Exploratory Studies of lp17-encoded Genetic Factors Important for Tick Colonization by the Lyme Disease Spirochete

对莱姆病螺旋体蜱定殖重要的 lp17 编码遗传因子的探索性研究

• 批准号: 10188065
• 负责人: Troy Michael Bankhead
• 金额: $ 19.13万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-16 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10188065
• 关键词: Animals; Area; Arthritis; Arthropods; Black-legged Tick; Borrelia burgdorferi; Carditis; Cell Density; Chemicals; Chromosomes; Clinical; Clonal Deletion; Complement; Complex; Data; Development; Environment; Gene Expression; Gene Expression Regulation; Generations; Genes; Genetic; Genome; Global Change; Goals; Health; Human; Immunofluorescence Immunologic; Impairment; In Vitro; Infection; Infection prevention; Intercistronic Region; Investigation; Knowledge; Larva; Lead; Life Cycle Stages; Lyme Disease; Lyme Infection; Maps; Measures; Mediating; Midgut; Mission; Molting; Mus; Nature; Neurologic; North America; Nymph; Parasites; Phenotype; Plasmids; Public Health; Publishing; RNA; Regulation; Research; Rest; Role; Salivary Glands; Starvation; System; Temperature; Testing; Therapeutic; Tick-Borne Diseases; Ticks; United States National Institutes of Health; Untranslated RNA; Vaccines; Work; base; cohort; differential expression; disability; effective therapy; enzootic; feeding; genetic approach; host colonization; human pathogen; mutant; new therapeutic target; novel; pathogen; prevent; tick feeding; tick transmission; time use; transmission process; vaccine development; vector tick

Project Summary Borrelia burgdorferi is an obligate parasite, and is maintained in nature through a complex cycle involving both a tick and mammalian host. The transition between these two very different host types requires the ability to rapidly adapt through changes in gene expression. B. burgdorferi possesses a segmented genome comprised of a single linear chromosome and upwards of 23 linear and circular plasmids. Previous studies have provided information on a number of genes that may be differentially expressed under conditions intended to mimic that of the vertebrate or arthropod host. However, investigation has only just begun to elucidate the importance of lp17 for colonization of the host and tick vector by B. burgdorferi. Published and preliminary work in our lab has recently shown that a small non-coding RNA and the bbd21 gene encoded on lp17 have roles in the regulation of genes important for host adaptation. Despite these advances, there remains a fundamental gap in our understanding of the role and function of many genes for adaptation to the tick vector. Our long-term goal is to identify and characterize factors necessary for B. burgdorferi adaptation to the tick and mammalian host environments. The overall objective of this application is to identify lp17-resident genes required for colonization of the tick vector by B. burgdorferi. Based on published work and preliminary data, the central hypothesis of this proposal is that a number of lp17-resident genes of B. burgdorferi are important for tick colonization, survival, and/or transmission. The rationale for the proposed research is that these identified factors will represent potential targets for the development of a vaccine and/or therapeutics against human infection by the Lyme disease pathogen, as well as targeting factors critical for its enzootic life cycle. Thus, the proposed research is relevant to that part of NIH’s mission that pertains to developing fundamental knowledge that will potentially help to reduce the burdens of human illness and disability. Guided by cited work and preliminary data, our hypothesis will be tested by pursuing the following specific aim and two sub aims: 1) Determine the requirement of lp17-resident genes for tick acquisition, survival, and/or transmission of Bb. Under the first sub aim, Ixodes scapularis tick larvae will first be infected with either wild type or lp17 mutant B. burgdorferi clones using a novel continuous flow tick feeding system to identify genetic regions of lp17 important for tick acquisition and transstadial survival. Under the second sub aim, nymphal ticks infected with either a lp17 mutant or wild type control will be allowed to feed for a given time using our tick feeding system, after which the bacterial burden in isolated midgut and salivary glands will be assessed via immunofluorescence analysis. When applied, the results from the proposed studies are expected to ultimately lead to new control measures to disrupt the pathogen’s enzootic cycle and prevent infection by the Lyme disease spirochete.

项目概要 伯氏疏螺旋体是一种专性寄生虫，通过复杂的循环在自然界中维持 涉及蜱和哺乳动物宿主。这两种截然不同的主机类型之间的转换需要 通过基因表达的变化快速适应的能力。伯氏疏螺旋体 (B. burgdorferi) 具有分段的 基因组由一条线性染色体和超过23个线性和环状质粒组成。以前的 研究提供了一些在条件下可能差异表达的基因的信息 旨在模仿脊椎动物或节肢动物宿主。然而调查才刚刚开始 阐明 lp17 对于伯氏疏螺旋体定植宿主和蜱载体的重要性。已发表和 我们实验室的初步工作最近表明，一个小的非编码RNA和编码的bbd21基因 lp17 在调节对宿主适应很重要的基因中发挥作用。尽管取得了这些进步，但仍有 我们对许多适应环境的基因的作用和功能的理解仍然存在根本差距 刻度向量。我们的长期目标是确定和表征伯氏疏螺旋体适应的必要因素 蜱和哺乳动物宿主环境。该应用程序的总体目标是识别 lp17 驻留者 伯氏疏螺旋体蜱载体定植所需的基因。基于已发表的工作和初步 数据，该提案的中心假设是伯氏疏螺旋体的许多 lp17 驻留基因是 对于蜱的定植、生存和/或传播很重要。拟议研究的理由是 这些已确定的因素将代表开发疫苗和/或疗法的潜在目标 抵抗莱姆病病原体的人类感染，以及对其地方性生活至关重要的目标因素 循环。因此，拟议的研究与 NIH 使命的一部分相关，即开发 可能有助于减轻人类疾病和残疾负担的基础知识。 在引用的工作和初步数据的指导下，我们的假设将通过以下内容进行检验 具体目标和两个子目标：1) 确定蜱虫获取 lp17 驻留基因的要求， Bb 的存活和/或传播。在第一个子目标下，肩胛硬蜱幼虫将首先被感染 使用新型连续流蜱饲喂系统与野生型或 lp17 突变伯氏疏螺旋体克隆 确定 lp17 的遗传区域对于蜱的获得和跨斯塔生存很重要。在第二个子下 目标是，感染 lp17 突变体或野生型对照的若虫蜱将被允许在给定时间内进食 使用我们的蜱饲喂系统，之后分离的中肠和唾液腺中的细菌负荷将 通过免疫荧光分析进行评估。应用后，预期研究结果 最终导致新的控制措施，以破坏病原体的地方性循环并防止感染 莱姆病螺旋体。