Publications (5)24.99 Total impact
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Article: Generation of an allergy vaccine by disruption of the three-dimensional structure of the cross-reactive calcium-binding allergen, Phl p 7.
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ABSTRACT: The grass pollen allergen, Phl p 7, belongs to a family of highly cross-reactive calcium-binding pollen allergens. Because Phl p 7 contains most of the disease-eliciting epitopes of pollen-derived calcium-binding allergens, hypoallergenic variants were engineered according to the x-ray crystal structure of Phl p 7 for allergy vaccination. In three recombinant variants, amino acids essential for calcium binding were mutated, and two peptides comprising the N- and C-terminal half were obtained by synthetic peptide chemistry. As determined by circular dichroism analysis and size exclusion chromatography coupled to mass spectrometry, recombinant mutants showed altered structural fold and lacked calcium-binding capacity, whereas the two synthetic peptides had completely lost their structural fold. Allergic patients' IgE Ab binding was strongest reduced to the variant containing two mutations in each of the two calcium-binding sites and to the peptides. Basophil histamine release and skin test experiments in allergic patients identified the peptides as the vaccine candidates with lowest allergenic activity. Immunization of rabbits with the peptides induced IgG Abs that blocked allergic patients' IgE binding to Phl p 7 and inhibited allergen-induced basophil degranulation. Our results indicate that disruption of an allergen's three-dimensional structure represents a general strategy for the generation of hypoallergenic allergy vaccines, and demonstrate the importance of allergen-specific IgG Abs for the inhibition of immediate allergic symptoms.The Journal of Immunology 06/2004; 172(9):5684-92. · 5.79 Impact Factor -
Article: Microarrayed allergen molecules: diagnostic gatekeepers for allergy treatment.
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ABSTRACT: Type I allergy is an immunoglobulin E (IgE)-mediated hypersensitivity disease affecting more than 25% of the population. Currently, diagnosis of allergy is performed by provocation testing and IgE serology using allergen extracts. This process defines allergen-containing sources but cannot identify the disease-eliciting allergenic molecules. We have applied microarray technology to develop a miniaturized allergy test containing 94 purified allergen molecules that represent the most common allergen sources. The allergen microarray allows the determination and monitoring of allergic patients' IgE reactivity profiles to large numbers of disease-causing allergens by using single measurements and minute amounts of serum. This method may change established practice in allergy diagnosis, prevention, and therapy. In addition, microarrayed antigens may be applied to the diagnosis of autoimmune and infectious diseases.The FASEB Journal 04/2002; 16(3):414-6. · 5.71 Impact Factor -
Article: Molecular, structural, and immunologic relationships between different families of recombinant calcium-binding pollen allergens.
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ABSTRACT: Calcium-binding plant allergens can be grouped in different families according to the number of calcium-binding domains (EF hands). We sought to identify pollens containing crossreactive calcium-binding allergens and to investigate structural and immunologic similarities of members belonging to different families of calcium-binding allergens. By means of multiple sequence alignment and molecular modeling, we searched for structural similarities among pollen allergens with 2 (Phl p 7, timothy grass; Aln g 4, alder), 3 (Bet v 3, birch) and 4 EF hands (Jun o 4, prickly juniper). Purified recombinant Aln g 4 and Jun o 4 were used to determine the prevalence of IgE recognition in 210 patients sensitized to different pollens and to search, by means of ELISA competition, for the presence of cross-reactive epitopes in pollens from 16 unrelated plant species. IgE cross-reactivity among the allergen families was studied with purified rPhl p 7, rAln g 4, rBet v 3, and rJun o 4 and 2 synthetic peptides comprising the N-terminal and C-terminal EF hands of Phl p 7 by means of ELISA competition. Structural similarities were found by using molecular modeling among the allergens with 2, 3, and 4 EF hands. Pollens from 16 unrelated plants contained Aln g 4- and Jun o 4-related epitopes. Twenty-two percent of the patients with multiple pollen sensitization reacted to at least one of the calcium-binding allergens. A hierarchy of IgE cross-reactivity (rPhl p7 > rAln g 4 > rJun o 4 > rBet v 3) could be established that identified rPhl p 7 as the EF-hand allergen containing most IgE epitopes in the population studied. The demonstration that members of different families of calcium-binding plant allergens share similarities suggests that it may be possible to use representative molecules for the diagnosis and therapy of allergies to EF-hand allergens.Journal of Allergy and Clinical Immunology 02/2002; 109(2):314-20. · 11.00 Impact Factor -
Article: Synthetic and genetically engineered allergen derivatives for specific immunotherapy of type I allergy.
Clinical allergy and immunology 02/2002; 16:495-517. -
Article: Molecular Characterization, Expression inEscherichia coli,and Epitope Analysis of a Two EF-Hand Calcium-Binding Birch Pollen Allergen, Bet v 4
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ABSTRACT: Birch pollen belongs to the most potent elicitors of Type I allergic reactions in early spring. Using serum IgE from a birch pollen allergic patient, two cDNA clones (clone 6 and clone 13) were isolated from a birch pollen expression cDNA library constructed in phage λgt11. Clone 6 encoded a 9.3 kD two EF-hand calcium-binding protein, designated Bet v 4, with significant end to end sequence homology to EF-hand calcium-binding allergens from weed and grass pollen. Recombinant Bet v 4, expressed as β-galactosidase fusion protein, reacted with serum IgE from approximately 20% of pollen allergic individuals. Depletion of allergen-bound calcium by EGTA treatment lead to a substantial reduction of IgE-binding to Bet v 4, indicating that protein-bound calcium is necessary for the maintenance of IgE-epitopes. The greatly reduced IgE-binding capacity of clone 13, a Bet v 4 fragment that lacked the 16 N-terminal amino acids, indicated that the N-terminus contributes significantly to the proteins IgE-binding capacity. By IgE-inhibition experiments it was demonstrated that recombinant Bet v 4 shared IgE-epitopes with natural Bet v 4 and a homologous timothy grass pollen allergen. Recombinant Bet v 4 may therefore be considered as a relevant crossreactive plant allergen, which may be used for diagnosis and treatment of patients suffering from multivalent plant allergies.Biochemical and Biophysical Research Communications 11/1997; · 2.48 Impact Factor
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Institutions
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2004
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Medical University of Vienna
- Zentrum für Pathophysiologie, Infektiologie und Immunologie
Vienna, Vienna, Austria
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1997–2002
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University of Vienna
- Universitätsklinik für Innere Medizin I
Vienna, Vienna, Austria
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