Hypoallergenic derivatives of Fel d 1 obtained by rational reassembly for allergy vaccination and tolerance induction
Article first published online: 24 MAY 2014
© 2014 John Wiley & Sons Ltd
Clinical & Experimental Allergy
Volume 44, Issue 6, pages 882–894, June 2014
How to Cite
Clinical & Experimental Allergy, 2014 (44) 882–894., , , , , , , , , , , and ,
- Issue published online: 24 MAY 2014
- Article first published online: 24 MAY 2014
- Accepted manuscript online: 19 FEB 2014 05:34AM EST
- Manuscript Accepted: 5 FEB 2014
- Manuscript Revised: 30 OCT 2013
- Manuscript Received: 22 MAR 2013
- Austrian Science Fund (FWF). Grant Numbers: F4605, F4611
- Christian Doppler Research Association
- Swedish Research Council
- Swedish Asthma and Allergy Association's Research Foundation
- allergen-specific immunotherapy;
- cat allergy;
- Fel d 1;
- hypoallergenic vaccine;
- recombinant allergen;
- tolerance induction;
Background and objective
The major cat allergen Fel d 1 represents one of the most important respiratory allergens. Aim of this study was to engineer recombinant Fel d 1 derivatives with reduced IgE reactivity and preserved T cell epitopes for vaccination and tolerance induction.
Seven recombinant mosaic proteins were generated by reassembly of non-IgE-reactive peptides of Fel d 1 which contained the sequence elements for induction of allergen-specific blocking IgG antibodies and T cell epitopes. Mosaic proteins were expressed in Escherichia coli using codon-optimized synthetic genes and compared with Fel d 1 regarding structural fold by circular dichroism, IgE-binding capacity, activation of allergic patients' basophils and ability to induce allergen-specific blocking IgG antibodies upon immunization.
Although each of the mosaic proteins had lost the alpha-helical fold typical for Fel d 1, a strong reduction in IgE reactivity as well as allergenic activity in basophil activation assays was only obtained for three constructs, two reassembled fragments (Fel d 1 MB, Fel d 1 MC) and a fusion of the latter two (Fel d 1 MF) in which the cysteines of Fel d 1 MC were replaced by serines. Immunization of rabbits with Fel d 1 MB, MC and MF induced high levels of IgG antibodies that inhibited IgE reactivity of cat-allergic patients to Fel d 1 in a comparable manner as IgG induced with the wild-type allergen.
We report the development of hypoallergenic reassembled Fel d 1 proteins suitable for vaccination and tolerance induction in cat-allergic patients.