An analysis of Borrelia burgdorferi motility

描述（由申请人提供）：莱姆病是美国最普遍的节肢动物感染，自发现以来发病率稳步上升。伯氏疏螺旋体是病原体。对伯氏疏螺旋体致病宿主的毒力特性了解甚少。本文主要研究了伯氏疏螺旋体的趋化性和运动性，以及它们在疾病过程中的作用。趋化性和运动性可能是重要的毒力属性，因为这些生物渗透到其他细菌入侵的组织和器官中。在分子水平上理解趋化性的基础上，在目标1中，我们将识别那些作为引诱剂的化合物。将从伯氏疏螺旋体基因组序列和已知代谢的信息中确定推定的趋化剂，并使用既定的方法测试这些化合物的趋化能力。高传代（无毒）和低传代（有毒）菌株将在适当的环境条件下进行测试。在目标2中，我们提出在特定的运动性和趋化性基因中构建插入缺失和框内缺失突变。高传代和低传代菌株都可以作为亲本菌株。我们假设这些突变体中的每一个都有不同的表型。这些表型将在运动性、趋化性、结构、western blot、蛋白质组学和使用dna微阵列技术的转录分析方面进行分析。为了确保给定的表型是由于被研究的目标突变，我们将使用基因互补分析。在Aim 3中，我们将验证运动性和趋化性是伯氏疏螺旋体重要的毒力属性的假设。为了验证这一假设，我们将使用标准细胞渗透试验和莱姆病小鼠模型。我们预测，在这两种检测中，运动性和趋化性突变体的侵袭性和毒性都比亲本菌株小。本实验将提供有关伯氏疏螺旋体在莱姆病中的趋化性和运动性的信息，并可能为预防和治疗莱姆病的新方法奠定基础。

DESCRIPTION (provided by applicant): Lyme disease is the most prevalent arthropod borne infection in the United States, and has shown a steady increase in incidence since its discovery. The spirochete Borrelia burgdorferi is the causative agent. Very little is known about the B. burgdorferi virulence attributes that bring disease to the host. The present proposal focuses on the chemotaxis and motility of B. burgdorferi, and their rote in the disease process. Chemotaxis and motility are likely to be important virulence attributes, as these organisms penetrate into tissues and organs where other bacteria fall to invade. Basic to an understanding of chemotaxis on a molecular level, in Aim 1 we will identify those compounds that serve as attractants. Putative chemoattractants will be identified from information drawn from the genome sequence and known metabolism of B. burgdorferi The chemotactic ability of these compounds will be tested using established methodology. Both high passage (avirulent) and tow passage (virulent) strains will be tested under appropriate environmental conditions. in Aim 2, we propose to construct both insertion-deletion and in-frame deletions mutations in specific motility and chemotaxis genes. Both high and low passage strains will serve as parental strains. We hypothesize that each of these mutants will have a distinct phenotype. These phenotypes will be analyzed with respect to motility, chemotaxis, structure, western blot, proteomics and transcriptional analysis using DNA-microarray technology. To insure that a given phenotype is due to the targeted mutation being studied, we will use gene-complementation analysis. in Aim 3, we will test the hypothesis that motility and chemotaxis are important virulence attributes of B. burgdorferi. To test this hypothesis, we will use standard cell penetration assays, and the mouse model of Lyme disease. We predict that the motility and chemotaxis mutants will be less invasive and virulent than the parental strains in both of these assays. The experiments proposed should yield information with respect to the roles of chemotaxis and motility of B. burgdorferi in Lyme disease, and perhaps lay the foundation for new methods for prevention and treatment.