小干扰RNA干扰T淋巴细胞免疫球蛋白黏蛋白分子-3基因表达对支气管哮喘小鼠辅助性T淋巴细胞17细胞分化及致炎功能的影响

Effect of T cell immunoglobulin domain and mucin domain protein-3 gene interfered by short hairpin RNA on helper T lymphocytes 17 differentiation and proinflammatory capacity in asthmatic mice

目的 探讨T淋巴细胞免疫球蛋白黏蛋白分子-3基因（Tim-3基因）对辅助性T淋巴细胞17（Th17）细胞分化及支气管哮喘（哮喘）呼吸道炎症、呼吸道高反应性的影响.方法 用卵清蛋白致敏并激发建立哮喘小鼠模型,用Tim-3特异的小干扰RNA（shRNA）片段经鼻腔滴入以干扰哮喘小鼠Tim-3基因.采用有创肺阻抗法检测小鼠的呼吸道阻力;流式细胞分析技术检测Th17水平;酶联免疫吸附法检测细胞培养上清液中IL-17和TGF-β水平.结果 哮喘小鼠模型建立成功.使用Tim-3 shRNA干扰哮喘小鼠Tim-3,哮喘组呼吸道炎症减轻,呼吸道高反应下降.外周血单个核细胞中Th17细胞比例哮喘组[（6.43±1.01）％]较正常对照组[（1.75±0.02）％]明显升高,重组质粒干预后比例为[（2.36±0.28）％],明显降低,差异有统计学意义（F=40.05,P＜0.05）;哮喘组IL-17水平[（118.8±16.5）ng/L]较正常对照组[（72.5±13.6）ng/L]明显升高,重组质粒干预后为[（73.6±12.5）ng/L],明显降低,差异有统计学意义（F =32.80,P＜0.05）;TGF-β水平无明显变化.结论 沉默Tim-3基因表达可缓解呼吸道炎症及呼吸道高反应性,其机制可能与改变Th17细胞的分化有关.

Objective To investigate the effect of down-regulating of T cell immunoglobulin domain and mucin domain protein-3 （Tim-3） gene in asthmatic mouse model by short hairpin RNA（shRNA） and explore the role of Tim-3 on the differentiation of helper T lymphocytes 17 （Thl7）,airway inflammation,as well as airway hyperresponsiveness in pathogenesis of asthma.Methods An asthmatic murine model was established by way of ovalbumin （OVA） sensitization and challenge.Treating Tim-3 gene was intranasally administered with Tim-3-specific shRNA.Invasive pulmonary impedance method was adopted to detect mice airway resistance.Flow cytometry analysis was performed to determine the levels of Th17 ; enzyme linked immunosorbent assay was performed to determine the concentrations of IL-17 and transforming growth factor-beta（TGF-β） in supematant.Results Asthmatic mice model was successfully established.By using Tim-3 shRNA silencing Tim-3,airway inflammation was reduced and airway hyperresponsiveness was declined in asthmatic group ;the levels of Th17 cells in asthmatic group [（6.43 ± 1.01）％] were significantly increased compared with normal controls[（1.75 ± 0.02） ％].After using Tim-3 shRNA silencing Tim-3,the levels of Th17 cells [（2.36 ± 0.28） ％] were decreased （F =40.05,P ＜ 0.05） ; the level of IL-17 in asthmatic group [（118.8 ± 16.5） ng/L] was significantly increased compared with normal controls[（72.5 ± 13.6）ng/L],after using Tim-3 shRNA silencing Tim-3,the level of IL-17 [（73.6 ± 12.5） ng/L] was decreased （F =32.80,P ＜ 0.05）,while the expression of TGF-β did not change.Conclusions Down regulation of Tim-3 gene can decrease airway inflammation and airway hyperresponsiveness,which may be related to the change of Th17 cell differentiation.