Objective: To determine the proportion of Tc17 cells in the lungs of mice with neutrophilic(NEU) asthma, and to investigate the role of Tc17 cells in the pathogenesis of NEU asthma.
Methods: Thirty-two C57/B6 mice of clean grade were randomly divided into two groups: NEU asthma and control. The mice in the NEU asthma group were sensitized by airway instillation of ovalbumin (OVA) and lipopolysaccharide (LPS), and challenged with an aerosol of OVA, while those in the control group were sensitized and challenged with normal saline. At 24 hours after the final challenge, bronchoalveolar lavage fluid (BALF) was collected, and the total number and differential counts of nucleated cells and percentage of each type were determined. The lung tissues were separated and hematoxylin-eosin staining was performed to observe the pathological changes of lungs; flow cytometry was applied to determine the percentages of Tc17 and Th17 cells in the lung tissues. Enzyme-linked immunosorbent assay was applied to determine the levels of interleukin-6 (IL-6), transforming growth factor β (TGF-β), and interleukin-17 (IL-17) in BALF.
Results: The NEU asthma group had a significantly higher total number of nucleated cells, a significantly higher percentage of eosinophils, and a significantly higher percentage of neutrophils in BALF than the control group (P<0.01). The NEU asthma group also had significantly higher percentages of Tc17 and Th17 cells than the control group (P<0.01). In the NEU asthma group, the percentage of Tc17 cells was positively correlated with that of Th17 cells (P<0.05). The NEU asthma group had significantly higher concentrations of IL-6, TGF-β, and IL-17 in BALF than the control group (P<0.05).
Conclusions: The expression of Tc17 cells in the lung tissues increases in mice with NEU asthma, and the increased number of Tc17 cells may be involved in the pathogenesis of NEU asthma. Tc17 cells may play an important role in NEU asthma through IL-17.
目的: 检测中性粒细胞(NEU)哮喘小鼠肺脏Tc17细胞比例, 初步探讨Tc17细胞在NEU哮喘发病机制中的作用。
方法: 32只清洁级C57B/6小鼠, 随机分成NEU哮喘组和对照组。NEU哮喘组用卵蛋白(OVA)和脂多糖(LPS)气道滴入致敏, 予OVA雾化激发, 对照组用生理盐水致敏和激发。在最后一次雾化结束后24 h, 收集支气管肺泡灌洗液(BALF)并检测其有核细胞总数及分类比例, 分离肺组织行HE染色, 流式细胞术检测小鼠肺脏Tc17细胞与Th17细胞百分比, 酶联免疫吸附试验(ELISA)检测BALF中IL-6、TGF-β、IL-17水平。
结果: NEU哮喘组小鼠BALF中有核细胞总数、嗜酸性粒细胞(EOS)及中性粒细胞百分比均明显高于对照组(P < 0.01), 其肺脏Tc17细胞与Th17细胞百分比高于对照组(P < 0.01);NEU哮喘组小鼠肺脏Tc17细胞比例与Th17细胞比例呈正相关性(r=0.7932, P < 0.05);NEU哮喘组BALF的IL-6、TGF-β、IL-17浓度高于对照组(P < 0.05)。
结论: NEU哮喘组肺脏Tc17细胞表达增高, Tc17细胞可能参与了中性粒细胞哮喘的发病, IL-17很可能是Tc17细胞在NEU哮喘中发挥作用的方式之一。