P. aeruginosa type III secreted effectors in corneal disease

角膜疾病中铜绿假单胞菌 III 型分泌效应子

基本信息

批准号：
8217524
负责人：
Arne Rietsch
金额：
$ 39.25万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-01-01 至 2014-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8217524
关键词：
ADP Ribose Transferases Acute Address Animal Model Bacteria Blindness Cells Complement Contact Lenses Cornea Corneal Diseases Corneal Stroma Data Development Disease Disease Progression Dose Enzymes Epithelial Cells Extended-Wear Contact Lenses Eye Infections Eye Injuries Genome Grant Immune Immune response Immune system Individual Infection Infection prevention Invaded Keratitis Lead Left Link Lung Mediating Modeling Molecular Mus Neutrophil Infiltration Organism Pathogenesis Patients Peptide Hydrolases Phenotype Phospholipase Pilum Positioning Attribute Production Properdin Proteins Pseudomonas aeruginosa Reporting Research Role Severity of illness Shapes Signal Transduction Site Staging Syringes TLR4 gene TLR5 gene Toll-like receptors Type III Secretion System Pathway Virulence Virulence Factors Visual impairment bacterial genetics chemokine combat corneal epithelium cytotoxic design extracellular in vivo killings macrophage microbial neutrophil prevent research study rho uptake

项目摘要

DESCRIPTION (provided by applicant): P. aeruginosa infections are a common cause of corneal disease associated with extended-wear contact lens use here in the US. One of the primary virulence factors P. aeruginosa uses to promote disease is its type III secretion system, a molecular syringe that allows the bacterium to directly inject effector proteins into targeted host cells. The role of type III secretion in corneal disease has not been studied extensively, but initial reports suggest that corneal disease depends on the complement of effectors being expressed by the infecting bacteria. "Cytotoxic" strains expressing the potent phospholipase ExoU rely extensively on type III secretion to promote disease, whereas ExoS-producing "invasive" strains appear to not rely on type III secretion in order to elicit corneal disease. We have revisited the role of type III secretion in the pathogenesis of corneal disease elicited by ExoS+ "invasive" isolates of P. aeruginosa. Our preliminary data demonstrates that corneal disease relies critically on type III secretion and on the two effectors ExoS and ExoT, in particular. In addition, we provide evidence that the primary role of type III secretion in corneal disease is to stave off killing by infiltrating neutrophils. Accordingly, the focus of this proposal is to determine the role of the individual enzymatic activities of ExoS and ExoT in preventing clearance by neutrophils in vivo. We will correlate these findings with experiments aimed at examining the role of ExoS and ExoT in preventing phagocytic killing by isolated primary neutrophils. We will also examine the difference in pathogenesis between ExoU-expressing "cytotoxic" and ExoS-expressing "invasive" strains of P. aeruginosa in order to determine if any differences can be directly linked to the activities of these two effectors. Understanding the role of effector proteins in corneal disease is an important step towards formulating new strategies for preventing and treating P. aeruginosa infections of the eye. PUBLIC HEALTH RELEVANCE: Pseudomonas aeruginosa is a common cause of eye infections, particularly in contact lens wearers. If left untreated these infections can result in rapid loss of vision. The bacterium injects toxic proteins into host immune cells that normally engulf and kill the invading bacteria. Our research is aimed at understanding how these toxic proteins stave off killing by the host immune system, with the hope that a better understanding of their function will lead to the design of targeted therapies to combat or prevent these infections.

描述（由申请人提供）：铜绿假单胞菌感染是美国在美国使用延长的衣服隐形眼镜相关的角膜疾病的常见原因。铜绿假单胞菌用来促进疾病的主要毒力因子之一是其III型分泌系统，这是一种分子注射器，使细菌可以将效应蛋白直接注入靶向宿主细胞。 III型分泌在角膜疾病中的作用尚未得到广泛的研究，但初始报道表明，角膜疾病取决于感染细菌所表达的效应子的补充。表达有效的磷脂酶的“细胞毒性”菌株广泛依赖于III型分泌来促进疾病，而产生外部的“侵入性”菌株似乎并不依赖于III型分泌来引起角膜疾病。我们已经重新探讨了III型分泌在Exos+铜绿假单胞菌“侵入性”分离株引起的角膜疾病发病机理中的作用。我们的初步数据表明，角膜疾病严重依赖于III型分泌，尤其是两个效应子和外观。此外，我们提供了证据表明，III型分泌在角膜疾病中的主要作用是通过浸润性嗜中性粒细胞来避免杀死。因此，该提案的重点是确定外os和Exot的个体酶活性在预防体内嗜中性粒细胞清除方面的作用。我们将将这些发现与旨在检查外Exos和Exot在防止孤立的原代嗜中性粒细胞杀死吞噬细胞中的作用的实验相关。我们还将研究表达铜绿假单胞菌的“细胞毒性”和表达外部的“侵入性”菌株之间的发病机理差异，以确定是否可以直接将任何差异与这两个效应子的活性联系起来。了解效应蛋白在角膜疾病中的作用是制定预防和治疗眼睛铜绿假单胞菌感染的新策略的重要一步。公共卫生相关性：铜绿假单胞菌是眼部感染的常见原因，尤其是在隐形眼镜佩戴者中。如果未治疗，这些感染可能会导致视力迅速丧失。细菌将有毒蛋白注射到通常吞噬并杀死入侵细菌的宿主免疫细胞中。我们的研究旨在了解这些有毒蛋白如何阻止宿主免疫系统杀死，希望更好地了解其功能，从而导致设计有针对性的疗法以对抗或防止这些感染。