling, experimental analyses in gnotobiotic mice, and analyses of human metagenomic datasets to understand the ecological relevance of secreted antimicrobial molecules of the gut Bacteroidales and how they contribute to ecosystem invasion, defense, and stability. Currently, we are the only group studying secreted antimicrobial proteins of the gut Bacteroidales and their ecological implications. The comprehensive analyses that will be performed in this proposal are unprecedented in the field and the ecological properties that we uncover will serve as guiding principles that can be applied to numerous human health applications such as restoring a healthy microbiota to dysbiotic patients, and the creation of improved probiotics.