Immune defenses against Neisseria gonorrhoeae

针对淋病奈瑟菌的免疫防御

基本信息

批准号：
8963568
负责人：
SANJAY RAM
金额：
$ 62.99万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
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：
2015-05-05 至 2020-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8963568
关键词：
Address Affect Antibiotics Antibodies Binding Ceftriaxone Centers for Disease Control and Prevention (U.S.)Chemotactic Factors Clinical Complement Complement 3a Complement 5a Complement Activation Complement Factor H Complement Inactivators Complement Membrane Attack Complex Complement Receptor Contracts Data Dependence Development Disease Ectopic Pregnancy Epitopes Genital system Genotype Glycosyltransferase Gene Gonorrhea Human Human Factor H Immune Immune response Inbred BALB C Mice Individual Infection Infection prevention Infertility Knowledge Light Location Measures Membrane Proteins Modeling Molecular Movement Mucous Membrane Mus Neisseria gonorrhoeae Opsonin Pathogenesis Pelvic Inflammatory Disease Peptides Phase Phenotype Play Polysaccharides Preparation Proteins Public Health Reproductive Health Resistance Role Sexually Transmitted Diseases Site Specificity Structure Superbug Surface Transgenic Mice Vaccines Vagina Variant Virulence Woman Work arm bactericide base chronic pelvic pain complement 4b-binding protein design fitness high risk in vivo inhibitor/antagonist killings lipooligosaccharide macrophage mouse model mutant neutrophil novel novel therapeutics novel vaccines pathogen prevent public health relevance receptor resistant strain vaccine candidate vaccine development vaccine efficacy

项目摘要

DESCRIPTION (provided by applicant): Neisseria gonorrhoeae (Ng) is the causative agent of the sexually transmitted infection, gonorrhea. Gonorrhea causes over 100 million new cases worldwide annually and adversely affects the reproductive health of women. Ng has become resistant to almost every antibiotic that has been used and has now achieved "superbug" status. Vaccines against Ng are urgently needed. Complement (C) is a critical arm of innate immune defenses against Ng. Gonorrhea is characterized by an influx of polymorphonuclear leukocytes (PMNs) into the genital tract, which in concert with Ab and C may facilitate clearance of infection. Vaccine development against Ng has been hindered by lack of knowledge of the correlates of protection. Our vaccine candidate is a peptide mimic (mimitope) of a Ng lipooligosaccharide (LOS) epitope that elicits bactericidal and opsonophagocytic Ab in mice. In Specific Aim 1, we will elucidate the roles of PMNs, C and C receptors in vaccine Ab efficacy to define the correlates of protection in vivo. Vaccine Ab will be evaluated in mice that lack either PMNs, C3 (opsonin) or C5a (chemotaxin) receptor. Ng binds the C inhibitors, factor H (fH) and C4b- binding protein (C4BP) in a human-specific manner. Binding of human C inhibitors blunts the bactericidal activity of vaccine Ab. We have developed transgenic mice that express both human fH and C4BP, which will be used to evaluate the efficacy of vaccine Ab in vivo and simulate conditions in humans where Ab must surmount human C inhibitors. Ng LOS plays a central role in the pathogenesis of gonorrhea. The ability of Ng to alter its LOS glycan extensions through phase variation contributes to its versatility in immune evasion. We have constructed eight Ng mutants where LOS glycan expression has been 'genotypically fixed'. In Specific Aim 2a the ability of each of these mutants to infect mice will be examined, which will elucidate how defined LOS structures driven by fixed genotypes contribute to bacterial fitness in vivo. In light of our data which show that altering LOS glycans modulates the bactericidal activity of vaccine anti-LOS Ab, we will study the efficacy of the vaccine Ab against each 'fit' LOS genotype in Specific Aim 2b. Studies in Aim 2 will correlate LOS geno/phenotypes with fitness and enable us to identify LOS structures that could supplement our current vaccine candidate. Individuals who possess Ab directed against an Ng conserved and ubiquitous outer membrane protein called reduction modifiable protein (Rmp) show impaired bactericidal activity against Ng and are at a higher risk of contracting gonorrhea. In Specific Aim 3 we will determine the molecular basis whereby Abs directed against Rmp block C-dependent Ab killing of Ng and negatively impact the efficacy of vaccine Ab. Interestingly, anti-Rmp Ab does not block killing of N. meningitidis (Nm). Allelic replacement of rmp across the two species will be performed to define whether subtle sequence differences between Ng and Nm Rmp contribute to differences in blocking across the two pathogens. Corresponding Ng and Nm PorB molecules will also be exchanged across the two species to assess co-dependence of species specific PorB on the blocking effect. Completion of the proposed studies will represent an important step forward in the development of novel vaccines against gonorrhea.

描述（由适用提供）：淋病奈瑟氏菌（NG）是性传播感染淋病的严重药物。淋病每年在全球范围内导致超过1亿个新病例，并对妇女的生殖健康产生不利影响。 NG几乎对使用并已达到“超级虫”状态的每种抗生素具有抵抗力。迫切需要针对NG的疫苗。补体（C）是对NG先天免疫防御的关键部门。淋病的特征在于多形核白细胞（PMN）对生殖道的影响，与AB和C一起，它们可能会促进感染的清除。缺乏对保护相关性的知识，阻碍了针对NG的疫苗开发。我们的疫苗候选者是Ng脂糖酸（LOS）表位的肽模拟物（Mimitope），可在小鼠中引起细菌和近代型AB。在特定目标1中，我们将阐明PMN，C和C受体在疫苗AB效率中的作用，以定义体内保护的相关性。将在缺乏PMN，C3（Opsonin）或C5A（趋化素）受体的小鼠中评估疫苗AB。 NG以人为特异性的方式结合C抑制剂，因子H（FH）和C4B结合蛋白（C4BP）。人C抑制剂的结合钝化了疫苗AB的杀菌活性。我们已经开发了表达人FH和C4BP的转基因小鼠，这些小鼠将用于评估体内疫苗AB的效率，并模拟AB必须克服人C抑制剂的人类中的条件。 NG LOS在淋病的发病机理中起着核心作用。 NG通过相变改变其LOS聚糖扩展的能力有助于其在免疫进化中的多功能性。我们已经构建了八个NG突变体，其中LOS糖表达已被“基因型固定”。在特定的目标2a中，将检查每个突变体感染小鼠的能力，这将阐明由固定基因型驱动的定义LOS结构如何在体内促进细菌适应性。鉴于我们的数据表明，改变LOS糖可以调节细菌活性在疫苗抗LOS AB中，我们将研究疫苗AB在特定AIM 2B中对每种“拟合” LOS基因型的效率。 AIM 2中的研究将将LOS Geno/表型与适应性相关联，使我们能够鉴定可以补充我们当前疫苗候选者的LOS结构。具有针对NG构成和普遍存在的外膜蛋白的AB的个体称为还原性可修饰蛋白（RMP）的个体显示出针对NG的杀菌活性受损，并且患有淋病收缩的风险更高。在特定的目标3中，我们将确定针对Ng的RMP块c依赖性AB杀死的ABS基础，并对疫苗AB的有效性产生负面影响。有趣的是，抗RMP AB不会阻止杀死脑膜炎猪笼草（NM）。将执行RMP的等位基因替代，以定义NG和NM RMP之间的微妙序列差异是否有助于两种病原体的阻塞差异。相应的NG和NM PORB分子也将在这两个物种上交换，以评估物种特异性PORB对阻断效应的共依赖性。拟议研究的完成将代表着针对淋病的新型疫苗开发的重要一步。