Gonococcal interactions with human polymorphonuclear leukocytes

描述（由申请方提供）：由淋病奈瑟菌（Gc）引起的急性淋病感染，其特征是大量多形核白细胞（PMNs）聚集到泌尿生殖道。然而，感染持续存在的中性粒细胞，这表明Gc已经进化的方式来阻止中性粒细胞的杀伤。支持这些观察结果，我已经表明，GC可以在PMNs的存在下生存，并且确实发生的杀伤是非氧化性的。我的研究的目标是阐明是什么让一些Gc生存暴露于中性粒细胞，并确定中性粒细胞的因素，杀死其余的Gc。在目标1的建议，我将确定如何与中性粒细胞相关的Gc的亚细胞定位影响细菌的生存，通过量化的Gc粘附和内化的中性粒细胞的活力，并检查与中性粒细胞颗粒，溶酶体，和中性粒细胞胞外陷阱的Gc的共定位。在目标2中，我将通过测定暴露于单个PMN因子和PMN颗粒组分后的Gc存活率来确定对Gc有活性的PMN的杀菌组分。在这些研究中，我将比较野生型Gc的两个突变体，更容易受到中性粒细胞杀伤（ngo 1686和recN），这将提供解释如何野生型Gc生存暴露于中性粒细胞和如何ngo 1686和recN基因产物援助Gc生存。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，继续作为博士后研究员与H。史蒂文·塞弗特。在研究期间，我的研究重点已经从菌毛抗原变异，这有助于Gc逃避适应性免疫反应，Gc如何避免中性粒细胞清除，一个关键的，但了解甚少的Gc的发病机制方面。我的近期职业目标，将在指导阶段完成，是完成Gc-PMN相互作用的初步研究，这将为获得独立的教师职位奠定基础。这将支持我的长期职业目标，指导一个实验室进行尖端的Gc发病机制研究。与公共卫生的相关性：淋病是美国和全球第二大流行性传播疾病。感染导致生殖道疤痕和男性和女性的不育以及婴儿的失明，淋病患者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如何被破坏是寻找治疗这种疾病的新疗法的关键第一步。

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.