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: 10266038
• 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/10266038
• 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; 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 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.

继发性细菌性肺炎并发流感和呼吸道病毒感染更为严重 比原发性肺炎更严重，而且往往是致命的，但为什么会发生这种情况还不清楚。我们的数据证明 中性粒细胞是最丰富的白色血细胞，对抵抗细菌感染至关重要， 流感感染的动物显示出摄入和杀死细菌的能力受损，与来自 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一种 同源细胞群体，其中最重要的因素是受感染的宿主是否具有足够的 中性粒细胞的数量来对抗感染。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，我们分析的中性粒细胞分离的基因表达模式， 流感或肺炎链球菌感染后的小鼠肺显示， 感染的动物（“流感-PMN”）与从细菌-（S.肺炎） 感染的动物（“Sp-PMNs”），表明在感染的背景下出现了不同的中性粒细胞表型 不同类型的感染。然而，中性粒细胞特化是一个概念，一直认识不足 特别是在感染的背景下，尽管癌症文献的研究强烈地 支持这一新兴概念。该应用程序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（S.肺炎）肺炎，这是一种机制， 导致继发性细菌感染。此外，我们将测试的假设，即I型干扰素， 其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中的研究将研究病毒与细菌感染如何调节关键的中性粒细胞 功能，包括吞噬作用、细菌杀伤、活性氧生成、嗜中性粒细胞 细胞外陷阱形成、细胞因子产生和脱粒反应。此外，转录组 从骨髓、全身（脾）和局部（肺）隔室分离的中性粒细胞的变化 流感与S.肺炎感染的动物，以确定不同的嗜中性粒细胞亚型的发展， 什么样的分子通路被激活，可能导致不同的中性粒细胞表型出现， 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，质谱细胞术，以确定是否之间的平衡 在中性粒细胞上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。 目的2将研究I型干扰素如何调节肿瘤发生的体内机制。 流感中性粒细胞表型，并探讨机制的观察，流感感染的动物， 接受来自细菌感染动物的嗜中性粒细胞， 与接受来自病毒感染动物的中性粒细胞的对应者相比，炎性 通过检查肺的细胞计数和分化、细胞因子水平 随时间的匀浆和组织学。在体内调节吞噬作用和杀菌活性 将定量外源性中性粒细胞给药。这些研究的结果将确定中性粒细胞 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增加受试者对细菌性肺炎的易感性 流感感染。这些发现将是免疫学领域的范式转移，免疫学主要考虑 中性粒细胞作为功能有限的相当同质的效应细胞群体。此外，结果将 确定新的靶点，这些靶点可以形成旨在调节中性粒细胞的免疫调节疗法的基础。 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。