Probing the role of sensory cues in the regulation of bacterial biofilm development

项目摘要 细菌有一种非凡的能力，可以感知各种刺激，并做出调节决定，以引起适当的反应。 反应我们的研究项目的目标是了解这种细胞的分子基础， 在三维（3D）结构化社区的发展过程中， 生物膜生物膜代表了主要的细菌生活方式，并且对于抗菌剂耐受性、毒力、 和环境持久性在不同的病原体，包括多药耐药铜绿假单胞菌。 P.铜绿假单胞菌作为一个理想的临床相关的模型系统，为我们的基础研究，在生物膜，因为它 适应并在多种环境中形成生物膜，并且该生物膜中的生物膜基质组分 有机体的特性很好。这项研究的首要目标是确定细菌如何解码 并在生物膜形成过程中整合感官线索--物理的、化学的和生物的 周期我的工作表明，通过细菌光敏色素BphP感光体检测到的光（物理线索） 介导的光感应和通过RhlR介导的群体感应检测的群体密度（生物线索 抑制生物膜。此外，我们还发现，养分的可利用性（化学线索）与 群体感应（生物线索）来控制生物膜基质成分和结构。在接下来的五年里， 我们将以我们最近的发现为基础，使用多学科的方法，结合细菌遗传学， 分子生物学，生物化学，荧光显微镜，数学建模，结构生物学和 基因组规模的研究，以确定在不断增长的生物膜的背景下的感觉信号。首先，我们会调查 光如何在异质生物膜中被局部和全局感知，并表征BphP光传感 信号系统，以了解铜绿假单胞菌（项目1）的光传感调节。二是 剖析CbrA-Crc营养传感途径，了解营养物质的可用性如何控制生物膜的发展 （项目2）。第三，我们将描述RhlR介导的群体感应抑制生物膜的不同方式， （项目3）。最后，我们将定义来自两个或更多个不同的感觉信号通路的信息是如何 结合在集体行为的控制中（项目4）。我们的研究将建立一个广泛相关的 理解如何提取和整合不同感官输入中编码的信息的框架， 推动集体行为-知识对于设计成功的综合战略至关重要， 以抑制生物膜和用于开发新的治疗干预。

PROJECT SUMMARY Bacteria have a remarkable ability to sense diverse stimuli and make regulatory decisions to elicit an appropriate response. The objective of our research program is to understand the molecular underpinnings of this cellular decision-making process during the development of three dimensional (3D) structured communities called biofilms. Biofilms represent a predominant bacterial lifestyle and are crucial for antimicrobial tolerance, virulence, and environmental persistence in diverse pathogens including multi-drug resistant Pseudomonas aeruginosa. P. aeruginosa serves as an ideal clinically relevant model system for our basic research in biofilms because it adapts to and forms biofilms in a wide variety of environments, and the biofilm matrix components in this organism are well characterized. The overarching goal of the proposed research is to define how bacteria decode and integrate sensory cues – physical, chemical and biological – over the course of the biofilm development cycle. My work has shown that light (physical cue) detected via bacteriophytochrome BphP photoreceptor mediated photo sensing and population density (biological cue) detected via RhlR mediated quorum sensing represses biofilms. Furthermore, we have discovered that nutrient availability (chemical cue) converges with quorum sensing (biological cue) to control biofilm matrix components and architecture. Over the next five years, we will build on our recent discoveries and use a multidisciplinary approach combining bacterial genetics, molecular biology, biochemistry, fluorescence microscopy, mathematical modeling, structural biology and genome-scale studies to define sensory signaling in the context of a growing biofilm. First, we will investigate how light is perceived locally and globally in heterogenous biofilms and characterize the BphP photo-sensing signaling system to understand the regulation of photo sensing in P. aeruginosa (Project 1). Second, we will dissect the CbrA-Crc nutrient-sensing pathway to learn how nutrient availability controls biofilm development (Project 2). Third, we will delineate the different ways by which RhlR mediated quorum sensing represses biofilm formation (Project 3). Finally, we will define how information from two or more distinct sensory signaling pathways are combined in the control of collective behaviors (Project 4). Our research will establish a broadly relevant framework for understanding how information encoded in diverse sensory inputs is extracted and integrated to drive collective behaviors – knowledge that is crucial for designing successful synthetic strategies to enhance or to inhibit biofilms and for developing novel therapeutic interventions.