Linking the behavior of individual host cells to their transcriptional signatures

描述 摘要： 在结核病中，将单个宿主细胞的行为与它们的转录签名联系起来结核病是一种巨大比例的传染病，没有有效的疫苗，而且出现了广泛耐药的菌株。我们对其发病机制的理解存在重大漏洞，阻碍了新的治疗和预防措施。我的实验室已经发展出由海洋分枝杆菌感染斑马鱼，作为探索结核病发病机制的一个强大的替代模型。斑马鱼幼体的透明度使其能够以前所未有的细节实时检查细胞运动和行为。我们在结核病发病机制的核心方面取得了令人惊讶的发现，特别是关于免疫细胞的有组织的聚集，称为肉芽肿。长期以来，这种标志性的结构被认为是关键的宿主保护元件。然而，对肉芽肿形成的详细动力学监测显示，肉芽肿被分枝杆菌转化为扩张和扩散的工具。吞噬细胞被招募到新生肉芽肿中，在那里它们吞噬即将死亡的感染细胞的内容。一部分新感染的细胞离开肉芽肿，将感染扩散到新的病灶。在这里，我建议系统地将免疫细胞的行为与其表达谱联系起来，以深入了解促进发病的宿主过程的分子蓝图。我建议使用激光捕获显微切割技术结合多个荧光细菌和宿主记者来分离参与不同运动的细胞，即迁移到新感染的细菌，从周围感染部位返回组织，迁移到形成肉芽肿，以及离开肉芽肿。然后将使用单细胞基因表达技术破译这些细胞的基因表达谱。然后，我们将用基因技术扰乱这些分子特征，以确定它们对感染的影响。这些研究应该对所有炎症性疾病的根源如细胞迁移和聚集等基本过程产生广泛的机械性理解，并提出新的宿主指导的干预策略来对抗这些疾病。

DESCRIPTION Abstract: Linking the behavior of individual host cells to their transcriptional signatures in tuberculosis Tuberculosis is an infectious disease of enormous proportions with no effective vaccine and the emergence of extensively drug resistant strains. Major holes in our understanding of its pathogenesis present roadblocks to new therapeutic and preventive interventions. My laboratory has developed zebrafish infection by Mycobacterium marinum as a powerful surrogate model for exploring tuberculosis pathogenesis. The transparency of zebrafish larvae allows real-time examination of cellular movements and behaviors in unprecedented detail. We have made surprising discoveries about central aspects of tuberculosis pathogenesis, in particular regarding the organized aggregate of immune cells called the granuloma. This hallmark structure was long thought to be a key host protective element. However, detailed kinetic monitoring of granuloma formation revealed that granulomas are converted by mycobacteria into tools for expansion and dissemination. Phagocytes are recruited to the nascent granuloma, where they phagocytose the contents of dying infected cells. A subset of newly infected cells leaves the granuloma to disseminate infection to new foci. Here I propose to systematically link the behaviors of immune cells to their expression profiles to gain insight into the molecular blueprint of the host processes that promote pathogenesis. I propose to use laser capture microdissection techniques combined with multiple fluorescent bacterial and host reporters to isolate cells engaged in distinct movements, i.e. migrating towards newly infecting bacteria, returning to tissues from peripheral infection sites, migrating to forming granulomas, and departing granulomas. The gene expression profiles of these cells will then be deciphered using single cell gene expression techniques. We will then perturb these molecular signatures with genetic techniques to determine their impact on infection. These studies should yield a broad mechanistic understanding of basic processes such as cell migration and aggregation that are at the root of all inflammatory diseases and suggest new host-directed intervention strategies to fight them.