Icahn School of Medicine at Mount Sinai, New York, New York, USA,
Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Int Arch Allergy Immunol. 2022;183(3):249-261. doi: 10.1159/000519618. Epub 2021 Nov 24.
Molecular studies of hen's egg allergens help define allergic phenotypes, with IgE to sequential (linear) epitopes on the ovomucoid (OVM) protein associated with a persistent disease. Epitope profiles of other egg allergens are largely unknown. The objective of this study was to construct an epitope library spanning across 7 allergens and further evaluate sequential epitope-specific (ses-)IgE and ses-IgG4 among baked-egg reactive or tolerant children.
A Bead-Based Epitope Assay was used to identify informative IgE epitopes from 15-mer overlapping peptides covering the entire OVM and ovalbumin (OVA) proteins in 38 egg allergic children. An amalgamation of 12 B-cell epitope prediction tools was developed using experimentally identified epitopes. This ensemble was used to predict epitopes from ovotransferrin, lysozyme, serum albumin, vitellogenin-II fragment, and vitellogenin-1 precursor. Ses-IgE and ses-IgG4 repertoires of 135 egg allergic children (82 reactive to baked-egg, the remaining 52 tolerant), 46 atopic controls, and 11 healthy subjects were compared.
183 peptides from OVM and OVA were screened and used to create an aggregate algorithm, improving predictions of 12 individual tools. A final library of 65 sequential epitopes from 7 proteins was constructed. Egg allergic children had higher ses-IgE and lower ses-IgG4 to predominantly OVM epitopes than both atopic and healthy controls. Baked-egg reactive children had similar ses-IgG4 but greater ses-IgE than tolerant group. A combination of OVA-sIgE with ses-IgEs to OVM-023 and OVA-028 was the best predictor of reactive phenotype.
We have created a comprehensive epitope library and showed that ses-IgE is a potential biomarker of baked-egg reactivity.
鸡卵过敏原的分子研究有助于确定过敏表型，卵类黏蛋白（OVM）蛋白上的 IgE 对顺序（线性）表位与持续性疾病相关。其他卵过敏原的表位谱在很大程度上尚不清楚。本研究的目的是构建跨越 7 种过敏原的表位文库，并进一步评估烘焙蛋过敏或耐受儿童的顺序表位特异性（ses）IgE 和 ses-IgG4。
使用基于珠的表位分析来鉴定 38 名鸡蛋过敏儿童的 OVM 和卵清白蛋白（OVA）蛋白全长的 15 个重叠肽中的信息性 IgE 表位。使用实验鉴定的表位开发了 12 种 B 细胞表位预测工具的组合。该集合用于预测卵转铁蛋白、溶菌酶、血清白蛋白、卵黄蛋白原-II 片段和卵黄蛋白原-1 前体的表位。比较了 135 名鸡蛋过敏儿童（82 名对烘焙蛋过敏，其余 52 名耐受）、46 名特应性对照和 11 名健康受试者的 ses-IgE 和 ses-IgG4 谱。
筛选了来自 OVM 和 OVA 的 183 个肽，并用于创建聚合算法，提高了 12 个单独工具的预测能力。构建了来自 7 种蛋白质的 65 个连续表位的最终文库。鸡蛋过敏儿童对 OVM 表位的 ses-IgE 较高，而对 OVM 和健康对照的 ses-IgG4 较低。与耐受组相比，烘焙蛋过敏儿童的 ses-IgG4 相似，但 ses-IgE 更高。OVA-sIgE 与 OVM-023 和 OVA-028 的 ses-IgE 结合是反应性表型的最佳预测指标。
我们创建了一个全面的表位文库，并表明 ses-IgE 是烘焙蛋反应性的潜在生物标志物。
