Mechanisms of adaptive immunity to P. aeruginosa in the lung

肺部对铜绿假单胞菌的适应性免疫机制

基本信息

批准号：
8448644
负责人：
Gregory P Priebe
金额：
$ 40.95万
依托单位：
BRIGHAM AND WOMEN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-01 至 2014-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8448644
关键词：
Active Immunization Acute Acute Pneumonia Acylation Adoptive Transfer Antibodies Antigens Attenuated Attenuated Live Virus Vaccine Attenuated Vaccines Bacterial Pneumonia Bronchoalveolar Lavage Fluid CD4 Positive T Lymphocytes Cell secretion Cells Chronic Complex Cystic Fibrosis Cystic Fibrosis Transmembrane Conductance Regulator Data Defect Development Dose Effectiveness Effector Cell Engineering Evaluation Generations Goals Health Helper-Inducer T-Lymphocyte Human Immune Immune response Immunity Immunization Immunophenotyping In Vitro Infection Inflammation Integration Host Factors Interleukin-17 Knowledge Leukocytes Life Lipid A Lipopolysaccharides Lung Mechanical ventilation Molecular Mus Neutrophil Infiltration Nose O Antigens Passive Immunization Passive Transfer of Immunity Patients Pattern Pneumonia Protein Array Proteins Pseudomonas aeruginosa Recruitment Activity Relative (related person)Research Role Serum Signal Transduction Site T-Lymphocyte Transcript Transgenic Mice Transgenic Organisms Vaccinated Vaccination Vaccine Production Vaccines Variant Virulent Wild Type Mouse Work adaptive immunity base chemokine cystic fibrosis mouse cystic fibrosis patients cytokine fighting improved in vivo mouse model mutant neutrophil pathogen prevent protective efficacy receptor research study response toll-like receptor 4 vaccine efficacy vector

项目摘要

DESCRIPTION (provided by applicant): Pseudomonas aeruginosa is an important cause of serious infections in humans with a predilection for lung infections in the form of either acute pneumonia in hospitalized patients (usually associated with mechanical ventilation) or chronic pneumonia in people with cystic fibrosis (CF). The central goal of the proposed project is a better understanding of the host factors contributing to pulmonary immunity to P. aeruginosa infections, with the ultimate goal of developing an intranasal vaccine for use in humans. We have shown that nasal immunization with live-attenuated aroA deletion mutants of P. aeruginosa is highly protective against pneumonia in mice caused by P. aeruginosa strains having the same lipopolysaccharide (LPS) O antigen as the vaccine (called serogroup-homologous strains). New preliminary studies have shown that intact toll-like receptor 4 (TLR4) signaling is required for optimal protective efficacy of the vaccine but not for generation of opsonic antibody while immunization of transgenic CF mice results in deficient levels of opsonic antibody yet the vaccine's protective efficacy is preserved. We recently constructed an attenuated vaccine strain that can protect against pneumonia caused by LPS-heterologous strains in the absence of serum opsonic antibody. With this vaccine, preliminary studies have found that early after bacterial challenge of wild-type mice, the cytokine IL- 17 is produced by a greater number of lung T cells, can be found at higher levels in bronchoalveolar lavage fluid compared with control vaccines, and is associated with more rapid recruitment of neutrophils to the airways. Depletion of IL-17 before challenge of immunized mice or absence of its receptor abrogates the vaccine's efficacy. These preliminary experiments have led to the hypothesis that in the adaptive immune response to P. aeruginosa in the lung, T cell-derived IL-17, and thus the recently described Th17 lineage of helper T cells, is required for optimal vaccine-induced protection. We propose to explore this hypothesis by analyzing the immunophenotypes and transcripts of T cells recruited to the lungs of immunized mice after bacterial challenge of wild-type as well as TLR4-deficient mice and transgenic CF mice. We also will determine which P. aeruginosa proteins elicit Th17 responses using a P. aeruginosa protein array. The relative contributions of Th17 cells and opsonic antibody in vaccine-induced protection from acute pneumonia and the mechanisms underlying protection will be evaluated by adoptive transfer experiments combined with passive immunization, by neutralization of IL-17 prior to challenging immunized mice, and by immunization of transgenic mice deficient in IL-17. Finally, we will assess whether expression of heterologous O antigens by the vaccine or changes in its LPS lipid A acylation pattern can enhance its effectiveness. Knowledge gained from these studies will be instrumental not only for a better understanding of the role of Th17 cells in the adaptive immune response to P. aeruginosa in the lung but also for the development of an effective vaccine against this significant human pathogen.

描述（由申请人提供）：铜绿假单胞菌是人类严重感染的重要原因，肺部感染偏爱住院患者（通常与机械通气有关）或慢性肺炎患者（CF）患者的急性肺炎形式（通常与机械通气有关）或慢性肺炎。拟议项目的核心目标是更好地理解宿主因素对铜绿假单胞菌感染的肺部免疫，最终目标是开发用于人类使用的鼻内疫苗。我们已经表明，铜绿假单胞菌的活体降生的AROA缺失突变体具有高度保护性的铜绿假单胞菌菌株引起的小鼠肺炎，具有相同的脂多糖（LPS）O抗原与疫苗（称为血清群菌株）。新的初步研究表明，完整的TOLL样受体4（TLR4）信号传导是为了使疫苗的最佳保护功效而不是产生Opsonic抗体，而转基因CF小鼠的免疫接种则导致疫苗抗体水平不足，但疫苗的保护效率却保留下来。我们最近建立了一种减毒的疫苗菌株，可以在没有血清opsonic抗体的情况下预防由LPS定位菌株引起的肺炎。借助这种疫苗，初步研究发现，在野生型小鼠的细菌挑战之后，细胞因子IL-17由更多的肺T细胞产生，与对照疫苗相比，在支气管肺泡灌洗液中可以发现较高水平，并且与中性粒细胞的快速募集相关。 IL-17在挑战免疫小鼠或缺乏其受体之前的耗竭可消除疫苗的功效。这些初步实验导致了以下假设：在对肺中对铜绿假单胞菌的自适应免疫反应中，T细胞衍生的IL-17，因此最近描述的助手T细胞的Th17谱系是最佳疫苗诱导的保护所必需的。我们建议通过分析野生型细菌挑战以及TLR4缺陷型小鼠和转基因CF小鼠的细菌挑战后，募集到免疫小鼠肺部的T细胞的免疫表型和转录本来探讨这一假设。我们还将确定使用铜绿假单胞菌蛋白阵列会产生哪种铜绿假单胞菌蛋白。 Th17细胞和OPSONIC抗体在疫苗诱导的急性肺炎的保护中的相对贡献以及通过在有挑战性的免疫小鼠之前对IL-17进行中和IL-17的中和IL-17的相结合以及通过在IL-17中进行免疫接种，通过中和IL-17的中和IL-17来评估IL-17的无源转移实验。最后，我们将评估疫苗异源O抗原的表达或其LPS脂质A酰基化模式的变化是否可以提高其有效性。从这些研究中获得的知识将不仅可以更好地理解Th17细胞在肺中对铜绿假单胞菌的适应性免疫反应中的作用，而且还为针对这种重要的人类病原体的有效疫苗开发。