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.

继发性细菌性肺炎合并流感和呼吸道病毒感染更为严重。 比起原发肺炎通常是致命的，但为什么会发生这种情况还不清楚。我们的数据表明 中性粒细胞是最丰富的白细胞，对抵抗细菌感染至关重要，来自 与中性粒细胞相比，感染流感的动物摄取和杀灭细菌的能力受到损害。 未受感染和细菌感染的动物。到目前为止，中性粒细胞基本上被认为是一种 同质细胞群体，其中最重要的因素是受感染的宿主是否有足够的 抗击感染的中性粒细胞数量。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，我们对从中国分离的中性粒细胞的基因表达模式的分析 流感或肺炎链球菌感染后的小鼠肺显示，来自病毒的中性粒细胞 受感染的动物(流感-中性粒细胞)与从细菌性肺炎链球菌分离的中性粒细胞有很大的不同。 感染动物(“Sp-PMN”)，表明不同的中性粒细胞表型出现在 不同类型的感染。然而，中性粒细胞的特化是一个很少被认识的概念。 尤其是在感染的背景下被理解，尽管来自癌症文献的研究强烈 支持这一新兴概念。这一应用验证了中性粒细胞采用不同表型的假设。 在病毒性(流感)和细菌性(肺炎链球菌)肺炎的条件下，这是一种机制 导致继发性细菌感染。此外，我们将测试I型干扰素的假设， 它们是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》上的研究将检验病毒感染和细菌感染如何调节关键的中性粒细胞。 随着时间的推移，功能包括吞噬、杀菌、产生活性氧物种、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 小鼠骨髓、全身(脾)和局部(肺)室分离的中性粒细胞的变化 流感与肺炎链球菌感染动物的对比，以确定不同的中性粒细胞亚型在哪里发展， 以及哪些分子途径被激活，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--质量细胞术--来确定 中性粒细胞上表达的激活和抑制免疫受体控制中性粒细胞活性的变化。 目的2将研究体内机制如何I型干扰素调节的发展 流感-PMN表型，并调查观察到流感感染动物的潜在机制 从受细菌感染的动物体内获得中性粒细胞，提高了对抗后续细菌的能力 与接受来自受病毒感染的动物的中性粒细胞的同行相比，他们更容易受到感染。炎症性 肺的反应将通过检测肺的细胞计数和分化、细胞因子水平来确定。 随着时间的推移同质化，和组织学。在体内调节吞噬和杀菌活性 外源性中性粒细胞给药将被量化。这些研究的结果将确定中性粒细胞 在深入表型调查的基础上，以及帮助我们了解 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 感染了流感。这些发现将是向免疫学领域的范式转移，免疫学在很大程度上考虑了 中性粒细胞作为功能有限的同质效应细胞群。此外，结果将是 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。