To investigate adenoviral vector mediated exogenous gene expression in mouse lungs and the effect of mIFN γ transgene expression on allergen induced pulmonary eosinophil infiltration in a murine asthmatic model Methods LacZ marker gene was transduced into CD 1 mouse airway epithelial cells by installation of a replication deficient adenovirus with LacZ gene (AdCMVLacZ) 5×10 9 plaque forming unit (pfu) in the intratrachea or nostril C57 mice were sensitized intraperitoneally and challenged by aerosol with ovalbumin (OVA) to produce an asthmatic model AdCMVmIFNγ 5×10 9 pfu was administered via nostril in asthmatic mice 48 h before OVA challenge Sera, bronchial alveolar lavage (BAL) and lungs were recovered 48 h after OVA challenge Results After administration with AdCMVLacZ by intratracheal installation or nose drop, the lungs revealed a high level of widespread LacZ transduction with X gal staining, mainly along airways IFN γ via adenoviral vector transduction could be overexpressed both in vitro and in vivo (1624 7±1321 5 pg/ml in BAL 96 h after AdCMVIFNγ infection) In AdCMVIFNγ treated asthmatic models, histological evaluation revealed marked suppression of eosinophil peribronchial and perivascular infiltration; the recoverable percentage of eosinophils in BAL was an average of 9 00%±4 58%, which was a statistically significant decrease versus that of the positive control group (75 13%±6 85%) ( P <0 001) The total cell number in BAL ((145±55 6)×10 3 cells/ml) in AdCMVmIFNγ treated mice also was tremendously reduced compared to the positive control group ((216 6±71 1)×10 3 cells/ml) Conclusions Adenoviral vector was able to overexpress exogenous gene in murine lungs IFN γ overexpression via adenoviral vector in pulmonary epithelia in vivo can abrogate allergen induced eosinophilic infiltration in lungs in an asthmatic model, which may suggest a new preventively therapeutic method for cytokine immunogenetic transfer in allergic asthma