变应原对哮喘患者外周血CD4^+ T细胞功能的影响

Effect of allergen on function of peripheral blood CD4+T cells in patients with asthma

目的探讨CD4+T细胞增殖以及白细胞介素-10(IL-10)和转化生长因子-β1(TGF-β1)水平与过敏性哮喘发病之间的关系。方法制备粉尘螨抗原作为变应原。以25例哮喘患者和15名健康者为研究对象。采集静脉血样本后分为空白对照组、变应原组和自体对照组。流式细胞术检测各组CD4+细胞增殖及CD4+/IL-10+、CD4+/TGF-β1+、CD4+/IL-10+/TGF-β1+细胞亚群分布情况。结果哮喘患者和健康者之空白对照组的外周血样本中几乎不能检测到CD4+/IL-10+、CD4+/TGF-β1+和CD4+/IL-10+/TGF-β1+细胞。健康者变应原组外周血CD4+T细胞增殖明显,CD4+、CD4+/IL-10+T细胞所占比例均较其自体对照组明显增高,而CD4+/TGF-β1+和CD4+/IL-10+/TGF-β1+亚群所占比例无显著性增加。哮喘患者变应原组外周血CD4+T细胞及CD4+/IL-10+、CD4+/TGF-β1+和CD4+/IL-10+/TGF-β1+亚群所占比例与其自体对照组比较均未见明显增加。变应原刺激后,哮喘患者外周血CD4+/IL-10+亚群明显少于健康者(P<0.05),但两者间CD4+T细胞及CD4+/TGF-β1+、CD4+/IL-10+/TGF-β1+亚群所占比例无显著性差异。结论哮喘患者受特异性变应原刺激后,CD4+T细胞产生的IL-10水平不能相应提高,可能是导致或加重哮喘发病的原因之一。TGF-β1在支气管哮喘发病中的作用尚不明确,有待进一步研究。

Objective To investigate the relationship among the proliferation of CD4^＋T cells, the intracellular levels of interleukin-10 （IL-10） and transforming growth factor-β1 （TGF-β1 ）, and allergic bronchial asthma. Methods Dermatophagoides farinae antigen were prepared as allergen. Twenty-five patients with asthma and 15 healthy individuals were enrolled and divided into blank control group, allergen group and self control group, respectively, after venous blood sample collection. The proliferation of CD4^＋T cells and the distributions of CD4^＋/IL-10^＋ , CD4^＋/TGF-β1^＋ and CD4^＋/IL-10^＋/TGF-β1^＋ were measuredby flow cytometry （FCM）. Results The distributions of CD4^＋/IL-10^ ＋ , CD4^＋/TGF-β1^＋ and CD4^＋/IL-10^＋/TGF-β1^＋ could hardly be detected in the peripheral blood samples of the blank controls of the patients with asthma and healthy ones. In the allergen group of the healthy individuals, the peripheral blood CD4^＋T cells were significantly proliferated, and the proportions of CD4^＋T cells and CD4^＋/IL-10^＋ cells were much higher than the self control group, while there was no significantly increase in the proportions of CD4^＋/TGF-β1^＋ and CD4^＋/IL-10^＋/TGF-β1^＋ ubgroups. In the allergen group of those with asthma, the proportions of peripheral blood CD4^＋ , CD4^＋/IL-10^＋ , CD4^＋/TGF-β1^＋ and CD4^＋/IL-10^＋/ TGF-β1^＋ cells were not found significantly increased compared with those self controls. After being activated by allergen, the proportion of peripheral blood CD4^＋/IL-10^＋ cells was significantly lower in the patients with asthma than the healthy individuals（P 〈0.05）. However, there was no significant difference in the proportion of CD4^＋T cells, CD4^＋/TGF-β1^＋ and CD4^＋/IL-10^＋/TGF-β1^＋ cells between the two groups. Conclusion After being activated by specific allergen, the level of IL-10 generated by CD4^＋T cells in the patients with asthma may not be increased correspondingly, which may be one of the causes for the exacerbation of asthma. The role of TGF-β1^＋ on the pathogenesis of asthma shall be elucidated further.