Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food and Health, Beijing Technology and Business University, Beijing 100048, P. R. China.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food and Health, Beijing Technology and Business University, Beijing 100048, P. R. China.
J Dairy Sci. 2020 Nov;103(11):9815-9824. doi: 10.3168/jds.2020-18250. Epub 2020 Sep 28.
Some infants allergic to cow milk-based formula are also sensitive to soybean-based formula. This paper aimed to explore the association of IgE and IgG cross-reactivity between α-casein in cow milk (CM) and soybean proteins. The IgE and IgG cross-reactive allergens and epitopes were identified using sera from infants allergic to CM or mice monoclonal antibodies. The AA sequence alignment was performed using bioinformatics software. Finally, the digestion and heating stability of the cross-reactive allergen were explored by sodium dodecyl sulfate (SDS)-PAGE and Western blotting. The results showed that the IgE and IgG cross-reactive allergen was α subunit of β-conglycinin named Gly m Bd 60K. The IgE and IgG epitopes were the sequences at AA 319-341 and AA 164-182. No intact Gly m Bd 60K allergen could be observed after 2 min in simulated gastric fluid by SDS-PAGE. Heating did not change IgE and IgG cross-reactivity by Western blotting. Therefore, the existence of cross-reactivity between CM α-casein and soybean proteins possibly contributes to the frequently observed cosensitization for these allergens in cow milk-allergic patients. The same IgE- and IgG-binding epitopes of cross-reactive allergens may provide important information for elucidation of the association between IgG and IgE antibody generation.
一些对牛奶配方过敏的婴儿也对大豆配方敏感。本文旨在探讨牛奶（CM）α-酪蛋白与大豆蛋白之间 IgE 和 IgG 交叉反应的相关性。使用对 CM 过敏的婴儿的血清或小鼠单克隆抗体鉴定 IgE 和 IgG 交叉反应性过敏原和表位。使用生物信息学软件进行 AA 序列比对。最后，通过 SDS-PAGE 和 Western blot 探讨交叉反应性过敏原的消化和热稳定性。结果表明，IgE 和 IgG 交叉反应性过敏原是 β-伴大豆球蛋白的α亚基，称为 Gly m Bd 60K。IgE 和 IgG 表位是 AA 319-341 和 AA 164-182 的序列。SDS-PAGE 模拟胃液中 2 分钟后，未观察到完整的 Gly m Bd 60K 过敏原。加热不会通过 Western blot 改变 IgE 和 IgG 交叉反应性。因此，CM α-酪蛋白与大豆蛋白之间可能存在交叉反应性，这可能导致牛奶过敏患者对这些过敏原的频繁共致敏。交叉反应性过敏原的相同 IgE 和 IgG 结合表位可能为阐明 IgG 和 IgE 抗体产生之间的关系提供重要信息。
