Functional genomics for Chlamydia

项目摘要 对于细菌病原体，开始确定微生物功能遗传性质的第一项研究是在 在全基因组范围内，通常代表着一个里程碑式的、具有高度影响力的成就。主要人体 病原体沙眼衣原体是一种细菌，这种研究在很大程度上还没有进行 由于衣原体的专性细胞内的性质和历史上的棘手性，以现代遗传操纵。 随着我们小组对衣原体的两种主要遗传工具-转座子诱变和 横向基因转移嵌合体-衣原体功能基因组研究现在是可能的。 我们的长期目标是在全球范围内定义和功能性地描述与C。沙眼衣原体 感染和发病机制。利用转座子突变和 种间嵌合体，我们建议：（i）确定衣原体感染的主要遗传决定因素，使用 临床相关的小鼠模型和体外试验;（ii）确定与宿主相关的衣原体基因 通过利用衣原体内的种间横向基因转移和衣原体的标志性宿主向性来适应 亲本菌株;（iii）通过分泌的包涵体表征宿主细胞颠覆的机制 膜效应蛋白IncU和IncS。 这些努力对于获得对独特衣原体基因在以下方面所起作用的功能性评价是必不可少的： 生物体的生长和发育，以及衣原体的进化适应， 在复杂的哺乳动物宿主中维持感染和发病机制。我们预计衣原体将作为 专性细胞内细菌的模型，因此，从这项工作中获得的知识将广泛地 扩展到在哺乳动物宿主中进化出专性细胞内生态位的其他病原体。 这些位点的鉴定对于我们理解衣原体感染的机制至关重要。 适应于哺乳动物宿主，代表了阐明主要毒力的重要一步 相关的C.沙眼病毒

PROJECT SUMMARY For bacterial pathogens, the first studies that begin to define the microorganism’s functional genetic nature on a genome-wide scale, frequently represent a landmark and highly impactful achievement. The major human pathogen Chlamydia trachomatis is a bacterium for which such studies have not been performed, in large part due to Chlamydia’s obligate intracellular nature and historical intractability to modern genetic manipulation. With the development of two major genetic tools for Chlamydia by our group—transposon mutagenesis and lateral gene transfer chimeras—functional genomic investigations in Chlamydia are now possible. Our long term goal is to globally define and functionally characterize the genetic correlates to C. trachomatis infection and pathogenesis. Using the complementary approaches of transposon mutagenesis and interspecies chimeras, we propose to: (i) identify the major genetic determinants of Chlamydia infection using a clinically relevant mouse model and in vitro assays; (ii) determine the Chlamydia genes associated with host adaptation by exploiting interspecies lateral gene transfer within Chlamydia and the signature host tropisms of the parental strains; (iii) characterize the mechanisms of host cell subversion by the secreted inclusion membrane effector proteins IncU and IncS. These efforts are essential for gaining a functional appreciation of the role that unique chlamydial genes play in the organism’s growth and development, and also Chlamydia’s evolutionary adaptation to successfully maintain infection and pathogenesis in complex mammalian hosts. We anticipate that Chlamydia will serve as a model obligate intracellular bacterium, and, therefore, the knowledge obtained from this work will broadly extend to other pathogens that have evolved an obligate intracellular niche in their mammalian hosts. Identification of these loci is critical for our understanding of the mechanisms through which Chlamydia have adapted to mammalian hosts, and represents an important step towards elucidating the major virulence correlates of C. trachomatis in humans.