Borrelia burgdorferi tick phase genes and Lyme disease pathogenesis

描述（由申请人提供）：莱姆病是美国最常见的节肢动物传播疾病，由螺旋体伯氏疏螺旋体感染引起。B的维护。自然界中的伯氏螺旋体需要通过节肢动物载体从受感染的哺乳动物宿主获得，螺旋体在该载体中生长和维持，以及从受感染的载体传播到哺乳动物宿主。研究表明，B. burgdorferi调节其基因表达以响应载体和哺乳动物环境的变化，并且以这种方式调节的蛋白质的表达在B中起重要作用。burgdorferi生活史和发病机制。该项目的长期目标是表征对维持B至关重要的基因和/或蛋白质。蜱媒介中的伯氏螺旋体及其在哺乳动物宿主中的传播和传播。我们采用功能和比较基因组学来鉴定B。在这些过程中表达受调控的burgdorferi基因，并确定RpoS和Rrp 1调节子的成员。这些研究强调了这样一个事实，即在体内环境中的基因表达的分析提供的信息，不能通过在体外条件下的研究，旨在模拟体内环境中获得。这些全球监管研究的结果为我们关于需要进一步研究的基因/蛋白质的决定提供了依据。所选基因在蜱中显示独特的表达模式，因此可以作为研究载体中基因调控的范例。具体目标1和2将涉及详细的表达分析和诱变研究的组合，旨在表征以下蛋白的表达和调控：1）BBA 74，一种在载体的螺旋体定殖期间具有独特表达谱的Rpos调节的滴答期蛋白; 2）编码甘油摄取和利用所需蛋白的Glp操纵子，该过程可能在B期间特别重要。蜱中的伯氏螺旋体生长和维持。在具体目标3中，我们将进行B的全局转录组分析。在蜱虫载体的不同发育阶段的burgdorferi和阐明RpoS，Rrp 1和BosR调节子在蜱使用一种新开发的方法，允许全球评估B。来自体内衍生的转录物的burgdorferi基因表达。这些研究将为B的自然历史提供新的见解。这反过来可能对预防和治疗人类莱姆病有意义。 公共卫生相关性：莱姆病是美国最常见的蜱传疾病，由螺旋体伯氏疏螺旋体感染引起。在上一个资助期获得的发现开辟了几条新的研究途径，有望揭示B的重要方面。在蜱虫环境中工作的burgdorferi基因调控和过程。这里提出的功能基因组学和遗传方法的结合应该阐明发生在载体-宿主界面的重要事件。这将为B的自然历史提供新的见解。这反过来可能对预防和治疗人类莱姆病有意义。

DESCRIPTION (provided by applicant): Lyme disease, the most commonly reported arthropod-borne disease in the United States, is caused by infection with the spirochete, Borrelia burgdorferi. Maintenance of B. burgdorferi in nature requires its acquisition from an infected mammalian host by an arthropod vector, growth and maintenance of the spirochete in that vector, and transmission from the infected vector to a mammalian host. Studies indicate that B. burgdorferi modulates its gene expression in response to changes in the vector and mammalian environments and expresion of proteins regulated in this maner play an important role in the B. burgdorferi life cycle and pathogenesis. The long-term objective of this project is characterization of genes and/or proteins that are crucial to maintenance of B. burgdorferi in the tick vector and its transmission to, and dissemination in, the mammalian host. We have employed functional and comparative genomics to identify B. burgdorferi genes whose expression is regulated during these processes and to define members of the RpoS and Rrp1 regulons. These investigations highlighted the fact that analysis of gene expression in the in vivo environment provides information that cannot be obtained by study under in vitro conditions designed to mimic the in vivo milieu. The results from these global regulatory studies have informed our decisions regarding genes/proteins that warrant further study. The selected genes display unique expression patterns in the tick and thus can serve as paradigms for the study of gene regulation in the vector. Specific aims 1 and 2 will involve a combination of detailed expression analyses and mutagenesis studies aimed at characterization of the expression and regulation for: 1) BBA74, an RpoS-regulated tick-phase protein with a unique expression profile during spirochete colonization of the vector; 2) the Glp operon that encodes proteins required for glycerol uptake and utilization, a process likely to be particularly important during B. burgdorferi growth and maintenance in ticks. In specific aim 3 we will perform global transcriptome analysis of B. burgdorferi during different developmental stages of the tick vector and elucidate the RpoS, Rrp1 and BosR regulons in ticks using a newly developed methodology that allows global assessment of B. burgdorferi gene expression from in vivo-derived transcripts. These studies will provide new insights into the natural history of B. burgdorferi in the tick vector that, in turn, may have implications for prevention and treatment of human Lyme disease. PUBLIC HEALTH RELEVANCE: Lyme disease, the most commonly reported tick-borne disease in the United States, is caused by infection with the spirochete, Borrelia burgdorferi. The findings obtained during the previous grant period have opened several new avenues of investigation that promise to reveal important aspects of B. burgdorferi gene regulation and processes at work in the tick environment. The combination of functional genomics and genetic approaches proposed here should illuminate important events that occur at the vector- host interface. This will provide new insights into the natural history of B. burgdorferi infection in nature which, in turn, may have implications for prevention and treatment of human Lyme disease.