The expression and mechanisms of interleukin-17 in CD8+ T cells of mice with cigarette smoke-induced emphysema / 中华内科杂志

ABSTRACT

Objective To evaluate the expression of Tc17 in a cigarette smoke-induced mice model of emphysema.To explore the probable mechanisms about how Tc17 cells to elevate in lungs of mice.Methods Forty male Balb/c mice were randomly divided into four groups,including control group ( 12 weeks,C12),control group (24 weeks,C24),smoke-exposure group (12 weeks,S12) and smoke-exposure group (24 weeks,S24 ),10 mice each group,Emphysema of mice was observed by HE pigmentation.Morphological changes were evaluated by mean linear intercepts (Lm) and destructive index (DI).The proportion of CD8+ IL-17 + Tc17,CD8+ IL-17 + CC chemokine receptor type 6 ( CCR6 ) + and 6CCR6 + Tc17 cells in lungs of mice was determined by flow cytometry.The mRNA expressions of retinoidrelated orphan nuclear receptor(RORγt) and IL-17 were evaluated by real-time PCR.The levels of IL-1 β,IL-6,IL-23,transforming growth factor β (TGFβ) and CC chemokine ligand 20 (CCL20) were tested by ELISA.Correlations among these indexes were analyzed.Results Lm and DI were significantly higher in S12 and S24 than in C12 and C24,S24 in particular (t value 4.378-15.188,all P ＜ 0.05).The percentages of Tc17 in S12 and S24[(9.28 ± 1.12)%,( 13.13 ±3.56)%]was significantly increased as compared with that in C12 and C24[(2.40 ±0.60 )%,(2.64 ±0.96 )%],S24 in particular.The mRNA levels of RORγt and IL-17 in S12 and S24 were higher than in C12 and C24,S12 and S24 in particular.There was significant difference (all P ＜0.05 ).The frequency of Tc17 cells had a positive correlation with Lm and DI ( r value were 0.734 and 0.884 respectively,P ＜ 0.01 ).The percentages of CD8+ IL-17 + CCR6 +T cells and CCR6 + Tc17 were significantly elevated in S12 and S24 compared to C12 and C24,S24 in particular (all P ＜ 0.05 ).There was positive correlation between Tc17 cell ratio and CCL20 levels( r =0.899,P ＜0.01 ).The levels of IL-1 β,IL-6,IL-23 and TGFβ in S12 and S24 were significantly increased as compared with that in C12 and C24.There was significant difference (all P ＜0.05).Meanwhile,the frequency of Tc17 cells had a positive correlation with IL-1β,IL-6,IL-23,and TGFβ.Conclusions An up-regulation of proportions Tc17 in lungs of cigarette smoke-induced emphysema mice were detected.The CCR6/CCL20 axis and the increased IL-1β,IL-6,IL-23 and TGFβ probably contributed to this up-regulation.