SELECTIVE DELETION OF NEUTROPHIL NADPH OXIDASE AND INNATE RESPONSES TO ASPERGILLUS FUMIGATUS

中性粒细胞 NADPH 氧化酶的选择性缺失和对烟曲霉的先天反应

• 批准号: 9368526
• 负责人: Mary C Dinauer
• 金额: $ 38.13万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-09 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9368526
• 关键词: Abscess; Address; Affect; Alveolar; Alveolar Macrophages; Antifungal Agents; Aspergillosis; Aspergillus; Aspergillus fumigatus; Attenuated; Bacterial Infections; Breathing; Cell Wall; Cells; Chemotactic Factors; Chronic Granulomatous Disease; Complication; Data; Disease; Dose; Enzymes; Exhibits; Failure; Gene Targeting; Genetic; Genetically Engineered Mouse; Goals; Granulomatous; Heritability; Hour; Human; Hyphae; Immune; Immune response; Immunity; Immunologic Deficiency Syndromes; Impairment; In Vitro; Infection; Infiltration; Inflammation; Inflammation Mediators; Inflammatory; Inflammatory Response; Inherited; Knockout Mice; Leukocytes; Life; Lung; Mediating; Mediator of activation protein; Molds; Molecular; Mus; Mutation; Mycoses; Myeloid Cells; NADPH Oxidase; Natural Immunity; Opportunistic Infections; Oxidants; Oxidases; Pathway interactions; Patients; Pattern; Phagocytes; Pharmaceutical Preparations; Phenotype; Play; Pneumonia; Production; Reactive Oxygen Species; Recurrence; Reporting; Reproduction spores; Residual state; Resistance; Risk; Role; S100A8 gene; Source; Sterility; Surface; Transgenes; Transgenic Organisms; Wild Type Mouse; Work; chemotherapy; cytokine; improved; in vivo; insight; killings; macrophage; microbicide; monocyte; mouse model; neutrophil; novel; novel therapeutic intervention; pathogen; patient population; prevent; receptor; response; restoration; superoxide-generating NADPH oxidase; translational impact

Summary Pneumonia resulting from inhaling spores of the opportunistic mold Aspergillus fumigatus (AF) remains a life- threatening complication of chronic granulomatous disease (CGD) and other conditions with compromised innate antifungal immunity. CGD is a heritable immunodeficiency arising from inactivating mutations in the phagocyte NADPH oxidase that generates superoxide (O2-).1, 2 Lack of microbicidal O2--derived reactive oxygen species (ROS) leads to recurrent bacterial and fungal infections. CGD patients are also prone to excessive and detrimental inflammation. Aspergillus pneumonia in CGD is associated with pyogranulomatous inflammation that complicates treatment. After conidia are inhaled, host receptors for fungal pathogen- associated molecular patterns (PAMPs) trigger inflammatory mediator production and activate killing by macrophages, neutrophils (polymorphonuclear leukocytes, PMN) and other leukocytes, which rapidly eliminates AF from normal hosts. Failure to do so results in AF pneumonia. Although patients with CGD and mice genetically engineered with similar mutations (CGD mice) are among the most susceptible, our understanding of how NADPH oxidase ROS control AF and its associated inflammation in the lung are ill- defined. To address this question, we developed new mouse models in which the NADPH oxidase is selectively deleted in PMN or resident lung alveolar macrophages (AM). Our preliminary data show that mice lacking only PMN NADPH oxidase ROS exhibited a phenotype similar to CGD mice, and were susceptible to both AF pneumonia and hyperinflammation following challenge with sterile fungal cell walls, despite intact NADPH oxidase activity in other cells. In contrast, mice lacking NADPH oxidase in AM, but with residual oxidase activity in most PMN and monocytes, resembled WT mice in these studies. We propose to determine how the PMN NADPH oxidase is crucial in the early innate responses to AF, including an unexplained role in regulating fungal PAMP-induced inflammation. In Aim 1, we will assess whether PMN ROS play a non- redundant role in the initial response to AF that is critical to prevent lung infection, although it is possible that other sources of oxidase ROS or non-oxidative mechanisms could suffice at low inocula. In Aim 2, we will determine how PMN NADPH oxidase regulates fungal PAMP-induced inflammation. We hypothesize that lack of PMN ROS leads to excessive release inflammatory cytokines, including PMN chemoattractants produced by PMN themselves. We will examine the response of oxidase-deficient PMN to sterile fungal PAMPs both in vitro and in the lung to determine how loss of PMN ROS exacerbates inflammation independent of active infection. We will investigate the impact of blocking specific inflammatory mediators after fungal cell wall challenge. If effective, we will evaluate this approach in CGD mice as a means to reduce excessive inflammation and improve control of AF. The proposed studies will provide novel insights into incompletely characterized factors that contribute to life-threatening infection with AF and guide new therapeutic strategies.

总结 由吸入机会性霉菌烟曲霉（AF）孢子引起的肺炎仍然是一种生命- 慢性肉芽肿病（CGD）和其他疾病的威胁并发症， 先天抗真菌免疫CGD是一种遗传性免疫缺陷，由免疫缺陷细胞中的失活突变引起。 吞噬细胞NADPH氧化酶，产生超氧化物（O2-）。1，2缺乏杀微生物O2-衍生反应 氧物种（ROS）导致反复的细菌和真菌感染。CGD患者也容易出现 过度和有害的炎症。CGD中的曲霉菌肺炎与脓肉芽肿相关 使治疗复杂化的炎症。分生孢子被吸入后，真菌病原体的宿主受体- 相关分子模式（PAMPs）触发炎症介质的产生并激活杀伤， 巨噬细胞、中性粒细胞（多形核白细胞，PMN）和其他白细胞， 消除正常主机的AF。否则会导致AF肺炎。尽管CGD患者和 具有类似突变的基因工程小鼠（CGD小鼠）是最易感的，我们 了解NADPH氧化酶ROS如何控制AF及其相关的肺部炎症， 定义了为了解决这个问题，我们开发了新的小鼠模型，其中NADPH氧化酶是 在PMN或肺泡巨噬细胞（AM）中选择性缺失。我们的初步数据显示， 仅缺乏PMN NADPH氧化酶的ROS表现出与CGD小鼠相似的表型，并且对 无菌真菌细胞壁激发后的AF肺炎和炎症过度，尽管完整 其他细胞中的NADPH氧化酶活性。相反，AM中缺乏NADPH氧化酶的小鼠， 在这些研究中，大多数PMN和单核细胞的氧化酶活性与WT小鼠相似。我们建议确定 PMN NADPH氧化酶如何在AF的早期先天反应中起关键作用，包括在 调节真菌PAMP诱导的炎症。在目标1中，我们将评估PMN ROS是否发挥非- 在对AF的初始反应中起着多余的作用，这对预防肺部感染至关重要，尽管有可能 其它来源的氧化酶ROS或非氧化机制在低接种量下可能足够。在目标2中，我们将 确定PMN NADPH氧化酶如何调节真菌PAMP诱导的炎症。我们假设缺乏 PMN ROS的过度释放导致炎性细胞因子的过度释放， PMN自己我们将在体外研究氧化酶缺陷型PMN对无菌真菌PAMPs的反应， 以及在肺中，以确定中性粒细胞活性氧的丧失如何独立于活动性感染而加重炎症。 我们将研究真菌细胞壁攻击后阻断特定炎症介质的影响。如果 有效，我们将在CGD小鼠中评估这种方法作为减少过度炎症的手段， 改善AF的控制。拟议的研究将提供新的见解不完全特征的因素 这有助于威胁生命的房颤感染，并指导新的治疗策略。