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

• 批准号: 8583139
• 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
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-06 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8583139
• 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; Image; 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; member; mutant; novel; novel vaccines; pathogen; pathogenic bacteria; prevent; promoter; public health relevance; response; therapeutic development; therapeutic target; transcriptomics; vaccine candidate

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）：已经确定，莱姆病的病原伯氏疏螺旋体在节肢动物媒介和哺乳动物宿主之间移动时适应不同的环境。伯氏疏螺旋体在温度、pH、O2、CO2和其他未知宿主因素的影响下调节基因表达和蛋白质合成。二氧化碳是细胞呼吸的副产物，其水平在哺乳动物宿主内波动，可能向病原生物发出信号，促使宿主作出适应性反应。病原体利用CO2和HCO3检测来激活毒素表达或诱导cAMP信号通路。我们假设伯氏疏螺旋体采用类似的机制来充分适应哺乳动物宿主的发病机制。