Role of mechanosensation in P. aeruginosa virulence and colonization

机械感觉在铜绿假单胞菌毒力和定植中的作用

基本信息

批准号：
9232992
负责人：
Albert Siryaporn
金额：
$ 10.61万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2018-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9232992
关键词：
Adhesions Affect Antibiotic Therapy Antibiotics Atomic Force Microscopy Bacteria Bacterial Infections Biological Assay Biophysics Caenorhabditis elegans Cell surface Cells Cellular biology Chemicals Cues Data Development Employee Strikes Engineering Environment Foundations Future Genes Genetic Transcription Goals Gram-Negative Bacteria Hospitals Immunocompromised Host Infection Kinetics Liquid substance Measures Mechanical Stimulation Mechanics Microarray Analysis Microbial Biofilms Microbiology Microfluidic Microchips Microfluidics Modeling Molecular Biology Monitor Mus Nutrient Organism Pathway interactions Phase Physics Pilum Pneumonia Process Property Proteins Pseudomonas aeruginosa Reporter Role Sepsis Signal Transduction Signal Transduction Pathway Specificity Stimulus Surface Swimming Testing Therapeutic Urinary tract infection Virulence Virulence Factors Virulent Work Wound Infection base blind cell motility cell type comparative cystic fibrosis patients experimental study fluid flow gene repression insight interdisciplinary approach killings laser tweezer mechanical force mechanotransduction mutant novel novel strategies pathogen physical science public health relevance quorum sensing response shear stress

项目摘要

DESCRIPTION (provided by applicant: The Gram-negative bacterium Pseudomonas aeruginosa is an opportunistic pathogen that infects an exceptionally broad range of host cell types. The mechanisms that regulate the broad host specificity of P. aeruginosa host remain largely unknown. Previous studies of how P. aeruginosa regulates expression of its virulence factors have largely focused on chemical cues such as quorum sensing and nutrient availability. The goal of my work is to investigate whether mechanical cues regulate P. aeruginosa virulence and colonization. During the infection process, bacteria encounter a variety of mechanical forces such as adhesion forces when bacteria attach to host cells and directional forces in liquid environments. Detecting mechanical cues in host organisms could thus be part of an infection strategy. My preliminary data show that P. aeruginosa activates virulence genes as cells transition from swimming to adhesion on abiotic surfaces. In addition, my previous work shows that P. aeruginosa responds to the mechanical effects of fluid flow with striking changes in surface motility and surface adhesion, which are determining factors in host colonization. Based on these findings, I hypothesize that specific mechanical cues activate signal transduction pathways that regulate colonization and virulence in P. aeruginosa cells. In this study, I will characterize how mechanical stimuli regulate virulence and colonization using an interdisciplinary approach that combines molecular biology, cell biology, mechanical engineering, and physics. I have enlisted guidance from Dr. Howard Stone, who has expertise in fluid dynamics, Dr. Joshua Shaevitz, who has expertise in bacterial biophysics, and Dr. George O'Toole, who has expertise in P. aeruginosa virulence and biofilm formation. I will test the hypothesis that P. aeruginosa virulence is activated by mechanical cues during the transition from swimming to adhesion on mammalian host cell surfaces. Using optical tweezers, microfluidics, and atomic force microscopy, I will test whether direct mechanical stimulation of cells is sufficient to activate virulence. I will also characterize the P. aeruginosa transcriptionl response to mechanical stimulation by fluid flow and the effect of fluid flow on colonization of P. aeruginosa cells on host cells surfaces. Finally, I will test the hypothesis that the proteins PilX and PilY1 are the mechanosensors that regulate virulence and colonization. Altogether, these experiments will determine the role of mechanical forces in the bacterial infection process. These insights will provide a foundation for developing novel approaches to antibiotic therapies that perturb the ability of P. aeruginosa to infect a broad range of host organisms. In addition, this study would represent one of the first attempts to characterize mechanosensation as a regulator of virulence and colonization in bacteria.

描述（由申请人提供：革兰氏阴性细菌铜绿假单胞菌是一种机会性病原体，可感染极其广泛的宿主细胞类型。调节铜绿假单胞菌宿主的广泛宿主特异性的机制仍然很大程度上未知。之前关于铜绿假单胞菌如何感染的研究铜绿假单胞菌调节其毒力因子的表达主要集中在化学线索上，例如群体感应和营养可用性。我的工作目标是研究机械线索是否存在。调节铜绿假单胞菌毒力和定植过程中，细菌会遇到各种机械力，例如细菌附着到宿主细胞时的粘附力和液体环境中的定向力，因此检测宿主生物体中的机械线索可能是感染的一部分。我的初步数据表明，当细胞从游动过渡到非生物表面粘附时，铜绿假单胞菌会激活毒力基因。此外，我之前的工作表明，铜绿假单胞菌对流体流动的机械效应做出反应。表面运动性和表面粘附力发生显着变化，这是宿主定植的决定因素。基于这些发现，我假设特定的机械信号激活调节铜绿假单胞菌细胞定植和毒力的信号转导途径。在这项研究中，我将采用结合分子生物学、细胞生物学、机械工程和物理学的跨学科方法来描述机械刺激如何调节毒力和定植。我得到了具有流体动力学专业知识的 Howard Stone 博士、具有细菌生物物理学专业知识的 Joshua Shaevitz 博士和具有铜绿假单胞菌毒力和生物膜形成专业知识的 George O'Toole 博士的指导。我将检验这样的假设：在哺乳动物宿主细胞表面从游动到粘附的转变过程中，铜绿假单胞菌毒力是由机械信号激活的。我将使用光镊、微流体和原子力显微镜来测试对细胞的直接机械刺激是否足以激活毒力。我还将描述铜绿假单胞菌对流体流动机械刺激的转录反应以及流体流动对铜绿假单胞菌定植的影响。宿主细胞表面的铜绿假单胞菌细胞。最后，我将检验蛋白质 PilX 的假设 PilY1 和 PilY1 是调节毒力和定植的机械传感器。总而言之，这些实验将确定机械力在细菌感染过程中的作用。这些见解将为开发抗生素疗法的新方法奠定基础，这些方法会干扰铜绿假单胞菌感染广泛宿主生物的能力。此外，这项研究将是首次尝试将机械感觉表征为细菌毒力和定植的调节剂。