Mapping Sequential IgE-Binding Epitopes on Major and Minor Egg Allergens

Maria Suprun, Scott H. Sicherer, Robert A. Wood, Stacie M. Jones, Donald Y.M. Leung, A. Wesley Burks, David Dunkin, Marc Witmer, Galina Grishina, Robert Getts, Mayte Suárez-Fariñas, Hugh A. Sampson
2021 International Archives of Allergy and Immunology  
<b><i>Introduction:</i></b> 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 (<i>ses-</i>)IgE and <i>ses-</i>IgG<sub>4</sub> among baked-egg reactive or tolerant
more » ... hildren. <b><i>Methods:</i></b> 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. <i>Ses-</i>IgE and <i>ses-</i>IgG<sub>4</sub> repertoires of 135 egg allergic children (82 reactive to baked-egg, the remaining 52 tolerant), 46 atopic controls, and 11 healthy subjects were compared. <b><i>Results:</i></b> 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 <i>ses-</i>IgE and lower <i>ses-</i>IgG<sub>4</sub> to predominantly OVM epitopes than both atopic and healthy controls. Baked-egg reactive children had similar <i>ses-</i>IgG<sub>4</sub> but greater <i>ses-</i>IgE than tolerant group. A combination of OVA-sIgE with <i>ses-</i>IgEs to OVM-023 and OVA-028 was the best predictor of reactive phenotype. <b><i>Conclusion:</i></b> We have created a comprehensive epitope library and showed that <i>ses-</i>IgE is a potential biomarker of baked-egg reactivity.
doi:10.1159/000519618 pmid:34818647 fatcat:nzeakyzvobh4de64a3ierrpqzm