Gut pathogen virulence and its therapeutic modulation during surgical injury

1我们在小鼠和重症患者中证明，在手术损伤/感染后， 2微生物群在结构、成员和功能上的崩溃（即，健康相关代谢物的生产），例如 3.免疫功能和宿主恢复受损。在本提案中，我们试图确定这些代谢物 4由肠道微生物群产生，在决定手术结果方面发挥关键和因果作用。 5损伤/感染，通过它们对巨噬细胞进行编程的能力，使得它们消除病原体并解决 6炎症与适当的时间和协调。我们第一次证明，肠道微生物来源的 7种代谢物（即，丁酸盐、吲哚和其他）可使巨噬细胞从M1表型转变为M2表型 8导致从潜在致命的外科感染中恢复（即，S.粘质性腹膜炎）。从我们的工作 9合作者（Lev Becker，PhD）最近描述了一种“计时器机制”，通过该机制，关键代谢物（即乳酸） 10和其他）在巨噬细胞内积累，与组蛋白结合并驱动稳态基因表达， 11从M1（病原体消除）到M2（炎症消退）的适当过渡。因此，我们将测试 12假设手术损伤/感染的恢复依赖于肠道微生物组产生的 13代谢物，程序巨噬细胞清除病原体和解决炎症在一个适当的 14、定时和定时。了解这个过程中的分子细节将揭示一个未知的 15手术损伤/感染后维持健康肠道微生物组的机制 16幸存者因此，在本提案中，我们将处理以下具体目标： 目标1：确定肠道微生物群、其产生的代谢物及其代谢产物之间的关系。 18对巨噬细胞表型的影响，预测手术感染的恢复。 19目的2：确定激活巨噬细胞协同的肠道微生物组代谢物的组成。 20个菌株与S. marcescens表达生存相关的表型，并确定其机制 21参与 目标3：用选择的微生物财团丰富小鼠肠道，这些微生物财团是存活率高的生产者。 23相关的肠道代谢物，并确定其增强巨噬细胞功能的机制 24和手术损伤/感染后的存活率。 25我们目前正在与免疫学和微生物组科学领域的两位世界级专家合作， 26开展拟议的研究，并已产生令人兴奋和令人信服的初步数据。这些 27人包括本·梅癌症研究委员会副教授列夫·贝克尔博士， 28癌症生物学和分子代谢与营养委员会以及 29传染病和全球健康，唐纳德·F。施泰纳教授;主任，Duchossois家庭研究所。 本文提出的工作是机械的，可推广的，并且高度可转化为外科损伤和感染。

1 We demonstrated in both mice and critically ill humans, that following surgical injury/infection, the gut 2 microbiota collapse in structure, membership and function (i.e., production of health-relevant metabolites) such 3 that both immune function and host recovery is impaired. In this proposal we seek to identify those metabolites 4 produced by the gut microbiota that play a key and causal role in determining the outcome from surgical 5 injury/infection via their ability to program macrophages such that they eliminate pathogens and resolve 6 inflammation with proper timing and coordination. We show, for the first time that gut microbiome-derived 7 metabolites (i.e., butyrate, indoles and others) can shift macrophages from the M1 to the M2 phenotype 8 leading to recovery from potentially lethal surgical infection (i.e., S. marcescens peritonitis). Work from our 9 collaborator (Lev Becker, PhD) recently described a “timer mechanism” by which key metabolites (i.e. lactate 10 and others) accumulate within macrophages, bind to histones and drive homeostatic gene expression so they 11 properly transition from M1 (pathogen elimination) to M2 (inflammation resolution). Therefore we will test the 12 hypothesis that recovery from surgical injury/infection is dependent on gut microbiome-generated 13 metabolites that program macrophages to clear pathogens and resolve inflammation in a properly 14 timed and regulated manner. Understanding the molecular details in this process will uncover a yet unknown 15 mechanism by which maintaining a healthy gut microbiome following surgical injury/infection enhances 16 survival. Therefore, in this proposal we will address the following specific aims: 17 Aim 1: Define the relationship between the gut microbiota, the metabolites it produces and their 18 effects on macrophage phenotypes that predicts recovery from surgical infection. 19 Aim2: Determine the composition of gut microbiome metabolites that activate macrophages co- 20 cultured with S. marcescens to express a survival-related phenotype and define the mechanisms 21 involved. 22 Aim 3: Enrich the mouse gut with select microbial consortia that are high producers of survival- 23 related gut metabolites and determine the mechanisms by which they enhance macrophage function 24 and survival following surgical injury/infection. 25 We are currently working with two world class experts in the field of immunology and microbiome sciences to 26 carry out the proposed studies and have already generated exciting and compelling preliminary data. These 27 include Dr Lev Becker, Associate Professor of Ben May Department of Cancer Research Committee on 28 Cancer Biology and the Committee on Molecular Metabolism and Nutrition and Dr Eric Pamer, Section of 29 Infectious Diseases and Global Health, Donald F. Steiner Professor; Director, The Duchossois Family Institute. 30 The work herein proposed is mechanistic, generalizable and highly translatable to surgical injury and infection.