title: Hypoallergenic derivatives of Fel d 1 obtained by rational reassembly for allergy vaccination and tolerance induction.
abstract: 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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  We report the development of hypoallergenic reassembled Fel d 1 proteins suitable for vaccination and tolerance induction in cat-allergic patients.
authors.affiliation: Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Allergy Research, Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Curin
authors.forename: M
authors.initials: M
authors.lastname: Weber
authors.forename: T
authors.initials: T
authors.lastname: Thalhamer
authors.forename: I
authors.initials: I
authors.lastname: Swoboda
authors.forename: M
authors.initials: M
authors.lastname: Focke-Tejkl
authors.forename: K
authors.initials: K
authors.lastname: Blatt
authors.forename: P
authors.initials: P
authors.lastname: Valent
authors.forename: K
authors.initials: K
authors.lastname: Marth
authors.forename: T
authors.initials: T
authors.lastname: Garmatiuk
authors.forename: H
authors.initials: H
authors.lastname: Grönlund
authors.forename: J
authors.initials: J
authors.lastname: Thalhamer
authors.forename: S
authors.initials: S
authors.lastname: Spitzauer
authors.forename: R
authors.initials: R
authors.lastname: Valenta
mesh_terms: D000485:Allergens / Q000276:immunology*; D000818:Animals; D001491:Basophils / Q000276:immunology; D002415:Cats; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D006023:Glycoproteins / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology* / Q000517:prevention & control*; D007108:Immune Tolerance; D007073:Immunoglobulin E / Q000276:immunology / Q000378:metabolism; D007074:Immunoglobulin G / Q000276:immunology; D010455:Peptides / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D011817:Rabbits; D051381:Rats; D011994:Recombinant Proteins / Q000276:immunology; D014612:Vaccines / Q000276:immunology*
chemical_list: D000485:Allergens; D018984:Epitopes, T-Lymphocyte; D006023:Glycoproteins; D007074:Immunoglobulin G; D010455:Peptides; D011994:Recombinant Proteins; D014612:Vaccines; D007073:Immunoglobulin E; C059296:Fel d 1 protein, Felis domesticus
keywords: Fel d 1; allergen-specific immunotherapy; cat allergy; hypoallergenic vaccine; recombinant allergen; tolerance induction; vaccination