Natural Killer Cell Responses of Aged Mice to Primary Influenza Infection

老年小鼠对原发性流感感染的自然杀伤细胞反应

• 批准号: 8143449
• 负责人: Elizabeth M. Gardner
• 金额: $ 34.91万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8143449
• 关键词: Ablation; Acute; Address; Adoptive Transfer; Affect; Age; Age-Years; Animal Model; Antibodies; Apoptosis; Body Weight decreased; C57BL/6 Mouse; Cause of Death; Cell Count; Cell Proliferation; Cell physiology; Cells; Cessation of life; Cytokine Receptors; Cytolysis; Cytotoxic T-Lymphocytes; Data; Defect; Dendritic Cells; Dendritic cell activation; Dependence; Dose; Elderly; Environment; Exhibits; Family suidae; Future; Goals; Histology; Homing; Hospitalization; Human; Immune; Immune response; Immunoglobulin G; Individual; Infection; Infiltration; Influenza; Influenza A Virus, H1N1 Subtype; Influenza vaccination; Leucocytic infiltrate; Lung; Lytic; Measures; Mus; Natural Killer Cells; Pathology; Persons; Pneumonia; Population; Predisposition; Prevalence; Production; Recovery; Reporting; Research; Resistance; Role; Signal Transduction; Therapeutic; Transgenic Mice; United States; Vaccines; Virus; Virus Diseases; Vulnerable Populations; Weight Gain; age related; aged; base; cytokine; cytotoxicity; human old age (65+); in vivo; influenzavirus; mouse model; novel; prophylactic; public health relevance; receptor function; response; seasonal influenza; statistics; Ablation; Acute; Address; Adoptive Transfer; Affect; Age; Age-Years; Animal Model; Antibodies; Apoptosis; Body Weight decreased; C57BL/6 Mouse; Cause of Death; Cell Count; Cell Proliferation; Cell physiology; Cells; Cessation of life; Cytokine Receptors; Cytolysis; Cytotoxic T-Lymphocytes; Data; Defect; Dendritic Cells; Dendritic cell activation; Dependence; Dose; Elderly; Environment; Exhibits; Family suidae; Future; Goals; Histology; Homing; Hospitalization; Human; Immune; Immune response; Immunoglobulin G; Individual; Infection; Infiltration; Influenza; Influenza A Virus, H1N1 Subtype; Influenza vaccination; Leucocytic infiltrate; Lung; Lytic; Measures; Mus; Natural Killer Cells; Pathology; Persons; Pneumonia; Population; Predisposition; Prevalence; Production; Recovery; Reporting; Research; Resistance; Role; Signal Transduction; Therapeutic; Transgenic Mice; United States; Vaccines; Virus; Virus Diseases; Vulnerable Populations; Weight Gain; age related; aged; base; cytokine; cytotoxicity; human old age (65+); in vivo; influenzavirus; mouse model; novel; prophylactic; public health relevance; receptor function; response; seasonal influenza; statistics

DESCRIPTION (provided by applicant): Despite vaccination, influenza and secondary pneumonias are the fourth leading cause of death in individuals 65 years and older. The recent emergence of the novel 2009-H1N1 influenza, to which vaccines are limited or unavailable, has the potential to cause 30,000-90,000 deaths in people under 65 years of age. These staggering statistics mandate the need to better understand age-related changes in primary immune responses to acute influenza infection. We have recently identified a critical role for natural killer (NK) cells in controlling early influenza infection ex vivo and in vivo. Aged C57BL/6 mice exhibited increased lung virus titers, weight loss, decreased NK cytotoxicity, and a reduced number of NK cells during early influenza infection. Importantly, in vivo NK cell depletion by anti-NK1.1 IgG antibody (PK136) treatment induced marked weight loss and increased lung virus titers after influenza infection of both young and aged mice. These data suggest that NK cells are essential in early control of influenza infection. Thus, our overarching hypothesis is that the induction of an effective NK cell response is vital for controlling early influenza infection in vulnerable populations, including the elderly. Our studies will characterize age-related changes in NK cell function, elucidate potential intrinsic and extrinsic mechanisms for impaired NK cell function, and establish the critical role of NK cells in controlling early infection to influenza virus in vivo. In Aim 1, age-related differences in susceptibility and the role of NK cell function during the first critical four days of infection will be assessed. We will perform influenza dose responses and measure age-related differences lung virus titers, pathology, histology and cellular infiltrates in lung, weight loss, and recovery from infection. Age-related changes in NK subsets, cytolytic function of NK cells, dendritic cell (DCs) function, and local and systemic cytokine production will be measured during infection. In Aim 2, we will elucidate age-related changes in intrinsic and extrinsic mechanism(s) for impaired NK cell function during influenza infection. Age-related differences in lytic efficiency, activation receptor function/signaling, and cytokine receptor/function will be measured in purified NK cells to identify intrinsic NK cell defects. Adoptive transfer studies will delineate between intrinsic and extrinsic effects on NK cell proliferation, apoptosis, and homing as related to susceptibility to influenza. We hypothesize that DCs are critical extrinsic effectors on NK cell function in early infection. Thus, we will measure DC activation of NK cells, DC cytokine production, and the effects of DC ablation on NK cell function. In Aim 3, we will validate the essential role of NK cells in controlling the in vivo response to influenza. In vivo NK cytolysis in young and aged mice will be assessed along with survival, weight loss, and lung virus titers. The specific role of NK cells in controlling susceptibility to influenza will be addressed in mice after NK depletion in vivo with PK136 or in RAG-1-/- or NKD transgenic mice. These three mouse models will afford a clear delineation of the specific contribution of NK cells in controlling the early response to influenza. PUBLIC HEALTH RELEVANCE: The prevalence of seasonal influenza and the recent emergence of swine 2009-H1N1 mandate the need to study age-related changes in the primary response to influenza infection. Aged mice show decreased NK cell function and elevated lung virus titers during the first four days of infection, and more importantly, die prior the initiation of an adaptive primary response. If applicable to humans, this suggests that the ability of young and aged individuals to mount an early and effective NK cell response to influenza infection is vital, especially when vaccine is limited or unavailable.

描述（由申请人提供）：尽管疫苗接种，流感和次要肺炎是65岁以上个人的第四大死亡原因。疫苗受到限制或不可用的新颖的2009-H1N1流感疫苗的最近出现，有可能在65岁以下的人中造成30,000-90,000人死亡。这些惊人的统计数据要求更好地了解对急性流感感染的原发性免疫反应的与年龄相关的变化。我们最近确定了自然杀伤（NK）细胞在控制早期流感感染的体内和体内的关键作用。年龄的C57BL/6小鼠表现出增加的肺病毒滴度，体重减轻，NK细胞毒性降低以及早期流感感染期间NK细胞数量减少。重要的是，抗NK1.1 IgG抗体（PK136）治疗在体内NK细胞的耗竭诱导了年轻小鼠和老年小鼠流感感染后的显着体重减轻和肺部病毒滴度增加。这些数据表明，NK细胞对早期控制流感感染至关重要。因此，我们的总体假设是，有效的NK细胞反应的诱导对于控制包括老年人在内的脆弱人群中的早期流感感染至关重要。我们的研究将表征与年龄相关的NK细胞功能的变化，阐明了NK细胞功能受损的潜在内在和外在机制，并确定了NK细胞在控制体内感染早期感染中的关键作用。在AIM 1中，将评估与年龄相关的易感性差异和NK细胞功能在感染的第一个关键四天中的作用。我们将执行流感剂量反应，并测量与年龄相关的差异，肺病毒滴度，病理学，组织学和细胞浸润，体重减轻和感染中恢复。在感染期间，将测量与年龄相关的NK亚群，NK细胞的细胞溶解功能，树突状细胞（DCS）功能以及局部和全身细胞因子的产生。在AIM 2中，我们将阐明流感感染期间NK细胞功能受损的内在和外在机制的年龄相关变化。将在纯化的NK细胞中测量与年龄相关的裂解效率，激活受体功能/信号传导和细胞因子受体/功能的差异，以鉴定内在的NK细胞缺损。收养转移研究将在内在和外在影响对NK细胞增殖，凋亡和与流感易感性有关的归因之间描述。我们假设DC是早期感染中NK细胞功能的关键外部效应子。因此，我们将测量NK细胞的直流激活，直流细胞因子的产生以及直流消融对NK细胞功能的影响。在AIM 3中，我们将验证NK细胞在控制体内对流感的反应中的重要作用。将评估年轻小鼠和老年小鼠的体内NK胞解以及生存，体重减轻和肺病毒滴度。 NK细胞在控制对流感易感性的易感性中的特定作用将在NK用PK136或RAG-1 - / - 或NKD转基因小鼠体内耗尽后的小鼠中解决。这三种小鼠模型将清楚地描述NK细胞在控制早期对流感反应中的特定贡献。 公共卫生相关性：季节性流感的流行和猪2009-H1N1的最新出现，要求需要研究与流感感染的主要反应中与年龄相关的变化。老年小鼠在感染的前四天显示NK细胞功能降低和肺部病毒滴度升高，更重要的是，在自适应初级反应开始之前死亡。如果适用于人类，这表明年轻人和老年人对疫苗感染的早期和有效的NK细胞反应的能力至关重要，尤其是在疫苗有限或无法获得的情况下。