Effects of Shear on Specific Adhesion Receptor Expression and Binding in the Bact

剪切对细菌中特异性粘附受体表达和结合的影响

基本信息

批准号：
7860401
负责人：
James D. Bryers
金额：
$ 7.33万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-06-05 至 2011-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7860401
关键词：
Address Adherence Adhesions Adsorption Affect Affinity Albumins American Avidity Bacteria Bacterial Adhesins Bacterial Adhesion Benign Binding Biological Biological Models Biosensor Carbohydrates Cardiovascular system Cause of Death Cell Wall Cell surface Cells Cessation of life Chemistry Collagen Cues Data Development Devices Diagnostic Diffusion Ecosystem Electrostatics Epitopes Event Exposure to Extracellular Matrix Proteins Fibrinogen Fibronectin Receptors Fibronectins Figs - dietary Film Genes Genitourinary system Glycoconjugates Glycoproteins Goals Grant Growth Hospitals Human Immunoglobulins Implant In Vitro Infection Kinetics Ligand Binding Ligands Liquid substance Macor Mammalian Cell Mediating Medical Medical Device Microbial Biofilms Modeling Molecular Mucous Membrane Nose Nosocomial Infections Nutrient Organism Patients Physiological Physiology Plasma Plasma Proteins Polysaccharides Prevention Process Proteins Protocols documentation Research Signal Transduction Site Skin Staphylococcus epidermidis Surface System Terrorism Text Tissues Titanium United States National Institutes of Health Vaccines Virulence Virulence Factors Virulent Vitronectin Work adhesion receptor base cell growth cost density design implantable device inhibitor/antagonist macromolecule micro-total analysis system pathogen polyether urethane prevent public health relevance receptor receptor binding receptor expression shear stress small molecule wound

项目摘要

DESCRIPTION (provided by applicant): Bacterial specific adhesion to biological (host tissue) and synthetic substrata (e.g., biomedical devices) through receptor:ligand interactions with adsorbed molecules (e.g., blood plasma proteins, carbohydrates, and glycoconjugates) is a critical first step in a cascade of processes leading to biofilm formation; host tissue invasion, virulence and infection; and potentially death. Nosocomial infections are the fourth leading cause of death in the U.S. with >2 million cases annually (or ~10% of American hospital patients). About 60-70% of all such infections are associated with an implanted medical device causing >$4.5 billion medical costs in 2002 and ~99,000 deaths annually. One of the first steps in biofilm formation is the specific adhesion of bacterial cells via `adhesins' (or receptors) to ligand molecules present on the target surface. Prevention of this initial adherence binding could potentially abrogate biofilm formation and any subsequent infection. Development of small molecule therapies or vaccines to prevent specific adhesion to biomedical devices or, conversely, the fabrication of "lab-on-a-chip" arrays designed to promote adhesion and identify specific pathogens will require detailed information on bacterial specific binding events, under pertinent hydrodynamic conditions. Attempts to identify binding epitopes on both bacterial receptors and their immobilized ligands, in vitro, are complicated by (1) the inability to "present" the ligand in a defined and consistent orientation and (2) lack of detailed kinetics for adhesion receptor expression, as a function of cell growth and ambient hydrodynamic conditions, Based on prior work, we hypothesize that to precisely quantify bacterial specific adhesion will require (1) controlling the orientation and surface density of the binding ligand; (2) determination of the number, affinity and avidity of bacterial adhesion receptors; and (3) characterization of the binding interactions of the receptor:ligand pair - all under pertinent conditions of growth and fluid shear. Our ultimate goal is to develop a general protocol that will define bacterial adhesion receptor:ligand interactions, in their native states as a function of fluid shear - for both pure and mixed culture biofilms. PUBLIC HEALTH RELEVANCE: Our ultimate goal is to develop a general protocol that will define bacterial adhesion receptor:ligand interactions, in their native states as a function of fluid shear - for both pure and mixed culture biofilms. With NIH support, we will develop this protocol using the model pure culture system of Staphylococcus epidermidis (SE) binding to immobilized fibronectin (FN). Our specific aims in this two-year project will be: 1. Quantify, as a function of prevailing fluid shear, the specific binding of SE strains via fibronectin binding receptors (FNBR) to FN immobilized in a controlled orientation and known surface density. 2. Quantify the kinetics of FNBR adhesin receptor expression on SE surfaces, as function of bacterial growth condition and prevailing fluid shear; both as planktonic and adherent cells.

描述（由申请人提供）：细菌通过受体：配体与吸附分子（例如血浆蛋白、碳水化合物和复合糖）的相互作用对生物（宿主组织）和合成基质（例如生物医学装置）进行特异性粘附，这是关键的第一步在导致生物膜形成的一系列过程中；宿主组织的侵袭、毒力和感染；以及潜在的死亡。医院感染是美国第四大死亡原因，每年有超过 200 万例病例（约占美国医院患者的 10%）。所有此类感染中约 60-70% 与植入医疗设备有关，2002 年造成的医疗费用超过 45 亿美元，每年约有 99,000 人死亡。生物膜形成的第一步是细菌细胞通过“粘附素”（或受体）与目标表面上存在的配体分子特异性粘附。防止这种最初的粘附结合可能会消除生物膜的形成和任何后续的感染。开发小分子疗法或疫苗以防止对生物医学设备的特异性粘附，或者相反，制造旨在促进粘附和识别特定病原体的“芯片实验室”阵列将需要有关细菌特异性结合事件的详细信息，相关的水动力条件。在体外鉴定细菌受体及其固定配体上的结合表位的尝试因以下原因而变得复杂：(1) 无法以明确且一致的方向“呈现”配体；(2) 缺乏粘附受体表达的详细动力学，作为细胞生长和环境流体动力学条件的函数，基于先前的工作，我们假设要精确量化细菌特异性粘附需要（1）控制结合配体的方向和表面密度； (2)细菌粘附受体的数量、亲和力和亲合力的测定； (3) 受体：配体对的结合相互作用的表征——所有这些都在相关的生长和流体剪切条件下进行。我们的最终目标是开发一个通用方案，定义细菌粘附受体：配体相互作用，在其天然状态下作为流体剪切的函数 - 对于纯培养物和混合培养物生物膜。公共健康相关性：我们的最终目标是开发一个通用方案，定义细菌粘附受体：配体相互作用，在其天然状态下作为流体剪切的函数 - 对于纯培养物和混合培养物生物膜。在 NIH 的支持下，我们将使用表皮葡萄球菌 (SE) 与固定化纤连蛋白 (FN) 结合的模型纯培养系统来开发该协议。我们在这个为期两年的项目中的具体目标是： 1. 作为主要流体剪切的函数，量化 SE 菌株通过纤连蛋白结合受体 (FNBR) 与以受控方向和已知表面密度固定的 FN 的特异性结合。 2. 量化 SE 表面 FNBR 粘附素受体表达的动力学，作为细菌生长条件和主要流体剪切的函数；作为浮游细胞和贴壁细胞。