Innate Regulation of Pollen-Oxidase Induced Inflammation

接触花粉是呼吸道过敏如过敏性鼻炎和过敏性鼻炎的最常见原因之一。 全球过敏性哮喘我们先前已经证明花粉中含有一种叫做NADPH的酶 氧化酶（花粉-NOX），这种酶是诱导过敏性炎症的关键。然而，在这方面， 关于这些氧化酶诱导变应性疾病的分子机制知之甚少。的 该项目的目标是解决关于花粉-NOX如何诱导过敏性反应的知识的关键空白 炎症呼吸道上皮细胞是抵御花粉有害影响的第一道防线。 上皮细胞和上皮内树突状（DC）细胞是气道上皮中的两种类型的细胞，它们是气道上皮细胞的主要组成部分。 吸入花粉过敏原的关键第一反应细胞。我们认为，最早的事件之一， 在气道上皮细胞上，花粉-NOX与DCs表面的Toll样受体结合， 受体（TLR 4）。这种细胞表面受体最为人所知的是它能够与一种细菌产物结合， LPS，但其结合花粉-NOX的能力尚未被描述。这种结合引发了细胞内的氧化应激， DCs严重到足以破坏DNA，细胞的遗传物质。这些受损的DNA被修复， 一种叫做OGGI的DNA修复酶和8-oxoG-DNA中受损的碱基被释放出来。OGGI和8- 然后oxoG在DC中形成称为OGGI-guanine nucleotide exchange factor或OGG 1gef的信号复合物。 这诱导了激活DC并促进过敏性炎症的信号级联。这一模式将 在三个具体目标中进行测试。在目标1中，一种称为293的细胞系和小鼠DC将用于测试花粉- NOX与TLR 4结合，并确定这种结合在DC活化中的重要性。目标2将测试 花粉-NOX诱导的DNA损伤和修复是否对激活信号级联至关重要， 诱导小鼠过敏性肺部炎症。目标3将检验在2004年和2005年期间所作观察与人类的相关性。 目的1和2中的细胞系和小鼠。我们将确定花粉-NOX与TLR 4的结合是否激活 来自健康人受试者和患有糖尿病的受试者的DC中的DNA损伤/修复介导的信号通路 过敏性鼻炎我们还将用花粉提取物对健康受试者和患有 过敏性鼻炎，并确定这种挑战是否会导致鼻子中的DNA损伤和修复。实现这些 目的是鉴定花粉NADPH氧化酶激活DCs的新分子途径， 诱导人类过敏性炎症，从而为过敏性疾病的新治疗方法确定新的分子靶点 鼻炎和过敏性哮喘。

Exposure to pollens is one of the most common causes of respiratory allergies such as allergic rhinitis and allergic asthma worldwide. We have previously shown that pollens contain an enzyme called NADPH oxidase (pollen-NOX), and that this enzyme is critical for the induction of allergic inflammation. However, very little is known about the molecular mechanism by which these oxidases induce allergic diseases. The goal of this project is to address this critical gap in knowledge about how pollen-NOX induces allergic inflammation. The airway epithelium is the first line of defense against the harmful effects of pollens. Epithelial and intraepithelial dendritic (DCs) cells are two types of cells in the airway epithelium that are the key first responder cells to inhaled pollen allergens. We propose that one of the earliest events when pollens land on the airway epithelium is that pollen-NOX binds to a receptor on the surface of DCs called Toll-like receptor (TLR4). This cell-surface receptor is best known for its ability to bind to a bacterial product called LPS, but its ability to bind pollen-NOX has not been described. This binding initiates oxidative stress in the DCs that is sufficiently severe to damage DNA, the cells' genetic material. This damaged DNA is repaired by a DNA repair enzyme called OGGI, and 8-oxoG- the damaged base in the DNA, is released. OGGI and 8- oxoG then form a signaling complex in DCs called OGGI-guanine nucleotide exchange factor, or OGG1gef. This induces a signaling cascade that activates DCs and promotes allergic inflammation. This model will be tested in three Specific Aims. In Aim 1 a cell line called 293 and mouse DCs will be used to test how pollen- NOX binds to TLR4, and determine the importance of this binding in the activation of DCs. Aim 2 will test whether DNA damage and repair induced by pollen-NOX is crucial for activating a signaling cascade that induces allergic lung inflammation in mice. Aim 3 will test the human relevance of the observations made in cell lines and mice in Aims 1 and 2. We will determine whether binding of pollen-NOX to TLR4 activates DNA damage/repair-mediated signaling pathways in DCs from healthy human subjects and those with allergic rhinitis. We will also perform nasal challenge with pollen extract to healthy subjects and subjects with allergic rhinitis, and determine if this challenge induces DNA damage and repair in the nose. Achieving these Aims should identify novel molecular pathways utilized by pollen NADPH oxidases to activate DCs and induce allergic inflammation in humans, and so identify novel molecular targets for new treatments of allergic rhinitis and allergic asthma.