Surface sensing, memory, and motility control in biofilm formation

生物膜形成中的表面传感、记忆和运动控制

• 批准号: 10080709
• 负责人: George A. O'Toole
• 金额: $ 38.98万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-22 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10080709
• 关键词: Adenylate Cyclase; Behavior; Biology; Biomass; Biophysics; Cell Lineage; Cell surface; Cells; Chemotaxis; Clinical; Communities; Complex; Coupled; Cyclic AMP; Cystic Fibrosis; Data; Detection; Devices; Disease; Event; Genealogical Tree; Generations; Genetic study; Glues; Health Care Costs; Infection; Lead; Lung diseases; Measures; Mechanics; Membrane; Memory; Methods; Microbial Biofilms; Modeling; Molecular; Molecular Genetics; Pathway interactions; Phase; Pilum; Population; Production; Pseudomonas aeruginosa; Reporter; Reporting; Resolution; Role; Second Messenger Systems; Series; Signal Transduction; Surface; System; Testing; Time; Translating; Work; antibiotic tolerance; appendage; base; behavioral phenotyping; burn wound; cell behavior; cell motility; cost; cystic fibrosis infection; experimental study; genetic approach; microbial community; monomer; novel; prevent; protein protein interaction; receptor; residence; single cell analysis; ventilator-associated pneumonia

PROJECT SUMMARY Biofilms are surface-attached microbial communities that pose a significant clinical problem, in part because biofilm cells are highly antibiotic tolerant. Device-related biofilm infections incur costs of >1 billion dollars annually. Moreover, lethal Pseudomonas aeruginosa biofilm infections are common in cystic fibrosis (CF) and other respiratory diseases. A better understanding of how microbial communities form is required to prevent or reverse biofilm formation. Our reported studies show that P. aeruginosa can detect surface contact via a pathway requiring Type IV pili (TFP) and a membrane-bound signaling complex that generates the second messenger cAMP. Our recent findings using cell tracking of entire communities at single-cell resolution and combined with a cAMP reporter lead to our Central Hypothesis: Surface sensing is predicated on cAMP-TFP- based memory, and does not occur by gradually increasing surface residence times of attached cells and their intracellular cAMP. Rather, the surface induces phase-shifted temporal waves of intracellular cAMP levels and TFP activity that constitute a `memory' of the surface. This memory, which is multigenerational and surprisingly robust, allows planktonic descendants of surface-exposed cells to adapt to the surface and increase surface cell populations orders of magnitude faster than their ancestors upon attachment. To understand this pivotal event, we will use population-level and single-cell analyses, combined with molecular genetic approaches within a rigorous biophysical theoretical framework, to explore the mechanistic underpinnings of these earliest events in biofilm formation. We will (1) test the hypothesis that surface contact induces phase-shifted waves of cAMP levels and TFP activity that encode a memory of the surface, allowing for surface adaptation that drastically modifies behavior of cells on surfaces, (2) test the hypothesis that surface sensing is transmitted via integrating TFP mechanical retraction, inner membrane dynamics of PilA, and the formation of an inner membrane PilJ-PilA complex required for cAMP signaling. Upon completion of the proposed studies, we will have established the mechanism by which P. aeruginosa senses and irreversibly attaches to a surface. Given that irreversible attachment is the first committed step in biofilm formation, our work uncovers a key aspect of bacterial biology.

项目摘要 生物膜是构成重大临床问题的表面附着的微生物群落，部分原因是 生物膜细胞具有高度抗生素的耐受性。与设备有关的生物膜感染产生了> 10亿美元 每年。此外，铜绿假单胞菌生物膜感染在囊性纤维化（CF）和 其他呼吸系统疾病。更好地了解如何预防微生物群落形成或 反向生物膜形成。我们报道的研究表明，铜绿假单胞菌可以通过A检测表面接触 需要IV型PILI（TFP）和膜结合信号复合物的途径，生成第二个 信使营。我们最近在单细胞分辨率和 结合一个营地记者，导致我们的中心假设：表面传感是基于营地-TFP- 基于内存，并且不会通过逐渐增加附着的细胞的表面停留时间而发生 细胞内营地。相反，表面诱导细胞内营地水平的相移颞波和 构成表面“记忆”的TFP活动。这种记忆，是多代的，令人惊讶的是 强大的，允许表面暴露细胞的浮游后代适应表面并增加表面 附着后，细胞种群的数量级比其祖先快。了解这个关键 事件，我们将使用种群级和单细胞分析，结合分子遗传方法 在严格的生物物理理论框架内，探索最早的机械基础 生物膜形成的事件。我们将（1）检验以下假设：表面接触引起相移波 编码表面记忆的营地水平和TFP活动，可以进行表面适应 （2）测试表面传感通过 整合TFP机械缩回，pila的内膜动力学以及内部的形成 cAMP信令所需的膜Pilj-Pila复合物。拟议的研究完成后，我们将 已经建立了铜绿假单胞菌感官并不可逆地附着在表面上的机制。给出 不可逆转的依恋是生物膜形成的第一步，我们的作品揭示了一个关键方面 细菌生物学。