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Factors Mediating Host Resistance to Chlamydia trachomatis

介导宿主对沙眼衣原体抵抗力的因素

基本信息

批准号：
8186804
负责人：
MICHAEL N STARNBACH
金额：
$ 48.35万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-02-01 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8186804
关键词：
Affect Alleles Amino Acids Animal Model Bacterial Infections Bacterial Sexually Transmitted Diseases Cataloging Catalogs Cell Communication Cell Culture Techniques Cells Chlamydia Chlamydia Infections Chlamydia trachomatis Chromosome Mapping Chronic Chronic Disease Cleaved cell Cytosol Development Disease Ectopic Pregnancy Engineering Enzymes Epithelium Family Genes Genetic Screening Genital system Global Change Goals Grant Growth Growth and Development function Guanosine Triphosphate Phosphohydrolases Host resistance Human Immune response Immunity In Vitro Individual Induced Mutation Infection Infertility Interferons Lead Link Maps Mass Spectrum Analysis Mediating Methods Morbidity - disease rate Mouse Strains Mus Organism Pathogenesis Pathology Pathway interactions Pelvic Inflammatory Disease Peptide Hydrolases Prevalence Proteins Proteome Proteomics Resistance Screening procedure Severities Stable Isotope Labeling Techniques Testing Time Transgenes Variant Woman Work combat cytokine genital infection hormone regulation in vivo in vivo Model indole-2,3-dioxygenase medical schools mouse model novel novel strategies pathogen response time use

项目摘要

DESCRIPTION (provided by applicant): Infection with Chlamydia trachomatis is responsible for significant morbidity throughout the world. Chronic genital infections with C. trachomatis can lead to pelvic inflammatory disease, infertility, and other complications in women. Our overall goal in this grant is to define how C. trachomatis interacts with and manipulates the mammalian host during infection. In the previous project period we focused on a large-scale forward genetic screen in mice to map variant alleles that affect resistance to C. trachomatis. We identified a family of Immunity-Related-GTPases (IRGs) as responsible for mouse resistance to C. trachomatis. However in humans, IRGs are not responsible for C. trachomatis resistance; instead humans resist infection through the expression of indole-2,3-dioxygenase (IDO). The identification of IRGs and IDO as the key differences between mice and humans with regard to IFNg-mediated resistance leads us now to propose the development of a mouse model that mimics human infection with C. trachomatis. To achieve this goal we will engineer strains of humanized mice in which the mouse-specific immune response driven IRGs is replaced with the human response that depends on IDO expression. Currently, no small animal model exists that recapitulates the chronic disease as it manifests itself in humans, particularly the prolonged or recurring infections that cause pathologies of the genital tract and infertility in humans. We have also shown that a number of C. trachomatis protein effectors are translocated into the host cell cytosol during infection where they cleave or otherwise alter host proteins. Because alteration of host cell protein stability appears to be a general strategy used by C. trachomatis, we are applying two novel screening methods called "stable isotope labeling with amino acids in cells culture" (SILAC) and "Global Protein Stability" (GPS) to analyze, on a global scale, which host proteins are perturbed during infection with C. trachomatis. Once we have identified host proteins stabilized or destabilized during C. trachomatis infection, we will test whether reducing or increasing the prevalence of these proteins in cells impairs C. trachomatis development. Although pathogen-induced alterations of the host are a key to pathogenesis, it has not previously been possible to simultaneously assess the impact of infection on individual host proteins at the scale now possible with these approaches. The methods explored in this application allow, for the first time, an appreciation of how bacterial infection globally regulates host cell proteins and pathways beyond the transcriptional level. Understanding the interaction of C. trachomatis with its human host requires a large-scale approach to catalog the changes C. trachomatis induces in host proteins during infection. Once these proteins and the pathways in which they act are understood, the impact of disrupting these Chlamydia-induced manipulations can only be appreciated using small animal models that accurately reflect the pathogenesis of human C. trachomatis infection. PUBLIC HEALTH RELEVANCE: Chlamydia trachomatis is the most common cause of bacterial sexually transmitted disease and can lead to pelvic inflammatory disease, ectopic pregnancy, infertility, and other complications in women. First, we propose to engineer mice that will, for the first time, allow us to study in mice the chronic Chlamydia infections that cause diseases such as ectopic pregnancy and infertility in humans. Second, we propose to identify the ways in which C. trachomatis manipulates the cells of humans - with the goal of disrupting these manipulations and conquering this disease.

描述(由申请人提供)：沙眼衣原体感染在世界各地造成了严重的发病率。慢性生殖器感染沙眼衣原体可导致女性盆腔炎、不孕和其他并发症。我们在这笔赠款中的总体目标是定义沙眼衣原体在感染期间如何与哺乳动物宿主相互作用并操纵宿主。在之前的项目期间，我们专注于在小鼠中进行大规模的正向遗传筛查，以定位影响对沙眼衣原体抗性的变异等位基因。我们鉴定了一个免疫相关GTP酶家族(IRGS)，该家族与小鼠对沙眼衣原体的抗性有关。然而，在人类中，IRGS并不是沙眼衣原体耐药性的原因；相反，人类通过表达吲哚-2，3-双加氧酶(IDO)来抵抗感染。在IFNG介导的耐药性方面，IRGS和IDO是小鼠和人类之间的关键差异，这使得我们现在提议开发一种模拟人类感染沙眼衣原体的小鼠模型。为了实现这一目标，我们将设计人源化小鼠品系，在这些品系中，由小鼠特异性免疫反应驱动的IRGS被依赖于IDO表达的人类反应所取代。目前，没有小动物模型可以概括这种慢性疾病在人类中的表现，特别是导致人类生殖道和不孕不育的长期或反复感染。我们还发现，一些沙眼衣原体蛋白效应物在感染期间被转移到宿主细胞胞浆中，在那里它们切割或以其他方式改变宿主蛋白。由于改变宿主细胞蛋白稳定性似乎是沙眼衣原体普遍采用的策略，我们正在应用两种新的筛选方法--细胞培养中氨基酸稳定同位素标记(SILAC)和全球蛋白稳定性(GPS)--在全球范围内分析哪些宿主蛋白在感染沙眼衣原体期间受到干扰。一旦我们确定了在沙眼衣原体感染期间稳定或不稳定的宿主蛋白，我们将测试减少或增加这些蛋白在细胞中的流行是否会损害沙眼衣原体的发育。虽然病原体诱导的宿主改变是致病机制的关键，但以前还不可能同时评估感染对单个宿主蛋白的影响，目前使用这些方法是可能的。本申请中探索的方法首次允许人们了解细菌感染是如何在转录水平之外对宿主细胞蛋白质和途径进行全球调控的。要了解沙眼衣原体与其人类宿主的相互作用，需要一种大规模的方法来记录沙眼衣原体在感染期间引起宿主蛋白的变化。一旦了解了这些蛋白质及其作用途径，只有使用准确反映人类沙眼衣原体感染发病机制的小动物模型才能评估干扰这些衣原体诱导的操作的影响。公共卫生相关性：沙眼衣原体是细菌性传播疾病的最常见原因，可导致女性盆腔炎、宫外孕、不孕和其他并发症。首先，我们提议改造小鼠，这将首次允许我们在小鼠身上研究导致人类宫外孕和不孕不育等疾病的慢性衣原体感染。其次，我们建议确定沙眼衣原体操纵人类细胞的方式，目的是破坏这些操纵并征服这种疾病。