title: Conversion of grass pollen allergen-specific human IgE into a protective IgG(1) antibody.
abstract: More than 100 million individuals exhibit IgE-mediated allergic reactions against Phl p 2, a major allergen from timothy grass pollen. We isolated cDNA coding for three Phl p 2-specific human IgE antibodies from a combinatorial library, which was constructed from lymphocytes of a grass pollen-allergic patient. Recombinant Phl p 2-specific IgE antibody fragments (Fab) recognized a fragment comprising the 64 N-terminal amino acids of Phl p 2 and cross-reacted with group 2 allergens from seven grass species. cDNA coding for the variable regions of one of the IgE Fab were cloned into aplasmid vector expressing the constant region of human IgG(1) to obtain a complete, recombinant Phl p 2-specific human IgG(1). This antibody blocked the binding of grass pollen-allergic patients IgE (n=26; mean inhibition: 58%) to Phl p 2 and caused a 100-fold reduction of Phl p 2-induced basophil histamine release. The recombinant human Phl p 2-specific IgG(1) may be used for environmental allergen detection, for standardization of diagnostic as well as therapeutic grass pollen allergen preparations and for passive therapy of grass pollen allergy.
authors.affiliation: Department of Pathophysiology, Vienna General Hospital, University of Vienna, Vienna, Austria.
authors.forename: Sabine
authors.initials: S
authors.lastname: Flicker
authors.forename: Peter
authors.initials: P
authors.lastname: Steinberger
authors.forename: Lars
authors.initials: L
authors.lastname: Norderhaug
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Sperr
authors.forename: Yasamin
authors.initials: Y
authors.lastname: Majlesi
authors.forename: Peter
authors.initials: P
authors.lastname: Valent
authors.forename: Dietrich
authors.initials: D
authors.lastname: Kraft
authors.forename: Rudolf
authors.initials: R
authors.lastname: Valenta
mesh_terms: D000485:Allergens / Q000276:immunology*; D003429:Cross Reactions; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000235:genetics / Q000276:immunology*; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology*; D010940:Plant Proteins / Q000276:immunology*; D011058:Pollen / Q000276:immunology*; D015202:Protein Engineering
chemical_list: D000485:Allergens; D007074:Immunoglobulin G; C084984:PHLPII protein, Phleum pratense; D010940:Plant Proteins; D007073:Immunoglobulin E