Abstract
Background: Egg white proteins are usually subjected to heating, making them edible for the majority of children with egg allergy. Objective: We sought to investigate the underlying mechanisms responsible for the reduced allergenicity displayed by heat-treated egg white allergens. Methods: C3H/HeJ mice were orally sensitized with ovalbumin (OVA) or ovomucoid and challenged with native or heated proteins to evaluate their allergenicity. Immunoreactivity was assessed by immunoblotting using sera from children with egg allergy. In vitro gastrointestinal digestion of native and heated OVA and ovomucoid was studied by SDS-PAGE and liquid chromatography. Intestinal uptake of intact native and heated OVA and ovomucoid by human intestinal epithelial (Caco-2) cells was investigated. Rat basophil leukemia cells passively sensitized with mouse serum and human basophils passively sensitized with serum from children with egg allergy were used to assess the effector cell activation by heated, digested, and transported OVA and ovomucoid. Results: Heated OVA and ovomucoid did not induce symptoms of anaphylaxis in sensitized mice when administered orally. Heating did not completely destroy IgE-binding capacity of OVA or ovomucoid but enhanced in vitro digestibility of OVA. Digestion of both OVA and ovomucoid diminished mediator release in rat basophil leukemia 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. Conclusion: Heat treatment reduces allergenicity of OVA and ovomucoid. This is partially a result of the enhanced gastrointestinal digestibility of heated OVA and the inability of heated OVA or ovomucoid to be absorbed in a form capable of triggering basophils.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 990-997.e2 |
| Journal | Journal of Allergy and Clinical Immunology |
| Volume | 127 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2011 |
Funding
G.M. was supported by the Spanish Research Council through the JAE program and by the Ministry of Science and Innovation through project AGL2008-01740 . R.B. was supported in part by the Nutricia Foundation . C.B. was supported by National Institutes of Health (NIH)–NIAID AI044236 . A.N.-W. was supported in part by NIH-NIAID AI059318 . The project was supported in part by grant no. CTSA ULI RR 029887 from the National Center for Research Resources , a component of the NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of National Center for Research Resources or the NIH. Disclosure of potential conflict of interest: G. Martos receives research support from the Spanish Research Council . A. Nowak-Węgrzyn receives research support from the National Institutes of Health–NIAID . The rest of the authors have declared that they have no conflict of interest.
Keywords
- Egg allergy
- anaphylaxis
- antigen absorption
- basophil activation
- gastrointestinal digestion
- heat treatment
- heating
- mice oral sensitization
- ovalbumin
- ovomucoid
- passive sensitization
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology
