Fahlbusch B, Rudeschko O, Schumann C, Steurich F, Henzgen M, Schlenvoigt G, Jäger L
Institute of Clinical Immunology, Friedrich-Schiller-University, Jena, Germany.
J Investig Allergol Clin Immunol. 1998 Nov-Dec;8(6):325-32.
Fruit allergy is frequently associated with birch pollinosis. The aim of this study was to investigate which kiwi allergens were involved in subjects allergic to fruit alone and in patients allergic to both fruit and birch pollen. Sera of nine patients (five with both kiwi and birch pollen allergy and four with isolated kiwi allergy) were studied by immunoblot of kiwi extract. Eight of the nine sera reacted with the 30 kDa protein. Furthermore, IgE-binding proteins were seen at approximately 23 kDa (detected by five sera), 43 kDa and 80 kDa (four sera), and > 80 kDa (two sera). One serum showed no IgE binding to any kiwi allergen. The 30 kDa is the major allergen in kiwi and was purified by anion-exchange chromatography and characterized by isoelectrofocusing and amino acid sequencing. The comparison of its partial amino acid sequence with data from the Swiss Protein Bank revealed that this protein is actinidine. The carbohydrate structures in kiwi and birch pollen extracts were investigated with seven lectins. On kiwi blot, Aleuria aurantia agglutinin showed strong reactivity (indicating fucose residues) to the components of 35 to 92 kDa, while concanavalin A (indicating mannose, glucose or N-acetylglucosamine residues) showed weak binding at 67 kDa. In contrast, strong binding of Galanthus nivalis agglutinin (indicating mannose residues) and concanavalin A was found on birch pollen blots. The presence of IgE against carbohydrate structures was determined by means of enzyme-linked immunosorbent assay (ELISA) after periodate treatment of kiwi extract. The IgE binding was reduced by periodate treatment of kiwi coated microtiter plates, but not by sera reacting exclusively with the 30 kDa protein. Furthermore, selected sera were treated with proteinase K-digested kiwi and birch pollen extracts as the sources of crossreactive carbohydrate determinants. In accordance with the results of sodium periodate treatment, significant levels of anti-cross-reactive carbohydrate determinant IgE were found in sera from patients allergic to both kiwi and birch pollen. Our results show that the major allergen for kiwi allergy is the 30 kDa protein and additionally that the cross-reaction between kiwi and birch pollen allergy is mainly due to carbohydrate moieties.
水果过敏常与桦树花粉症相关。本研究的目的是调查哪些猕猴桃过敏原与仅对水果过敏的受试者以及对水果和桦树花粉都过敏的患者有关。通过猕猴桃提取物的免疫印迹法研究了9名患者（5名对猕猴桃和桦树花粉都过敏，4名对猕猴桃单独过敏）的血清。9份血清中有8份与30 kDa蛋白发生反应。此外，在约23 kDa（5份血清检测到）、43 kDa和80 kDa（4份血清）以及>80 kDa（2份血清）处可见IgE结合蛋白。1份血清未显示与任何猕猴桃过敏原的IgE结合。30 kDa蛋白是猕猴桃中的主要过敏原，通过阴离子交换色谱法进行纯化，并通过等电聚焦和氨基酸测序进行表征。将其部分氨基酸序列与瑞士蛋白质数据库的数据进行比较，发现该蛋白是猕猴桃蛋白酶。用7种凝集素研究了猕猴桃和桦树花粉提取物中的碳水化合物结构。在猕猴桃印迹上，橙黄银耳凝集素对35至92 kDa的成分显示出强反应性（表明有岩藻糖残基），而伴刀豆球蛋白A（表明有甘露糖、葡萄糖或N-乙酰葡糖胺残基）在67 kDa处显示出弱结合。相反，在桦树花粉印迹上发现雪花莲凝集素（表明有甘露糖残基）和伴刀豆球蛋白A有强结合。在用高碘酸盐处理猕猴桃提取物后，通过酶联免疫吸附测定（ELISA）确定了针对碳水化合物结构的IgE的存在。用高碘酸盐处理包被有猕猴桃的微量滴定板后，IgE结合减少，但仅与30 kDa蛋白反应的血清则无此现象。此外，用蛋白酶K消化的猕猴桃和桦树花粉提取物作为交叉反应性碳水化合物决定簇的来源，对选定的血清进行处理。与高碘酸钠处理的结果一致，在对猕猴桃和桦树花粉都过敏的患者血清中发现了显著水平的抗交叉反应性碳水化合物决定簇IgE。我们的结果表明，猕猴桃过敏的主要过敏原是30 kDa蛋白，此外，猕猴桃和桦树花粉过敏之间的交叉反应主要是由于碳水化合物部分。
