title: Genetic engineering of trimers of hypoallergenic fragments of the major birch pollen allergen, Bet v 1, for allergy vaccination.
abstract: An immunotherapy trial performed in allergic patients with hypoallergenic recombinant fragments, comprising aa 1-74 and 75-160 of the major birch pollen allergen, Bet v 1, has indicated that the induction of allergen-specific IgG responses may be an important mechanism of this treatment. To investigate whether the immunogenicity of the rBet v 1 fragments can be increased, recombinant trimers of the fragments were produced. For this purpose, DNA trimers of rBet v 1 aa 1-74 as well as of rBet v 1 aa 75-160 were subcloned into expression plasmid pET 17b, expressed in Escherichia coli and purified. The fragments as well as the fragment trimers showed a reduced IgE-binding capacity and allergenic activity compared to rBet v 1 wildtype when tested in allergic patients. Both rBet v 1 aa 75-160 monomer and trimer induced high titers of allergen-specific IgG1 Abs in mice. Interestingly, rBet v 1 aa 1-74 trimer induced a much higher IgG(1) response to rBet v 1 than rBet v 1 aa 1-74 monomer. Consequently, IgG Abs induced with the rBet v 1 aa 1-74 trimer inhibited birch pollen allergic patients' IgE-binding 10-fold more efficiently than IgG Abs induced with the monomer. Our data show that the immunogenicity of allergy vaccines can be increased by oligomerization.
authors.affiliation: Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
authors.forename: Susanne
authors.initials: S
authors.lastname: Vrtala
authors.forename: Monika
authors.initials: M
authors.lastname: Fohr
authors.forename: Raffaela
authors.initials: R
authors.lastname: Campana
authors.forename: Christian
authors.initials: C
authors.lastname: Baumgartner
authors.forename: Peter
authors.initials: P
authors.lastname: Valent
authors.forename: Rudolf
authors.initials: R
authors.lastname: Valenta
mesh_terms: D000485:Allergens / Q000235:genetics / Q000276:immunology*; D000818:Animals; D000917:Antibody Formation; D000918:Antibody Specificity; D052179:Antigens, Plant / Q000235:genetics / Q000276:immunology*; D029662:Betula / Q000276:immunology*; D003001:Cloning, Molecular; D003888:Desensitization, Immunologic; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005260:Female; D005818:Genetic Engineering; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011058:Pollen / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000628:therapy
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D007073:Immunoglobulin E