Study of M. tuberculosis under human host selection to identify virulence and barrier lipids (Project 1)

项目1.人类宿主选择下的结核分枝杆菌毒力和屏障脂类鉴定研究 项目负责人：D·布兰奇·穆迪 联合调查员：李京姬，雅各布·梅菲尔德 合作调查人员：阿德里安·明纳德(核心C)，杰里米·洛克(核心D)，克莱尔·史密斯(核心E) 摘要 比较基因组学已成为追踪结核病(TB)流行的主导范式， 了解结核分枝杆菌(Mtb)的毒力并开发新药和诊断方法。 相比之下，分枝杆菌的代谢被认为是所有临床结核分枝杆菌菌株的不变特征。穿过 比较84个患者来源的结核分枝杆菌菌株中的~10,000种脂类的代谢谱，我们发现 结核分枝杆菌致病性脂被膜在流行的菌株之间显示出可识别的变异模式 人类人口。为了确定感染细菌群体中表型多样性的影响， 我们将绘制来自南方Masiphulemele的140株结核分枝杆菌患者的细胞壁脂变异图谱 非洲。由此得到的脂质图谱将描述传播到日本的结核分枝杆菌菌株之间的脂质成分变化。 社区。从生物学角度来看，结核分枝杆菌的脂膜形成了与宿主的主要界面，并且是 因此，一个直接和持续的进化选择的生化目标。该项目旨在揭示 以前未曾描述过的化学多样性和脂类产物，是由于宿主和 药物衍生的临床压力。使用生物体范围的脂肪图谱和基因组范围的测序，我们有 确定了42对在结核分枝杆菌菌株变异中占主导地位的脂类基因对，以及1150种脂类过度表达 在毒力Mtb和250脂中选择性地在宿主界面表达。初步数据支持我们有能力 然后将这些脂质与特定的细菌基因联系起来，即使在知道代谢物的结构或 一种基因的功能缺失。CRISPR干扰策略随后将在基因之间建立因果联系 未知的功能和新发现的脂类。我们将在合作杂交中进一步测试脂质缺陷菌株 揭示新发现的脂类在结核杆菌毒力中的具体作用。这些发现研究将确定 决定毒力、宿主界面和结核分枝杆菌存活的关键结果的生物重要脂类 活体，支持结核病诊断和治疗的新方法。

Project 1. Study of M. tuberculosis under human host selection to identify virulence and barrier lipids Project Leader: D. Branch Moody Coinvestigators: Kyu Rhee, Jacob Mayfield Collaborating Investigators: Adriaan Minnaard (Core C), Jeremy Rock (Core D), Clare Smith (Core E) ABSTRACT Comparative genomics has served as a dominant paradigm for tracking the tuberculosis (TB) epidemic, understanding Mycobacterium tuberculosis (Mtb) virulence and developing new drugs and diagnostics. Mycobacterial metabolism, in contrast, has been viewed as invariant feature of all clinical Mtb strains. Through comparative metabolomic profiling of ~10,000 lipids among 84 patient-derived Mtb strains, we discovered that Mtb’s pathognomonic lipid envelope shows identifiable patterns of variance among strains circulating among human populations. To determine the impact of phenotypic diversity within the infecting bacterial population, we will map cell wall lipid variation among 140 Mtb strains among TB patients from Masiphulemele, South Africa. The resulting lipid map will describe variations in lipid composition among Mtb strains transmitting in community. From a biological perspective, Mtb’s lipid envelope forms the primary interface with the host and is therefore a direct and ongoing biochemical target of evolutionary selection. This project aims to reveal the previously undescribed chemical diversity and lipid products that have arisen as a consequence of host- and drug-derived clinical pressure. Using organism wide lipid profiling and genome wide sequencing, we have identified 42 lipid-gene pairs that dominate in Mtb strain variance, as well as 1150 lipid species overexpressed in virulent Mtb and 250 lipids selectively expressed at the host interface. Preliminary data support our ability to then link these lipids to specific bacterial genes, even when prior to knowledge of the metabolite’s structure or a gene’s function is lacking. CRISPR interference strategies will then establish causal linkages between genes of unknown function and newly discovered lipids. We will further test lipid deficient strains in collaborative cross mice to reveal specific roles of newly identified lipids in Mtb virulence. These discovery studies will identify biologically important lipids that determine key outcomes in virulence, the host interface and Mtb survival in vivo, supporting new approaches for tuberculosis diagnosis and treatment.