Volume 4 Supplement 2

5th International Symposium on Molecular Allergology (ISMA 2013)

Open Access

In silico prediction of B cell epitopes and experimental validation on wheat allergens

  • Sandra Denery-Papini1,
  • Virginie Lollier1,
  • Hamza Mameri1,
  • Manon Pietri1,
  • Colette Larre1,
  • Jean-Charles Gaudin1,
  • Olivier Tranquet1,
  • Martine Drouet2,
  • Evelyne Paty3,
  • Anne-Marie Jonathan4,
  • Etienne Beaudouin5,
  • Anne Denise Moneret-Vautrin5 and
  • Dominique Tessier1
Clinical and Translational Allergy20144(Suppl 2):O4

DOI: 10.1186/2045-7022-4-S2-O4

Published: 17 March 2014

Background

B cell epitopes corresponding to interaction zones between proteins and immune system are a mean to explore intrinsic features of proteins linked to allergenicity. The project PREDEXPITOPE was funded by the French National Research Agency to develop a bioinformatics strategy for prediction of B cell epitopes of allergens. The objective was to distinguish epitopic from non epitopic areas on the basis of frequently used criteria of surface exposition. In silico prediction was confronted with experimental results on wheat allergens.

Method

Epitope sequences and description were exported from Immune Epitope DataBase (IEDB). Epitopes were mapped to 61 3D structures, extracted from PDB site. A pipeline program computed relative surface exposure of amino acids for each PDB file. Data were loaded into R environment for statistical comparison between epitopic and non epitopic amino acids. B epitopes were searched on wheat allergens for which 3D structure could be known. Sera were obtained from patients with food allergy to wheat or baker's asthma.

Results

On the basis of the 61 antigen structures no clear-cut classification of epitopic and non-epitopic values could be statistically achieved. The amino acids within epitopes are not distributed above any threshold for both relative surface accessibility and protrusion index. The wheat serpin was a good candidate to validate our bioinformatics conclusion. A 3D structural model was constructed and areas of strong surface accessibility could be selected. These areas did not correspond to those bound by patient's IgE.

Conclusion

Our work did not deny the requisite for B-cell epitopes to be exposed on surface. However, it indicates that the level of surface exposure has no discriminatory ability. The difficulty in establishing a system of prediction lies in the heterogeneity of data on B-cell epitopes, which varies from a few amino acids actually in contact with the antibodies to shorter or longer peptides, able to interact with these antibodies. The integration of experimental context or epidemiological aspects in epitope data bases may improve such a prediction.

Authors’ Affiliations

(1)
INRA, UR1268 BIA, NANTES
(2)
Angers University Hospital, General Allergology Unit
(3)
Necker Hospital, Pneumology and allergology department
(4)
Occupational disease department, Cochin Hospital
(5)
Epinal Hospital, Allergology Unit

References

  1. Lollier : A generic approach to evaluate how B-cell epitopes are surface-exposed on protein structures. Mol. Immunol. 2011, 48 (4): 577-585.View ArticlePubMedGoogle Scholar
  2. Mameri : Molecular and immunological characterization of wheat Serpin (Tri a 33). MNFR. 2012, 56: 1874-1883. The project was funded by ANR-08 ALIA-014Google Scholar

Copyright

© Denery-Papini et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Advertisement