Determining the role of sphingolipids in Mycobacterium tuberculosis infection

项目摘要/摘要 世界上近三分之一的人口感染了结核分枝杆菌(Mtb)，这是一种病原体 结核病(TB)。这个蓄水池导致结核病发病率增加，约有1100万人 每年新增病例和180万人死亡。结核分枝杆菌致病的巨大成功取决于它的 能够有效地利用宿主的脂肪代谢，包括鞘脂生物合成途径，以 颠覆免疫系统。肉芽肿是结核病感染的病理标志，其特征是 存在脂质负载的免疫细胞，如泡沫巨噬细胞，其能力显著降低 在控制细菌生长方面。尽管众所周知，结核分枝杆菌可以调节脂质代谢，尤其是 在感染过程中的鞘脂通路，目前还没有系统地了解感染细菌如何改变 宿主类脂体。我们最近发现，鞘脂是一类独特的脂类，具有狮身人面像的基本骨架 富含在细胞膜中的物质，对结核分枝杆菌的进入和杀死至关重要。我们计划延长我们的 研究确定每种鞘磷脂在结核分枝杆菌发病机制中的作用。该计划的主要目标是 建议的工作是系统地扰乱宿主的关键鞘磷脂生物合成途径以揭示 它们在结核分枝杆菌的发病机制和抗微生物细胞过程中的作用，如炎症小体。为了这个 目的：缺乏参与巨噬细胞生物合成的关键基因的单个敲除巨噬细胞系 鞘脂将使用CRISPR/CAS9技术生成。我们将使用多功能鞘糖脂 前体类似物，以确定神经鞘脂在感染过程中的流量、定位和相互作用组- 和依赖空间的方式。此外，我们还将研究神经鞘脂脂在 炎症体，一种对控制结核分枝杆菌感染很重要的先天免疫过程。了解这些 对于结核分枝杆菌的发病至关重要的途径或过程是至关重要的，因为它们代表着 新疗法。

Project Summary/Abstract Nearly one-third of the world population is infected with Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). This reservoir contributes towards an increasing incidence of TB, with about 11 million new cases and 1.8 million deaths every year. The profound success of Mtb in causing disease depends on its ability to effectively utilize the host's lipid metabolism, including the sphingolipid biosynthesis pathway, to subvert the immune system. The granuloma, the pathological hallmark of TB infection, is characterized by the presence of lipid-loaded immune cells such as foamy macrophages that have a significantly reduced capability in controlling bacterial growth. Although Mtb is known for modulating lipid metabolism, and in particular the sphingolipid pathways during infection, there is no systematic understanding of how infective bacteria alter the host lipidome. We recently found that sphingolipids, a distinct class of lipids with a sphingoid base backbone that are enriched in cellular membranes, are essential for entry and killing of Mtb. We plan to extend our investigation to define the role of each sphingolipid repertoire in Mtb pathogenesis. The main goal of the proposed work is to systematically perturb the key sphingolipid biosynthetic pathways of the host to uncover their function in Mtb pathogenesis and antimicrobial cellular processes such as the inflammasome. For this purpose, individual knockout macrophage cell lines that lack key genes involved in the biosynthesis of sphingolipids will be generated using CRISPR/Cas9-technology. We will use multifunctional sphingolipid precursor analogs to define the flux, localization and the interactome of sphingolipids during infection in time- and space-dependent manner. Furthermore, we will study the significance of sphingolipids in the inflammasome, an innate immune process that is important in controlling Mtb infection. Understanding these pathways or processes essential for the pathogenesis of Mtb is crucial, as they represent potential targets for new therapeutics.