Genetic Variation in genes involved in Neisseria gonorrhoeae LOS biosynthesis

描述（由申请人提供）：淋病奈瑟菌每年在美国导致超过100万例淋病病例。与治疗淋病相关的医疗保健费用，以及由这种有机体引起的感染引起的并发症，每年超过10亿美元。淋球菌感染可以传播，从最初的感染部位引起盆腔炎（PID），可导致输卵管性不孕、异位妊娠和慢性盆腔疼痛，或进入血流引起播散性淋球菌感染（DGI）。低脂寡糖（LOS）是一种重要的表面抗原和毒力因子，在这些疾病的发病机制中起重要作用。寡糖可以在单个细胞中以多种化学相关成分的形式存在，寡糖部分的变化很容易在不同形式之间相互转换。虽然这种分子的一种形式已被广泛研究，但已知存在许多其他新结构。事实上，这种病原体拥有如此多不同的方式来操纵其LOS，并且可以产生如此多样化的结构，这表明这种修饰在发病机制中很重要。本提案的目的是确定与LOS生物合成相关的遗传变异性，并通过定义淋球菌表达的结构以及表征这些结构表达调节的分子和功能基础，确定特定LOS结构是否与感染的特定临床结果相关。提出的研究的中心假设是，LOS的生物合成变化具有尚未表征的额外遗传和生化基础，并且它们导致合成额外的LOS结构，这些结构有助于细菌的不同生物学特性。我将描述存在于该物种中的结构变异性，并将使用获得的遗传信息构建具有不变定义LOS的菌株。然后，我将通过确定这些结构对血清抗性的贡献来分析它们的生物学意义。公共卫生相关性：想要了解淋病奈瑟菌的LOS结构，LOS结构的变化如何发生以及这种调节如何影响生物体的致病性的理由是，一旦了解了这些信息，就有可能对发病机制有全面的了解。这反过来又有望导致预防和控制感染的创新方法。我很适合进行拟议的研究，因为我已经开发了必要的遗传工具；克隆和鉴定了许多目前已知的LO S生物合成基因；鉴定出具有不同LOS结构的菌株；开展必要的合作，并采用适当的组织培养模型来研究LOS在疾病发病机制中的作用。

DESCRIPTION (provided by applicant): Neisseria gonorrhoeae is responsible for over 1 million cases of gonorrhea each year in the United States. The total health care costs associated with treating gonorrhea, and complications that arise from infections caused by this organism exceed 1 billion dollars per year. Gonococcal infections can disseminate, from the initial site of infection causing pelvic inflammatory disease (PID), which can lead to tubal infertility, ectopic pregnancy, and chronic pelvic pain, or into the blood stream causing disseminated gonococcal infections (DGI). Lipooligosaccharide (LOS) is a prominent surface antigen and a virulence factor that makes a major contribution to the pathogenesis of these diseases. LOS can exist as multiple chemically related components on a single cell, with variations in the oligosaccharide portion readily interconverting between forms. While one form of this molecule has been extensively studied, there are many other novel structures that are known to exist. The fact that this pathogen possesses so many different ways to manipulate its LOS, and can make such a diversity of structures, indicates that such modifications are important in pathogenesis. The objective of this proposal is to determine the genetic variability associated with LOS biosynthesis and determine if specific LOS structures are associated with specific clinical outcomes of infection by defining the structures expressed by the gonococcus and characterizing the molecular and functional basis for the modulation of the expression of these structures. The central hypothesis of the proposed research is that variation in the biosynthesis of LOS has additional genetic and biochemical underpinnings that have yet to be characterized, and that they lead to the synthesis of additional LOS structures that contribute to different biological properties of the bacterium. I will characterize the structural variability that exists in this species and will use the genetic information obtained to construct strains with invariant defined LOS. I will then analyze the biological significance of these structures by determining their contribution to serum resistance. PUBLIC HEALTH RELEVANCE: rationale for wanting to know what LOS structures can be made in Neisseria gonorrhoeae, how changes in LOS structures occur and how such modulation affects the organism's pathogenicity is that, once this information becomes known, it will be possible to develop a comprehensive understanding of pathogenesis. This, in turn, is expected to lead to innovative new ways of preventing and controlling infection. I am well-positioned to undertake the proposed research because I have: developed the requisite genetic tools; cloned and characterized many of the currently known LO S biosynthetic genes; identified strains possessing alternative LOS structures; developed the requisite collaborations and adapted the appropriate tissue culture models to study the role of LOS in disease pathogenesis.