Gut pathogen virulence and its therapeutic modulation during surgical injury

我们在小鼠和危重病人身上都证明了，在手术损伤/感染之后，肠道 2微生物区系在结构、成员和功能(即与健康有关的代谢物的产生)等方面崩溃 3免疫功能和宿主恢复均受损。在这项提案中，我们试图识别这些代谢物 4由肠道微生物区系产生，在决定手术结果的过程中起关键和因果作用 5通过对巨噬细胞进行编程以消除病原体和解决问题而造成的损伤/感染 6适当的时机和配合，发炎。我们首次展示了肠道微生物群起源于 7种代谢物(即丁酸盐、吲哚等)可将巨噬细胞从M1表型转变为M2表型。 8导致从潜在的致命外科感染(即粘质链球菌腹膜炎)中康复。从我们的工作 9合作者(Lev Becker，PhD)最近描述了一种“计时机制”，通过这种机制，关键代谢物(即乳酸) 10和其他)在巨噬细胞内蓄积，与组蛋白结合并驱动动态平衡基因表达，因此它们 11正确地从M1(病原体消除)过渡到M2(炎症消退)。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群的产生 13种代谢产物，对巨噬细胞进行编程，以清除病原体并适当地化解炎症 14计时、规范的方式。了解这一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群的机制 16人幸存。因此，在这项建议中，我们将解决以下具体目标： 17目标1：确定肠道微生物区系、其产生的代谢物和它们之间的关系 18对巨噬细胞表型的影响，预测从外科感染中恢复。 19 AIM2：确定激活巨噬细胞的肠道微生物代谢产物的组成。 20与粘质链霉菌一起培养表达与生存相关的表型并确定其机制 涉案21起。 22目标3：用精选的微生物联合体来丰富小鼠的肠道，这些微生物是存活的高产生者- 23相关肠道代谢物及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。 我们目前正在与免疫学和微生物科学领域的两名世界级专家合作，以 26开展了拟议的研究，并已经产生了令人兴奋和令人信服的初步数据。这些 27包括本·梅癌症研究委员会副教授Lev Becker博士 28癌症生物学和分子代谢与营养委员会和Eric Pamer博士， 29传染病与全球健康，唐纳德·F·施泰纳教授；杜卡索家庭研究所所长。 30这里提出的工作是机械性的、概括性的，并且对外科损伤和感染具有很高的可译性。

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.