Gonococcal interactions with human polymorphonuclear leukocytes

淋病奈瑟菌(GC)是一种人类特有的细菌病原体，可引起性传播 疾病淋病。在感染者中，大量的中性粒细胞(PMN)是 被招募到感染现场。然而，由此产生的渗出物中含有可存活的生物体 传播给新宿主，表明PMN的抗菌机制不足以清除淋病 感染。在体外，PMN可以杀死它们所呈现的一定比例的GC，但其余的 生存和繁衍。中性粒细胞具有多亚基NADPH氧化酶，可产生活性氧 具有杀菌活性的物种(ROS)。然而，NADPH氧化酶的活性对于PMN的杀伤是必不可少的 GC，我发现这是因为GC具有惊人的抑制ROS生成的能力 PMN。因此，PMN正在引导他们的非氧化性抗微生物机制来对抗GC。我有过 鉴定了两个GC基因产物ngol 686和recN，它们保护GC免受PMN的杀伤。这样做的目的是 建议1)确定可杀死GC的非氧化性PMN抗微生物因子；2)确定 Ngo1686和recN突变体对PMN杀伤敏感性增加的机制。这就做 确定对GC具有体外杀菌活性的PMN抗菌因子，我将确定 在暴露于PMN期间，GC是否与这些因素共存。所有这些研究都将在 GC与纯化的PMN杀菌因子、PMN颗粒提取物或完整的人PMN 从静脉血中分离出来。 12年来，我一直在研究粘膜病原体与宿主细胞的相互作用。在我的 在西北大学H.Steven Seifert博士的实验室担任博士后研究员期间，我开始在 GC如何逃避PMN清除，这是GC发病机制中一个关键但研究很少的方面。在一年的K99 在独立之路奖阶段，我完成了GC-PMN相互作用的初步研究，奠定了 为这份Roo提案中概述的具体目标奠定基础。我将在以下时间进行这项独立研究 弗吉尼亚大学健康科学中心的微生物学系，我一直在那里 任命一名终身教职助理教授，开始日期为2008年10月1日。这项研究支持 Roo奖将为我的实验室当前和未来的重点领域提供关键基础， 探索奈瑟氏菌感染的先天免疫反应。

Neisseria gonorrhoeae (Gc) is a human-specific bacterial pathogen that causes the sexually transmitted disease gonorrhea. In infected individuals, massive numbers of polymorphonuclear leukocytes (PMNs) are recruited to the site of infection. However, the resulting exudate contains viable organisms that are transmitted to new hosts, indicating that PMN antimicrobial mechanisms are insufficient to clear gonorrheal infections. In vitro, PMNs can kill a percentage of Gc with which they are presented, but the remainder survive and proliferate. PMNs possess a multisubunit NADPH oxidase that generates reactive oxygen species (ROS) with bactericidal activity. However, NADPH oxidase activity is dispensable for PMN killing of Gc, and I have found that this is because Gc have the surprising ability to suppress ROS generation in PMNs. As a result, PMNs are directing their non-oxidative antimicrobial machinery against Gc. I have identified two Gc gene products, ngol 686 and recN, that protect Gc from killing by PMNs. The goals of this proposal are 1) to identify the non-oxidative PMN antimicrobial factors that can kill Gc and 2) to define the mechanisms underlying the increased sensitivity of the ngo1686 and recN mutants to PMN killing. I will identify PMN antimicrobial factors that have in vitro bactericidal activity against Gc and I will determine whether Gc colocalize with these factors during exposure to PMNs. All these studies will be conducted with Gc in combination with purified PMN bactericidal factors, PMN granule extracts, or intact human PMNs isolated from venous blood. I have been studying the interplay of mucosal pathogens with host cells for 12 years. During my postdoctoral fellowship in Dr. H. Steven Seifert's laboratory at Northwestern University, I began to address how Gc evade PMN clearance, a critical but poorly studied aspect of Gc pathogenesis. In the one-year K99 phase of the Pathway to Independence award, I completed initial studies of Gc-PMN interactions that laid the groundwork for the specific aims outlined in this ROO proposal. I will conduct this independent research in the Department of Microbiology at the University of Virginia Health Sciences Center, where I have been appointed a tenure-track Assistant Professor with a start date of October 1, 2008. The research supported by the ROO award will provide the critical foundation for my laboratory's current and future area of focus, exploring the innate immune response to Neisserial infection.