Host Responses to Mycobacterium Infection in Zebrafish

描述（由申请人提供）：结核病是全球传染病死亡的主要原因，由于艾滋病毒流行，其后果日益严重。感染和疾病是由细胞内细菌病原体结核分枝杆菌引起的。现有的疫苗BCG具有边际效力，药物治疗时间长且复杂，导致不依从性和多重耐药细菌的快速传播。此外，在发达国家，越来越多地使用TNF阻断剂治疗风湿性和免疫性疾病，导致这些患者中结核病的活化。面对复杂的免疫反应，分枝杆菌可以在肉芽肿中无限期地存在，高度分化的巨噬细胞和其他免疫细胞紧密聚集。与大多数传染病一样，宿主免疫的不同组成部分对结核病感染和疾病的确切影响还不清楚。为了更好地了解宿主对结核感染的反应，我们将利用海洋分枝杆菌，一种与M。结核病是斑马鱼的天然病原体，引起具有人类结核病的所有基本病理特征的结核病样疾病。斑马鱼是遗传学上易处理的脊椎动物，被用作疾病和发育的模型。我们已经利用斑马鱼胚胎和幼虫的光学透明度和遗传易处理性来真实的实时监测和调节结核病的宿主-病原体相互作用。由于我们能够对感染的各个步骤进行实时成像，我们已经能够确定关键宿主免疫决定因素（例如TNF）和细菌毒力决定因素在发病过程中起作用的精确步骤。我们将联合收割机多种分子和遗传学技术来截取宿主免疫功能的表达，从而通过多种真实的时间显微镜技术来确定它们对结核病各个步骤和最终结果的影响。

DESCRIPTION (provided by applicant): Tuberculosis is the leading cause of death from infectious diseases worldwide, with increasing consequences due to the HIV epidemic. Infection and disease are caused by the intracellular bacterial pathogen Mycobacterium tuberculosis. The existing vaccine, BCG, has marginal efficacy and drug therapies are long and complex leading to noncompliance and the rapid spread of multi-drug resistant bacteria. Additionally, in the developed world, the increasing use of TNF blockade for the treatment of rheumatologic and immunological conditions has led to the activation of tuberculosis in these patients. In the face of a complex immune response, mycobacteria can persist indefinitely in granulomas, tight aggregates of highly differentiated macrophages and other immune cells. As with most infectious diseases, the exact impact of the different components of host immunity on tuberculosis infection and disease are not well understood. To better understand the host responses to tuberculous infections, we will take advantage of the fact that Mycobacterium marinum, a close relative of M. tuberculosis, is a natural pathogen of zebrafish, causing a tuberculosis-like disease with all the basic pathologic features of human tuberculosis Zebrafish are genetically tractable vertebrates that are used as models of disease and development. We have exploited the optical transparency and the genetic tractablility of zebrafish embryos and larvae to monitor and modulate host-pathogen interactions of tuberculosis in real time. Due to our ability to perform real-time imaging of the individual steps of infection, we have been able to determine the precise steps at which key host immune determinants (e.g. TNF) and bacterial virulence determinants act during pathogenesis. We will combine a variety of molecular and genetic techniques to intercept the expression of host immune functions so as to determine their impact on the individual steps and final outcomes of tuberculosis by a variety of real- time microscopy techniques.