Functional genomics for Chlamydia

项目总结 对于细菌病原体，第一批开始定义微生物功能遗传性质的研究 全基因组的规模，往往代表着一项里程碑式的、极具影响力的成就。最重要的人类 病原体沙眼衣原体是一种在很大程度上没有进行过此类研究的细菌 由于衣原体专属的细胞内性质和历史上对现代基因操作的顽固性。 随着我们团队开发了两种主要的衣原体基因工具-转座子诱变和 侧向基因转移嵌合体-衣原体的功能性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沙眼衣原体，并从功能上确定沙眼衣原体的遗传相关性 感染和发病机制。利用转座子突变和转座子突变的互补方法 对于物种间嵌合体，我们建议：(I)通过使用 临床相关小鼠模型和体外检测；(Ii)确定与宿主相关的衣原体基因 利用衣原体内物种间的侧向基因转移和沙眼衣原体的特征寄主取向进行适应 (3)分泌型包涵体颠覆宿主细胞的机制 膜效应蛋白INCU和INCS。 这些努力对于获得对独特的衣原体基因在其中所起作用的功能认识是至关重要的 有机体的生长和发育，以及衣原体的进化适应 维持复杂哺乳动物宿主的感染和发病机制。我们预计衣原体将作为 细胞内细菌的模型，因此，从这项工作中获得的知识将广泛 延伸到其他在哺乳动物宿主中进化出专有细胞内生态位的病原体。 识别这些基因座对于我们理解衣原体感染的机制是至关重要的。 适应于哺乳动物宿主，代表着向阐明主要毒力迈出的重要一步 沙眼衣原体在人类中的相关性。

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.