Abstract:ObjectiveTo investigate the impact of cigarette smoke exposure on the expression of CCR6 in airway of asthmatic rats. MethodsForty male Wistar rats were randomly divided into four groups with 10 rats in each group:control group, cigarette smoke exposure group, aerosolized ovalbumin (OVA) exposure group and OVA combined with cigarette smoke exposure group. Rats were exposed to either aerosolized OVA , tobacco smoke, or both tobacco smoke and OVA. White blood cells in BALF were quantitatively analyzed and classified. The expressions of CCR6 mRNA and protein in the airway were detected by immunohistochemistry and real-time RT-PCR. Results① The number of white blood cells, the percentage of eosinophils and neutrophils to total cells in BALF in the aerosolized OVA exposure group (69.0±3.5,4.1±1.0,8.9±2.0) and OVA combined with smoke exposure group (86.7±5.2,2.2±1.0,9.0±2.8) were higher than that in the control group (10.1±3.8,1.3±0.7,2.2±1.1) and smoke exposure group (47.7±6.8,0.5±0.3,2.7±1.4) (all P<0.05). The number of white blood cells, the percentage of neutrophils to total white cells in BALF in the OVA combined with smoke exposure group were significantly higher than that in the aerosolized OVA exposure (P<0.05). The percentage of eosinophils to total white cells in BALF in the OVA combined with smoke exposure group was lower than that in the aerosolized OVA exposure group (P<0.05). ② The expression of CCR6 mRNA and protein in the aerosolized OVA exposure group (8.15±0.88;0.452±0.013) and OVA combined with cigarette smoke exposure group (15.16±0.7,0.531±0.024) were significantly higher than that in the control group (1.01±0.2,0.299±0.027) and the smoke exposure group (5.55±0.4,0.442±0.018) (all P<0.01). The expressions of CCR6 mRNA and protein in the OVA combined with smoke exposure group were significantly higher than that in the aerosolized OVA exposure group (all P<0.01). ConclusionsThe data of this study suggest that cigarette smoke can aggravate chronic airway inflammation by increasing the expression levels of CCR6 mRNA and protein in asthmatic rats.