Role of motility in Borrelia burgdorferi pathogenesis

描述（由申请人提供）： 莱姆病是美国最普遍的节肢动物骨骼感染。该疾病由伯氏疏螺旋体引起，是一种具有多种临床表现的多系统性疾病。在美国，急性疾病的主要表现之一是莱姆关节炎。大约60%未经治疗的患者会出现单关节或少关节关节炎的间歇性发作，主要发生在大关节，如膝关节。 以往的研究表明，B。伯氏病具有高度侵袭性。这些螺旋体穿过细胞间基质，穿透血管内皮细胞衬里，最后在蜱叮咬后沉积在皮肤中后侵入关节。然而，这种侵入性过程的机制仍然未知。 本建议侧重于B的能动性。Burgdorferi及其在疾病过程中的作用。直到最近才为B开发了基因靶向工具。此外，对其复杂运动性的理解还处于非常早期的阶段。 我推测鞭毛基因fliG2和fliG1在B中起着关键但不同的作用。伯氏运动初步结果表明，fliG1无效突变体持续游泳，但不能翻译（即显示位移），而fliG2无效突变体完全不运动。我还假设，fliG1的功能，以协调运动细胞器，周质鞭毛，允许定向细胞运动的旋转。为了验证这些假设，我将详细描述这些突变体。利用绿色荧光蛋白融合体和酵母双杂交系统对FliG 1和FliG 2的功能进行深入研究。 所获得的信息将有助于更好地理解B的分子机制。伯氏运动 其次，我假设运动是一个毒力因子。为了验证这一假设，我将在一个难以操作的强毒株中靶向这两个基因，深入分析所产生的突变体，并通过莱姆病小鼠模型测试这些突变体的毒力。我预测这两个突变株的毒性会比亲本菌株弱。获得的结果将产生有关B的关键信息。以及与毒力的关系。这些结果可能导致疾病预防和治疗的新方法。

DESCRIPTION (provided by applicant): Lyme disease is the most prevalent arthropod bone infection in the United States. The disease, caused by the spirochete Borrelia burgdorferi, is a multiple systemic disorder with various clinical manifestations. In the United States, one of the major manifestations of the acute disease is Lyme arthritis. Approximately 60% of untreated patients develop intermittent attacks of monoarticular or oligoarticular arthritis, primarily in large joints such as knees. Previous studies indicate that B. burgdorferi is highly invasive. These spirochetes traverse the intercellular matrix, penetrate the vascular endothelial cell lining, and finally invade the joints after being deposited in the skin following a tick bite. However, the mechanisms involved in this invasive process is still unknown. The present proposal focuses on the motility of B. burgdorferi, and its role in the disease process. Only recently have the tools for gene targeting been developed for B. burgdorferi, In addition, an understanding of its complex motility is at a very early stage. I hypothesize that the flagellar genes fliG2 and fliG1 play critical but different roles in B. burgdorferi motility. Preliminary results suggest that a fliG1 null mutant continuously swims but is unable to translate (i.e. show displacement), and a fliG2 null mutant is completely non-motile. I also hypothesize that fliG1 functions to coordinate the rotation of the motility organelles, the periplasmic flagella, that allow for directed cell movement. To test these hypotheses, I will characterize these mutants in detail. Green fluorescent protein fusions, and the yeast two hybrid system, will be used to analyze the function of FliG1 and FliG2 in depth. The information obtained should yield a better understanding of molecular mechanisms of B. burgdorferi motility. Second, I hypothesize that motility is a virulence factor. To test this hypothesis, I will target these two genes in a difficult to manipulate virulent strain, analyze the resultant mutants in depth, and test the virulence of these mutants by the mouse model of Lyme disease. I predict that these two mutants will be less virulent than the parental strain. The results obtained will yield critical information on B. burgdorferi motility and and its relationship to virulence. These results could lead to new means of disease prevention and treatment.