A Meningococcal LOS Vaccine

脑膜炎球菌 LOS 疫苗

基本信息

批准号：
7364618
负责人：
JOHN McLeod GRIFFISS
金额：
$ 38.01万
依托单位：
NORTHERN CALIFORNIA INSTITUTE/RES/EDU
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-06-15 至 2010-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7364618
关键词：
4 year old Adolescence Adult Affect Affinity Age Age-Years Americas Anions Antibiotic Therapy Antibiotics Antibodies Bacteriophages Binding Birth Cells Child Class Conjugate Vaccines Consensus Coupled Data Diphtheria Toxoid Disease Endemic Diseases Epidemic Europe Failure Flow Cytometry Future Galactose Gel Genes Goals Human Human Activities Immunity Immunoglobulin G Infant Intravenous Immunoglobulins Lead Libraries Licensing Life Location MALDI-TOF Mass Spectrometry Mass Chromatography Mediating Membrane Proteins Meningococcal vaccine Neisseria meningitidis Neural Cell Adhesion Molecules Oligosaccharides Organism Pan Genus Peptides Performance Phage Display Polysaccharides Population Preparation Prevention Protein Dephosphorylation Proteins Resistance development Sampling Sepharose Serotyping Specificity Spectrometry Structure Surface Plasmon Resonance Target Populations Time Transferase United States Food and Drug Administration Vaccines Week antimicrobial bactericide base capsule chemical genetics cross reactivity deacylation disorder risk early childhood fetal immunogenic infancy killings lipooligosaccharide mutant numb protein phosphoethanolamine prevent response sialylation vaccine development

项目摘要

DESCRIPTION (provided by applicant): Group B meningococci affect very young children. The group B capsule is not immunogenic, and protein vaccines provide only short-lived, serotype restricted, protection in older children. A vaccine for infants is needed. Protection is mediated by bactericidal antibodies that are induced by commensal organisms that share lipooligosaccharides (LOS). LOS are immunogenic at birth, and infants make bactericidal LOS antibodies during disease. By adolescence most children have LOS IgG that are bactericidal for most meningococcal strains. These antibodies bind to one or more conserved structures that have not been identified. It is these antibodies that prevent meningococcal disease in older children and adults. It is the goal of this project to develop a vaccine that reliably will induce bactericidal LOS IgG during infancy. To do this we first need to define the optimal LOS structure that can bind bactericidal IgG. We purified human LOS IgGs by passage of IVIG through Sepharose to which we coupled L1; L1,1a,8; L2,4; L8v; L2; and L7 LOS. These IgGs avidly bind one or more conserved structure within heterologous LOS and are bactericidal for strains that express heterologous LOS. We identified a consensus peptide that mimics the conserved LOS structure by panning a phage display library. Preliminary analyses suggest that: a) the LOS oligosaccharide must have at least one galactose residue for optimal binding; b) sialylation decreases binding; c) the pools contain both L-type and conserved specificities, and d) the number and location - cyclic or exocyclic - of basal phosphoethanolamine (PEA) influences the specificity and/or affinity of binding. We now propose to enrich for IgG that binds the conserved LOS structure by sequential passage of IgG over heterologous affinity gels and assess how well each IgG kills a representative sample of endemic case strains, and whether they can opsonize these strains for PMN killing. We will use High Performance Anion- Exchange Chromatography and Mass Spectrometry, each combined with genetic, chemical and/or enzymatic degradations, including O-deacylation of lipoidal moieties and dephosphorylation of glycose and lipoidal moieties, to identify the optimal conserved LOS structure that binds bactericidal LOS IgG. We will sequence the Igt genes that encode LOS glycosyl transferases and create mutants with sequential loss of glycoses from their LOS oligosaccharides and loss of cyclic and/or exocyclic PEA residues. We will assess the binding of IgG to these mutants by Flow cytometry and determine the affinity with which LOS IgG binds native and altered LOS by surface plasmon resonance. We will compare the ability of peptide mimics, identified by phage display panning with different LOS IgG, to inhibit the heterologous binding to, and killing of, the case strains, in order to determine whether more than one conserved structure is involved. The results should lead to the development of a vaccine against group B disease in infants.

描述（由申请人提供）：B 组脑膜炎球菌影响幼儿。 B 组胶囊不具有免疫原性，而蛋白质疫苗只能为年龄较大的儿童提供短暂的、血清型限制的保护。需要针对婴儿的疫苗。保护作用是由共享脂寡糖 (LOS) 的共生生物诱导的杀菌抗体介导的。 LOS 在出生时具有免疫原性，婴儿在患病期间会产生杀菌性 LOS 抗体。到了青春期，大多数儿童都具有 LOS IgG，对大多数脑膜炎球菌菌株具有杀菌作用。这些抗体与一种或多种尚未鉴定的保守结构结合。正是这些抗体可以预防年龄较大的儿童和成人的脑膜炎球菌病。该项目的目标是开发一种能够在婴儿期可靠诱导杀菌 LOS IgG 的疫苗。为此，我们首先需要定义可以结合杀菌 IgG 的最佳 LOS 结构。我们通过 IVIG 通过琼脂糖凝胶纯化人 LOS IgG，并偶联 L1； L1,1a,8； L2,4； L8v； L2；和 L7 视距。这些 IgG 强烈结合异源 LOS 内的一种或多种保守结构，并且对表达异源 LOS 的菌株具有杀菌作用。我们通过淘选噬菌体展示文库鉴定了一种模拟保守 LOS 结构的共有肽。初步分析表明： a) LOS 寡糖必须具有至少一个半乳糖残基才能实现最佳结合； b) 唾液酸化降低结合； c) 池包含 L 型和保守特异性，d) 基础磷酸乙醇胺 (PEA) 的数量和位置（环状或环外）影响结合的特异性和/或亲和力。我们现在建议通过 IgG 在异源亲和凝胶上连续传代来富集结合保守 LOS 结构的 IgG，并评估每种 IgG 杀死地方性病例菌株代表性样本的效果，以及它们是否可以调理这些菌株来杀死 PMN。我们将使用高效阴离子交换色谱法和质谱法，分别与遗传、化学和/或酶促降解相结合，包括类脂部分的 O-脱酰化以及糖和类脂部分的去磷酸化，以确定结合杀菌剂的最佳保守 LOS 结构LOS IgG。我们将对编码 LOS 糖基转移酶的 Igt 基因进行测序，并创建突变体，其 LOS 寡糖中的糖连续丢失，并且环状和/或环外 PEA 残基丢失。我们将通过流式细胞术评估 IgG 与这些突变体的结合，并通过表面等离子共振确定 LOS IgG 结合天然和改变的 LOS 的亲和力。我们将比较通过噬菌体展示淘选不同 LOS IgG 鉴定的肽模拟物抑制与病例菌株异源结合和杀死病例菌株的能力，以确定是否涉及多个保守结构。研究结果应有助于开发针对婴儿 B 组疾病的疫苗。