The role of immunity in shaping Mycobacterium tuberculosis metabolism

项目摘要 结核分枝杆菌(结核分枝杆菌)是传染病死亡的主要原因，有200万人。 每年的死亡人数。为了让结核杆菌在宿主体内茁壮成长，细菌必须获得包括碳在内的营养。 对增长至关重要的资源。MTB可以使用四种主要碳源来满足其在以下方面的需求 碳利用。结核分枝杆菌主要存在于宿主巨噬细胞的吞噬小体内，必须获得 碳源来自巨噬细胞，而在这个利基。而在这个隔间里，Mtb也 经历各种各样的压力，包括活性氮物种(RNS)的压力。以前的工作 已经表明，在体外，结核分枝杆菌暴露在一氧化氮(NO)下会导致蛋白质的亚硝化，从而 对糖酵解是必不可少的。来自我们实验室的其他初步数据显示，要么暴露出结核分枝杆菌 转座子文库在体外导致脂肪酸降解的重要性增加和 在没有暴露的情况下，减少对糖酵解途径的依赖。这导致我们假设 暴露在RNS压力下会导致Mtb对碳的使用发生变化。开始确定RNS如何 压力影响碳的利用，目标1将利用一个菌株库，这些菌株既不能利用也不能利用 获取每一种碳源。这个文库将在单一碳源存在的情况下生长 和RNS，并对每个菌株的生长进行监测，以确定RNS压力如何影响 每个突变体在各种碳源上生长的能力。在目标2中，这个文库将被用来感染 巨噬细胞和小鼠，要么是野生型，要么是没有诱导表达能力的小鼠。这些 研究将使我们能够确定实际感染条件如何影响结核分枝杆菌使用各种不同 碳源。最后，目标3将侧重于确定RNS应激导致 Mtb碳使用量的变化。这些研究将提供有关结核杆菌如何利用碳的重要数据。 在应激条件下，以及允许体内碳利用变化的机制。

Project Summary Mycobacterium tuberculosis (Mtb) is the leading cause of death by infectious disease, with two million deaths annually. For Mtb to thrive within the host, the bacterium must obtain nutrients, including carbon sources which are essential for growth. Mtb can use four primary carbon sources to meet its needs for carbon utilization. Mtb primarily resides within the phagosome of host macrophages and must acquire carbon sources from the macrophage while in this niche. While in this compartment, Mtb also experiences a wide variety of stresses including reactive nitrogen species (RNS) stress. Previous work has shown that in vitro exposure of Mtb to nitric oxide (NO) leads to the nitrosylation of proteins that are essential for glycolysis. Additional preliminary data from our lab shows that either exposing Mtb transposon libraries to NO in vitro leads to an increased importance of fatty acid degradation and decreased reliance on glycolytic pathways during NO exposure. This has led us to hypothesize that exposure to RNS stress leads to changes in the use of carbon by Mtb. To begin to identify how RNS stress effects carbon utilization, Aim 1 will utilize a library of strains that are unable to either utilize or acquire each of the carbon sources. This library will be grown in the presence of single carbon sources and RNS, and growth of each strain will be monitored to determine how the RNS stress affects the ability of each mutant to grow on each carbon source. In Aim 2, this library will be used to infect macrophages and mice that are either wildtype or lack the ability to induce NO expression. These studies will allow us to determine how actual infection conditions affect the ability of Mtb to use various carbon sources. Finally, Aim 3 will focus on identifying the mechanisms by which RNS stress leads to changes in carbon usage by Mtb. These studies will provide important data on how Mtb utilizes carbon under stress conditions and the mechanisms which allow for changes in carbon utilization in vivo.