ROLE OF FOOD HYPERSENSITIVITY IN ATOPIC DERMATITIS

食物过敏在特应性皮炎中的作用

• 批准号: 6245304
• 负责人: Hugh A Sampson
• 金额: $ 2.23万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-05 至 1997-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6245304
• 关键词: B lymphocyte; T lymphocyte; antibody specificity; atopic dermatitis; child (0-11); clinical research; enzyme linked immunosorbent assay; food hypersensitivity; human subject; immunoglobulin E; ovomucoid; protein purification

We previously demonstrated that ovomucoid, Gal d 1, is the dominant allergen in hen's egg. Ovomucoid is a highly glycosylated protein comprised of 186 amino acids arranged in 3 tandem domains [Gal d 1.1, 1.2, 1.3], each about 60 amino acids in length. The purpose of this study was to evaluate the allergenic properties of ovomucoid. We isolated the 3 ovomucoid domains by enzymatic digestion and chromatographic purification. Sera from 45 egg allergic patients with atoppic dermatitis were anlyzed by ELISA to determine B cell domain specificity; sera from egg allergic patients were analyzed by inhibition-ELISA to reduce and alkylated, oxidized, and deglycosylated ovomucoid in order to evaluate the importance of linear and conformational structures, and carbohydrate to B cell epitopes. Peripheral blood T cells from 13 egg allergic patients were used to evaluate T-dominant domains and reactivity to reduced and oxidized ovomucoid. Virtually all patients had IgE antibodies to the 3 domains, although there was significalty more IgE activity to Gal d 1.2 [percentage of ovomucoid- specific IgE; median: Gal d 1.2: 40%; Gal d 1.1:23%; Gal d 1.3 26%]. Quantities of patient IgG antibody was comparable to all 3 domains. IgE antibody binding to reduced ovomucoid and IgG binding to oxidized ovomucoid were significantly reduced compared to native ovomucoid [28% and 69%, respectively]. Twenty-one of 33 peripheral blood T cells reacted to Gal d 1.3, 18 of 33 to Gal d 1.2, and 18 of 33 to Gal d 1.1. T cell proliferation in vitro to reduced and oxidized ovomucoid were significantly greater than to the native protein. These results indicate a dichotomy between T cell and B cell comain dominance, and differences in IgE and IgG epitopes. Furthermore results suggest that conformational B cell epitopes play a more significant role in ovomucoid allergenicity in some patients, especially those with "transient" egg hypersensitivity than previously appreciated, and that carbohydrate moieties have a minor effect on allergenicity.

我们以前证明了类卵粘蛋白Gald1是占优势的 鸡蛋中的过敏原。卵粘蛋白是一种高度糖基化的蛋白质 由186个氨基酸组成，排列在3个串联结构域[Gald 1.1， 1.2，1.3]，每个约60个氨基酸。这项研究的目的 评价类卵粘蛋白的过敏性。我们分离出了 3个卵粘蛋白结构域的酶切和层析 净化。特应性皮炎鸡蛋过敏患者45例血清分析 用ELISA法分析以确定B细胞域的特异性； 应用抑制-酶联免疫吸附试验对鸡蛋过敏患者进行分析。 烷基化、氧化和脱糖基化的卵粘蛋白 线型和构象结构以及碳水化合物对B的重要性 细胞表位。13例鸡蛋过敏患者外周血T细胞的检测 被用来评估T-优势结构域和对还原和 氧化的卵粘蛋白。 几乎所有患者都有针对这三个区域的IgE抗体，尽管有 IgE活性显著高于Gald 1.2[卵粘蛋白百分比- 特异性IgE；中位数：Gal d 1.2：40%；Gal d 1.1：23%；Gal d 1.3 26%]。 患者免疫球蛋白抗体的量与所有3个区域相当。免疫球蛋白 抗体与还原的卵粘蛋白结合，与氧化的免疫球蛋白结合 与天然卵粘蛋白相比，卵粘蛋白显著减少[28%和 分别为69%]。33个外周血T细胞中有21个对 Gal d 1.3，33中18至Gal d 1.2，33中18至Gal d 1.1。T细胞 体外增殖减少和氧化的卵粘液样物质 明显大于天然蛋白质。 这些结果表明T细胞和B细胞疾病之间存在着二分性。 优势，以及免疫球蛋白和免疫球蛋白表位的差异。进一步的结果 提示构象B细胞表位起着更重要的作用 在一些患者中，特别是在那些有 “暂时性”的鸡蛋超敏反应比之前所认为的要好，而且 碳水化合物对过敏性的影响很小。