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A human monoclonal IgE antibody defines a highly allergenic fragment of the major timothy grass pollen allergen, Phl p 5: molecular, immunological, and structural characterization of the epitope-containing domain

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Version 1 2019-07-18, 14:41
journal contribution
posted on 2024-06-03, 12:45 authored by S Flicker, S Vrtala, P Steinberger, L Vangelista, A Bufe, A Petersen, M Ghannadan, WR Sperr, P Valent, L Norderhaug, B Bohle, H Stockinger, Cenk SuphiogluCenk Suphioglu, Eng Kok Ong, D Kraft, R Valenta
Almost 90% of grass pollen-allergic patients are sensitized against group 5 grass pollen allergens. We isolated a monoclonal human IgE Fab out of a combinatorial library prepared from lymphocytes of a grass pollen-allergic patient and studied its interaction with group 5 allergens. The IgE Fab cross-reacted with group 5A isoallergens from several grass and corn species. By allergen gene fragmentation we mapped the binding site of the IgE Fab to a 11.2-kDa N-terminal fragment of the major timothy grass pollen allergen Pld p 5A. The IgE Fab-defined Phl p 5A fragment was expressed in Escherichia coli and purified to homogeneity. Circular dichroism analysis revealed that the rPhl p 5A domain, as well as complete rPld p 5A, assumed a folded conformation consisting predominantly of an a helical secondary structure, and exhibited a remarkable refolding capacity. It reacted with serum IgE from 76% of grass pollen-allergic patients and revealed an extremely high allergenic activity in basophil histamine release as well as skin test experiments. Thus, the rPhl p 5A domain represents an important allergen domain containing several IgE epitopes in a configuration optimal for efficient effector cell activation. We suggest the rPhl p 5A fragment and the corresponding IgE Fab as paradigmatic tools to explore the structural requirements for highly efficient effector cell activation and, perhaps later, for the development of generally applicable allergen-specific therapy strategies.

History

Journal

Journal of immunology

Volume

165

Pagination

3849-3859

Location

Bethesda, Md.

Open access

  • Yes

ISSN

0022-1767

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2000, The American Association of Immunologists

Issue

7

Publisher

American Association of Immunologists

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