探讨汽车尾气污染艾蒿花粉，对哮喘小鼠辅助性T细胞(Th)17/调节性T细胞(Treg)比例失衡的影响。

选择60只6～8周龄的雄性BALB/c小鼠为研究对象。采用随机数字表方法，将60只受试小鼠随机分为A～D与对照组，共计5组，每组均为12只。A组变应原和激发物均为艾蒿花粉提取液；B组变应原为艾蒿花粉提取液，激发物为汽车尾气污染艾蒿花粉提取液；C组变应原为汽车尾气污染艾蒿花粉提取液，激发物为艾蒿花粉提取液；D组变应原和激发物均为汽车尾气污染艾蒿花粉提取液；对照组变应原和激发物均为磷酸缓冲液(PBS)。收集这5组受试小鼠肺组织、支气管肺泡灌洗液(BALF)和脾脏标本分别进行：①HE染色、高倍镜下观察各组小鼠肺组织病理学改变；②统计学比较各组小鼠BALF中IL-17A、-10含量及细胞计数、分类的差异；③统计学比较各组小鼠脾脏单个核细胞中Th17及Treg占CD₄⁺T细胞比例，以及Th17/Treg比值的差异。实验过程中对动物的处置符合动物伦理学标准。

①A～D组哮喘小鼠均存在不同程度小支气管管腔收缩及周围组织炎性细胞浸润，以D组程度最严重。②A～D组哮喘小鼠BALF中，IL-17A含量均分别较对照组高，而IL-10含量均分别较对照组低，且差异均有统计学意义(P<0.01)。A～C组哮喘小鼠BALF中，IL-17A含量均分别较D组低，而IL-10含量均分别较D组高，且差异均有统计学意义(P<0.05)。A～D组小鼠BALF中，细胞总数及嗜酸性粒细胞(EOS)、中性粒细胞(NEU)分类计数，均分别较对照组高；A～C组BALF中EOS及NEU分类计数均分别较D组低，且差异均有统计学意义(P<0.05)。③A～D组小鼠脾脏单个核细胞中，Th17细胞占CD₄⁺T细胞比例及Th17/Treg均分别较对照组高，而Treg细胞占CD₄⁺T细胞比例均分别较对照组低，且差异均有统计学意义(P<0.01)；其中D组小鼠脾脏单个核细胞中Th17/Treg较A组高，且差异有统计学意义(P<0.05)。

汽车尾气污染花粉诱发的哮喘，其细胞免疫失衡更明显，释放更多炎性介质，导致更严重的气道炎症反应。

To investigate the effect of polluted pollen by vehicle exhaust on T helper cell(Th)17/regulatory T cell(Treg) imbalance in asthmatic mice.

A total of 60 cases of 6-8 weeks of age male BALB/c mice were chosen as study objects.According to random digits table, they were randomly divided into A to D groups and control group, 12 mice in each group. In group A, mice were treated with Artemisia pollen extracts as allergen and stimulator. In group B, mice were treated with Artemisia pollen extracts and polluted Artemisia pollen extracts by vehicle exhaust as allergen and stimulator, respectively. In group C, mice were treated with polluted Artemisia pollen extracts by vehicle exhaust and Artemisia pollen extracts as allergen and stimulator, respectively.In group D, mice were treated with polluted Artemisia pollen extracts by vehicle exhaust as allergen and stimulator. In control group, mice were treated with phosphate buffered saline(PBS) as allergen and stimulator. Lung tissues, bronchoalveolar lavage fluid(BALF) and spleen tissues were collected from the 5 groups and processed as following: ①Histopathological changes in lung tissue of mice in different groups were observed at high magnification by hematoxylin-eosin(HE) staining.②Statistical differences among 5 groups in levels of IL-17A, -10 and the cell countings and differentiations in BALF were compared.③Statistical differences of ratios of Th17 to CD₄⁺ T cells, Treg cells to CD₄⁺ T cells and Th17/Treg in the spleens mononuclearcell among 5 groups were also compared. The disposition of the animals in experimental process was in accordance with the ethical standard of animals.

①In asthmatic mice of groups A to D, varying degrees of bronchiolar contraction and inflammatory cellular infiltration were observed, and all were the most serious in group D. ②In BALF of asthmatic mice of group A to D, higher IL-17A and lower IL-10 contents than those of control group, and the differences were statistically significant(P<0.01); In BALF of asthmatic mice of group A to C, lower IL-17A and higher IL-10 contents than those of group D, and the differences were statistically significant(P<0.05); The total cells, eosinophils(EOS) and neutrophils(NEU) counts in BALF of asthmatic mice of group A to D were higher than those of control group, EOS and NEU counts in BALF of asthmatic mice of group A to C were lower than those of group D, and the differences were statistically significant(P<0.05). ③The ratio of Th17 cells to CD₄⁺ T cells and Th17/Treg in the spleens mononuclearcell of asthmatic mice of group A to D were higher than those of control group, and ratio of Treg to CD₄⁺ T cells was lower than that of control group, and the differences were statistically significant(P<0.01); The ratio of Th17/Treg of group D was higher than that of group A, and the difference was statistically significant(P<0.05).

The cellular immunity imbalance is more severe in asthma mice which is induced by polluted pollen by vehicle exhaust, and cause more inflammatory mediators released, resulting in more severe airway inflammation.