Abstract: AIM: To investigate the effects of CpG ODN on the airway inflammation and the expression of signal transducers and activators of transcription 6(STAT6) in asthma. METHODS: Thirty-two male BALB/c mice were randomly divided into 4 equal groups: control group,asthma group, DXM group and CpG ODN group ,the mice model of asthma was established by the ovalbumin(OVA) challenge methods. The lung tissue was gained from the left lung, bronchoalveolar lavage fluid(BALF) was obtained from the right lung. The total cell numbers,eosinophils(EOS) numbers in BALF were counted by different count fluids; Left lung tissue was stained by HE and the changes of inflammation were observed. The protein expressions of STAT6 were detected by immunohistochemistry. RESULTS: The total cell numbers in BALF, the absolute numbers of EOS were all significantly higher in asthma group than those in the control group(P<0.05); the total cell numbers in BALF, the absolute numbers of EOS were all significantly lower in DXM group and CpG ODN group than those in asthma group(P<0.05), CpG ODN and DXM attenuated the airway inflammation of asthmatic mice. The expressions of STAT6 were mainly on the bronchial epithelium. STAT6 protein levels were increased in asthma group. CpG ODN significantly reduced STAT6 protein expression. DXM significantly reduced the levels of STAT6 protein. There was a significant positive correlation between the absolute numbers of EOS in BALF, the content of STAT6 in the epithelial cells(r=0.748). CONCLUSION: CpG ODN and DXM can extenuate the progression of airway inflammation following down regulated allergen challenge via regulation of STAT6/IL-4 signal pathway.

Key words: Asthma, CpG oligonucleotides, Signal transducer and activator of transcription factor 6, Dexamethasone