title: Chronic inhaled ovalbumin exposure induces antigen-dependent but not antigen-specific inhalational tolerance in a murine model of allergic airway disease.
abstract: Sensitized mice acutely challenged with inhaled ovalbumin (OVA) develop allergic airway inflammation, characterized by OVA-specific IgE production, airway eosinophilia, increased pulmonary B and T lymphocytes, and airway hyperreactivity. In this study, a chronic exposure model was developed and two distinct patterns of response were observed. Discontinuous inhalational exposure to OVA (6 weeks) produced airway inflammation and hyperreactivity that were similar to acute (10 days) responses. Continuous inhalational exposure to OVA (6 or 11 weeks) resulted in attenuation of airway eosinophilia and hyperresponsiveness without reduction of OVA-specific IgE and IgG(1) levels. The inhibition of airway inflammation was dependent on continuous exposure to antigen, because continuously exposed mice with attenuated inflammatory responses redeveloped allergic airway disease if the OVA aerosols were interrupted and then restarted (11-week-discontinuous). Inhalational tolerance induced by continuous OVA exposure demonstrated bystander suppression of cockroach allergen-mediated airway eosinophilia. These findings may be attributed to changes in production of the anti-inflammatory cytokine interleukin-10 during continuous OVA aerosol exposure. The symptomatic and asymptomatic allergic responses in human asthmatics could be explained by similar variable or discontinuous exposures to aeroantigens.
authors.affiliation: Department of Pediatrics, Pulmonary Research Consortium, University of Connecticut School of Medicine, Farmington, Connecticut, USA. cschram@ccmckids.org
authors.forename: Craig M
authors.initials: CM
authors.lastname: Schramm
authors.forename: Lynn
authors.initials: L
authors.lastname: Puddington
authors.forename: Carol
authors.initials: C
authors.lastname: Wu
authors.forename: Linda
authors.initials: L
authors.lastname: Guernsey
authors.forename: Mehrnaz
authors.initials: M
authors.lastname: Gharaee-Kermani
authors.forename: Sem H
authors.initials: SH
authors.lastname: Phan
authors.forename: Roger S
authors.initials: RS
authors.lastname: Thrall
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D000941:Antigens / Q000008:administration & dosage / Q000276:immunology*; D001249:Asthma / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology; D016535:Bronchial Hyperreactivity / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology*; D016207:Cytokines / Q000032:analysis; D004195:Disease Models, Animal; D005260:Female; D007108:Immune Tolerance / Q000502:physiology*; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D051379:Mice; D010047:Ovalbumin / Q000008:administration & dosage / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
chemical_list: D000941:Antigens; D016207:Cytokines; D007074:Immunoglobulin G; D007073:Immunoglobulin E; D010047:Ovalbumin