Reversal of Inflammatory Processes in CGD

描述（申请人提供）：慢性肉芽肿病（CGD）是一种由吞噬细胞NADPH氧化酶突变引起的遗传性疾病。虽然氧化酶功能的丧失导致免疫缺陷，但显著的疾病发病率与夸大的、通常是无菌的炎症（如阻塞性肉芽肿、结肠炎和自身免疫）有关。NADPH氧化酶的下游信号提供了必要的炎症控制，但知之甚少。数据支持凋亡的CGD中性粒细胞及其被CGD巨噬细胞识别和吞噬（efferocytosis）的信号是有缺陷的；这些过程通常导致产生抗炎信号（如TGFß），并且是解决炎症所必需的。具体来说，假设NADPH氧化酶缺乏活性氧会导致：i)激活和死亡的CGD中性粒细胞缺乏信号显示，这需要促进巨噬细胞识别和清除，ii)巨噬细胞缺乏PPARγ，这是炎症和巨噬细胞编程的主要控制器。炎症程序在CGD中持续存在，巨噬细胞无法清除死亡的中性粒细胞，这反过来又会积累，恶化，并加剧炎症和自身免疫。本研究的具体目的是：i)确定氧化剂和PPAR的正常作用？\γ在巨噬细胞编程中的作用及其与CGD中潜在的efferocytosis缺陷和炎症介质过度产生的关系，ii)确定PPARγ激动剂在CGD巨噬细胞功能恢复中的作用，iii)确定PPARγ激动作用过程中由替代机制产生的氧化剂在逆转CGD中性粒细胞和巨噬细胞功能障碍中的作用。这项研究将在小鼠和人类CGD中性粒细胞和单核细胞/巨噬细胞中进行，使用复杂的生化，遗传和药理学方法。一个定义良好的小鼠CGD肉芽肿炎症模型将被采用，并与人类CGD吞噬细胞的探索性终点一起，将i)阐明有缺陷的ROS产生与错误的吞噬细胞功能之间的联系，ii)确定恢复的PPARγ信号是否以及如何逆转受损的effocytosis和炎症反应。一个解释CGD持续炎症反应及其通过PPARγ缓解的新假设将支持一种新的治疗方法。这项研究旨在成为现有治疗方法的临床前试验，PPARγ激动剂可用于治疗CGD患者。需要深入了解巨噬细胞编程和PPARγ信号在CGD和正常情况下对凋亡细胞的识别和清除中的作用。这些发现也应该对其他炎性疾病状态提供重要的见解，其中巨噬细胞编程和凋亡细胞的识别似乎存在缺陷。

DESCRIPTION (provided by applicant): Chronic Granulomatous Disease (CGD) is a genetic disease resulting from mutation of the phagocyte NADPH oxidase. While loss of the functioning oxidase results in immunodeficiency, significant disease morbidity is associated with exaggerated, and often sterile, inflammation (e.g. obstructing granuloma, colitis and autoimmunity). Signals downstream of the NADPH oxidase provide necessary control of inflammation, but are poorly understood. Data support that signaling by apoptosing CGD neutrophils and their recognition and engulfment (efferocytosis) by CGD macrophages are defective; these processes ordinarily result in production of anti-inflammatory signals (e.g. TGFß), and are required to resolve inflammation. Specifically, it is hypothesized that absence of reactive oxygen species from the NADPH oxidase results in: i) deficient display of signals on activated and dying CGD neutrophils needed to facilitate macrophage recognition and clearance, and ii) deficient macrophage PPARγ , a master controller of inflammation and macrophage programming for efferocytosis. Inflammatory programming persists in CGD with macrophages unable to clear dying neutrophils, which in turn, accumulate, deteriorate, and fuel exaggerated inflammation and autoimmunity. The specific aims of this investigation are to i) define the normal role of oxidants and PPAR?\γ in macrophage programming and their relationship to underlying deficient efferocytosis and over-production of inflammatory mediators in CGD, ii) define the actions of PPARγ agonists in the restoration of CGD macrophage functioning and iii) define the role of oxidants produced by alternative mechanism(s) during PPARγ agonism in reversing the dysfunction of CGD neutrophils and macrophages. This investigation will be carried out in murine and human CGD neutrophils and monocyte/macrophages using sophisticated biochemical, genetic and pharmacological approaches. A well-defined model of granulomatous inflammation in murine CGD will be employed, and together with exploratory endpoints in human CGD phagocytes, will i) elucidate the interconnection between defective ROS production and miscued phagocyte function, and ii) determine whether, and how, restored PPARγ signaling reverses impaired efferocytosis and inflammatory responses. A new hypothesis to explain the persistent inflammatory response in CGD along with its mitigation through PPARγ will support a novel therapeutic approach. This investigation is intended to be a pre-clinical trial of an existing therapy, PPARγ agonists, available for treatment of CGD patients. A thorough understanding of macrophage programming and PPARγ signaling in the recognition and clearance of apoptotic cells in CGD and under normal circumstances is needed. Such findings should also give critical insight into other inflammatory disease states in which macrophage programming and recognition of apoptotic cells appears to be defective.