Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Blvd. W. Saint-Hyacinthe, QC J2S 8E3, Canada.
Sherbrooke University Hospital Center, Hôtel-Dieu de Sherbrooke, Department of Pediatrics, 580 Bowen south, Sherbrooke, QC J1G 2E3, Canada.
Biomolecules. 2020 Jul 22;10(8):1091. doi: 10.3390/biom10081091.
Peanut allergic individuals can be both co-sensitized and co-allergic to peanut and tree nuts. At the moment, standard diagnostic approaches do not always allow differentiation between clinically relevant sensitization and nonsignificant cross-reactions, and the responsibility of each allergen remains unclear. The objective of this study was therefore to determine a peanut sensitization profile in a cohort of Canadian peanut allergic children and assess the immunoglobulin E (IgE) molecular cross-reactivity between peanut, almond, hazelnut and pistachio. The specific IgE (sIgE) levels of each patient serum were determined by ImmunoCAP, indirect ELISA and immunoblot to examine their sIgE-binding levels and profiles to peanut proteins. Reciprocal inhibition ELISA and immunoblotting were used to study sIgE cross-reactions between peanut and the selected tree nuts using an adjusted and representative serum pool of the nine allergic patients. The results showed that the prepared peanut and tree nut protein extracts allowed for the detection of the majority of peanut and selected tree nut known allergens. The reciprocal inhibition ELISA experiments showed limited sIgE cross-reactivities between peanut and the studied tree nuts, with peanut being most likely the sensitizing allergen and tree nuts the cross-reactive ones. In the case of hazelnut and pistachio, a coexisting primary sensitization to hazelnut and pistachio was also demonstrated in the serum pool. Reciprocal inhibition immunoblotting further revealed that storage proteins (2S albumin, 7S vicilin and 11S legumin) could possibly account for the observed IgE-cross-reactions between peanut and the studied tree nuts in this cohort of allergic individuals. It also demonstrated the importance of conformational epitopes in the exhibited cross-reactions.
花生过敏患者可能同时对花生和树坚果产生致敏和过敏反应。目前，标准的诊断方法并不总是能够区分临床相关的致敏和非显著的交叉反应，并且每个过敏原的责任仍然不清楚。因此，本研究的目的是确定加拿大花生过敏儿童队列中的花生致敏谱，并评估花生、杏仁、榛子和开心果之间的 IgE（免疫球蛋白 E）分子交叉反应性。通过 ImmunoCAP、间接 ELISA 和免疫印迹测定每个患者血清的特异性 IgE（sIgE）水平，以检查其 sIgE 结合水平和对花生蛋白的谱。使用经过调整的和代表性的 9 名过敏患者血清池，通过相互抑制 ELISA 和免疫印迹来研究花生和选定树坚果之间的 sIgE 交叉反应。结果表明，制备的花生和树坚果蛋白提取物允许检测到大多数已知的花生和选定树坚果过敏原。相互抑制 ELISA 实验表明，花生和研究的树坚果之间存在有限的 sIgE 交叉反应性，花生可能是致敏过敏原，而树坚果是交叉反应过敏原。在榛子和开心果的情况下，还在血清池中证明了榛子和开心果的同时原发性致敏。相互抑制免疫印迹进一步表明，在该组过敏个体中，储存蛋白（2S 白蛋白、7S 豆球蛋白和 11S 球蛋白）可能是观察到的花生和研究的树坚果之间 IgE 交叉反应的原因。它还证明了构象表位在展示的交叉反应中的重要性。
