Mechanisms underlying differential food allergy response to heated egg.
Mechanisms underlying differential food allergy response to heated egg.
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DOI：
10.1016/j.jaci.2011.01.057
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发表时间：
2011-04
期刊：
影响因子：
--
通讯作者：
Nowak-Węgrzyn A
中科院分区：
文献类型：
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作者：
Martos G;Lopez-Exposito I;Bencharitiwong R;Berin MC;Nowak-Węgrzyn A
蛋清蛋白通常经过加热，适合大多数对鸡蛋过敏的儿童食用。我们试图研究热处理蛋清过敏原降低过敏性的潜在机制。 C3H/HeJ 小鼠经口服卵清蛋白 (OVA) 或卵类粘蛋白 (OM) 致敏，并用天然或加热蛋白质激发以评估其过敏性。使用鸡蛋过敏儿童的血清通过免疫印迹评估免疫反应性。通过 SDS-PAGE 和液相色谱研究了天然和加热的 OVA 和 OM 的体外胃肠消化情况。研究了人肠上皮 (Caco-2) 细胞对完整天然和加热的 OVA 和 OM 的肠道摄取。使用小鼠血清被动致敏的大鼠嗜碱性粒细胞白血病（RBL）细胞和鸡蛋过敏儿童血清被动致敏的人嗜碱性粒细胞用于评估加热、消化和运输的 OVA 和 OM 对效应细胞的活化作用。口服加热的 OVA 和 OM 不会引起致敏小鼠的过敏反应症状。加热并没有完全破坏OVA或OM的IgE结合能力，但增强了OVA的体外消化率。 OVA 和 OM 的消化减少了 RBL 测定中介质的释放和嗜碱性粒细胞的活化。加热过敏原可阻止其以能够触发嗜碱性粒细胞活化或 T 细胞活化的形式穿过人体肠上皮细胞。热处理可降低 OVA 和 OM 的致敏性。这部分是由于加热的 OVA 的胃肠道消化率增强，并且加热的 OVA 或 OM 无法以能够触发嗜碱性粒细胞的形式被吸收。加热蛋清蛋白的过敏原性降低部分归因于胃肠道消化和吸收的改变，这可能解释了大多数鸡蛋过敏儿童对深度加热鸡蛋的临床耐受性。大多数对鸡蛋过敏的儿童都能耐受高度加热的鸡蛋。这项研究表明，加热的卵清蛋白和卵类粘蛋白的过敏原性降低很大程度上是由于胃肠道消化和加工的改变所致。
Egg white proteins are usually subjected to heating, making them edible for the majority of egg-allergic children. We sought to investigate the underlying mechanisms responsible for the reduced allergenicity displayed by heat-treated egg white allergens. C3H/HeJ mice were orally sensitized with ovalbumin (OVA) or ovomucoid (OM) and challenged with native or heated proteins to evaluate their allergenicity. Immunoreactivity was assessed by immunoblotting using sera from egg-allergic children. In vitro gastrointestinal digestion of native and heated OVA and OM was studied by SDS-PAGE and liquid chromatography. Intestinal uptake of intact native and heated OVA and OM by human intestinal epithelial (Caco-2) cells was investigated. Rat basophil leukemia (RBL) cells passively sensitized with mouse serum and human basophils passively sensitized with egg-allergic children’s serum were used to assess the effector cell activation by heated, digested and transported OVA and OM. Heated OVA and OM did not induce symptoms of anaphylaxis in sensitized mice when administered orally. Heating did not completely destroy IgE-binding capacity of OVA or OM but enhanced in vitro digestibility of OVA. Digestion of both OVA and OM diminished mediator release in RBL assay and basophil activation. Heating of allergens prevented transport across human intestinal epithelial cells in a form capable of triggering basophil activation or T cell activation. Heat treatment reduces allergenicity of OVA and OM. This is partially due to the enhanced gastrointestinal digestibility of heated OVA and the inability of heated OVA or OM to be absorbed in a form capable of triggering basophils. Reduced allergenicity of heated egg white proteins partially resulting from altered digestion and absorption in the gastrointestinal tract may explain the clinical tolerance of extensively heated egg in the majority of egg-allergic children. The majority of egg-allergic children tolerate extensively heated egg. This study demonstrates that the decreased allergenicity of heated ovalbumin and ovomucoid in large part results from altered digestion and processing in the gastrointestinal tract.