IgE-binding epitopes of enolases, a class of highly conserved fungal allergens - 04/09/11
Abstract |
Background: Cladosporium herbarum and Alternaria alternata are two of the most prominent fungal species inducing type I allergy. Previously, we have demonstrated that enolase (Cla h 6) is the second most important allergen of C herbarum in terms of frequency of sensitization. Objective: IgE-reactive B-cell epitopes of C herbarum enolase were analyzed, and cross-reactivity between fungal enolases was investigated. Methods: Cla h 6 glutathione-S-transferase fusion peptides were constructed by means of PCR cloning. A alternata enolase (Alt a 5) was isolated by screening a complementary (c)DNA expression library with a C herbarum enolase DNA probe. Results: Mapping of Cla h 6 IgE-binding epitopes identified a peptide with a length of 69 amino acids (peptide 9), which bound IgE from 8 of 8 patients. Analysis of the conformation of peptide 9 revealed that it does not form a compact structure but rather spans the whole length of the protein, with side chains exposed to solvent at 3 locations. Peptide 9 in the context of Escherichia coli glutathione-S-transferase not only binds IgE but also competitively inhibits IgE binding to Alt a 5. This result indicates that the epitope or epitopes on peptide 9 constitute a major cross-reacting epitope or epitopes on the enolases from C herbarum and A alternata in the case of the one patient tested. Conclusions: We demonstrated that the glycolytic enzyme enolase is an allergen not only in C herbarum but also in A alternata . Additionally, enolase was shown to exhibit high cross-reactivity to other fungal enolases. On the basis of the results presented here, we propose the use of recombinant Cla h 6 or maybe even peptide 9 of Cla h 6 for diagnosis and possibly therapy of mold allergy. (J Allergy Clin Immunol 2000;106:887-95.)
Le texte complet de cet article est disponible en PDF.Keywords : Enolase, structure, epitope, mold, allergy, Cladosporium herbarum, Alternaria alternata, Aspergillus fumigatus, Candida albicans, Saccharomyces cerevisiae
Abbreviations : DOC, GST, rnf
Plan
![]() | Supported by a grant to Michael Breitenbach from Biomay (Linz, Austria). Work at SIAF was supported by the Swiss National Science Foundation grant No. 31-50515.97. |
![]() ![]() | Reprint requests: Birgit Simon-Nobbe, PhD, Institute of Genetics and General Biology, University of Salzburg, Hellbrunnerstr 34, A-5020 Salzburg, Austria. |
Vol 106 - N° 5
P. 887-895 - novembre 2000 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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