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Allergen hybrids – next generation vaccines for F agales pollen immunotherapy
Author(s) -
Pichler U.,
Hauser M.,
Hofer H.,
Himly M.,
Hoflehner E.,
Steiner M.,
Mutschlechner S.,
Hufnagl K.,
Ebner C.,
Mari A.,
Briza P.,
Bohle B.,
Wiedermann U.,
Ferreira F.,
Wallner M.
Publication year - 2014
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/cea.12250
Subject(s) - allergen , pollen , epitope , biology , immunoglobulin e , immunotherapy , immunology , desensitization (medicine) , antibody , immune system , allergy , botany , biochemistry , receptor
Summary Background Trees belonging to the order of F agales show a distinct geographical distribution. While alder and birch are endemic in the temperate zones of the N orthern Hemisphere, hazel, hornbeam and oak prefer a warmer climate. However, specific immunotherapy of F agales pollen‐allergic patients is mainly performed using birch pollen extracts, thus limiting the success of this intervention in birch‐free areas. Objectives T cells are considered key players in the modification of an allergic immune response during specific immunotherapy ( SIT ), therefore we thought to combine linear T cell epitope‐containing stretches of the five most important F agales allergens from birch, hazel, alder, oak and hornbeam resulting in a F agales pollen hybrid (FPH) molecule applicable for SIT . Methods A Fagales pollen hybrid was generated by PCR ‐based recombination of low I g E ‐binding allergen epitopes. Moreover, a structural‐variant FPH 4 was calculated by in silico mutagenesis, rendering the protein unable to adopt the B et v 1‐like fold. Both molecules were produced in E scherichia coli , characterized physico‐chemically as well as immunologically, and tested in mouse models of allergic sensitization as well as allergy prophylaxis. Results Using spectroscopic analyses, both proteins were monomeric, and the secondary structure elements of FPH resemble the ones typical for B et v 1‐like proteins, whereas FPH 4 showed increased amounts of unordered structure. Both molecules displayed reduced binding capacities of B et v 1‐specific I g E antibodies. However, in a mouse model, the proteins were able to induce high I g G titres cross‐reactive with all parental allergens. Moreover, prophylactic treatment with the hybrid proteins prevented pollen extract‐induced allergic lung inflammation in vivo . Conclusion The hybrid molecules showed a more efficient uptake and processing by dendritic cells resulting in a modified T cell response. The proteins had a lower I g E ‐binding capacity compared with the parental allergens, thus the high safety profile and increased efficacy emphasize clinical application for the treatment of F agales multi‐sensitization.