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

• 批准号: 8597435
• 负责人: Arne Rietsch
• 金额: $ 38.47万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-01 至 2015-07-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8597435
• 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

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.

铜绿假单胞菌感染是与长衣相关的角膜疾病的常见原因 在美国，隐形眼镜在这里使用。铜绿假单胞菌用于促进疾病的主要毒力因素之一是 它的III型分泌系统，一种分子注射器，允许细菌直接注入效应蛋白 进入靶向宿主细胞。 III型分泌在角膜疾病中的作用尚未得到广泛的研究，而是 最初的报告表明，角膜疾病取决于效应子的补充 感染细菌。表达有效的磷脂酶的“细胞毒性”菌株非常依赖于III型 促进疾病的分泌物，而产生外部的“侵入性”菌株似乎并不依赖于III型 分泌以引起角膜疾病。 我们重新探讨了III型分泌在Exos+引起的角膜疾病发病机理中的作用 铜绿假单胞菌的“侵入性”分离株。我们的初步数据表明，角膜疾病严重依赖 III型分泌，尤其是在两个效应器外观上。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中性粒细胞来避免杀死。 因此，该提案的重点是确定外osos个体酶活性的作用 并防止嗜中性粒细胞在体内清除。我们将将这些发现与实验相关联 旨在检查外来者和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。 我们还将检查表达外毒性和外exos-之间的发病机理差异 表达铜绿假单胞菌的“侵入性”菌株，以确定是否可以直接链接到 这两个效应子的活动。 了解效应蛋白在角膜疾病中的作用是迈向制定的重要一步 预防和治疗眼睛的铜绿假单胞菌感染的新策略。