Immune mediated exocytosis of intravesicular UPEC from bladder cells

免疫介导的膀胱细胞囊内 UPEC 胞吐作用

基本信息

批准号：
9265085
负责人：
Soman N Abraham
金额：
$ 34.11万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-07 至 2018-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9265085
关键词：
Actins Adaptor Signaling Protein Antibiotics Apical Bacteria Bacterial Infections Binding Biochemical Bladder Caveolae Cell Culture Techniques Cell Survival Cell membrane Cells Complex Defense Mechanisms Detection Development Docking Drug Targeting Drug Utilization Epithelial Cells Epithelium Escherichia coli Event Exocytosis Flushing Gastrointestinal tract structure Human Immune Immune system In Vitro Infection Infectious Agent Innate Immune Response Lead Lipopolysaccharides Mediating Mediator of activation protein Mining Molecular Monomeric GTP-Binding Proteins Mus Neutrophil Infiltration Pathway interactions Pattern Recognition Play Process Proteins Proteome Reporting Research Role SNAP receptor SNAP23 gene Signal Transduction TLR4 gene Tubulin Urethra Urinary tract Urinary tract infection Urine Uropathogenic E. coli Vesicle Virulence apical membrane chemokine combat community-acquired UTI cytokine experimental study in vivo man microbial microbial colonization novel novel strategies novel therapeutics protein complex public health relevance rab GTP-Binding Proteins response target SNARE proteins trafficking

项目摘要

DESCRIPTION (provided by applicant): Urinary tract infections (UTIs) continue to be the second most common bacterial infections in man. Most of these infections are caused by uropathogenic E. coli (UPEC) that gain access into bladder epithelial cells and persist intracellularly, where they are inaccessible to the immune system and also antibiotics. Remarkably, recent in vivo and in vitro studies on infected bladder epithelial cells have revealed that these cells have a powerful capacity to exocytose large proportions of infecting UPEC without loss of cell viability. These observations point to a powerful capacity of BECs to sense intracellular bacteria and initiate bacterial exocytosis. They also suggest that if the underlying mechanism were understood, it may be possible to utilize drugs targeting this pathway to boost this cellular defense mechanism. To date, using biochemical and molecular approaches, we have determined that a key molecule responsible for recognizing intracellular UPEC is the imunosurveillance molecule, Toll like Receptor (TLR) 4. We have also identified several key mediators of bacterial exocytosis, which include components of the exocyst complex a Rab GTPase, Rab11 and the SNARE complex. Additionally, we have implicated subcellular microdomains called caveolae in this exocytic process, in the extrusion of bacteria through the plasma membrane. Here we propose to examine how these various signaling components, pathways and subcellular microdomians integrate and achieve bacterial expulsion. We plan to confirm and extend this observation in the following specific aims: (i) Elucidate how intravesicular UPEC are detected by TLR4 in BECs. (ii) Determine how cellular machinery for vesicle trafficking mediates bacterial exocytosis. (iii) Investigate the role of SNARE proteins to docking and discharge of intravesicular UPEC (IV). Identify novel bacterial expulsion components using proteome mining approach.

描述（由申请人提供）：尿路感染（UTI）仍然是人类中第二常见的细菌感染。这些感染中的大多数是由肝癌大肠杆菌（UPEC）引起的，这些大肠杆菌（UPEC）可以进入膀胱上皮细胞并持续细胞内，在那里它们无法获得免疫系统和抗生素。值得注意的是，最近对感染的膀胱上皮细胞的体内和体外研究表明，这些细胞具有强大的胞糖胞糖性能力，可以大量的感染UPEC，而不会丧失细胞活力。这些观察结果表明，BEC具有强大的能力感知细胞内细菌并启动细菌胞吐作用。他们还建议，如果了解了基本机制，则有可能利用针对该途径的药物来促进这种细胞防御机制。迄今为止，使用生化和分子方法，我们确定了负责识别细胞内UPEC的关键分子是含量的监视分子，像受体TOLL（TLR）4。我们还鉴定了几个关键的细菌胞外病介质，包括capys a Rab gtpase，rab11的细菌胞外病，其中包括复合体的组成部分。此外，我们在这种外囊肿过程中牵涉到称为小窝的亚细胞微区域，这是通过质膜挤出细菌的。在这里，我们建议研究这些各种信号成分，途径和亚细胞微Nymosians如何整合并实现细菌驱动。我们计划在以下特定目的中确认并扩展这一观察结果：（i）阐明BEC中TLR4检测到的内部内部UPEC。（ii）确定囊泡运输的细胞机制如何介导细菌胞吐作用。（iii）研究核心蛋白在插入式UPEC（IV）的对接和排放中的作用。使用蛋白质组挖掘方法鉴定新的细菌驱动组件。