Manipulating Quorum Sensing to Control Bacterial Pathogenicity

描述(由申请人提供)：这项研究的长期目标是探索细菌用于细胞间通信的分子机制，并利用这一知识设计具有潜在治疗用途的广谱群体感应拮抗剂。在这里，我们建议对来自两种人类病原体，紫色杆菌和铜绿假单胞菌的LuxR型群体感应受体进行跨学科研究。我们建议结合合成有机化学、细菌遗传学、生物化学和X射线结晶学来鉴定和表征信号拮抗剂；这些拮抗剂将作为先导化合物用于开发旨在调节群体感应的抗菌药物。在我们的第一个目标中，我们将使用高通量筛选和体内试验来鉴定活跃在诸葛菜属中的新的群体感应拮抗剂。在我们的第二个目标中，我们将使用生化分析和X射线结晶学来研究这些拮抗剂发挥作用的机制。这项工作利用了大量的初步数据，并为努力优化在第一个目标中发现的拮抗剂奠定了基础。第三个目标是将这项工作的范围扩大到临床上重要的铜绿假单胞菌。我们提出了一系列类似的方法来识别和表征其LuxR型群体感应受体的拮抗剂。有效的拮抗剂将在小鼠感染试验中进行评估，目的是推动先导分子发展成为新的抗菌疗法。

DESCRIPTION (provided by applicant): The long-term goal of this research is to explore the molecular mechanisms that bacteria use for cell-cell communication, and to use this knowledge to design broad-spectrum quorum sensing antagonists with potential therapeutic uses. Here we propose a cross-disciplinary investigation of LuxR-type quorum-sensing receptors from two human pathogens, Chromobacterium violaceum and Pseudomonas aeruginosa. We propose to combine synthetic organic chemistry, bacterial genetics, biochemistry and x-ray crystallography to identify and characterize signaling antagonists; these antagonists will serve as lead compounds for the development of antibacterial drugs designed to modulate quorum sensing. In our first aim, we will use high-throughput screening and in vivo assays to identify novel quorum-sensing antagonists active in C. violaceum. In our second aim, we will investigate the mechanisms by which these antagonists function using biochemical assays and x-ray crystallography. This work draws upon extensive preliminary data and provides a foundation for efforts to optimize the antagonists discovered in the first aim. The third aim extends the scope of this work to the clinically important bacterium P. aeruginosa. We propose a similar array of approaches to identify and characterize antagonists of its LuxR-type quorum-sensing receptor. Potent antagonists will be evaluated in a mouse infection assay with the aim of moving forward lead molecules for development into novel anti-bacterial therapeutics.