中文摘要：

目的探讨TBX21基因T-1993C多态性对T-bet表达及Ⅰ类辅助性T细胞极化群体的影响。方法通过EMSA实验观察TBX21启动子区-1993位点顺式调控作用,采用PCR-RFLP方法对2010年1月10日至20日我院体检中心收集的370例健康献血员[男性206例,女性110例,年龄21～57（36±9.2）岁]全血样本进行TBX21-1993位点基因分型,应用流式细胞仪检测不同基因型个体T-bet及Th1极化相关细胞因子IFN-γ表达水平。结果 TBX21基因-1993位点T/C等位探针均与一未知核因子发生特异性结合,且与C等位亲和力明显高于T等位;不同基因型个体T-bet及Th1极化相关细胞因子IFN-γ表达由TT→TC→CC基因型呈递减趋势,差异显著（P〈0.05）。结论 TBX21基因-1993位点是一个重要的功能位点,T/C等位均与一未知核转录因子特异性结合并负性调控T-bet及Th1极化相关细胞因子IFN-γ表达,从而反馈性调节TH1分化。

英文摘要：

Objective To study the effects of TBX21 gene T-1993C polymorphism on T-bet expression and type 1 helper T cell（Th1） polarized population.Methods The cis-acting regulation at-1993T/C site of TBX21 gene promoter region was studied with electrophoretic mobility shift assay（EMSA）.TBX21-1993 site genotyping was conducted via PCR-RFLP using whole blood specimens collected from healthy volunteers.The expression levels of T-bet and Th1 polarization-associated cytokine IFN-γ in individuals with different genotypes were tested with flow cytometry.Results TBX21-1993TT and TBX21-1993CC probes specifically bound with an unknown nuclear factor that had higher affinity to C allele than T allele.The expression levels of T-bet and IFN-γ in individuals with different genotypes showed an order of TTTCCC,with significant difference（P0.05）.Conclusion The-1993 site is important to gene TBX21.An unknown nuclear factor can specifically bind with-1993 site T/C alleles and negatively regulate the expression of T-bet and IFN-γ,so as to affect Th1 differentiation.