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：
7649187
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/7649187
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）：通过受体对生物学（宿主组织）和合成底层（例如生物医学设备）的细菌特异性粘附：与吸附分子的配体相互作用（例如，血浆蛋白质，碳水化合物，碳水化合物和糖果酶）是Cass cass casc concade concade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade cascade;宿主组织入侵，毒力和感染；并可能死亡。医院感染是美国第四大死亡原因，每年约200万例（约占美国医院患者的10％）。所有此类感染中约有60-70％与植入的医疗装置有关，2002年造成45亿美元的医疗费用，每年约99,000人死亡。生物膜形成的第一步之一是通过“粘附素”（或受体）与靶表面上存在的配体分子的特异性粘附。预防这种初始粘附结合可能会消除生物膜的形成和随后的任何感染。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，旨在促进粘附并识别特定病原体的“实验室”芯片阵列的制造将需要有关细菌特异性结合事件的详细信息。试图在体外鉴定细菌受体及其固定的配体的结合表位，在（1）无法在定义且一致的方向上“呈现”配体以粘附受体表达的粘附受体表达，因为细胞的量化和环境方面的函数，是在定义且一致的方向上“呈现”配体，并且（2）缺乏详细的动力学。粘附将需要（1）控制结合配体的方向和表面密度；（2）测定细菌粘附受体的数量，亲和力和亲和力；（3）表征受体的结合相互作用：配体对 - 均在相关的生长条件和流体剪切条件下。我们的最终目标是开发一种将定义细菌粘附受体的一般方案：在其本地状态下，配体相互作用是纯和混合培养生物膜的函数。公共卫生相关性：我们的最终目标是制定一种将定义细菌粘附受体的一般方案：在其本地状态下，配体相互作用是液体剪切的函数 - 对于纯和混合培养物生物膜。在NIH支持的情况下，我们将使用葡萄球菌表皮（SE）与固定纤维蛋白（FN）结合的模型纯培养系统开发此方案。我们在这个为期两年的项目中的具体目的是：1。量化，作为流体剪切的函数，通过纤连蛋白结合受体（FNBR）与在受控方向和已知的表面密度中固定的FN的特异性结合。 2。量化Se表面上FNBR粘附受体表达的动力学，作为细菌生长条件和流体液体剪切的功能；作为浮游细胞和粘附细胞。