Modulation of neonatal alveolar macrophage by cftr mutation

cftr 突变对新生儿肺泡巨噬细胞的调节

基本信息

批准号：
8822087
负责人：
Lou Ann S Brown
金额：
$ 23.4万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-22 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8822087
关键词：
AGTR2 gene Address Alveolar Macrophages Antioxidants Attenuated Bacteria Breathing Bronchoalveolar Lavage Fluid Caring Cell Line Characteristics Chronic Cystic Fibrosis Data Depressed mood Development Diagnosis Early identification Epithelial Cells Functional disorder Glutathione Health Human Immune response Immunosuppression Infant Infection Infiltration Inflammation Inflammatory Inflammatory Response Investigation Knock-out Laboratories Lower Respiratory Tract Infection Lung Lung diseases Macrophage Activation Mediating Microbe Modeling Morbidity - disease rate Mus Mutate Mutation Neonatal Neutrophil Infiltration Newborn Infant Outcome Oxidants Oxidative Stress Phagocytosis Play Pneumonia Pulmonary Pathology Respiratory Syncytial Virus Infections Respiratory syncytial virus Risk Role Signal Transduction Symptoms Therapeutic Therapeutic Intervention Up-Regulation Viral Virus Virus Diseases Work arginase children with cystic fibrosis endoplasmic reticulum stress extracellular immune function improved mouse model neonatal human neonate oxidant stress pathogen pathogen exposure respiratory response

项目摘要

DESCRIPTION (provided by applicant): In this proposal, we will address the often debated role of the neonatal alveolar macrophage (AM) as an important contributor to impaired immune responses in the developing cystic fibrosis (CF) lung. AM are important in the initial defenses against bacteria and viruses, including respiratory syncytial virus (RSV), an important viral pathogen which causes significant morbidity in the CF lung. As one of few laboratories focused on the effects of oxidative stress on the function of AM in the newborn lung, we have begun to evaluate the effects of cftr mutation on neonatal AM using a mouse cftr knockout gut corrected model (cftr KO). While cftr KO mice do not spontaneously develop characteristic pulmonary pathologies of human CF lung per se, they serve as excellent models to evaluate the intrinsic cftr alterations in neonatal AM, in the absence of pulmonary infection. In cftr KO neonatal mice, oxidative stress was increased in the bronchoalveolar lavage fluid (BALF), even in the absence of infection. Cftr KO AM had dramatic increases in TGFβ1 and the M2 marker arginase 1 (Arg1), and depressed phagocytosis. This suggests that the cftr mutation shifts the neonatal AM's activation state away from pathogen clearance (classically activated, M1) towards immunosuppression (alternative activation,M2). Interestingly, control neonatal AM treated with the BALF obtained from young children with CF also mimic the effects of the cftr KO AM with increased oxidant stress, TGFβ1 and M2 polarization. A central role for CF-related decreases in the antioxidant glutathione (GSH) was demonstrated by the ability of extracellular GSH to attenuate the increased TGFβ1 and Arg1 and improve phagocytosis in cftr KO AM and CFBALF-exposed AM. This suggested that oxidant-induced up- regulation of TGFβ1 modulated the neonatal cftr KO AM's inflammatory state; but increasing extracellular GSH blunted CF-induced TGFβ1 signaling and its downstream effects on AM polarity and function. Our central hypothesis is that decreased GSH pools due to cftr mutation increase AM oxidant stress and impair phagocytosis by increasing TGFβ1 thereby shifting neonatal AM towards M2 activation and diminishing the neonatal lung's defenses against RSV. In Aim 1, we will determine the effects of cftr mutations on baseline and RSV-stimulated state of manipulated cells lines, and primary neonatal AM isolated from cftr KO, ΔF508 and G551D mutated neonatal mice. In Aim 2, we will examine the mechanisms by which maintaining GSH pools modulates the immune functions of neonatal CF AM. Alterations in AM activation state and subsequent changes in inflammatory signaling may compromise RSV clearance. This impaired response by AM may then be the signal that promotes sustained neutrophil recruitment into the airspace. With early identification of the CF newborn, the development of potential early therapeutic interventions could modify pulmonary inflammation and infection before respiratory symptoms occur. This proposal will begin to address whether the neonatal AM is an appropriate target for the development of such potential therapeutic strategies.

描述（由申请人提供）：在本提案中，我们将讨论新生儿肺泡巨噬细胞 (AM) 的作用，它是发育中的囊性纤维化 (CF) 肺中免疫反应受损的重要因素，AM 在最初的过程中很重要。防御细菌和病毒，包括呼吸道合胞病毒 (RSV)，这是一种重要的病毒病原体，可导致 CF 肺显着发病。作为少数几个专注于氧化应激对肺的影响的实验室之一。为了了解 AM 在新生儿肺中的功能，我们已经开始使用小鼠 cftr 基因敲除肠道校正模型 (cftr KO) 评估 cftr 突变对新生儿 AM 的影响，而 cftr KO 小鼠不会自发出现人类 CF 肺的特征性肺部病变。就其本身而言，它们是评估新生 AM 内在 cftr 变化的优秀模型，在没有肺部感染的情况下，cftr KO 新生小鼠的氧化应激增加。支气管肺泡灌洗液 (BALF) 中，即使在没有感染的情况下，TGFβ1 和 M2 标记精氨酸酶 1 (Arg1) 也显着增加，并且吞噬作用降低，这表明 cftr 突变使新生儿 AM 的激活状态发生偏离。病原体清除（经典激活，M1）朝向免疫抑制（替代激活，M2），用获得的 BALF 处理的对照新生儿 AM。患有 CF 的幼儿也模仿了 cftr KO AM 的影响，增加了氧化应激、TGFβ1 和 M2 极化，CF 相关的抗氧化剂谷胱甘肽 (GSH) 减少的核心作用通过细胞外 GSH 减弱细胞外 GSH 的能力得到了证实。增加 TGFβ1 和 Arg1 并改善 cftr KO AM 和 CFBALF 暴露的 AM 中的吞噬作用。 TGFβ1 的调节调节了新生儿 cftr KO AM 的炎症状态；但细胞外 GSH 的增加减弱了 CF 诱导的 TGFβ1 信号传导及其对 AM 极性和功能的下游影响。 In Aim 通过增加 TGFβ1 的吞噬作用，从而将新生儿 AM 转向 M2 激活，并削弱新生儿肺对 RSV 的防御能力。 1，我们将确定 cftr 突变对操作细胞系的基线和 RSV 刺激状态的影响，以及从 cftr KO、ΔF508 和 G551D 突变新生小鼠中分离的原代新生 AM。在目标 2 中，我们将检查维持的机制。 GSH 池调节新生儿 CF AM 的免疫功能。AM 激活状态的改变和随后炎症信号的变化可能会损害 RSV 的清除。促进中性粒细胞持续募集到空域的信号通过早期识别 CF 新生儿，开发潜在的早期治疗干预措施可以在呼吸道症状出现之前改变肺部炎症和感染。该提案将开始解决新生儿 AM 是否合适的问题。开发此类潜在治疗策略的目标。