Novel approaches to identify host genes required for Chlamydia pathogenesis

描述(申请人提供)：沙眼衣原体和肺炎衣原体是人类感染和疾病的重要原因。沙眼衣原体是第三世界非先天性失明的主要原因，也是西方国家性传播疾病和非先天性不孕症的主要原因。肺炎衣原体可引起多种呼吸道感染。这些疾病的异常流行和一系列，以及它们导致不孕、失明和各种慢性病的能力，使它们成为公众关注的问题 第一个重要因素。虽然感染可以用抗生素治疗，但没有一种药物的成本效益足以在不发达国家广泛消除这种疾病，疫苗的尝试也没有成功。衣原体遗传学的缺乏阻碍了对衣原体生活史和致病机制的详细了解，但通过监测衣原体对宿主细胞生物学的影响，我们现在已经在了解衣原体的发病机制方面取得了实质性进展。这些研究对确定新战略至关重要。 用于治疗和预防。所有衣原体物种都是专性的细胞内寄生虫，它们必须建立一个特权的生态位(称为包涵体的膜结合区)，以便在恶劣的细胞内环境中生存和复制。最近来自我们实验室和其他实验室的变革性研究表明，包涵体并不是一个孤立的隔间，没有与宿主的相互作用。相反，我们现在了解到，尽管衣原体的基因组很小，但它编码的蛋白质远远超过100种，分泌的蛋白质具有选择性地招募细胞器和操纵宿主细胞转运途径的功能，使衣原体能够获得必要的营养并逃避宿主免疫反应的检测。事实上，颠覆宿主细胞运输途径正在成为成功的细胞内微生物的共同主题。进一步解开这些复杂的事件将为传染病的发病机制提供重要线索，并为基础真核细胞生物学提供新的见解，其影响范围从发育生物学到癌症生物学。我们的短期目标如下：目标1.我们将研究沙眼衣原体如何利用Arf1建立独特的细胞内生态位。目的2.我们将研究一种假设，即衣原体在包涵体膜上建立一个“现场”脂质生物合成工厂，这是细菌复制、包涵体生长和稳定性所必需的。目标3。我们将使用状态 技术、生化和成像技术，以获得对衣原体包涵体融合的机制了解。总之，这些发现将增加我们对细胞内感染发病机制的基本知识。此外，它们还有可能为开发新的治疗、诊断和预防疗法确定新的靶点。

DESCRIPTION (provided by applicant): Chlamydia trachomatis and C. pneumoniae are important causes of human infections and disease. C. trachomatis , is the major cause of non-congenital blindness in the third world and a leading cause of sexually transmitted diseases and non-congenital infertility in Western countries. C. pneumoniae causes a wide range of respiratory infections. The extraordinary prevalence and array of these diseases as well as their capacity to lead to infertility, blindness, and various chronic states make them public concerns of the first importance. Although infections can be treated with antibiotics, no drug is cost-effectiv enough for widespread elimination of the disease in underdeveloped countries, and attempts at vaccines have been unsuccessful. A detailed understanding of the life cycle and the mechanisms of pathogenesis have been hindered by the lack of Chlamydia genetics, but we have now made substantial inroads into understanding Chlamydia pathogenesis by monitoring its effects on the cell biology of the host. These studies are essential to identify new strategies for treatment and prevention. All Chlamydia species are obligate intracellular parasites that must establish a privileged niche (a membrane bound compartment termed the inclusion) in order to survive and replicate in the hostile intracellular environment. Recent transformative research from our lab and others reveals that the inclusion is not an isolated compartment devoid of interactions with the host. Instead, we now understand that Chlamydia, despite its small genome size, encodes well over 100 proteins that are secreted that function to selectively recruit organelles and to manipulate host cell trafficking pathways, allowing Chlamydia to acquire essential nutrients and escape detection by the host immune response. Indeed, subversion of host cell trafficking pathways is emerging as a common theme in successful intracellular microbes. Further unraveling these complex events will yield important clues into the pathogenesis of infectious disease as well as provide novel insights into fundamental eukaryotic cell biology, with implications ranging from developmental biology to cancer biology. Our short term goals are as follows: Aim 1. We will investigate how C. trachomatis utilizes Arf1 to establish a unique intracellular niche. Aim 2. We will investigate the hypothesis that Chlamydia establishes an "onsite" lipid biosynthetic factory at the inclusion membrane that is necessary for bacterial replication and inclusion growth and stability. Aim 3. We will use state of the art biochemical and imaging techniques to gain a mechanistic understand of chlamydial inclusion fusion. Together, these findings will increase our basic knowledge of the pathogenesis of intracellular infections. In addition, they have the potential to identify new targets for the development of new therapeutic, diagnostic, and preventative therapies.