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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：
8288686
负责人：
MICHAEL N STARNBACH
金额：
$ 46.61万
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/8288686
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.

描述（由申请人提供）：沙眼衣原体感染是全世界发病率显着的原因。沙眼衣原体慢性生殖器感染可导致女性盆腔炎、不孕症和其他并发症。我们这笔赠款的总体目标是确定沙眼衣原体在感染过程中如何与哺乳动物宿主相互作用并对其进行操纵。在上一个项目期间，我们重点关注小鼠的大规模正向遗传筛选，以绘制影响沙眼衣原体抗性的变异等位基因图谱。我们确定了免疫相关 GTP 酶 (IRG) 家族负责小鼠对沙眼衣原体的抵抗。然而，在人类中，IRG 并不导致沙眼衣原体耐药。相反，人类通过表达吲哚-2,3-双加氧酶（IDO）来抵抗感染。 IRGs 和 IDO 的鉴定是小鼠和人类之间在 IFNg 介导的耐药性方面的主要区别，这使得我们现在建议开发一种模拟人类沙眼衣原体感染的小鼠模型。为了实现这一目标，我们将设计人源化小鼠品系，其中由小鼠特异性免疫反应驱动的 IRG 被依赖于 IDO 表达的人类反应所取代。目前，尚无小动物模型能够重现人类慢性疾病，特别是导致人类生殖道病变和不孕症的长期或反复感染。我们还表明，许多沙眼衣原体蛋白效应子在感染过程中易位到宿主细胞胞浆中，在那里它们裂解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使用的一般策略，因此我们正在应用两种新颖的筛选方法，称为“细胞培养物中氨基酸稳定同位素标记”(SILAC) 和“全局蛋白稳定性”(GPS)，以在全球范围内分析哪些宿主蛋白在沙眼衣原体感染期间受到干扰。一旦我们确定了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。尽管病原体诱导的宿主改变是发病机制的关键，但以前不可能同时评估感染对单个宿主蛋白质的影响，而现在这些方法可能达到这样的规模。本申请中探索的方法首次允许了解细菌感染如何在转录水平之外全局调节宿主细胞蛋白和途径。了解沙眼衣原体与其人类宿主的相互作用需要采用大规模方法来记录沙眼衣原体在感染过程中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，就只能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来了解破坏这些衣原体诱导的操作的影响。