SENSITIZATION MECHANISM OF FOOD ALLERGY BY PATHOGENESIS-RELATED PROTEINS DERIVED FROM PLANT FOODSTUFFS

近年来，致病相关蛋白(PR-P或防御蛋白，DF)在食物过敏中发挥重要作用。这些蛋白质中存在的结构相似性肯定是导致交叉反应的可能性的原因。研究PR-P或DF诱导IgE抗体和引起过敏表现的原因是非常有趣的。本研究旨在探讨其结构或/和功能与致敏后诱导产生IgE的能力之间的关系。本研究旨在筛选各种植物食品提取物中与植物过敏患者血清中的IgE抗体识别的蛋白质。在植物食品中发现了几种独特的蛋白作为IgE结合的过敏原蛋白，它们被鉴定为与发病相关的蛋白。分别与马铃薯Bet v1(桦树花粉变应原)同源的18 kDa过敏性蛋白、胡萝卜亲环素的20 kDa过敏性蛋白、番茄亚硫化相关过氧化物酶的45 kDa过敏性蛋白、谷胱甘肽S转移酶的37 kDa过敏性蛋白、萝卜的25 kDa feredoxine/NADH氧化还原酶等过敏性蛋白。在轻度化学胁迫(水杨酸处理)下生长的萝卜植株中，有两种致敏蛋白的表达增加，说明这两种致敏蛋白是致病蛋白，胁迫负荷会增加致敏性。此外，重组致病蛋白PR-5d具有杀虫活性，并计划转移到马铃薯中，不显示与患者IgE抗体的结合能力。现在我们已经构建了一个过敏原数据库，供过敏原研究人员使用。

Recently, the pathogenesis-related proteins (PR-P or known as defense proteins, DF) were shown to play an important role in food allergy. Structural similarity present in these proteins must be responsible for the potential of cross reactivity. It is of very interesting to investigate why the PR-P or DF induces IgE antibodies and elicits allergic manifestation. This study aimed to investigate the relationship between the structure or/and function and the ability to induce IgE production after sensitization.We tried to screen the proteins in the extract of various plant foodstuffs which was recognized by IgE antibodies in sera of the patients allergic to plant food stuffs. Several unique proteins were found in plant foods as IgE binding allergenic proteins, which were identified to be pathogenesis-related proteins,. such as 18kDa allergenic protein homologous to Bet v1 (Birch pollen allergen) from potato, 20kDa allergenic protein of cyclophilin from carrot, 45kDa allergenic protein as suberization-associated peroxidase from tomato, 37kDa allergenic protein as glutathione S-transferase, and 25kDa feredoxine/NADH oxidoreductase fro turnip, respectively. Last two allergenic proteins were shown to increase in turnip plants grown under a mild chemical stress (salicylic acid treatment), indicating that these proteins were the pathogenesis proteins and the allergenicity would be increase by a stress loading. In addition, the recombinant pathogenesis protein, PR-5d which has an insecticide activity and will be planed to transfer into potato, did not show the binding ability to patients IgE antibodies. Now we have constructing a allergen database to be used for allergen investigators.