title: A hypoallergenic hybrid molecule with increased immunogenicity consisting of derivatives of the major grass pollen allergens, Phl p 2 and Phl p 6.
abstract: Allergen-specific immunotherapy is currently based on the administration of allergen extracts containing natural allergens. However, its broad application is limited by the poor quality of these extracts. Based on recombinant allergens, well-defined allergy vaccines for allergen-specific immunotherapy can be produced. Furthermore, they can be modified to reduce their allergenic activity and to avoid IgE-mediated side effects. Here, we demonstrate that the immunogenicity of two grass pollen-derived hypoallergenic allergen derivatives could be increased by engineering them as a single hybrid molecule. We used a hypoallergenic Phl p 2 mosaic, generated by fragmentation of the Phl p 2 sequence and reassembly of the resulting peptides in an altered order, and a truncated Phl p 6 allergen, to produce a hybrid protein. The hybrid retained the reduction of IgE reactivity and allergenic activity of its components as shown by ELISA and basophil activation assays. Immunization with the hybrid molecule demonstrated the increased immunogenicity of this molecule, leading to higher levels of allergen-specific IgG antibodies compared to the single components. These antibodies could inhibit patients' IgE binding to the wild-type allergens. Thus, the described strategy allows the development of safer and more efficacious vaccines for the treatment of grass pollen allergy.
authors.affiliation: Division of Immunopathology, Department of Pathophysiology, Center of Physiology, Pathophysiology and Immunology, Medical University of Vienna, Vienna, Austria. birgit.linhart@meduniwien.ac.at
authors.forename: Birgit
authors.initials: B
authors.lastname: Linhart
authors.forename: Nadine
authors.initials: N
authors.lastname: Mothes-Luksch
authors.forename: Susanne
authors.initials: S
authors.lastname: Vrtala
authors.forename: Michael
authors.initials: M
authors.lastname: Kneidinger
authors.forename: Peter
authors.initials: P
authors.lastname: Valent
authors.forename: Rudolf
authors.initials: R
authors.lastname: Valenta
mesh_terms: D000485:Allergens / Q000737:chemistry* / Q000276:immunology* / Q000627:therapeutic use; D000595:Amino Acid Sequence; D000918:Antibody Specificity; D003888:Desensitization, Immunologic; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology* / Q000627:therapeutic use; D011058:Pollen / Q000276:immunology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000627:therapeutic use; D014611:Vaccination
chemical_list: D000485:Allergens; D007106:Immune Sera; C084984:PHLPII protein, Phleum pratense; C095238:PHLPVI protein, Phleum pratense; D010940:Plant Proteins; D011994:Recombinant Proteins; D007073:Immunoglobulin E