Neutrophil heterogeneity and function in host defense during pulmonary infection

肺部感染期间中性粒细胞的异质性和宿主防御功能

• 批准号: 10645077
• 负责人: Jane C Deng
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10645077
• 关键词: Adopted; Animals; Anti-Bacterial Agents; Antibiotics; Bacteria; Bacterial Infections; Bacterial Pneumonia; Biological Response Modifiers; Bone Marrow; Cause of Death; Cell Count; Cell Surface Receptors; Cells; Characteristics; Chronic; Circulation; Clinical Management; Cytometry; Data; Development; Effector Cell; Elderly; Equilibrium; Focal Infection; Gene Expression; Gene Expression Profiling; Generations; Heterogeneity; Histology; Host Defense; Human; Immune; Immunologic Receptors; Immunology; Impairment; Individual; Infection; Inflammatory; Inflammatory Response; Influenza; Ingestion; Interferon Type I; Investigation; Lead; Leukocytes; Literature; Lung; Lung infections; Malignant Neoplasms; Mediating; Mediator; Medical; Molecular; Mus; Myelogenous; Nature; Pathway interactions; Patients; Pattern; Performance; Phagocytosis; Phenotype; Pneumococcal Infections; Pneumonia; Population; Predisposition; Production; Reactive Oxygen Species; Regulation; Reporting; Research; Resistance; Role; Secondary to; Site; Spleen; Stimulus; Streptococcus pneumoniae; Techniques; Technology; Testing; Time; Veterans; Viral; Viral Pathogenesis; Viral Respiratory Tract Infection; Virus Diseases; antimicrobial; bactericide; cell type; cytokine; demographics; extracellular; fighting; flu; high risk; immunomodulatory therapies; immunoregulation; improved; in vivo; infection risk; influenza infection; influenza pneumonia; military veteran; mouse model; neutrophil; novel; pandemic influenza; pathogen; patient population; receptor expression; recruit; response; transcriptome; transcriptome sequencing

Secondary bacterial pneumonias complicating influenza and respiratory viral infections are more severe than primary pneumonias and often fatal, but why this occurs is unclear. Our data demonstrate that neutrophils, which are the most abundant white blood cell and critical for fighting bacterial infections, from influenza-infected animals display impaired ability to ingest and kill bacteria, compared to neutrophils from uninfected and bacteria-infected animals. To date, neutrophils have been largely considered to be a homogenous cell population, where the most important factor is whether an infected host has sufficient numbers of neutrophils to fight infection or not. However, our preliminary data suggest that neutrophils can adopt different subtypes - for example, our analysis of gene expression patterns of neutrophils isolated from mouse lung following influenza or Streptococcus pneumoniae infection reveal that neutrophils from virally infected animals ("flu-PMNs") significantly differ from neutrophils isolated from bacterially- (S. pneumoniae) infected animals ("Sp-PMNs"), suggesting that distinct phenotypes of neutrophils emerge in the context of different types of infection. However, neutrophil specialization is a concept that has been poorly recognized and understood particularly in the context of infection, although studies from the cancer literature strongly support this emerging concept. This application tests the hypothesis that neutrophils adopt distinct phenotypes under conditions of viral (influenza) versus bacterial (S. pneumoniae) pneumonia, which is a mechanism contributing to secondary bacterial infections. In addition, we will test the hypothesis that type I interferons, which are a central immune mediator induced by viral infections, lead to the development of the flu-PMN phenotype. The studies in Aim 1 will examine how viral versus bacterial infections regulate critical neutrophil functions over time, including phagocytosis, bacterial killing, reactive oxygen species generation, neutrophil extracellular trap formation, cytokine production, and degranulation responses. In addition, transcriptome changes in neutrophils isolated from the bone marrow, systemic (spleen), and local (lung) compartments of influenza versus S. pneumoniae-infected animals to determine where different neutrophil subtypes develop, and what molecular pathways are activated that might result in different neutrophil phenotypes that emerge during viral and bacterial infection. Finally, the expression pattern of multiple immune receptors will be performed using a powerful novel technique, mass cytometry, to determine whether the balance between activating and inhibitory immune receptors expressed on neutrophils govern changes in neutrophil activities. Aim 2 will examine the in vivo mechanisms underlying how type I interferons regulate the development of the flu-PMN phenotype, and investigate the mechanisms underlying the observation that flu-infected animals who receive neutrophils from bacterially-infected animals have improved ability to fight subsequent bacterial infection compared to their counterparts who receive neutrophils from virally-infected animals. Inflammatory responses in the lung will be determined by examining cell counts and differentials, cytokine levels of lung homogenates over time, and histology. In vivo regulation of phagocytosis and bactericidal activity by exogenous neutrophil administration will be quantified. The results of these studies will identify neutrophil subtypes on the basis of deep phenotyping investigations, as well as help us understand how the effects of type I interferons on neutrophil phenotypes might increase susceptibility to bacterial pneumonia in subjects with flu infection. These findings will be paradigm-shifting to the field of immunology, which largely considers neutrophils as a fairly homogenous effector cell population with limited functionality. In addition, the results will identify new targets that can form the basis for immune regulating therapies aimed at modulating neutrophil function, instead of simply focusing on whether patients have sufficient numbers of neutrophils.

次生细菌性肺炎使流感和呼吸道病毒感染复杂化更为严重 比原发性肺炎和经常致命，但是为什么会发生这种情况。我们的数据表明 中性粒细胞是最丰富的白细胞，对于与细菌感染作斗争至关重要 与来自中性粒细胞相比 未感染和细菌感染的动物。迄今为止，中性粒细胞在很大程度上被认为是 同质细胞种群，其中最重要的因素是感染宿主是否足够 中性粒细胞的数量是否与感染作斗争。但是，我们的初步数据表明中性粒细胞可以 采用不同的亚型 - 例如，我们对从中分离的中性粒细胞基因表达模式的分析 流感或肺炎链球菌感染后的小鼠肺肺部表明，嗜中性粒细胞来自病毒 感染的动物（“流感-PMN”）与从细菌（肺炎链球菌）分离的中性粒细胞显着不同 感染动物（“ SP-PMN”），表明中性粒细胞的不同表型在背景下出现 不同类型的感染。但是，嗜中性粒细胞专业化是一个概念很差的概念 尽管癌症文献的研究很强​​，但在感染的背景下特别理解 支持这个新兴概念。该应用检验了中性粒细胞采用不同表型的假设 在病毒（流感）与细菌（肺炎链球菌）肺炎的条件下，这是一种机制 导致继发细菌感染。此外，我们将测试I型干扰素的假设， 这是由病毒感染诱导的中央免疫介质，导致流感-PMN的发展 表型。 AIM 1中的研究将检查病毒和细菌感染如何调节关键中性粒细胞 随着时间的流逝，功能，包括吞噬作用，细菌杀伤，活性氧产生，中性粒细胞 细胞外陷阱形成，细胞因子产生和脱粒反应。另外，转录组 从骨髓，全身性（脾）和局部（肺）室分离出的中性粒细胞的变化 流感与肺炎链球菌感染动物，以确定不同的中性粒细胞亚型的发展中， 以及哪种分子途径被激活，可能导致出现的不同嗜中性粒细胞表型 在病毒和细菌感染期间。最后，多种免疫受体的表达模式将是 使用强大的新技术质量细胞仪进行，以确定是否在 嗜中性粒细胞表达的激活和抑制性免疫受体控制中性粒细胞活性的变化。 AIM 2将检查I型干扰物如何调节其发展的体内机制 流感-PMN表型，并研究了观察到感染流感动物的机制 从细菌感染的动物中接受嗜中性粒细胞具有提高随后的细菌作用的能力 与从病毒感染的动物接收中性粒细胞的对应物相比，感染。炎症 肺中的反应将通过检查细胞计数和差异，肺的细胞因子水平来确定 随着时间的推移和组织学的匀浆。体内调节吞噬作用和杀菌活性 外源性嗜中性粒细胞的给药将被定量。这些研究的结果将确定中性粒细胞 亚型基于深入的表型研究，并帮助我们了解 I型在中性粒细胞表型上的干扰素可能会增加受试者对细菌性肺炎的敏感性 感染流感。这些发现将是转移到免疫学领域的范式，这在很大程度上考虑了 中性粒细胞是功能有限的相当同质效应细胞群。此外，结果将 确定可以构成旨在调节嗜中性粒细胞的免疫调节疗法的基础的新靶标 功能，而不是仅仅关注患者是否有足够数量的中性粒细胞。