University of Verona, Department of Biotechnology, Strada Le Grazie, 15-CV1, I-37134 Verona, Italy.
Mol Immunol. 2010 Apr;47(7-8):1561-8. doi: 10.1016/j.molimm.2010.01.009. Epub 2010 Feb 11.
Green bean (GB) has been reported to cause allergic reactions after ingestion, contact or inhalation of particles deriving from processing or cooking. Up-to-date no food allergens have been fully characterized in GB.
To characterize the GB major allergen(s) on a molecular level and to verify the involvement of non-specific lipid transfer proteins (nsLTPs) in GB allergy.
We recruited 10 Spanish patients reporting adverse reactions to GB. Skin prick tests, specific IgE detection and oral provocation were performed. Two nsLTP cDNAs were cloned from GB and over-expressed in Pichia pastoris. The recombinant LTPs (rLTPs) were characterized by circular dichroism spectroscopy and IgE-binding assays (immunoblotting and ELISA) with the patients' sera. Three natural LTPs (nLTPs) were further purified from GB fruit by chromatography. In vitro histamine release test was applied to compare the allergenic potency of rLTPs and nLTPs.
Oral provocation test confirmed GB allergy. A 10kDa protein in GB extract was recognized by 80% of the sera and identified as nsLTP. The two rLTPs (named LTP1a and LTP1b), share 61.3% aa identity and present the typical nsLTP-like secondary structure. The IgE-binding and histamine release assays provided evidence that rLTPs and nLTPs possess different allergenic potency.
nsLTP (Pha v 3) is the major allergen in GB and constitute a potential risk for patients affected by LTP-syndrome. GB encodes for several LTPs with different immune reactivity.
已报道食用、接触或吸入加工或烹饪过程中产生的颗粒会导致绿豆过敏反应。目前尚未对绿豆中的所有过敏原进行全面鉴定。
从分子水平鉴定绿豆主要过敏原，并验证非特异性脂质转移蛋白（nsLTPs）是否与绿豆过敏有关。
我们招募了 10 名报告对绿豆有不良反应的西班牙患者。进行了皮肤点刺试验、特异性 IgE 检测和口服激发试验。从绿豆中克隆了 2 个 nsLTP cDNA，并在毕赤酵母中过表达。通过圆二色性光谱和患者血清的 IgE 结合试验（免疫印迹和 ELISA）对重组 LTP（rLTP）进行了鉴定。通过色谱法从绿豆果实中进一步纯化了 3 种天然 LTP（nLTP）。应用体外组胺释放试验比较 rLTP 和 nLTP 的致敏能力。
口服激发试验证实了绿豆过敏。绿豆提取物中 10kDa 的蛋白被 80%的血清识别，并被鉴定为 nsLTP。两种 rLTP（分别命名为 LTP1a 和 LTP1b）的 aa 序列同源性为 61.3%，具有典型的 nsLTP 二级结构。IgE 结合和组胺释放试验表明 rLTP 和 nLTP 具有不同的致敏能力。
nsLTP（Pha v 3）是绿豆中的主要过敏原，可能会对 LTP 综合征患者构成风险。绿豆编码多种具有不同免疫反应性的 LTP。
