中文摘要：

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5mL，Ficoll分离外周血淋巴细胞，以终质量浓度为100mg／L的植物血凝素（PHA）刺激48h，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-3mRNA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、IL-4与GATA-3 mRNA表达均呈正相关（r=0．57，0．60P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，-0．46P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．喘支组息儿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。

英文摘要：

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.