title: Immunologic characterization of monoclonal antibodies that modulate human IgE binding to the major birch pollen allergen Bet v 1.
abstract: BACKGROUND
  Bet v 1 and homologous proteins represent major allergens for almost 95% of patients allergic to tree pollen and approximately 70% of those allergic to fruits and vegetables. As yet, no continuous (sequential) IgE epitopes have been determined for Bet v 1, and evidence has accumulated that Bet v 1 IgE epitopes belong to the conformational (discontinuous) type.
  
  
  OBJECTIVE
  A panel of 85 mouse monoclonal anti-Bet v 1 antibodies was raised as a tool with which to study the interaction of human IgE antibodies with Bet v 1.
  
  
  METHODS
  The epitopes of selected monoclonal antibodies (mAbs) were characterized by mapping with synthetic overlapping peptides and by cross-competition experiments. Cross-reactivity of Bet v 1-specific mAbs with tree and plant food allergens was investigated by Western blotting. The influence of Bet v 1-specific mAbs on the IgE-Bet v 1 interaction was studied by competition assays with immobilized purified recombinant Bet v 1 and by basophil histamine release experiments.
  
  
  RESULTS
  Antibodies that increased the IgE binding to Bet v 1 up to fivefold could be defined, whereas others inhibited IgE binding to Bet v 1 up to 99% and competed with the Bet v 1-induced histamine release from patients' basophils.
  
  
  CONCLUSIONS
  The activity of the enhancing antibodies is interpreted as a stabilization of Bet v 1 states/IgE epitopes, which are either more accessible for certain IgE antibodies or are recognized with higher affinity. Those mAbs that competed with the Bet v 1-IgE interaction, if humanized or produced as recombinant antibody fragments, might be considered as potential tools for local allergy therapy.
authors.affiliation: Schering-Plough, Laboratory for Immunological Research, Dardilly, France.
authors.forename: S
authors.initials: S
authors.lastname: Lebecque
authors.forename: C
authors.initials: C
authors.lastname: Dolecek
authors.forename: S
authors.initials: S
authors.lastname: Laffer
authors.forename: V
authors.initials: V
authors.lastname: Visco
authors.forename: S
authors.initials: S
authors.lastname: Denépoux
authors.forename: J J
authors.initials: JJ
authors.lastname: Pin
authors.forename: C
authors.initials: C
authors.lastname: Guret
authors.forename: G
authors.initials: G
authors.lastname: Boltz-Nitulescu
authors.forename: A
authors.initials: A
authors.lastname: Weyer
authors.forename: R
authors.initials: R
authors.lastname: Valenta
mesh_terms: D000485:Allergens; D000818:Animals; D019138:Antibodies, Blocking / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000276:immunology* / Q000302:isolation & purification; D000937:Antigen-Antibody Reactions; D052179:Antigens, Plant; D001491:Basophils / Q000276:immunology / Q000378:metabolism; D015153:Blotting, Western; D002846:Chromatography, Affinity; D003429:Cross Reactions / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis*; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010449:Peptide Mapping; D010940:Plant Proteins / Q000235:genetics / Q000276:immunology*; D011233:Precipitin Tests; D011994:Recombinant Proteins / Q000276:immunology
chemical_list: D000485:Allergens; D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; D000939:Epitopes; D010940:Plant Proteins; D011994:Recombinant Proteins; C061312:Bet v 1 allergen, Betula; D007073:Immunoglobulin E