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.

革兰氏阴性菌的外膜蛋白（OMP）和脂蛋白（IP）具有巨大的作用 作为毒力因子、外膜完整性稳定剂和保护性免疫靶标的重要性 （疫苗）。迄今为止，人们对土拉弗朗西斯菌（A 型）菌株的 OMP 知之甚少。 对人类致病（例如 F. tularensis SCHU S4）。然而，选定的 OMP 可能会被证明是无价的，因为 兔热病亚单位疫苗。在这方面，我们已经实现了两个重要的里程碑，值得进一步 OMP 作为兔热病非细胞疫苗的研究。首先，我们开发了蔗糖密度梯度 物理分离 F. tularensis 外膜和细胞质膜的方法（J.F. Huntley 等人， 2007，细菌杂志。 189:561）。该方法首次允许直接检查 OMP 这一重要的 A 类选择剂的组成部分。其次，我们证明了 OMP 免疫 SCHU S4 可以保护小鼠免受鼻内攻击。我们现在希望通过以下方式扩展这些研究 完成 F. tularensis SCHU S4 中 OMP 全谱的鉴定（目标 1）。我们也会测试 使用兔热病小鼠模型研究 SCHU S4 的天然和重组 OMP 的疫苗接种潜力 （目标 2）。小鼠免疫接种（腹膜内、鼻内）和肺部免疫的多种途径 将使用（鼻内、气雾剂）。作为该计划的一部分，我们还将研究更新的佐剂（例如， 阳离子脂质-DNA 脂质体、ISCOM、CpG 和 AdDP）可潜在增强免疫保护。在目标 3 中，我们 应通过进行被动研究来研究 OMP 疫苗诱导的保护性免疫的体液方面 在小鼠中进行转移实验，并通过评估引发的抗体类别和同种型。包含在这些研究中 将评估保护性免疫的关键相关因素（Th1 和 Th2 细胞因子、调节因子等）； 人源化小鼠可能对这些研究特别有用。作为该项目的一个分支，我们还将 通过检查 OMP 缺陷来评估选定的 OMP 和 LP 作为 F. tularensis 毒力因子的作用 体外（人类单核细胞的感染/生长）和体内（小鼠感染）系统中的突变体。这 联合研究将为理解 F. tularensis 发病机制和 设计新的兔热病非细胞疫苗。