Oxidative killing of Pneumococcus

氧化杀死肺炎球菌

• 批准号: 10116271
• 负责人: Balazs Rada
• 金额: $ 22.65万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10116271
• 关键词: Affect; Air; Animal Model; Anions; Anti-Bacterial Agents; Attention; Attenuated; Autolysis; Automobile Driving; Bacteria; Biology; Cells; Child; Data; Economic Burden; Elderly; Encapsulated; Epithelial Cells; Foundations; Future; Goals; HIV; Human; Hydrogen Peroxide; Immune; Immune response; Impairment; In Vitro; Infection; Innate Immune Response; Innate Immune System; Intervention; Knowledge; Liquid substance; Lung; Lung infections; Mediating; Meningitis; Mission; Modeling; Mus; NADPH Oxidase; Outcome; Oxidases; Oxides; Pathogenesis; Patients; Pneumococcal Infections; Pneumonia; Production; Proteins; Public Health; Publishing; Research; Respiration; Role; Septicemia; Source; Streptococcus pneumoniae; System; Testing; Therapeutic; Thiocyanates; Time; Tissues; United States National Institutes of Health; Work; airway epithelium; airway surface liquid; anti-influenza; antimicrobial; apical membrane; base; bronchial epithelium; cell killing; co-infection; community acquired pneumonia; design; extracellular; fighting; human disease; hypothiocyanite; improved; in vitro testing; in vivo; influenza infection; influenza pneumonia; innate immune mechanisms; innovation; lung injury; microbicide; mortality; mouse model; novel; novel therapeutics; oxidation; respiratory; respiratory pathogen; weapons

Streptococcus pneumoniae (Spn) is the main cause of community acquired pneumonia and meningitis in children and the elderly, and of septicemia in HIV patients. Boosting the function of host immune responses could offer novel intervention strategies against Spn. There is a critical gap in our knowledge to identify new, broad range, anti-Spn mechanisms of the respiratory innate immune system. Bronchial epithelial cells (BEC) are the primary responders to Spn infection. BECs orchestrate an oxidative extracellular antimicrobial system present in the airway surface liquid consisting of the protein lactoperoxidase (LPO), the thiocyanate anion (SCN-) and hydrogen peroxide (H2O2). LPO oxidizes SCN- using H2O2 into microbicidal hypothiocyanite (OSCN-). Dual oxidase 1 (Duox1), an NADPH oxidase protein highly expressed in the apical membrane of BECs, is the H2O2 source for the antimicrobial action of LPO. Our preliminary result show that the Duox1/LPO-based system efficiently kills several strains of Spn in different experimental systems. Our long-term goal is to determine whether the Duox1/LPO/SCN- antibacterial system could be manipulated in Spn infection for therapeutic purposes in humans. The objective of this proposal is to establish the anti-Spn role of the Duox1/LPO-based oxidative mechanism. Based on preliminary data our central hypothesis is that the Duox1/H2O2/LPO/SCN- system kills Spn bacteria in a strain-independent manner, attenuates infection and associated tissue damage in a mouse model of Spn lung infection. To test this hypothesis, our specific aims are to determine the mechanism of Spn killing by Duox1/LPO in vitro, to establish the in vivo role of Duox1 in Spn killing, and to explore whether therapeutic manipulation of the Duox1/LPO-based system attenuates Spn pneumonia in an animal model. The rationale for the proposed research is that we need to characterize how powerful the Duox1/LPO-based system is in fighting Spn to explore its therapeutical potential in humans in the future. It is anticipated that our aims will yield the following expected outcomes: 1) identification of the antibacterial mechanism of the Duox1/LPO-based system against Spn, 2) establishing the in vivo relevance of Duox1 in Spn infection; and 3) providing essential results on the therapeutic potential of the Duox1/LPO-based mechanism to attenuate Spn lung infection. Our innovative work shows that a unique antimicrobial system is powerful in killing Spn and explores a novel, nontraditional immune mechanism for its potential to be used against a major lung pathogen. In summary, our proposal will have a positive impact in the fields of airway epithelial and Spn biology, and general antibacterial innate immune responses by identifying Duox1 and LPO, as a novel, crucial, innate immune weapons of the respiratory innate immune system against Spn.

肺炎链球菌（SPN）是社区获得肺炎的主要原因， 儿童和老年人的脑膜炎，以及HIV患者的败血病。增强主机的功能 免疫反应可以提供针对SPN的新干预策略。我们有关键的差距 知识以识别呼吸有先天免疫系统的新范围，抗SPN机制。 支气管上皮细胞（BEC）是对SPN感染的主要反应者。 BEC策划AN 由蛋白质组成的气道表面液体中的氧化细胞外抗菌系统 乳糖氧化酶（LPO），硫氰酸硫代阴离子（SCN-）和过氧化氢（H2O2）。 LPO氧化SCN- 使用H2O2进入杀生性下刺洋石（OSCN-）中。双氧化酶1（DUOX1），NADPH氧化酶 在BEC的顶端膜中高度表达的蛋白质是抗菌作用的H2O2来源 LPO。我们的初步结果表明，基于DUOX1/LPO的系统有效杀死了几种菌株 在不同的实验系统中的SPN。我们的长期目标是确定DUOX1/LPO/SCN-是否是否 可以在SPN感染中操纵抗菌系统，以实现人类的治疗目的。这 该建议的目的是建立基于DUOX1/LPO的氧化机制的抗SPN作用。 基于初步数据，我们的中心假设是DUOX1/H2O2/LPO/SCN-系统杀死SPN 细菌以应变非依赖性方式减弱小鼠的感染和相关组织损伤 SPN肺部感染的模型。为了检验这一假设，我们的具体目的是确定机制 Duox1/LPO在体外杀死SPN的杀戮，以确定Duox1在SPN杀死中的体内作用，并探索 DUOX1/基于LPO的系统的治疗操作是否会减弱SPN肺炎 动物模型。拟议研究的理由是，我们需要表征 DUOX1/基于LPO的系统正在与SPN进行战斗，以探索其未来在人类中的治疗潜力。 预计我们的目标将产生以下预期结果：1）识别 基于DUOX1/LPO的SPN系统的抗菌机制，2）建立体内 DUOX1在SPN感染中的相关性； 3）提供有关治疗潜力的基本结果 DUOX1/LPO基于减弱SPN肺部感染的机制。我们的创新工作表明，一个独特的 抗菌系统在杀死SPN并探索一种新颖的非传统免疫机制方面具有强大的功能 它的潜力用于用于主要的肺病原体。总而言之，我们的建议将有积极的 对气道上皮和SPN生物学领域的影响，以及一般的抗菌先天免疫 通过识别Duox1和LPO的反应，是一种新颖的，至关重要的先天免疫武器 对SPN的先天免疫系统。