Objective     To observe the change of IL-17

+

T cells and related cytokines in the airway inflammation induced by cigarette smoking in mice

and investigate the source of IL-17 and ratios of IL-17 producing cell subtypes in order to explore preliminarily their functions in the progress of the disease.      Methods    A total of 24 healthy C57/BL6 mice were randomly and equally divided into control group

CS (cigarette smoking)

10 days group (1 h in the morning and 1 h

in the afternoon for 10 d)

CS20 days group and CS30 days group. All mice were sacrificed after last smoking. Pathological changes of their lung was observed by hematoxylin eosin staining. The concentrations of IL-17

IL-23 and IL-22 in their sera and bronchoalveolar lavage fluid (BLAF) were detected by enzyme-linked immunosorbent assay (ELISA). The frequencies of subtype of IL-17

+

T cells in the lymphocytes from their lungs were detected by flow cytometry (FCM).     Results     Compared with control groups

the lung in CS groups showed different pathological changes

including increased lymphocytes infiltration

lodging epithelium

and thickening bronchial wall

and the changes were more serious with the elapse of cigarette smoking period. The concentrations of IL-17

IL-22 and IL-23 in the cigarette smoking groups was higher than those of the control groups (P0.05). The frequencies of IL-17

+

T cells and IL-17

+

γδT cells also were also higher than those of the control groups (P0.05).     Conclusion    IL-17

+

T and related cytokine may be the beginning factors of bronchitis. Their quantitative changes may indicate bronchitis development and prognosis.