Allergy to deamidated gluten in patients tolerant to wheat: specific epitopes linked to deamidation
Allergy to deamidated gluten in patients tolerant to wheat: specific epitopes linked to deamidation
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DOI：
10.1111/j.1398-9995.2012.02860.x
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发表时间：
2012-08-01
期刊：
影响因子：
12.4
通讯作者：
Moneret-Vautrin, D. -A.
中科院分区：
文献类型：
--
作者：
Denery-Papini, S.;Bodinier, M.;Moneret-Vautrin, D. -A.
背景：谷蛋白可以通过脱酰胺修饰来提高其溶解度和技术应用。然而，据报道，在食用含有脱酰胺谷蛋白（DG）的食品后，对小麦耐受的受试者出现了严重的过敏反应。这项工作旨在表征这些患者与小麦过敏患者的过敏原特征，并确定ige结合表位。方法：采集15例DG过敏患者和9例WP过敏患者的血清。在ELISA和人源化大鼠嗜碱性白血病（RBL）细胞模型中对ige结合谱进行了表征。通过Pepscan在γ -和- 2-麦胶蛋白序列上定位表位，并研究谷氨酰胺/谷氨酸取代的影响。结果：与白蜡过敏患者IgE检测的过敏原异质性相比，白蜡过敏患者的反应具有同质性。在ELISA中，所有血清都显示IgE与脱酰胺的γ -和ω - 2-麦胶蛋白和脱酰胺的总麦胶蛋白结合，通常浓度很高。这些修饰的蛋白在大多数dg过敏患者的血清中诱导RBL脱颗粒。在天然γ -和ω - 2-麦胶蛋白上发现了一致的表位（QPQQPFPQ）；它按照他们的顺序重复了好几次。在Q3、Q4和Q8 （QPEEPFPE）位置上替换2个或3个谷氨酰胺使其识别度提高最好。结论：对DG过敏与小麦过敏是一个独立的实体。这可以通过与QPEEPFPE型脱酰胺醇溶蛋白或肽的强IgE结合来证明。
Background: Gluten proteins can be modified by deamidation to enhance their solubility and technological applications. However, severe allergic reactions have been reported after the consumption of food products containing deamidated gluten (DG) in subjects tolerant to wheat. This work aimed to characterize allergen profiles for these patients in comparison with those of patients allergic to wheat and to identify IgE-binding epitopes.Methods: Sera were obtained from 15 patients allergic to DG and from nine patients allergic to wheat proteins (WP). IgE-binding profiles were characterized both in ELISA and in a humanized rat basophilic leukaemia (RBL) cell model. Epitopes were mapped on gamma- and omega 2-gliadin sequences by Pepscan, and effect of glutamine/glutamic acid substitutions was studied.Results: Compared to the heterogeneous pattern of allergens detected by IgE from patients allergic to WP, responses of patients allergic to DG were homogeneous. In ELISA, all the sera displayed IgE binding to deamidated gamma- and omega 2-gliadins and deamidated total gliadins, frequently with high concentrations. These modified proteins induced RBL degranulation with most of the sera from DG-allergic patients. A consensus epitope was found on native gamma- and omega 2-gliadins (QPQQPFPQ); it was repeated several times in their sequences. The substitution of two or three glutamines of this epitope into glutamic acid at positions Q3 or Q4 and Q8 (QPEEPFPE) increased its recognition the best.Conclusion: Allergy to DG is a separate entity from wheat allergy. It can be evidenced by strong IgE binding to deamidated gliadins or peptides of the type QPEEPFPE.