Genetic Variation in genes involved in Neisseria gonorrhoeae LOS biosynthesis

描述(申请人提供)：淋病奈瑟菌在美国每年造成100多万淋病病例。与治疗淋病和由这种微生物引起的感染引起的并发症相关的总医疗费用每年超过10亿美元。淋球菌感染可从引起盆腔炎(PID)的初始感染部位传播，可导致输卵管不孕、宫外孕和慢性盆腔疼痛，或进入血流导致播散性淋球菌感染(DGI)。脂低聚糖(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着重要作用。LOS可以在单个细胞上以多种化学相关成分的形式存在，低聚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经被广泛研究，但还有许多其他已知的新结构存在。事实上，这种病原菌具有如此多的不同方式来操纵其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是重要的。这项建议的目的是通过定义淋球菌表达的结构并表征这些结构表达的分子和功能基础，确定与LOS生物合成相关的遗传变异性，并确定特定的LOS结构是否与感染的特定临床结果相关。拟议研究的中心假设是，LOS生物合成的变异具有额外的遗传和生化基础，这些基础尚未确定，它们导致额外的LOS结构的合成，这些结构有助于细菌的不同生物学特性。我将描述这个物种中存在的结构变异性，并将使用获得的遗传信息来构建具有不变定义的LOS的菌株。然后，我将通过确定它们对血清抵抗力的贡献来分析这些结构的生物学意义。公共卫生相关性：想要了解淋球菌的LOS结构可以是什么，LOS结构是如何发生变化的，以及这种调节如何影响生物体的致病性是因为，一旦这些信息被知道，就有可能对发病机制进行全面的理解。这反过来有望带来预防和控制感染的创新新方法。我完全有能力开展这项拟议的研究，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；鉴定了具有替代LOS结构的菌株；开发了必要的合作并调整了适当的组织培养模型，以研究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.