烟碱样乙酰胆碱受体α7在支气管哮喘患儿CD4^+T淋巴细胞上的表达

Expression of Neuronal Acetylcholine Receptor Alpha 7 on CD4^+ T Lymphocytes of Peripheral Blood in Children with Asthma

目的探讨哮喘患儿血CD4+T淋巴细胞表达烟碱样乙酰胆碱受体α7(nAChRα7)与相应的细胞培养液IL-4、干扰素-γ(IFN-γ)水平的关系,分析nAChRα7在哮喘发病过程中的临床意义。方法哮喘患儿30例(哮喘组)与健康儿童20例(健康对照组),分别抽取静脉血8mL,分离外周血淋巴细胞,并分别加入100μmol/L烟碱、1.0mg/Lα-银环蛇毒(α-BTX),另设空白对照,恒温孵育24h后提取其淋巴细胞,并收取培养液置-20℃冰箱保存。用三色流式细胞仪检测各组淋巴细胞CD3+/CD4+/nAChRα7表达。ELISA法检测其淋巴细胞培养液中IFN-γ、IL-4水平。结果哮喘组患儿血CD3+/CD4+/nAChRα7表达较健康对照组儿童明显增高(P<0.05)。烟碱刺激24h后哮喘组、健康对照组外周血CD3+/CD4+/nAChRα7的表达均较空白对照明显增加(Pa<0.01);且烟碱刺激24h后哮喘组较健康对照组表达显著增加(P<0.05)。α-BTX刺激24h后外周血CD3+/CD4+/nAChRα7表达降低,但无统计学意义(Pa>0.05)。哮喘组培养液中IL-4水平较健康对照组增加,IFN-γ水平较健康对照组减低。烟碱刺激24h后IL-4水平较空白对照增高(P<0.01),IFN-γ水平较空白对照明显减低(P<0.05)。α-BTX刺激24h后IL-4、IFN-γ水平均无明显变化(Pa>0.05)。外周血CD4+T淋巴细胞nAChRα7表达与淋巴细胞培养液IL-4水平呈正相关(r=0.517P<0.05),与IFN-γ水平呈负相关(r=-0.288P<0.05)。结论哮喘患儿血CD4+T淋巴细胞表面的nAChRα7表达增加,nAChRα7表达影响培养液IL-4、IFN-γ水平和Th1/Th2平衡,是影响哮喘的发病的重要因子。

Objective To explore the relationship of the expression of neuronal acetylcholine receptor alpha 7（nAChRα7） and the le-vels of interferon-γ（IFN-γ） and IL-4 in the cultured supernatants in children with asthma,and analyze the role of nAChRα7 in the deve-lopment of asthma.Methods Thirty patients with asthma（asthma group） and 20 health children（control group） were included.Peripheral blood was collected,anticoagulated with EDTA and cultured regularly with nicotine（100 μmol/L） and α-bungarotoxin（α-BTX）（1.0 mg/L）,respectively.Cultured supernatants were collected after 24 hours.The expression of CD3^＋/CD4^＋/nAChRα7 in peripheral blood mononuclear cells（PBMC） was detected by flow cytometry.The levels of IFN-γ and IL-4 in the cultured supernatants of PBMC were detected by ELISA.Results The expression of CD3^＋/CD4^＋/nAChRα7 T lymphocytes of PBMC of children with asthma group was much higher than that of normal control group（P〈0.05）.The expression of CD3^＋/CD4^＋/nAChRα7 of PBMC after stimulated with nicotine of both groups were much higher than before（Pa〈0.01）and expression of nAChRα7 in asthma group increased much higher than that in control group（P〈0.05）.The expression of CD3^＋/CD4^＋/nAChRα7＋of PBMC after stimulated with α-BTX of both groups were lower slightly than that in control group（Pa〉0.05）.Compared with children in control group,the level of IL-4 in cultured supernatants of asthma group of PBMC was much higher（P〈0.01） and the level of IFN-γ was much lower（P〈0.05）;In both groups,the level of IL-4 in cultured supernatants of PBMC cultured with nicotine increased higher than that cultured regularly（Pa〈0.01）and the level of IFN-γ decreased more than cultured regularly（Pa〈0.01）.There was no statistical significance in the level of IL-4 and IFN-γ in cultured supernatants of PBMC after stimulated with α-BTX（Pa〉0.05）.There was positive correlation between nAChRα7 and IL-4（r=0.517 P〈0.05）and negative correlation between nAChRα7 and IFN-γ（r=-0.288 P〈0.05）.Conclusions The expression of nAChRα7 on CD4^＋ T lymphocytes of PBMC in children with asthma increased significantly.The expression of nAChRα7 can influence the levels of IL-4 and IFN-γ and the balance of Th1/Th2.It＇s an important role in the development of asthma.