PMU-Autor/inn/en
Hartl Arnulf JosefAbstract
On the basis of IgE epitope mapping data, we have produced three allergen fragments comprising aa 1-33, 1-57, and 31-110 of the major timothy grass pollen allergen Phi p 6 aa 1-110 by expression in Escherichia coli and chemical synthesis. Circular dichroism analysis showed that the purified fragments lack the typical a-helical fold of the complete allergen. Superposition of the sequences of the fragments onto the three-dimensional allergen structure indicated that the removal of only one of the four helices had led to the destabilization of the alpha helical structure of Phi p 6. The lack of structural fold was accompanied by a strong reduction of IgE reactivity and allergenic activity of the three fragments as determined by basophil histamine release in allergic patients. Each of the three Phi p 6 fragments adsorbed to CFA induced Phi p 6-specific IgG Abs in rabbits. However, immunization of mice with fragments adsorbed to an adjuvant allowed for human use (AluGel-S) showed that only the Phi p 6 aa 31-110 induced Phi p 6-specific IgG Abs. Anti-Phi p 6 IgG Abs induced by vaccination with Phi p 6 aa 31-110 inhibited patientsxxx IgE reactivity to the wild-type allergen as well as Phi p 6-induced basophil degranulation. Our results are of importance for the design of hypoallergenic allergy vaccines. They show that it has to be demonstrated that the hypoallergenic derivative induces a robust IgG response in a formulation that can be used in allergic patients.
Useful keywords (using NLM MeSH Indexing)
Allergens/administration*
dosage
Allergens/biosynthesis*
Allergens/genetics*
Allergens/immunology
Animals
Down-Regulation/genetics
Down-Regulation/immunology*
Female
Gene Expression Regulation/immunology
Humans
Immune Sera/biosynthesis
Immunoglobulin E/metabolism
Immunoglobulin G/biosynthesis
Immunoglobulin G/metabolism
Mice
Mice, Inbred BALB C
Peptide Fragments/administration*
dosage
Peptide Fragments/chemical synthesis
Peptide Fragments/genetics
Peptide Fragments/immunology
Phleum/genetics
Phleum/immunology
Plant Proteins/administration*
dosage
Plant Proteins/chemical synthesis*
Plant Proteins/genetics*
Plant Proteins/immunology
Pollen/genetics
Pollen/immunology
Protein Engineering/methods
Protein Folding
Protein Structure, Secondary
Rabbits
Recombinant Fusion Proteins/administration*
dosage
Recombinant Fusion Proteins/chemical synthesis*
Recombinant Fusion Proteins/genetics*
Recombinant Fusion Proteins/immunology
Vaccines/administration*
dosage
Vaccines/chemical synthesis
Vaccines/genetics*
Vaccines/immunology