title: Phl p 1-specific human monoclonal IgE and design of a hypoallergenic group 1 grass pollen allergen fragment.
abstract: Detailed understanding of how Abs of the IgE isotype interact with allergen at the onset of an allergic reaction is of great importance for deciphering mechanisms involved in the development of disease and may aid in the design of hypoallergenic variants. In this study, we have used a set of human monoclonal IgE Abs derived from the repertoires of allergic individuals, specific for the major timothy grass pollen allergen Phl p 1, to gain detailed information on the interaction between Abs and allergen. These allergen-specific IgE are to varying degrees cross-reactive toward both different allergen isoforms and various group 1 allergens originating from other grass species. The usage of human monoclonal IgE, as an alternative to polyclonal preparations or mouse Abs, allowed us to locate several important IgE-binding epitopes on the C-terminal domain of Phl p 1, all clustered to an IgE-binding "hot spot." By introducing three mutations in the IgE-binding area of the C-terminal domain we were able to significantly reduce its reactivity with serum IgE. In conclusion, our study shows the great potential of using human monoclonal IgE as a tool for studies of the molecular interactions taking place during allergic responses. Furthermore, we present a novel IgE-hyporeactive fragment with the potential to be used as a safer hypoallergenic alternative in specific immunotherapy than the pollen extracts used today.
authors.affiliation: Department of Immunotechnology, Lund University, S-223 81 Lund, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: Levin
authors.forename: Frida
authors.initials: F
authors.lastname: Rydnert
authors.forename: Eva
authors.initials: E
authors.lastname: Källström
authors.forename: Lor Wai
authors.initials: LW
authors.lastname: Tan
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Wormald
authors.forename: Malin
authors.initials: M
authors.lastname: Lindstedt
authors.forename: Lennart
authors.initials: L
authors.lastname: Greiff
authors.forename: Mats
authors.initials: M
authors.lastname: Ohlin
mesh_terms: D000485:Allergens / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D052179:Antigens, Plant / Q000276:immunology*; D001666:Binding Sites, Antibody; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D010936:Plant Extracts / Q000276:immunology*; D010940:Plant Proteins / Q000276:immunology*; D011058:Pollen / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology*; D016415:Sequence Alignment
chemical_list: D000485:Allergens; D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; D000939:Epitopes; D010936:Plant Extracts; D010940:Plant Proteins; C451253:grass pollen extract, alum-adsorbed; C090396:PHLPI protein, Phleum pratense; D007073:Immunoglobulin E