Linking Human TB Genetic Susceptibility Loci to Granuloma Biology

摘要 结核分枝杆菌每年导致约140万人死亡。人民 暴露在相似的初始剂量下可能会产生非常不同的结果，从清除 从活动性疾病到亚临床或潜伏感染。结核病的一个中心结构，即 肉芽肿是病原体和宿主之间的关键界面，它的动态变化 对疾病的结果有影响。肉芽肿巨噬细胞诱导一种不寻常的表达 决定肉芽肿结构和感染轨迹的上皮样程序。由于一项 缺乏完全复制肉芽肿关键方面的基因可处理的动物模型 生物学--即上皮样转化和坏死--肉芽肿的许多方面 编队还没有被探测到。对人类的全基因组关联研究 确定了几个潜在的结核病易感基因，但这些易感基因的机制 基因的作用，特别是在肉芽肿中的作用，还不是很清楚。在这里，我们将链接 建立了人类对分枝杆菌肉芽肿生物学的遗传易感基因。 我们将使用小鼠、斑马鱼和真性分枝杆菌肉芽肿的外植体模型。 直接探测肉芽肿结构、上皮样状态、免疫和药物通道以及 肉芽肿动力学。使用单细胞转录图谱和宿主和细菌 突变体，我们已经定义了一系列不同的细胞类型和转录状态， 与分枝杆菌肉芽肿的生理特性有关。我们将定义 全基因组人类遗传学研究中宿主免疫途径的改变 通过总结关键的小鼠和斑马鱼模型改变肉芽肿生物学 人类肉芽肿的特性，包括干酪性坏死和上皮样病变 转型。我们将在人类结核病肉芽肿标本中验证这些发现。最后， 我们将使用使用饱和Mtb转座子文库的全面TnSeq分析来 在结核病的背景下定义细菌和宿主之间的相互作用 肉芽肿。总体而言，这些方法将使我们对肉芽肿有更全面的了解。 生物学以及治疗干预的新机会。

Abstract Mycobacterium tuberculosis kills approximately 1.4 million people annually. People exposed to similar initial doses may have very different outcomes, ranging from clearance to active disease to subclinical or latent infection. A central structure of tuberculosis, the granuloma represents a key interface between pathogen and host, and its dynamics contribute to disease outcome. Granuloma macrophages induce expression of an unusual epithelioid program that dictates granuloma structure and infection trajectory. Due to a lack of genetically tractable animal models that fully reproduce key aspects of granuloma biology – namely, epithelioid transformation and necrosis – many aspects of granuloma formation have not been probed. Genome-wide association studies in humans have identified several potential TB susceptibility loci, but the mechanisms by which these genes act, particularly within the granuloma, are not well understood. Here we will link established human genetic susceptibility loci to the biology of mycobacterial granulomas. We will use murine, zebrafish, and explant models of bona fide mycobacterial granulomas to directly probe granuloma structure, epithelioid state, immune and drug access and granuloma dynamics. Using single cell transcriptional profiling and host and bacterial mutants, we have defined a repertoire of diverse cell types and transcriptional states that contribute to the physiological properties of the mycobacterial granuloma. We will define how alteration of host immune pathways identified in genome-wide human genetic studies alter granuloma biology through murine and zebrafish models that recapitulate key properties of human granulomas, including caseation necrosis and epithelioid transformation. We will validate these findings in human TB granuloma specimens. Finally, we will use comprehensive TnSeq profiling using saturating Mtb transposon libraries to define the interplay between bacteria and host within the context of the tuberculous granuloma. Overall, these approaches will lead to a fuller understanding of granuloma biology as well as new opportunities for therapeutic interventions.