title: Anti-IgE efficacy in murine asthma models is dependent on the method of allergen sensitization.
abstract: BACKGROUND
  Murine models used to delineate mechanisms and key mediators of asthma have yielded conflicting results and suggest that the dominant mechanism and mediators required for disease induction differ depending on the model and method of allergen sensitization used.
  
  
  OBJECTIVE
  The goal of this study was to determine whether the mode of allergen sensitization influenced the role that IgE had in allergen-induced pulmonary eosinophilic inflammation.
  
  
  METHODS
  Mice were exposed to dust mite extract in 2 models of allergic inflammation that differed in the method of sensitization. We compared sensitization by aerosol exposure with and without concomitant human respiratory syncytial virus infection with sensitization by means of systemic (intraperitoneal) exposure with adjuvant. After sensitization, animals were similarly challenged with aerosolized allergen. Animals were treated with anti-IgE mAb to deplete IgE and to determine its role in the induction of allergic inflammation and mucosa pathology in these models.
  
  
  RESULTS
  Concomitant respiratory syncytial virus infection significantly enhanced allergen sensitization by aerosol exposure and exacerbated eosinophilic inflammation and airway mucosa pathology. Depletion of IgE in this model significantly reduced lung eosinophilic inflammation and airway mucosa pathology. However, in the model in which animals were sensitized by means of systemic allergen exposure with adjuvant, depletion of IgE had no ameliorative effect on lung inflammation or pathology.
  
  
  CONCLUSIONS
  We demonstrated that the method of antigen sensitization can delineate the role of IgE in allergen-induced lung inflammation. In a murine model that more closely resembles ambient allergen exposure in human subjects, IgE had a critical role in the pathogenesis of allergic asthma and mucosa pathology. The results parallel the results reported with anti-IgE efficacy in allergic asthmatic human subjects.
authors.affiliation: Department of Pathology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080-4918, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Tumas
authors.forename: B
authors.initials: B
authors.lastname: Chan
authors.forename: W
authors.initials: W
authors.lastname: Werther
authors.forename: T
authors.initials: T
authors.lastname: Wrin
authors.forename: J
authors.initials: J
authors.lastname: Vennari
authors.forename: N
authors.initials: N
authors.lastname: Desjardin
authors.forename: R L
authors.initials: RL
authors.lastname: Shields
authors.forename: P
authors.initials: P
authors.lastname: Jardieu
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000627:therapeutic use*; D039741:Antigens, Dermatophagoides; D001249:Asthma / Q000276:immunology* / Q000503:physiopathology / Q000628:therapy; D004195:Disease Models, Animal; D004391:Dust / Q000009:adverse effects; D005260:Female; D006023:Glycoproteins / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000503:physiopathology; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D008168:Lung / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008925:Mites / Q000276:immunology; D009092:Mucous Membrane / Q000473:pathology; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology / Q000821:virology; D012136:Respiratory Syncytial Viruses / Q000276:immunology*
chemical_list: D000485:Allergens; D000911:Antibodies, Monoclonal; D039741:Antigens, Dermatophagoides; D004391:Dust; D006023:Glycoproteins; D007073:Immunoglobulin E