Experimental human infection with isogenic mutants of Neisseria gonorrhoeae

淋病奈瑟菌同基因突变体的实验性人类感染

基本信息

批准号：
9267906
负责人：
MARCIA METZGAR HOBBS
金额：
$ 73.5万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-05-15 至 2020-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9267906
关键词：
Affect Amendment Animal Model Antibiotic Resistance Antibiotics Attenuated Award Case Study Cells Centers for Disease Control and Prevention (U.S.)Clinical Trials Development Drug Targeting Employee Strikes Enzymes Future GC gene Gene Expression Generations Goals Gonococcal urethritis Gonorrhea HIV Hand Health Host Defense Human Immune Immune response Immunity Impairment In Vitro Infection Inflammation Inflammatory Innate Immune Response Lipid A Lytic Measures Mediating Mediator of activation protein Membrane Modality Molecular Mus Mutation Nature Neisseria gonorrhoeae North Carolina Outcome Output Pathogenesis Peptidoglycan Protocols documentation Public Health Pump Recovery Reporting Reproductive Health Research Resistance Severities Sexually Transmitted Diseases Signal Transduction Signs and Symptoms Structure Surface System Testing Therapeutic Time Transferase U-Series Cooperative Agreements Universities Urethra Urethritis Vaccines Work adaptive immune response antimicrobial bacterial resistance cell envelope clinically translatable cytokine derepression drug development efflux pump fitness genital infection high risk immune clearance immunoreaction immunoregulation in vivo indexing killings male men mouse model mutant novel novel therapeutics novel vaccines pathogen peptidoglycan monomer phosphoethanolamine programs public health relevance transmission process volunteer

项目摘要

DESCRIPTION (provided by applicant): Gonorrhea remains a global public health problem with over 106 million cases estimated by WHO in 2008 and over 334,000 cases reported to the US CDC in 2012, and rates are on the rise. With increasing Neisseria gonorrhoeae (GC) antibiotic resistance and no new antimicrobial therapies in the pipeline, the possibility of incurable gonorrhea is uncomfortably real. The potential adverse health consequences of untreatable GC and attendant increases in HIV transmission are alarming and highlight the urgent need for new therapeutic and vaccine targets. Our long term goals are to understand the molecular mechanisms of GC pathogenesis and identify bacterial structures required for infection with the aim of discovering potential novel targets for GC vaccines and/or treatments. In nature, GC only infects humans, which limits the extent to which results in animal models are clinically translatable. Accordingly, we propose a clinical trial with the immediate goals of 1) determining the requirement for several GC cell envelope structures in male urethral infection and 2) characterizing human immune responses to mutants lacking these structures. The expected outcome of the trial is the identification of one or more GC envelope structures required for human infection, which will validate these structures as potential novel targets for GC vaccines or treatments. The assembled research team manages the experimental human gonococcal infection program at the University of North Carolina, which is currently the only one of its kind in the world, providing a unique opportunity to study GC factors and host responses in human infection under controlled conditions. Experimental urethral infection of male volunteers is safe, and wild-type GC elicit signs and symptoms of natural gonorrhea. The proposed trial focuses on several surface structures that mediate GC resistance to human innate immune responses. We hypothesize that experimental male urethral infection with GC strains containing mutations that alter or eliminate these structures will show reduced mutant infectivity, decreased inflammation or increased GC mutant clearance compared to wild-type GC. We will use noncompetitive infections to measure GC survival and host immune responses in addition to changes in GC gene expression. We propose studies of three GC envelope structures that we have shown mediate resistance to human innate immune cells and human-derived antimicrobial compounds in the lab and in a mouse model. Aim 1 focuses on mutations affecting the GC MtrCDE efflux pump, which exports host antimicrobial compounds and is important for GC infection in human cell systems and in murine genital infection. Aim 2 focuses on mutations that alter the structure of lipid A, which is important for intracellular GC survival in vitro, and influences GC survival in mice. Finally, Aim 3 focuses on mutations in GC enzymes that cause release of peptidoglycan subunits that modulate innate immune responses in human cell systems and in mice. The GC envelope structures that we aim to test in the trial have not been well-studied in human infection, and they represent novel potential therapeutic and/or vaccine targets.

描述（由适用提供）：淋病仍然是一个全球公共卫生问题，2008年WHO估计的超过1.06亿例病例和2012年向美国疾病预防控制中心报告给美国疾病预防控制中心的334,000例病例，利率正在上升。随着淋病奈瑟氏菌（GC）抗生素耐药性的增加，管道中没有新的抗菌疗法，无法治愈的淋病的可能性是不舒服的。不可治疗的GC和艾滋病毒传播中伴随的增加的潜在不利健康后果令人震惊，并强调了对新疗法和疫苗靶标的迫切需求。我们的长期目标是了解GC发病机理的分子机制，并确定感染所需的细菌结构，目的是发现潜在的GC疫苗和/或治疗的新靶标。在自然界中，GC仅感染了人类，这限制了动物模型中导致的程度。彼此之间，我们提出了一项临床试验，其直接目标为1）确定男性尿道感染中几个GC细胞包膜结构的要求，以及2）将人类免疫回报表征为缺乏这些结构的突变体。该试验的预期结果是鉴定人类感染所需的一个或多个GC包膜结构，这将验证这些结构是GC疫苗或治疗的潜在新靶标。组装的研究团队管理北卡罗来纳大学的实验性人淋球菌感染计划，该计划目前是世界上唯一的同类人，为在受控条件下提供了研究GC因素和人类感染中宿主反应的独特机会。男性志愿者的实验性尿道感染是安全的，野生型GC引起了天然淋病的体征和症状。拟议的试验侧重于介导GC对人类先天免疫调查的几种表面结构。我们假设与野生型GC相比，含有改变或消除这些结构的突变的实验性男性尿道感染将显示突变体感染，降低或GC突变量增加的突变感染，降低或增加GC突变体清除率。除GC基因表达的变化外，我们还将使用非竞争性感染来测量GC存活和宿主免疫反应。我们提出了三种GC包膜结构的研究，我们表明了对人类先天免疫细胞和人类衍生的抗微生物化合物的中位数，在实验室和小鼠模型中。 AIM 1的重点是影响GC MTRCDE外排泵的突变，该突变导出宿主抗菌化合物，对于人类细胞系统和鼠类生殖器感染中的GC感染很重要。 AIM 2的重点是改变脂质A结构的突变，这对于体外细胞内GC存活很重要，并影响小鼠的GC存活。最后，AIM 3的重点是GC酶的突变，这些突变引起了释放的胡椒糖亚基，该亚基调节了人类细胞系统和小鼠的先天免疫回避。我们旨在在试验中测试的GC包膜结构在人类感染中尚未得到充分研究，它们代表了新型的潜在治疗和/或疫苗靶标。