Molecular basis for spotted fever group Rickettsia vector competence in ticks

蜱中斑疹热群立克次体载体能力的分子基础

• 批准号: 9132155
• 负责人: Kevin R. Macaluso
• 金额: $ 37万
• 依托单位: LOUISIANA STATE UNIV A&M COL BATON ROUGE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-20 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9132155
• 关键词: Accounting; Actins; Arthropod Vectors; Arthropods; Bacterial Infections; Biological; Bovine Anaplasmosis; Case Study; Cell Communication; Cells; Cessation of life; Competence; Coupled; Development; Ecology; Ehrlichiosis; Epidemiology; Equilibrium; Fever; Goals; Health; Horizontal Disease Transmission; Human; Immune; Immune response; In Vitro; Incidence; Individual; Infection; Invertebrates; Lead; Life Cycle Stages; Maintenance; Mechanics; Mediating; Microbe; Modeling; Molecular; Mutagenesis; Nature; Organism; Pathogenicity; Population; Process; Production; Proteins; RNA; Reporting; Research; Resources; Rickettsia; Rickettsia Infections; Rickettsia rickettsii; Rocky Mountain Spotted Fever; Role; Route; Signal Transduction; Specificity; Spottings; Surface Antigens; System; Tick-Borne Diseases; Ticks; United States; Vertebrates; Vertical Disease Transmission; Virulence; Virulence Factors; Work; base; defined contribution; feeding; fitness; in vivo; invertebrate host; knock-down; microbial; mutant; novel strategies; pathogen; polymerization; promoter; research study; response; transmission process; vector; vector transmission

 DESCRIPTION (provided by applicant): Rickettsia rickettsii is the causative agent of one of the most severe tick-borne diseases in the United States. The compounding factors of rickettsial pathogenicity and route of tick transmission (horizontal and vertical) influence the ecology and epidemiology of human rickettsioses. Our long term goal is to elucidate the molecular mechanisms that are central to rickettsial transmission by ticks. The bacterial-derived molecular determinants of rickettsial infection of vertebrate cells have been described using various in vitr models. Our research indicates that rickettsial infection of tick hosts also utilizes similar processes described for infection of vertebrate host cells. However, the role of rickettsial proteins in tick infection is unknown. Likewise, although the tick actively responds to the infecting rickettsiae, the central mechanisms orchestrating the tick-derived response are not known. Thus, the experimental focus of this application emphasizes the roles of pathogenic determinants underlying rickettsial infection and the bacterial-induced alterations of the tick immune response mediating successful rickettsial colonization of the vector. The following specific aims will provide a better understanding of the constituents of rickettsial infection and transmission in arthropod vectors. 1) Defining the contribution of conserved surface cell antigens (Sca) to SFG Rickettsia infection of the tick vector. Sca proteins are known to be essential to rickettsial infection and dissemination in vertebrate cells. We hypothesize that there will be a distinct profile associated with infection of the arthropod vector. The objective of this aim is to define the role for rickettsial proteins during the infection process in the tick host. 2 To determine how the tick immune response to SFG Rickettsia correlates to vector competence. A vigorous tick response to SFG Rickettsia supports a species-specific host response to rickettsial infection. Therefore we hypothesize that a central molecule, Relish, is responsible for the balance between successful rickettsial colonization and clearance from the arthropod host. The objective of this aim is to delineate the IMD immune signaling system focusing on the production of active Relish in the tick host.

 描述（由适用提供）：立克人士立克西ii是美国最严重的tick传播疾病之一的病因。立克疾病的致病性和壁虱传播途径（水平和垂直）的复合因素影响人体力学的生态学和流行病学。我们的长期目标是阐明tick虫的立克传播至关重要的分子机制。已经使用各种VITR模型描述了脊椎动物细胞的细菌衍生的分子确定剂。我们的研究表明，tick宿主的立克感染还利用了所描述的脊椎动物宿主细胞感染的相似过程。但是，立克蛋白在壁虱感染中的作用尚不清楚。同样，尽管壁虱积极回应感染的立克西亚，但尚不清楚策划tick衍生的反应的中心机制。这是该应用的实验重点强调了危险性感染的致病决定剂的作用，以及细菌诱导的tick免疫反应的改变，介导了载体的成功风险群殖民化。以下特定目的将更好地了解节肢动物载体中风险感染和传播的构成。 1）定义组成的表面细胞抗原（SCA）对tick载体的SFG立克感染的贡献。已知SCA蛋白对于脊椎动物细胞中的立克感染和传播是必不可少的。我们假设那里 将是与节肢动物载体的感染相关的独特特征。这个目的 目的是在tick宿主的感染过程中定义立克蛋白的作用。 2确定tick免疫反应如何与矢量能力相关。对SFG立克的剧烈反应支持对立克感染的特定宿主反应。因此，我们假设一个中央分子（柔软）是导致成功的立克殖民化和从节肢动物宿主清除之间的平衡。此目的的目的是描述IMD免疫信号系统，重点是在tick宿主中产生Active Felish。