IL-12p40 is essential for the down-regulation of airway hyperresponsiveness in a mouse model of bronchial asthma with prolonged antigen exposure.
Clin Exp Allergy 2008;
39:290-8. [PMID:
19032358 DOI:
10.1111/j.1365-2222.2008.03131.x]
[Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND
We previously reported a mouse model of bronchial asthma showing eosinophilic inflammation, but not airway hyperresponsiveness (AHR), after prolonged antigen exposure. This model showed an increase of IL-12 in the lung.
OBJECTIVE
The aim of this study was to investigate the role of IL-12p40 in a murine asthma model with prolonged antigen exposures.
METHODS
An ovalbumin (OVA)-induced asthma model was first established in wild-type (WT) and IL-12p40-deficient (IL-12p40(-/-)) mice. Both strains of mice were further exposed to either OVA (prolonged exposure group) or phosphate-buffered saline (positive control group) 3 days per week for 3 weeks. During week 4, both groups of mice were given a final challenge with OVA.
RESULTS
Prolonged antigen exposures resulted in marked suppression of airway eosinophilia in both WT and IL-12p40(-/-) mice. However, AHR persisted in IL-12p40(-/-) but not in WT mice. There were no significant differences of IL-5, IL-13 or IFN-gamma levels in bronchoalveolar lavage fluid between WT and IL-12p40(-/-) mice. The hydroxyproline content of the lung and peribronchial fibrosis were, however, significantly increased in IL-12p40(-/-) mice.
CONCLUSION
The results suggest that endogenous IL-12p40 is essential for inhibition of AHR and peribronchial fibrosis, but not eosinophilic inflammation, in a murine asthma model with prolonged antigen exposures.
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