The Role of the Major Alternaria Allergen Alt_a_1 in Airway Inflammation

主要链格孢过敏原 Alt_a_1 在气道炎症中的作用

• 批准号: 8313847
• 负责人: Christopher Brian Lawrence
• 金额: $ 19.6万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-05 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8313847
• 关键词: Allergens; Allergic Disease; Allergic inflammation; Alternaria; Amino Acid Motifs; Amino Acid Sequence; Amino Acids; Antigens; Asthma; Binding; Biochemical; Cell surface; Cells; Clinical; Complex; Country; Development; Disease Progression; Employee Strikes; Endocytosis; Environment; Environmental Risk Factor; Epithelial Cells; Etiology; Event; Exhibits; Exposure to; Extrinsic asthma; Functional disorder; Fungal Proteins; Fungal Spores; Goals; Human; Hypersensitivity; IgE; Immune; Immune response; Immune system; Immunity; In Vitro; Individual; Inflammatory; Inflammatory Response; Interleukin-13; Interleukin-4; Knock-out; Knowledge; Lead; Life; Liquid substance; Lung; Mediating; Modeling; Molecular; Movement; Mus; Organism; Pathogenesis; Patients; Phosphatidylinositols; Phospholipids; Play; Prevalence; Prevention; Prevention strategy; Property; Proteins; Recombinants; Recurrence; Reproduction spores; Role; Source; Testing; Th2 Cells; airway hyperresponsiveness; airway inflammation; allergic airway disease; base; cell type; clinically relevant; cytokine; design; effective therapy; esterase; experience; fungus; in vivo; innovation; inositol 3-phosphate; insight; microbial; mutant; novel; novel therapeutic intervention; pathogen; prevent; response; transcytosis; uptake

DESCRIPTION (provided by applicant): The inflammatory airway response in asthma may be the result of immune cells that are dysregulated towards environmental factors such as airborne fungi. The long-term goal of this project is to better understand the pathophysiological mechanisms of Th2-type airway inflammation in asthma. Exposure to the fungus, Alternaria, has long been implicated in the development and exacerbation of human asthma. After intranasal exposure to Alternaria spores and individual proteins, naive mice exhibit marked eosinophilic airway inflammation, enhanced Th2 sensitization to innocuous antigens, and airway hyperreactivity. Despite the well-documented clinical importance of Alternaria in the development, onset, and exacerbation of allergic airway diseases such as asthma, little knowledge exists about the role of individual fungal products in these pathological states. The importance of and detailed mechanisms of allergen uptake and movement through the epithelial cell layer (endocytosis and transcytosis) have not been explored to any great extent. This innovative project focuses on the secreted major Alternaria allergen Alt_a_1. It will assess the role of Alt_a_1 in allergic disease by utilizing bronchoalveolar epithelial cells and murine models of airway inflammation. We have discovered that Alt_a_1 is proinflammatory and harbors a unique amino acid motif (RXLR) that facilitates binding to cell surface PI-3-P and cellular entry. In aim 1 the role of Alt_a_1 in innate and adaptive immune responses in vitro and in murine models of asthma will be investigated. The effects of recombinant Alt_a_1 protein and fungal knockout mutants lacking Alt_a_1 will be examined. In specific aim 2 the importance of the Alt_a_1's esterase activity and RXLR motif in cellular entry and immunological responses will be characterized. Recombinant Alt_a_1 will be used to define amino acid residues required for esterase activity, for PI-3-P binding, and for cellular entry. Epithelial cell immune responses following treatment with the Alt_a_1 proteins will be investigated. This project will lead to a better understanding of the mechanisms of persistent and recurrent airway inflammation and may lead to the development of more specific and effective therapies and prevention strategies, especially if PI-3-P-mediated cell entry proves of general importance to allergenicity.

描述（由申请人提供）：哮喘中的炎症性气道反应可能是免疫细胞对环境因素（例如空气中的真菌）失调的结果。该项目的长期目标是更好地了解哮喘中Th2型气道炎症的病理生理机制。长期以来，接触链格孢菌一直与人类哮喘的发生和恶化有关。鼻内暴露于链格孢属孢子和单个蛋白质后，幼鼠表现出明显的嗜酸性气道炎症、Th2 对无害抗原的敏感性增强以及气道高反应性。尽管链格孢属在过敏性气道疾病（例如哮喘）的发生、发作和恶化中的临床重要性已得到充分证明，但人们对单个真菌产物在这些病理状态中的作用知之甚少。过敏原摄取和通过上皮细胞层移动（胞吞作用和转胞吞作用）的重要性和详细机制尚未得到很大程度的探索。该创新项目重点关注分泌的主要链格孢属过敏原 Alt_a_1。它将利用支气管肺泡上皮细胞和小鼠气道炎症模型来评估 Alt_a_1 在过敏性疾病中的作用。我们发现 Alt_a_1 具有促炎性，并具有独特的氨基酸基序 (RXLR)，有助于与细胞表面 PI-3-P 结合并进入细胞。在目标 1 中，将研究 Alt_a_1 在体外和小鼠哮喘模型中先天性和适应性免疫反应中的作用。将检查重组 Alt_a_1 蛋白和缺乏 Alt_a_1 的真菌敲除突变体的效果。在具体目标 2 中，将描述 Alt_a_1 酯酶活性和 RXLR 基序在细胞进入和免疫反应中的重要性。重组 Alt_a_1 将用于定义酯酶活性、PI-3-P 结合和细胞进入所需的氨基酸残基。将研究 Alt_a_1 蛋白治疗后的上皮细胞免疫反应。该项目将有助于更好地了解持续性和复发性气道炎症的机制，并可能导致开发更具体和有效的治疗和预防策略，特别是如果 PI-3-P 介导的细胞进入被证明对过敏性具有普遍重要性的话。

项目成果

Microbe-independent entry of oomycete RxLR effectors and fungal RxLR-like effectors into plant and animal cells is specific and reproducible.

• DOI: 10.1094/mpmi-02-13-0051-ia
• 发表时间: 2013-06
• 期刊: Molecular plant-microbe interactions : MPMI
• 作者: Tyler BM;Kale SD;Wang Q;Tao K;Clark HR;Drews K;Antignani V;Rumore A;Hayes T;Plett JM;Fudal I;Gu B;Chen Q;Affeldt KJ;Berthier E;Fischer GJ;Dou D;Shan W;Keller NP;Martin F;Rouxel T;Lawrence CB
• 通讯作者: Lawrence CB