title: IgE-mediated rat mast cell triggering with tryptic and synthetic peptides of bovine beta-lactoglobulin.
abstract: BACKGROUND
  Immunoglobulin E (IgE) epitopes of beta-lactoglubulin (betaLG) have been identified by ELISA inhibition methods using sera from allergic patients. However, the functional capacity of these epitopes to stimulate mast cells is unknown. It is the goal of the present study to identify bivalent IgE epitopes of betaLG able to trigger target mast cells.
  
  
  METHODS
  Peptides were obtained either by purification from tryptic hydrolysates of betaLG or by synthesis. They were examined for their triggering activity in vitro on peritoneal 3H-serotonin-labeled rat mast cells passively sensitized with IgE anti-betaLG antibodies. In vivo, rats immunized with betaLG were administered peptides by gavage for intestinal rat mast cell protease II release.
  
  
  RESULTS
  Compared with intact betaLG, purified or synthetic tryptic-like betaLG peptides have a sharply decreased allergenicity. Peptide 149-162 retains the highest bivalent IgE epitope-mediated triggering capacity.
  
  
  CONCLUSIONS
  A functional bivalent IgE epitope was identified at the C terminal end of betaLG.
authors.affiliation: Nestlé Research Center, Lausanne, Switzerland. rodolphe.fritsche@rdls.nestle.com
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Fritsché
authors.forename: Karine
authors.initials: K
authors.lastname: Adel-Patient
authors.forename: Hervé
authors.initials: H
authors.lastname: Bernard
authors.forename: Christine
authors.initials: C
authors.lastname: Martin-Paschoud
authors.forename: Catherine
authors.initials: C
authors.lastname: Schwarz
authors.forename: Sandrine
authors.initials: S
authors.lastname: Ah-Leung
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Wal
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D000939:Epitopes / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology*; D007782:Lactoglobulins / Q000276:immunology*; D008407:Mast Cells / Q000276:immunology*; D016269:Milk Hypersensitivity / Q000276:immunology*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology*; D051381:Rats; D011914:Rats, Inbred BN; D017207:Rats, Sprague-Dawley; D012697:Serine Endopeptidases / Q000097:blood
chemical_list: D000939:Epitopes; D007782:Lactoglobulins; D010446:Peptide Fragments; D007073:Immunoglobulin E; D012697:Serine Endopeptidases; C057818:cytotoxic T lymphocyte-specific serine protease