Wallner M, Erler A, Hauser M, Klinglmayr E, Gadermaier G, Vogel L, Mari A, Bohle B, Briza P, Ferreira F
Christian Doppler Laboratory for Allergy Diagnosis and Therapy, Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
Allergy. 2009 Mar;64(3):452-60. doi: 10.1111/j.1398-9995.2008.01788.x. Epub 2009 Jan 17.
Birch pollen allergy is one of the most common causes of spring pollinosis often associated with hypersensitivity reactions to pollen of other Fagales species. Yet, only the major disease eliciting allergens of alder and hazel have been fully characterized. Therefore, the aim of this study was to perform cloning, expression and immunologic characterization of the Bet v 1 homologues from oak (Que a 1) and hornbeam (Car b 1).
The isoform pattern of Car b 1 and Que a 1 was analyzed by proteomics using 2D gel electrophoresis and LC ESI-QTOF MS. Isoallergens showing high IgE-binding were cloned and expressed in Escherichia coli. IgE-binding activity of the recombinant proteins was determined by enzyme-linked immunosorbent assay (ELISA) and basophil mediator release assays using serum samples from patients mainly exposed either to oak and hornbeam or to birch pollen. Cross-reactivity of the allergens was further investigated at the T-cell level.
Dominant isoforms of Car b 1 and Que a 1, identified by mass spectrometry, showed different IgE-binding properties when testing Fagales pollen-allergic patients living in birch-free areas as compared to birch-sensitized individuals.
Tree pollen-allergic patients who are primarily exposed to Fagales pollen other than birch reacted stronger with rCar b 1 and rQue a 1 than with rBet v 1, as determined by inhibition ELISA and basophil mediator release assays. Thus, rCar b 1 and rQue a 1 allergens should be considered for improving molecule-based diagnosis and therapy of tree pollen allergies manifesting in birch-free areas.
桦树花粉过敏是春季花粉症最常见的病因之一，常与对其他壳斗目物种花粉的过敏反应相关。然而，只有桤木和榛树的主要致病过敏原已得到充分表征。因此，本研究的目的是对来自橡树（栎属花粉变应原1，Que a 1）和鹅耳枥（鹅耳枥花粉变应原1，Car b 1）的类Bet v 1同源物进行克隆、表达及免疫学表征。
采用二维凝胶电泳和液相色谱电喷雾四极杆飞行时间质谱联用的蛋白质组学方法分析Car b 1和Que a 1的异构体模式。克隆显示高IgE结合活性的同种变应原，并在大肠杆菌中表达。使用主要暴露于橡树和鹅耳枥或桦树花粉的患者血清样本，通过酶联免疫吸附测定（ELISA）和嗜碱性粒细胞介质释放试验测定重组蛋白的IgE结合活性。在T细胞水平进一步研究过敏原的交叉反应性。
通过质谱鉴定的Car b 1和Que a 1的主要异构体，在检测生活在无桦树地区的壳斗目花粉过敏患者时，与桦树致敏个体相比，显示出不同的IgE结合特性。
通过抑制ELISA和嗜碱性粒细胞介质释放试验确定，主要暴露于除桦树以外的壳斗目花粉的树花粉过敏患者，对重组Car b 1和重组Que a 1的反应比对重组Bet v 1的反应更强。因此，在改善无桦树地区出现的树花粉过敏基于分子的诊断和治疗方面，应考虑重组Car b 1和重组Que a 1过敏原。
