title: Exposure of adult mice to environmental tobacco smoke fails to enhance the immune response to inhaled antigen.
abstract: Epidemiologic evidence supports a role for environmental tobacco smoke (ETS) in the occurrence and severity of allergies/asthma. However, neither the precise combination of ETS and allergen exposure nor the mechanism (or mechanisms) by which these factors interact and contribute to asthma induction is known. Animal model studies have failed to establish a convincing relationship between ETS exposure and asthma induction, perhaps because of methodological inadequacies. Here, we tested the hypothesis that ETS inhalation would provoke an asthmatic response by overcoming normal airway tolerance to inhaled antigens. Our protocol combined daily ETS exposure with nose-only sensitization to ovalbumin. Three strains of mice were tested, each with a different level of susceptibility to airway hypersensitivity. Immunological responses were assessed by immunoglobulin production. Airway inflammation was assessed by bronchoalveolar lavage differentials and lung histopathology. Airway hyperresponsiveness was determined by methacholine challenge. The mice produced ovalbumin-specific antibodies following ovalbumin exposure in a strain-dependent manner. Only the A/J mice produced detectable levels of ovalbumin-specific immunoglobulin (Ig) E. Both A/J and BALB/c mice produced ovalbumin-specific IgG1 antibodies. The C57Bl/6 mice did not produce detectable levels of antibodies. The A/J mice also exhibited airway inflammation following ovalbumin exposure. Neither the C57Bl/6 nor the BALB/c mice exhibited signs of airway inflammation. Exposure to ETS failed to enhance ovalbumin-specific antibody production, airway inflammation, or hyperresponsiveness. Together these results indicate that ETS exposure accompanied by nose-only allergen sensitization fails to overcome aerosol tolerance in adult mice.
authors.affiliation: Department of Pathobiological Sciences School of Veterinary Medicine Louisiana State University, Baton Rouge, Louisiana, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Bowles
authors.forename: David
authors.initials: D
authors.lastname: Horohov
authors.forename: Daniel
authors.initials: D
authors.lastname: Paulsen
authors.forename: Casey
authors.initials: C
authors.lastname: Leblanc
authors.forename: Martha
authors.initials: M
authors.lastname: Littlefield-Chabaud
authors.forename: Terry
authors.initials: T
authors.lastname: Ahlert
authors.forename: Ken
authors.initials: K
authors.lastname: Ahlert
authors.forename: Susan
authors.initials: S
authors.lastname: Pourciau
authors.forename: Arthur
authors.initials: A
authors.lastname: Penn
mesh_terms: D000367:Age Factors; D000818:Animals; D000917:Antibody Formation; D000941:Antigens / Q000008:administration & dosage / Q000009:adverse effects*; D001249:Asthma / Q000209:etiology* / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D007074:Immunoglobulin G / Q000032:analysis; D007249:Inflammation; D019570:Inhalation Exposure; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D000941:Antigens; D007074:Immunoglobulin G; D014028:Tobacco Smoke Pollution; D010047:Ovalbumin