Gonococcal interactions with human polymorphonuclear leukocytes

描述（由申请人提供）：急性淋病感染，由淋病奈瑟菌（Gc）引起，其特征是向泌尿生殖道募集大量多形核白细胞（pmn）。然而，在PMN存在的情况下，感染仍然存在，这表明Gc已经进化出了阻止PMN杀伤的方法。为了支持这些观察结果，我已经证明Gc可以在pmn存在的情况下存活，并且确实发生的杀伤是非氧化性的。我的研究目标是阐明是什么使一些Gc在暴露于PMN中存活下来，并确定杀死剩余Gc的PMN因素。在提案的目标1中，我将确定Gc与PMN相关的亚细胞定位如何影响细菌存活，通过量化Gc粘附和被PMN内化的活力，并检查Gc与PMN颗粒、溶酶体和中性粒细胞胞外陷阱的共定位。在目标2中，我将通过分析暴露于单个PMN因子和PMN颗粒组分后的Gc存活率，确定PMN中对Gc有活性的杀菌成分。在这些研究中，我将比较野生型Gc与两种更容易被PMN杀死的突变体（ngo1686和recN），这将解释野生型Gc如何在PMN暴露下存活，以及ngo1686和recN基因产物如何帮助Gc存活。我已经研究粘膜病原体与宿主细胞的相互作用十年了，从研究生学习开始，继续作为H. Steven Seifert博士的博士后研究员。在此期间，我的研究重点从帮助Gc逃避适应性免疫反应的pilin抗原变异发展到Gc如何避免PMN清除，这是Gc发病机制的一个关键但尚不清楚的方面。我的近期职业目标是在导师阶段完成Gc-PMN相互作用的初步研究，为获得独立教师职位奠定基础。这将支持我的长期职业目标，领导一个实验室进行尖端的胃癌发病机制研究。与公共卫生相关：淋病是美国和全世界第二大流行的性传播疾病。感染会导致男性和女性的生殖道疤痕和不育，以及婴儿失明，而患有淋病的个体更容易感染艾滋病毒。了解急性淋病感染期间宿主免疫反应是如何被破坏的，是寻找治疗这种疾病的新疗法的关键的第一步。

DESCRIPTION (provided by applicant): Acute gonorrheal infection, caused by Neisseria gonorrhoeae (Gc), is characterized by the recruitment of massive numbers of polymorphonuclear leukocytes (PMNs) to the urogenital tract. However, infection persists in the presence of PMNs, suggesting Gc have evolved ways to thwart PMN killing. Supporting these observations, I have shown that Gc can survive in the presence of PMNs and that the killing that does occur is non-oxidative. The goals of my research are to elucidate what allows some Gc to survive exposure to PMNs and to identify the PMN factors that kill the remaining Gc. In Aim 1 of the proposal, I will determine how the subcellular localization of Gc associated with PMNs affects bacterial survival, by quantifying the viability of Gc adherent to and internalized by PMNs and examining the colocalization of Gc with PMN granules, lysosomes, and neutrophil extracellular traps. In Aim 2, I will identify the bactericidal components of PMNs that are active against Gc by assaying Gc survival after exposure to individual PMN factors and to PMN granule fractions. In these studies I will compare wild-type Gc to two mutants that are more susceptible to PMN killing (ngo1686 and recN), which will provide explanations for how wild-type Gc survive exposure to PMNs and how the ngo1686 and recN gene products aid in Gc survival. I have been studying the interplay of mucosal pathogens with host cells for ten years, beginning with graduate studies and continuing as a postdoctoral fellow with Dr. H. Steven Seifert. During the fellowship period, my research focus has evolved from pilin antigenic variation, which aids Gc in evading the adaptive immune response, to how Gc avoid PMN clearance, a crucial yet poorly understood aspect of pathogenesis of Gc. My immediate career goal, to be completed in the mentored phase, is to complete initial studies of Gc-PMN interactions that will lay the foundation for obtaining an independent faculty position. This will support my long-term career goal, to direct a laboratory performing cutting-edge Gc pathogenesis research. RELEVANCE TO PUBLIC HEALTH: Gonorrhea is the second-most prevalent sexually transmitted disease in the US and worldwide. Infection causes reproductive tract scarring and sterility in both men and women and blindness in infants, and individuals with gonorrhea are more susceptible to HIV infection. Understanding how the host immune response is subverted during acute gonorrheal infection is a critical first step in finding new therapies for treatment of this disease.