Elucidation of conformational epitopes of peanut allergens essential for allergic reactions

阐明过敏反应所必需的花生过敏原的构象表位

• 批准号: 8970024
• 负责人: Xueni Chen
• 金额: $ 23.33万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8970024
• 关键词: Allergens; Allergic; Allergic Reaction; Allergy to peanuts; Amino Acid Sequence; Anaphylaxis; Antibodies; Bacteriophages; Binding; Biological Assay; Clinical; Complex; Data; Effector Cell; Enzyme-Linked Immunosorbent Assay; Epitopes; Event; Food; Food Hypersensitivity; Generations; Heating; Hypersensitivity; IgE; Immunologic Monitoring; Immunologics; Immunotherapeutic agent; Individual; Knowledge; Lead; Libraries; Maps; Mediating; Mediator of activation protein; Methods; Microarray Analysis; Patients; Pattern; Pattern Recognition; Peptide Library; Peptide Phage Display Library; Peptide Sequence Determination; Peptides; Phage Display; Prevalence; Proteins; Publishing; Reaction; Recording of previous events; Research; Sequence Homology; Serum; Surface; Symptoms; Testing; Therapeutic; Therapeutic Intervention; Vaccines; base; clinically relevant; crosslink; design; improved; mast cell; monomer; novel; novel strategies; public health relevance; screening; three dimensional structure

 DESCRIPTION (provided by applicant): Hypersensitivity to food is a world-wide problem and its prevalence is increasing. IgE- mediated reactions to foods, particularly peanuts, are the most common cause of food induced anaphylaxis. Cross-linking of IgE antibody by specific epitopes on the surface of allergens is a prerequisite for triggering symptoms of peanut allergy. IgE epitopes are frequently categorized as linear or conformational epitopes. Although linear IgE-binding epitopes of peanut allergens have been defined, little is known about conformational IgE-binding epitopes. Recently, accumulating evidence points to importance of conformational IgE epitopes in peanut allergy. In the proposed studies, we will identify clinically relevant conformational IgE epitopes of the two most important peanut allergens, Ara h 2 and Ara h 6, and examine the impact of the identified epitopes on IgE binding and IgE/FceR1 cross-linking events. Aim 1 will identify clinically relevant conformational IgE epitopes of Ara h 2 and Ara h 6 by screening phage peptide display library with serum IgE from peanut allergic patients. The selected phage peptides will be analyzed for sequence homology with Ara h 2/ Ara h 6 protein sequences and mapped on the Ara h 2 and Ara h 6 monomer surface using three-dimensional structures. IgE recognition pattern of the identified epitopes will be determined among patients with varied clinical histories. Aim 2 will test the identified epitopes for their ability to inhibi IgE binding to folded native Ara h 2/6 and for their capacity to inhibit cross-linking of IgE/FceR1 by allergen on effector cells. This study is the first to propose to identify and functionally characterize clinically important conformational IgE epitopes of the two most important peanut allergens. A better understanding of potential allergy-causing epitopes would lead to improved therapeutic strategies and better monitoring of immune-therapeutic interventions.

 描述(申请人提供)：对食物的过敏是一个世界性的问题，而且它的流行率正在增加。免疫球蛋白介导的食物反应，尤其是花生，是引起食物过敏反应的最常见原因。过敏原表面的特定表位使IgE抗体发生交联是引发花生过敏症状的先决条件。免疫球蛋白E表位通常分为线性表位或构象表位。虽然花生变应原的线性IgE结合表位已经被定义，但关于构象的IgE结合表位却知之甚少。最近，越来越多的证据表明构象IgE表位在花生过敏中的重要性。在拟议的研究中，我们将确定两个最重要的花生变应原Ara h2和Ara h 6的临床相关构象IgE表位，并检查已识别的表位对IgE结合和IgE/FceR1交联事件的影响。目的1通过筛选花生过敏患者血清IgE噬菌体抗原肽展示文库，筛选与临床相关的Arah2和Arah6构象IgE表位。所选噬菌体多肽将与arah2/arah6蛋白序列进行序列同源性分析，并利用三维结构将其定位在arah2和arah6单体表面。已识别表位的免疫球蛋白识别模式将在具有不同临床病史的患者中确定。目的2将测试已确定的表位抑制IgE与折叠的天然Arah2/6结合的能力，以及它们抑制过敏原对效应细胞上的IgE/FceR1的交联性的能力。这项研究是首次提出鉴定和功能表征两个最重要的花生过敏原的临床上重要的构象IgE表位。更好地了解可能导致过敏的表位将导致改进治疗策略和更好地监测免疫治疗干预措施。