Change Of CD4+Foxp3+Regulatory T Cell And CD4+IL-17+T Cell In Cigarette Smoke Exposure Pats

Objective: To evaluate the levels of CD4+Foxp3+Treg cell(Treg) and CD4+IL-17+T cells(Th17) in peripheral blood and bronchoalveolar lavage fluid (BALF) of cigarette smoke exposure rats and to explore the role of them in cigarette smoke-induced airway inflammation/COPD of rats .Methods: Fourty male Wistar rats were randomly divided into four groups: 12 weeks control group(control group 1), 24 weeks control group(control group 2), 12 weeks smoke-exposure group(test group 1) and 24 weeks smoke-exposure group(test group 2), 10 rats each group. At 12 week, rats in control group 1 and test group1 were sacrificed, At 24 week, rats in control group 2 and test group 2 were sacrificed too. The cells in BALF were collected and analyzed by absolute and differential cell counts. IL-17, IL-6 levels in serum and BALF were tested by emzyme linked immunosorbent assay (ELISA). The proportion of CD4+Foxp3+Treg and CD4+IL-17+T cell in peripheral blood and BALF of rats were determined by Flow Cytometry. The mRNA expression of Foxp3 and IL-17 were measured by Real-Time PCR .Results: (1) Total and differential cells counts in BALF in test group 1 and test group 2 were increased compared with control group 1 and control group2 (P <0.01), especially in test group 2 (P <0.05). (2) Levels of IL-17 and IL-6 were remarkable increased in test group 1 and test group 2 compared with the control groups (P <0.01), and they increased obviously in test group 2 compared with test group 1 (P <0.05). (3) Ratio of Treg cell in BALF were higher in test group 1 and test group 2 compaered with control group 1 and control group2 (P <0.01), but the two test groups were not changed (P >0.05), and it was not different in all groups of surem (P >0.05); compare with control group 1 and control group 2, ratio of Th17 cell were regulated higher in test group 1 and test group 2 not only in surem but in BALF (P <0.01), and it was the highest in test group 2 (P <0.05). (4) There were increased in the expression of IL-17 mRNA in test groups compared with the control groups in surem and BALF (P <0.05), even though the expression of Foxp3 mRNA were rase in test groups (P <0.05), they were not statistically different in the four groups in surem (P >0.05). (5) Th17 cell in smoke exposure groups was positively correlated with counts of total cells and macrophage cell (r=0.512, r=0.543, P <0.05), but it was not correlated with lymphocytes and neutrophils cells number, or not correlated with Treg cell too (P >0.05), Treg cell was not correlated with all the cells in BLAF of the test groups (P >0.05).Conclusions: An elevated expression of Treg and Th17 cells and the inflammatory factors in airway inflammation of cigarette smoke exposure rats, it suggested that Treg involved in a immunological regulation and Th17 may correlated with the amplified inflammation in cigarette smoke-induced of airway inflammation in rats.