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: 8377059
• 负责人: MICHAEL V. NORGARD
• 金额: $ 42.2万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8377059
• 关键词: Acellular Vaccines; Adjuvant; Aerosols; Antibodies; Bacteria; Categories; Cell membrane; DNA; 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; induced pluripotent stem cell; 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.

革兰氏阴性细菌的外膜蛋白（OMP）和脂蛋白（IPS）是巨大的 重要性是毒力因素，外膜完整性的稳定器和保护性免疫靶标 （疫苗）。迄今 人类的致病性（例如F. tularensis schu S4）。但是，选定的OMP可能是无价的 亚基的亚基疫苗。在这方面，我们取得了两个重要的里程碑，需要进一步 研究OMPS作为细胞疫苗的细胞疫苗。首先，我们开发了一个蔗糖密度梯度 F. tularensis的外部和细胞质膜的物理分离方法（J.F. Huntley等， 2007年，J。Bacteriol。 189：561）。该方法首次允许直接检查OMP 此重要类别的组件选择代理。其次，我们已经证明了OMP免疫 小鼠受到Schu S4的鼻内挑战的保护。我们现在希望通过 完成tularensis schu S4中OMPS的整个频谱的识别（AIM 1）。我们还将测试 Schu S4的天然和重组OMP使用小鼠模型的疫苗生成电位 （目标2）。小鼠免疫的各种途径（腹膜内，鼻内）和肺挑战 （鼻内，气溶胶）将被使用。作为该倡议的一部分，我们还将检查更新的佐剂（例如， 阳离子脂质-DNA脂质体，ISCOMS，CPG和ADDP）可能会增强免疫保护。在AIM 3中，我们 应通过执行被动疫苗引起的保护性免疫的体外 在小鼠中转移实验，并通过评估引起的抗体类和同种异体。包括这些研究 将评估保护性免疫的关键相关性（Th1和Th2细胞因子，调节剂等）； 人源化小鼠可能对这些研究特别有用。作为该项目的分支，我们也将 通过检查OPM缺陷率，评估选定的OMP和LP作为F. tularensis的毒力因子的作用 体外（人单核细胞中的感染/生长）和体内（小鼠感染）系统中的突变体。这 合并的研究将为理解F. tularensis发病机理和用于 设计新的细胞疫苗来促进菌血症。