Outer Membrane Proteins of Francisella tularensis as Acellular Vaccines

土拉弗朗西斯菌外膜蛋白作为无细胞疫苗

• 批准号: 7676562
• 负责人: MICHAEL V. NORGARD
• 金额: $ 47.28万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-15 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7676562
• 关键词: Acellular Vaccines; Adjuvant; Aerosols; Antibodies; Bacteria; Categories; Cell membrane; Francisella tularensis; Gram-Negative Bacteria; Growth; Human; ISCOMs; Immune Targeting; Immune response; Immunity; Immunization; In Vitro; Infection; Investigation; Knowledge; Lipids; Lipoproteins; Liposomes; Lung; Membrane; Membrane Proteins; Methods; Mus; OprF protein; Pathogenesis; Recombinants; Role; Route; Subunit Vaccines; Sucrose; System; Testing; Time; Tularemia; Vaccines; Virulence Factors; biodefense; cytokine; density; in vivo; intraperitoneal; monocyte; mouse model; mutant; novel vaccines; pathogen; physical separation; research study

Outer membrane proteins (OMPs) and lipoproteins (IPs) of Gram-negative bacteria are of enormous importance as virulence factors, stabilizers of outer membrane integrity, and protective immune targets (vaccines). To date, little has been known regarding the OMPs of Francisella tularensis (Type A) strains that are pathogenic for humans (e.g., F. tularensis SCHU S4). However, selected OMPs could prove invaluable as subunit vaccines for tularemia. In this regard, we have achieved two important milestones that warrant further investigation of the OMPs as acellular vaccines for tularemia. First, we developed a sucrose density gradient method for the physical separation of the outer and cytoplasmic membranes of F. tularensis (J.F. Huntley et al., 2007, J. Bacteriol. 189:561). This method has allowed, for the first time, direct examination of the OMP components of this important Category A select agent. Second, we have demonstrated that OMP-immunized mice are protected against intranasal challenge with SCHU S4. We now wish to extend these studies by completing the identification of the entire spectrum of OMPs in F. tularensis SCHU S4 (Aim 1). We also will test native and recombinant OMPs of SCHU S4 for their vaccinogenic potentials using mouse models of tularemia (Aim 2). Various routes for mouse immunizations (intraperitoneal, intranasal) and pulmonary challenges (intranasal, aerosol) will be employed. As part of this initiative, we also will examine newer adjuvants (e.g., cationic lipid-DNA liposomes, ISCOMs, CpG, and AdDP) to potentially enhance immunoprotection. In Aim 3, we shall investigate the humoral aspect of protective immunity induced by OMP vaccines by performing passive transfer experiments in mice, and by assessing antibody classes and isotypes elicited. Included in these studies will be assessments of key correlates of protective immunity (Th1 and Th2 cytokines, regulators, etc.); humanized mice may be particularly useful for these studies. As an off-shoot of this project, we also shall evaluate the roles of selected OMPs and LPs as virulence factors for F. tularensis by examining OMP-deficient mutants in both in vitro (infection/growth in human monocytes) and in vivo (mouse infection) systems. The combined studies will provide important new knowledge for understanding F. tularensis pathogenesis and for devising new acellular vaccines for tularemia.

革兰氏阴性菌的外膜蛋白（OMPs）和脂蛋白（IPs）是革兰氏阴性菌的重要组成部分， 作为毒力因子、外膜完整性的稳定剂和保护性免疫靶标的重要性 （疫苗）。迄今为止，关于土拉热弗朗西丝菌（A型）菌株的外膜蛋白知之甚少， 对人致病（例如，F. tularensis SCHU S4）。然而，选定的办公室管理计划可以证明是非常宝贵的， 兔热病的亚单位疫苗。在这方面，我们取得了两个重要的里程碑， OMPs作为土拉菌病无细胞疫苗的研究。首先，我们开发了一种蔗糖密度梯度 一种物理分离F. tularensis（J.F.亨特利等人， 2007，J. Bacteriol. 189：561）。这种方法首次允许直接检查OMP 这一重要的A类选择代理的组成部分。第二，我们已经证明，OMP免疫 保护小鼠免受SCHUS 4的鼻内攻击。我们现在希望扩大这些研究， 完成了F.土拉热菌S4（Aim 1）。我们还将测试 SCHU S4的天然和重组外膜蛋白在兔热病小鼠模型中的疫苗原性潜力 (Aim 2）。用于小鼠免疫的多种途径（腹膜内、鼻内）和肺部激发 （鼻内，气雾剂）。作为这项倡议的一部分，我们还将研究新的佐剂（例如， 阳离子脂质-DNA脂质体、ISCOM、CpG和AdDP）以潜在地增强免疫保护。在目标3中，我们 应通过被动免疫试验研究OMP疫苗诱导的保护性免疫的体液方面。 小鼠中的转移实验，并通过评估引发的抗体类别和同种型。这些研究中包括 将评估保护性免疫的关键相关因素（Th 1和Th 2细胞因子、调节因子等）; 人源化小鼠可特别用于这些研究。作为该项目的一个分支，我们还将 评价选择的OMPs和LPs作为F.土拉热症通过检查OMP缺陷 突变体在体外（人单核细胞中的感染/生长）和体内（小鼠感染）系统中。的 联合研究将为认识F.土拉热病发病机制和形成 为兔热病设计新的无细胞疫苗。