Mechanisms of IL-33 secretion in allergic diseases

项目摘要/摘要 过敏性疾病和哮喘的流行在全世界范围内都在增加。这些疾病经常发生。 共同存在于同一个体中，表明存在共同的潜在免疫致病因素。 这个项目的长期目标是研究涉及到的基本免疫学机制 过敏性疾病的发展。越来越清楚的是，上皮细胞产生的细胞因子 屏障表面的细胞，包括胸腺基质淋巴生成素、IL-25和IL-33，在 塑造2型免疫和人类过敏性疾病的病理生理学。然而，主要差距仍然存在 我们对这些物质的产生和分泌的分子和细胞控制仍有了解 细胞因子。该应用程序的目标是通过专注于IL-33来解决这些差距。 IL-33通常储存在非血液病细胞的核中。我们最近发现，暴露在 人呼吸道上皮细胞对真菌变应原--互隔交链孢霉的刺激作用 ATP，触发细胞内钙离子浓度和IL-33分泌的持续增加 胞外环境。我们还发现，当血浆中的三磷酸腺苷水平升高时，ATP释放和IL-33的分泌都会被抑制 NRF2的ROS清除剂和小分子激活剂可降低ROS 增加内源性抗氧化酶的表达。分泌的IL-33已经被处理成19 KDA形式由全长31 kDa形式组成。因此，我们假设，当暴露在空气中时 过敏原，呼吸道上皮的氧化应激反应触发细胞外ATP的释放，导致 蛋白水解性加工和分泌高活性IL-33。 这项拟议的研究旨在详细调查这一过程的关键步骤。在目标1中，我们将 确定氧化应激如何启动和维持呼吸道上皮细胞释放ATP，这是一个关键的 触发IL-33分泌的步骤。在目标2中，我们将调查空气中的过敏原是如何诱导的 晚期糖基化终产物受体在呼吸道上皮细胞氧化应激中的作用研究 (愤怒)。在目标3中，我们将研究与IL-33的加工和分泌有关的细胞机制 通过研究上皮的内源性蛋白水解酶的作用。我们将采用以下组合 补充性分子、细胞生物学、药理学和免疫学专业知识 奥格雷迪医生和基塔医生。为了这个项目，已经开发了新的和健壮的体外和体内模型。 这些研究将更好地了解上皮细胞如何对环境过敏原做出反应。 并将确定导致IL-33分泌的关键免疫病理生理机制。最终， 这些研究将为S等参与变应原诱导的关键分子提供重要的表征 免疫反应，允许识别新的治疗靶点(S)以治疗和理想地预防 免疫介导性疾病，如哮喘、慢性鼻窦炎和过敏性疾病。

PROJECT SUMMARY/ABSTRACT The prevalence of allergic diseases and asthma is increasing worldwide. These diseases often occur together in the same individual, suggesting the presence of common underlying immunopathogenic factors. The long-term objective of this project is to investigate the fundamental immunological mechanisms involved in the development of allergic diseases. It is becoming increasingly clear that cytokines produced by epithelial cells at the barrier surface, including thymic stromal lymphopoietin, IL-25, and IL-33, play an important role in shaping type 2 immunity and in the pathophysiology of allergic diseases in humans. However, major gaps still remain in our knowledge concerning the molecular and cellular control of production and secretion of these cytokines. The objective of this application is to address these gaps by focusing on IL-33. IL-33 is generally stored in the nucleus of non-hematologic cells. We found recently that exposure of human airway epithelial cells to a fungal allergen, Alternaria alternata, evokes a rapid extracellular release of ATP, which triggers sustained increases in intracellular calcium concentration and IL-33 secretion into the extracellular milieu. We also found that both ATP release and IL-33 secretion are abolished when levels of reactive oxygen species (ROS) are reduced by ROS scavengers and small molecule activators of Nrf2, which increases the expression of endogenous antioxidant enzymes. Secreted IL-33 had been processed to a 19 kDa form from the full-length 31 kDa form. Therefore, we hypothesize that, upon exposure to airborne allergens, the oxidative stress response in airway epithelium triggers extracellular release of ATP, resulting in proteolytic processing and secretion of highly active IL-33. The proposed study is designed to investigate the key steps of this process in detail. In Aim 1, we will determine how oxidative stress initiates and sustains the release of ATP from airway epithelial cells, a critical step that triggers IL-33 secretion. In Aim 2, we will investigate how airborne allergen exposure induces oxidative stress in airway epithelium by studying roles for the receptor for advanced glycation endproducts (RAGE). In Aim 3, we will examine the cellular mechanisms involved in the processing and secretion of IL-33 by studying the roles for the epithelium's endogenous protease. We will employ a combination of complementary molecular, cell biological, pharmacological and immunological expertise in the laboratories of Dr. O'Grady and Dr. Kita. Novel and robust in vitro and in vivo models have been developed for this project. These studies will provide a better understanding of how the epithelium responds to environmental allergens and will define the key immunopathophysiologic mechanisms responsible for secretion of IL-33. Ultimately, these studies will provide an important characterization of key molecule(s) involved in allergen-induced immune responses, allowing for identification of novel therapeutic target(s) to treat and ideally to prevent immune-mediated diseases, such as asthma, chronic rhinosinusitis, and allergic disorders.