Neutrophil heterogeneity and function in host defense during pulmonary infection

肺部感染期间中性粒细胞异质性和宿主防御功能

• 批准号: 9974284
• 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 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9974284
• 关键词: Adopted; Animals; Anti-Bacterial Agents; Antibiotics; Bacteria; Bacterial Infections; Bacterial Pneumonia; Biological Response Modifiers; Blood Circulation; Bone Marrow; Cause of Death; Cell Count; Cell Surface Receptors; Cells; Characteristics; Chronic; Clinical; Cytometry; Data; Development; Effector Cell; Elderly; Equilibrium; Expression Profiling; Focal Infection; Foundations; 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; Interferon-alpha; Interferons; Investigation; Lead; Leukocytes; Literature; Lung; Lung infections; Malignant Neoplasms; Mediating; Mediator of activation protein; Medical; Molecular; Mus; Myelogenous; Nature; Pathway interactions; Patients; Pattern; Performance; Phagocytosis; Phenotype; Pneumococcal Infections; Pneumococcal Pneumonia; 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; base; cell type; cytokine; demographics; extracellular; fighting; flu; high risk; immunomodulatory therapies; immunoregulation; improved; in vivo; infection risk; influenza pneumonia; 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.

并发流感和呼吸道病毒感染的继发细菌性肺炎更为严重 比原发性肺炎更致命，但发生这种情况的原因尚不清楚。我们的数据表明 中性粒细胞是最丰富的白细胞，对于对抗细菌感染至关重要 与来自流感病毒的中性粒细胞相比，感染流感的动物摄入和杀死细菌的能力受损 未感染和细菌感染的动物。迄今为止，中性粒细胞主要被认为是 同质细胞群，其中最重要的因素是受感染宿主是否有足够的 中性粒细胞的数量是否可以抵抗感染。然而，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的基因表达模式进行分析 流感或肺炎链球菌感染后的小鼠肺部显示，来自病毒的中性粒细胞 受感染的动物（“flu-PMN”）与从细菌（肺炎链球菌）中分离出的中性粒细胞显着不同 受感染的动物（“Sp-PMN”），表明中性粒细胞的不同表型出现在 不同类型的感染。然而，中性粒细胞特化这一概念尚未得到充分认识 尽管癌症文献的研究强烈地表明了这一点，但尤其是在感染的背景下 支持这一新兴概念。该应用测试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）肺炎的情况下，这是一种机制 导致继发性细菌感染。此外，我们将检验 I 型干扰素的假设， 它们是由病毒感染诱导的中枢免疫介质，导致流感-中性粒细胞的发展 表型。目标 1 中的研究将检验病毒感染与细菌感染如何调节关键中性粒细胞 随着时间的推移发挥功能，包括吞噬作用、杀灭细菌、产生活性氧、中性粒细胞 细胞外陷阱的形成、细胞因子的产生和脱颗粒反应。此外，转录组 从骨髓、全身（脾）和局部（肺）区室中分离出的中性粒细胞的变化 流感与肺炎链球菌感染的动物，以确定不同的中性粒细胞亚型在哪里发育， 哪些分子途径被激活可能导致出现不同的中性粒细胞表型 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 使用一种强大的新技术——质谱流式细胞术，来确定两者之间的平衡是否 中性粒细胞上表达的激活性和抑制性免疫受体控制中性粒细胞活性的变化。 目标 2 将研究 I 型干扰素如何调节细胞发育的体内机制 流感-PMN 表型，并研究观察到的流感感染动物的机制 从受细菌感染的动物接收中性粒细胞可以提高抵抗后续细菌的能力 与接受来自病毒感染动物的中性粒细胞的同行相比。炎症 肺部反应将通过检查细胞计数和差异、肺部细胞因子水平来确定 随着时间的推移和组织学的匀浆。吞噬作用和杀菌活性的体内调节 外源性中性粒细胞的施用将被量化。这些研究的结果将鉴定中性粒细胞 亚型的基础上深入的表型研究，以及帮助我​​们了解如何影响 I 型干扰素对中性粒细胞表型的影响可能会增加受试者对细菌性肺炎的易感性 患有流感感染。这些发现将给免疫学领域带来范式转变，该领域主要考虑 中性粒细胞作为相当同质的效应细胞群，功能有限。此外，结果将 确定新的靶点，为旨在调节中性粒细胞的免疫调节疗法奠定基础 功能，而不是简单地关注患者是否有足够数量的中性粒细胞。