Jiang Yi, DU Yong-Cheng, Xu Jian-Ying
Department of Respiration Medicine, the First Hospital of Shanxi Medical University, Taiyuan 030001, China.
Zhonghua Jie He He Hu Xi Za Zhi. 2010 Aug;33(8):582-6.
To investigate the effect of cigarette smoke exposure on the ratio of CD(4)(+)CD(25)(+) regulatory T cells (Treg) and expression of transcription factor Foxp3 in asthmatic rats.
Forty male Wistar rats were randomly divided into 4 groups (n = 10 for each group): a normal saline group, an aerosolized ovalbumin (OVA) exposure group, a cigarette smoke exposure group and a combined OVA and cigarette smoke exposure group. The rats were exposed to air or cigarette smoke and to normal saline or OVA aerosol for 8 weeks respectively. The percentage of CD(4)(+)CD(25)(+) T cells was determined by flow cytometry analysis. The concentration of interleukin-4 (IL-4) and interferon-γ (INF-γ) in peripheral blood and lung homogenates were measured by enzyme-linked immunosorbent assay (ELISA). The protein expression of Foxp3 in the lung was detected by Western blot.
(1) The percentage of CD(4)(+)CD(25)(+) T cells in aerosolized OVA group [(6.4 ± 1.0)%] was significantly lower than that in the normal saline group [(9.9 ± 1.0)%] (P < 0.01). The percentage of CD(4)(+)CD(25)(+) T cells [(3.3 ± 0.8)%] in OVA combined cigarette smoke exposure group was remarkably lower than that in the aerosolized OVA exposure group and in the normal saline group(P < 0.01). (2) IL-4 in both plasma and lung [(22.6 ± 4.3) ng/L, (0.8 ± 0.1) ng/L] was significantly increased in the OVA-exposed rats compared with the normal saline group [(11.4 ± 2.9) ng/L, (0.3 ± 0.1) ng/L] (P < 0.01). Further remarkable increase in IL-4 of both plasma and lung was observed in the group exposed to both OVA and cigarette smoke [(34.1 ± 6.1) ng/L, (1.4 ± 0.3) ng/L] compared with the aerosolized OVA exposure group and the normal saline group (P < 0.05). INF-γ of plasma in OVA-exposed group [(59 ± 20) ng/L] was significantly decreased compared with the normal saline group [(151 ± 56) ng/L] (P < 0.01), and a further remarkable decrease in INF-γ of plasma was observed in the group exposed to both OVA and cigarette smoke [(10 ± 3) ng/L] compared with the aerosolized OVA exposure group and the normal saline group (P < 0.05). (3) Protein expression of Foxp3 in the aerosolized OVA group (8.18 ± 0.26) was lower than that in the normal saline group (10.27 ± 0.33, P < 0.01), while the protein expression of Foxp3 in OVA combined cigarette smoke exposure group (6.36 ± 0.38) was lower than that in the normal saline group and the aerosolized OVA exposure group (P < 0.01).
The number of CD(4)(+)CD(25)(+) Treg cells and the expression of Foxp3 are likely to be altered by cigarette smoke exposure, which might play an important role in cigarette smoking-induced Th1/Th2 imbalance in asthmatic rats.
探讨香烟烟雾暴露对哮喘大鼠CD4⁺CD25⁺调节性T细胞（Treg）比例及转录因子Foxp3表达的影响。
40只雄性Wistar大鼠随机分为4组（每组n = 10）：生理盐水组、雾化卵清蛋白（OVA）暴露组、香烟烟雾暴露组和OVA与香烟烟雾联合暴露组。大鼠分别暴露于空气或香烟烟雾以及生理盐水或OVA气雾剂中8周。通过流式细胞术分析测定CD4⁺CD25⁺T细胞的百分比。采用酶联免疫吸附测定（ELISA）法检测外周血和肺匀浆中白细胞介素-4（IL-4）和干扰素-γ（INF-γ）的浓度。通过蛋白质印迹法检测肺组织中Foxp3的蛋白表达。
（1）雾化OVA组CD4⁺CD25⁺T细胞百分比[（6.4±1.0）%]显著低于生理盐水组[（9.9±1.0）%]（P < 0.01）。OVA与香烟烟雾联合暴露组CD4⁺CD25⁺T细胞百分比[（3.3±0.8）%]显著低于雾化OVA暴露组和生理盐水组（P < 0.01）。（2）与生理盐水组[（11.4±2.9）ng/L，（0.3±0.1）ng/L]相比，OVA暴露大鼠血浆和肺组织中的IL-4[（22.6±4.3）ng/L，（0.8±0.1）ng/L]显著升高（P < 0.01）。与雾化OVA暴露组和生理盐水组相比，OVA与香烟烟雾联合暴露组血浆和肺组织中的IL-4进一步显著升高[（34.1±6.1）ng/L，（1.4±0.3）ng/L]（P < 0.05）。OVA暴露组血浆中的INF-γ[（59±20）ng/L]与生理盐水组[（151±56）ng/L]相比显著降低（P < 0.01），与雾化OVA暴露组和生理盐水组相比，OVA与香烟烟雾联合暴露组血浆中的INF-γ进一步显著降低[（10±3）ng/L]（P < 0.05）。（3）雾化OVA组Foxp3的蛋白表达（8.18±0.26）低于生理盐水组（10.27±0.33，P < 0.01），而OVA与香烟烟雾联合暴露组Foxp3的蛋白表达（6.36±0.38）低于生理盐水组和雾化OVA暴露组（P < 0.01）。
香烟烟雾暴露可能会改变CD4⁺CD25⁺Treg细胞数量及Foxp3表达，这可能在吸烟诱导的哮喘大鼠Th1/Th2失衡中起重要作用。
