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

基本信息

批准号：
10546429
负责人：
George A. O'Toole
金额：
$ 38.88万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-01-22 至 2024-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10546429
关键词：
Adenylate Cyclase Agreement Behavior Binding 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 Measures Mechanics Membrane Memory Methods Microbial Biofilms Modeling Molecular Molecular Genetics Pathway interactions Phase Pilum Population Production Pseudomonas aeruginosa Reporter Reporting Resolution Respiratory Disease Role Second Messenger Systems Series Signal Transduction Surface Swimming System Testing Time Traction Translating Work antibiotic tolerance appendage behavioral phenotyping burn wound cell behavior cell motility cost cystic fibrosis infection experimental study genetic approach member microbial community monomer novel prevent protein protein interaction receptor residence single cell analysis transmission process ventilator-associated pneumonia

项目摘要

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.

项目概要生物膜是表面附着的微生物群落，造成了重大的临床问题，部分原因是生物膜细胞对抗生素具有高度耐受性。与设备相关的生物膜感染造成的成本超过 10 亿美元每年。此外，致命的铜绿假单胞菌生物膜感染在囊性纤维化（CF）和其他呼吸道疾病。需要更好地了解微生物群落的形成方式，以预防或逆转生物膜形成。我们报道的研究表明，铜绿假单胞菌可以通过途径需要 IV 型菌毛 (TFP) 和产生第二个的膜结合信号复合物信使坎普。我们最近的研究结果是使用单细胞分辨率对整个群落进行细胞追踪，与 cAMP 报告基因相结合得出我们的中心假设：表面传感基于 cAMP-TFP- 基于记忆，并且不会通过逐渐增加附着细胞及其表面停留时间而发生细胞内cAMP。相反，表面诱导细胞内 cAMP 水平的相移时间波，并且 TFP活性构成了表面的“记忆”。这段记忆是多代人的，而且令人惊讶强大，允许表面暴露细胞的浮游后代适应表面并增加表面细胞群在附着时比其祖先快几个数量级。要理解这个关键活动中，我们将使用群体水平和单细胞分析，并结合分子遗传学方法在严格的生物物理理论框架内，探索这些最早的机制基础生物膜形成过程中的事件。我们将 (1) 检验表面接触引起相移波的假设 cAMP 水平和 TFP 活性编码表面记忆，允许表面适应极大地改变了表面细胞的行为，(2) 检验表面传感通过以下方式传输的假设：整合 TFP 机械收缩、PilA 内膜动力学以及内膜的形成 cAMP 信号传导所需的膜 PilJ-PilA 复合物。完成拟议的研究后，我们将已经建立了铜绿假单胞菌感知并不可逆地附着在表面上的机制。给定不可逆的附着是生物膜形成的第一步，我们的工作揭示了一个关键方面细菌生物学。