Interleukin-10 does not mediate inhalational tolerance in a chronic model of ovalbumin-induced allergic airway disease.

Objective: IL-10 is a potent anti-inflammatory cytokine, and IL-10-producing regulatory T cells are effective inhibitors of murine asthmatic responses. This study determined whether IL-10-dependent mechanisms mediated the local inhalational tolerance seen with chronic inhalational exposure to antigen.
Methods: Wildtype and IL-10(-/-) mice were sensitized with ovalbumin (OVA) and then challenged with daily OVA inhalations for 10 days or 6 weeks.
Results: The 10-day animals developed allergic airway disease, characterized by BAL eosinophilia, histologic airway inflammation and mucus secretion, methacholine hyperresponsiveness, and OVA-specific IgE production. These changes were more pronounced in IL-10(-/-) mice. The 6-week IL-10(-/-) and wildtype animals both developed inhalational tolerance, with resolution of airway inflammation but persistence of OVA-specific IgE production.
Conclusion: IL-10 may have anti-inflammatory effects in the acute stage of murine allergic airways disease, but the cytokine does not mediate the development of local inhalational tolerance with chronic antigen exposure.