Modulation of neonatal alveolar macrophage by cftr mutation

cftr 突变对新生儿肺泡巨噬细胞的调节

• 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
• 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

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（由适用提供）：在此提案中，我们将解决新生儿肺泡巨噬细胞（AM）的经常争论的作用，这是对发育中的囊性纤维化（CF）肺中免疫调查受损的重要因素。 AM在针对细菌和病毒的初始防御措施中很重要，包括呼吸综合病毒（RSV），这是一种重要的病毒病原体，在CF肺中引起明显的发病率。作为少数专注于氧化应激对AM在新生儿肺中功能的影响的实验室之一，我们已经开始使用小鼠CFTR敲除握把校正模型（CFTR KO）评估CFTR突变对新生儿AM的影响。虽然CFTR KO小鼠在没有肺部感染的情况下，虽然在没有肺部AM的固有性CFTR变化的情况下，并未在人类CF肺本身的特征性肺部病理上发育特征性的肺病理。在CFTR KO新生儿小鼠中，即使在没有感染的情况下，在支气管肺泡灌洗液（BALF）中，氧化应激也会增加。 CFTR KO AM在TGFβ1和M2标记精氨酸酶1（ARG1）和衰减抑制症中急剧增加。这表明CFTR突变将新生儿AM的激活状态从病原体清除（经典激活，M1）转移到免疫抑制（替代激活，M2）。用从CF的幼儿获得的BALF处理也模仿CFTR KO AM的氧化物应激，TGFβ1和M2极化的影响。抗氧化剂谷胱甘肽（GSH）的CF相关降低的核心作用通过细胞外GSH减弱TGFβ1和ARG1增加的能力以及改善CFTR KO AM和CFBALF暴露于CFBALF的AM的能力。这表明氧化剂引起的TGFβ1上调调节了新生儿CFTR KO AM的炎症状态。但是，增加细胞外GSH钝的CF诱导的TGFβ1信号及其对AM极性和功能的下游影响。我们的中心假设是，由于CFTR突变而导致的GSH池减少，增加了氧化应激，并通过增加TGFβ1来损害吞噬作用，从而将新生儿AM转移到M2激活并减少新生儿肺对RSV的防御能力。在AIM 1中，我们将确定CFTR突变对受操纵细胞系的基线和RSV刺激状态的影响，以及从CFTR KO，ΔF508和G551D突变的新生儿小鼠中分离出的原发性新生儿AM。在AIM 2中，我们将检查维持GSH池的机制调节新生儿CF AM的免疫功能。 AM激活状态的改变以及随后的炎症信号传导变化可能会损害RSV清除。然后，AM的这种受损的反应可能是促进中性粒细胞募集到空域的信号。随着新生儿CF的早期鉴定，潜在的早期理论干预措施的发展可能会在发生呼吸道症状之前改变肺部感染和感染。该建议将开始解决新生儿AM是否是发展这种潜在理论的适当目标。策略。