转录因子T-bet和GATA-3对婴幼儿喘息性支气管炎的免疫调控作用

Immune Regulation Function of Transcription Factor T-bet and GATA-3 in Infants with Wheezing Bronchitis

目的探讨转录因子T-bet和GATA-3对小儿喘息性支气管炎的免疫调控作用。方法对32例喘息性支气管炎(喘支组)和30例正常儿童(对照组)抽取抗凝静脉血5 mL,Ficoll分离外周血淋巴细胞,以终质量浓度为100 mg/L的植物血凝素(PHA)刺激48 h,采用酶联免疫吸附法(ELISA)检测培养上清液干扰素-γ(IFN-γ)和白细胞介素-4(IL-4)水平,用逆转录聚合酶链式反应(RT-PCR)检测淋巴细胞T-bet、GATA-3的mRNA表达水平。结果喘支组淋巴细胞培养上清液IFN-γ水平[(528±164)ng/L]低于对照组[(870±203)ng/L](P<0.05),而IL-4水平[(106±29)ng/L]明显高于对照组[(47±15)ng/L](P<0.01);喘支组和对照组淋巴细胞T-bet mRNA水平分别为(0.11±0.03)(、0.17±0.03),GATA-3 mRNA分别为(0.54±0.09)、(0.41±0.07),提示喘支组T-bet mRNA表达较对照组减少(P<0.05),而GATA-3 mRNA明显高于对照组(P<0.01);喘支组IFN-γ水平与T-bet mRNA表达I、L-4与GATA-3 mRNA表达均呈正相关(r=0.57,0.60 P均<0.01);IFN-γ与IL-4水平、T-bet mRNA与GATA-3 mRNA表达均呈负相关(r=-0.38,-0.46 P均<0.05)。结论1.喘支组患儿淋巴细胞合成IL-4水平增高,IFN-γ减少,存在以Th2细胞过度分化为特征的T辅助细胞分化失衡。2.喘支组患儿T细胞分化失衡受到核转录因子T-bet和GATA-3的调控,T-bet表达减少可能是一重要因素。

Objective To investigate the modulation function of transcription factor T- bet/GATA- 3 in infants with wheezing bronchitis. Methods Thirty - two cases with wheezing bronchitis were collected while 30 normal infants were served as control. Lymphocytes were isolated from peripheral blood by Ficoll and incubated with phytohemagglutinin （PHA） （ 100 mg/L） at 37℃,5% CO2 for 48 hours. Interferon-γ（ IFN- γ） and interleukin 4（IL-4） levels in the supernatant were detected by enzyme linked immunosorbent assay （ ELISA）. The mRNA levels of T - bet and GATA- 3 gene in lymphocytes were amplified by reverse transcription polymerase chain reaction （RT- PCR）. Results In infants with wheezing bronchitis, the levels of IFN - γ were lower than those of control（P 〈0.05） and IL- 4 were higher than those of control （P〈 0.01 ）. In the matter of the fact, the T- bet did also reduce when GATA- 3 relatively increased in this kind of dieseae. Two positive correlations were found between the level of IFN - γ and T - bet mRNA （ r = 0.57 P 〈0.01 ） as well as IL - 4 and GATA- 3 mRNA （ r = 0.60 P〈 0.01 ）. Two negative correlation were also proved in the level of IFN - γ and IL-4 （r= -0.38 P〈0.05）,T-bet mRNA and GATA-3 mRNA （r= -0.46 P〈0.05）.Conclusions In infants with wheezing bronchitis, there is a predominant differentiation of Th2 type cells accompanying with over- production of Th2 cytokine IL- 4 and lower production of Th1 cytokine IFN - γ. From this research, it is suggested that the imbalance differentiation of Th cells is regulated by transcription factor T- bet and GATA- 3,of which the less T- bet expression may be a key factor.