Mutagenesis in Chlamydia trachomatis via allelic exchange

 描述（由申请人提供）：沙眼衣原体在美国是一个重要的健康问题。由于急性和慢性疾病的流行及其对健康和社会经济的综合影响，造成了巨大的负担。衣原体是专性细胞内寄生虫，经历复杂的发育周期。所有衣原体物种都表达III型分泌系统（T3SS），并且基于与其他表达T3SS的病原体的类比，这种机制可能对整体发病机制有显著贡献。虽然T3S与衣原体毒力的明确关联已被证明是困难的，但新获得的基因操纵衣原体的能力为进展打开了新的大门。我们目前的初步数据描述了第一次衣原体特异性自杀载体，并建议利用这种新的方法来靶向T3SS基因失活。具体而言，我们将进一步开发自杀载体系统，并直接在特定的T3S效应基因中产生无效突变。我们还提出了有条件地提高T3S能力的方法。在这些研究结束时，我们将建立分子工具，这将有利于整个衣原体研究界。此外，我们将更好地了解T3SS如何促进衣原体毒力。

 DESCRIPTION (provided by applicant): Chlamydia trachomatis represents a significant health concern in the United States. A substantial burden exists due to the prevalence and the combined health and socioeconomic impact of acute and chronic disease. Chlamydiae are obligate intracellular parasites that undergo a complex developmental cycle. All Chlamydia species express a type III secretion system (T3SS), and based on analogy with other T3SS-expressing pathogens, this mechanism likely contributes significantly to overall pathogenesis. Although definitive association of T3S with chlamydial virulence has proven difficult, the newly-acquired ability to genetically manipulate chlamydiae has opened new doors for progress. We present preliminary data describing the first ever Chlamydia-specific suicide vector and propose to leverage this new approach to target T3SS genes for inactivation. Specifically we will further develop the suicide vector system and directly create null mutations in specific T3S effector genes. We also propose approaches to conditionally inactivate T3S capability. At the end of these studies, we will have established molecular tools that will benefit the entire Chlamydia research community. In addition, we will gain a better understanding of how the T3SS contributes to chlamydial virulence.