title: Immunogenicity of Phleum pratense depigmented allergoid vaccines: experimental study in rabbits.
abstract: BACKGROUND
  Immunogenicity studies are based on accurate preclinical and clinical assessment of pharmaceutical products. The immunogenicity of modified allergen vaccines has not been fully elucidated, and the mechanisms involved are not well understood. Animal and human models have recently shown that depigmented allergoids induce specific immunoglobulin (Ig) G against individual allergens, thus supporting the clinical efficacy of these vaccines.
  
  
  OBJECTIVE
  The aim of this study was to investigate the production of specific IgG against individual antigens and their isoforms in rabbits injected with depigmented allergoid extracts of Phleum pratense pollen.
  
  
  METHODS
  Two New Zealand rabbits were immunized with depigmented-polymerized extracts adsorbed onto aluminum hydroxide (Depigoid) of P pratense. Rabbits were injected 3 times (35 microg Phl p 5). Specific IgG titers against native, depigmented, and depigmented-polymerized extracts and individual allergens (rPhl p 1 and rPhl p 5a) were analyzed by direct enzyme-linked immunosorbent assay. The capacity of these synthesized antibodies to recognize individual native and depigmented allergens and different isoforms was evaluated by immunoblot and 2-D analysis.
  
  
  RESULTS
  All rabbits produced high titers of specific IgG against the 3 extracts. Rabbits injected with depigmented allergoids produced similar specific antibody titers against native, depigmented, and depigmented-polymerized extracts. Serum samples recognized individual allergens and their isoforms in the nonmodified extracts.
  
  
  CONCLUSIONS
  Vaccines containing depigmented allergoid extracts of P pratense induce immunogenicity in vivo. The antibodies produced after injection of these extracts clearly recognized allergens and different isoforms in their native configuration.
authors.affiliation: R&D Department, Laboratorios LETI, Tres Cantos, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Iraola
authors.forename: M T
authors.initials: MT
authors.lastname: Gallego
authors.forename: M A
authors.initials: MA
authors.lastname: López-Matas
authors.forename: M
authors.initials: M
authors.lastname: Morales
authors.forename: I
authors.initials: I
authors.lastname: Bel
authors.forename: N
authors.initials: N
authors.lastname: García
authors.forename: J
authors.initials: J
authors.lastname: Carnés
mesh_terms: D000485:Allergens / Q000008:administration & dosage* / Q000276:immunology; D000818:Animals; D001249:Asthma / Q000276:immunology*; D003888:Desensitization, Immunologic; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology; D031784:Phleum / Q000276:immunology*; D010936:Plant Extracts / Q000008:administration & dosage / Q000276:immunology; D011058:Pollen / Q000276:immunology; D011817:Rabbits; D014611:Vaccination; D014612:Vaccines / Q000276:immunology*
chemical_list: D000485:Allergens; D007074:Immunoglobulin G; D010936:Plant Extracts; D014612:Vaccines