Characterization of C02 Sensing and Regulatory Response in Borrelia burgdorferi

伯氏疏螺旋体中CO2感应和调节反应的表征

基本信息

批准号：
8715687
负责人：
Jenny A. Hyde
金额：
$ 7.28万
依托单位：
TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-08-06 至 2017-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8715687
关键词：
Adenylate Cyclase Antibiotics Arthritis Arthropod Vectors Arthropods Bacillus anthracis Bacteria sigma factor KatF protein Bicarbonates Binding Biochemical Bioluminescence Blood Borrelia Borrelia burgdorferi Borrelia oxidative stress regulator Carbon Dioxide Cardiac Carditis Case Study Cell Respiration Characteristics Complex Connective Tissue Cues Cyclic AMP Data Dermis Detection Diagnosis Disease Emerging Communicable Diseases Environment Exanthema Floods Fluorescence Gene Expression Gene Proteins Genes Genetic Transcription Goals Heart Homologous Gene In Vitro Individual Infection Infectious Agent Integration Host Factors Ixodes Joints Knowledge Life Life Cycle Stages Light Localized Disease Luciferases Lyme Disease Measures Midgut Modality Molecular Mus Neurologic North America Order Spirochaetales Organism Oxidative Stress Oxygen Parents Pathogenesis Pathology Pathway interactions Patients Phase Post-Transcriptional Regulation Process Production Promoter Regions Protein Biosynthesis Proteins Proteomics Public Health Publishing Recombinants Regulation Regulatory Pathway Regulon Relative (related person)Role Salivary Glands Signal Pathway Signal Transduction System Technology Temperature Testing Tick-Borne Diseases Ticks Time Tissues Toxin Transcript Transcription Coactivator Transcriptional Regulation Travel United States Vaccines Virulence Virulence Factors Vision Work combat design enzootic erythema migrans expectation feeding flu gel electrophoresis in vivo in vivo imaging member mutant novel novel vaccines pathogen pathogenic bacteria prevent promoter public health relevance response therapeutic development therapeutic target transcriptomics vaccine candidate

项目摘要

DESCRIPTION (provided by applicant): It is well established that Borrelia burgdorferi, the etiologic agent of Lyme disease, adapts to distinct environments as it moves between an arthropod vector and mammalian hosts. B. burgdorferi modulates gene expression and protein synthesis in response to environmental cues temperature, pH, O2, CO2 and other unknown host factors. CO2 is a byproduct of cellular respiration and levels fluctuate within the mammalian host potentially signaling to pathogenic organisms for host adaptive responses. Pathogens utilize CO2 and HCO3 detection for activation of toxin expression or induction of a cAMP signaling pathway. We hypothesize that B. burgdorferi employs similar mechanisms to adequately adapt for pathogenesis in the mammalian host. Our Preliminary Data suggests CO2 serves as a signal to B. burgdorferi to regulate the production of a transcriptional regulator and the expression of genes that are important for infectivity. Two borrelial regulatory systems, the Rrp2-RpoN-RpoS regulatory system and the BosR protein, are altered in response to CO2 suggesting that this environmental cue is critical for B. burgdorferi to sense, adapt, and survive in the mammalian host. BosR, borrelial oxidative stress regulator, is post-transcriptionally regulated in response to CO2 and interacts with the rpoS promoter potential resulting in CO2 transcriptional regulation of rpoS and RpoS-dependent genes. To this end we propose the following Specific Aims: (1) Ascertain the mechanism utilized by B. burgdorferi to sense and respond to environmental CO2; (2) Identify genes and proteins regulated by CO2 in infectious B. burgdorferi. In the proposed studies, the putative borrelial adenylate cyclase, cyaB, has been deleted and the CO2 regulation will be evaluated, as well as inhibition of cAMP accumulation, relative to the parent strain. We will determine how cyaB activity contributes to infectivity of B. burgdorferi via bioluminescence in vivo imaging. Recently we have used in vivo imaging to detect light emitting (i.e., luciferase [luc] expressing) infectiou B. burgdorferi following experimental infection. The advantage of this approach is that B. burgdorferi can be visualized numerous times in live mice over time to track the infectious process. This exciting approach provides a powerful non-invasive, real time modality to evaluate infectivity in a temporal and spatial manner. In addition, transcriptomic and proteomic technologies will be utilized to generate a comprehensive subset of genes and proteins that are responsive to CO2 with the long term goal that this will provide a platform to identify novel virulence determinants and potential therapeutic targets. A mechanism of direct detection of an environmental cue that is sensed by B. burgdorferi has not yet been characterized. The proposed work herein will characterize how CO2 sensing contributes to the complex regulation engaged by B. burgdorferi as it traverses through its complex life cycle.

描述（由申请人提供）：众所周知，莱姆病的病因学药Borrelia Burgdorferi在节肢动物载体和哺乳动物宿主之间移动时适应了不同的环境。 B. burgdorferi响应环境提示温度，pH，O2，CO2和其他未知宿主因子，调节基因表达和蛋白质合成。二氧化碳是细胞呼吸的副产品，哺乳动物宿主内的水平波动可能会向致病生物发出信号，以使病原体适应自适应反应。病原体利用CO2和HCO3检测来激活毒素表达或cAMP信号通路的诱导。我们假设B. burgdorferi采用相似的机制来充分适应哺乳动物宿主的发病机理。我们的初步数据表明，CO2是B. burgdorferi的信号，以调节转录调节剂的产生以及对感染性很重要的基因表达。两种疏松调节系统，即RRP2-RPON-RPOS调节系统和BOSR蛋白，随着二氧化碳的响应而改变，这表明该环境提示对于B. burgdorferi对哺乳动物宿主的感知，适应和生存至关重要。 BOSR是骨质氧化应激调节剂，在转录后对二氧化碳的响应进行调节，并与RPOS启动子电位相互作用，从而导致RPOS和RPOS依赖性基因的CO2转录调控。为此，我们提出了以下特定目的：（1）确定B. burgdorferi使用的机制来感知和应对环境二氧化碳；（2）鉴定在感染性B. burgdorferi中由CO2调节的基因和蛋白质。在拟议的研究中，已删除了推定的植物腺苷酸环化酶CyAB，并将评估CO2调控，并相对于父母菌株，并抑制cAMP积累的抑制作用。我们将确定CyAB活性如何通过体内成像中的生物发光来促进爆发芽孢杆菌的感染性。最近我们已经使用体内成像来检测实验感染后的发光（即表达荧光素酶[Luc]表达）Instectiou B. burgdorferi。这种方法的优点是，随着时间的推移，可以在活小鼠中多次将B. burgdorferi可视化，以跟踪传染性过程。这种令人兴奋的方法提供了一种强大的非侵入性实时方式，可以以时间和空间方式评估感染力。此外，转录组和蛋白质组学技术将被用于生成一部分基因和蛋白质的子集，这些基因和蛋白质对CO2有反应，其长期目标将提供一个平台来识别新颖的毒力确定因素和潜在的治疗靶标。尚未表征一种直接检测环境提示的机制。本文提出的工作将表征二氧化碳感应如何促进B. burgdorferi在其复杂的生命周期中穿越的复杂调节。