Objective To detect the role of AP-1 or ETS-1 transcription factor binding sites (TFBS) in activity of DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) pro-moter. Methods Genomic DNA was extracted from peripheral blood. Complete DC-SIGN promoter and those without AP-1 or ETS-1 TFBS were amplified by PCR using designed primers. The PCR products were digested with MLu Ⅰ and Bgl Ⅱ and then ligated into MLu Ⅰ and Bgl Ⅱ digested pGL-3/Basic and pGL-3/En-hancer vectors. Transfection in Hacat and 293 cells was accomplished with Trans Fast liposome. Activity of luciferase was detected after 48 h. Results The DC-SIGN promoters without AP-1 or ETS-1 TFBS and the recombined pGL-3 vectors were correctly constructed. The activity of DC-SIGN promoters without AP-1 was reduced 20% (293) and 10% (Hacat), which was 40%-50% with enhancer. The activity of DC-SIGN pro-moters without ETS-1 was nearly vanished, no matter with or without enhancer. Conclusion ETS-1 TFBS, not AP-1 TFBS, plays an important role in activity of DC-SIGN promoter.%目的 研究AP-1和ETS-1转录因子结合位点(TFBS)缺失对树突状细胞特异性胞间黏附分子-3结合非整合素(DC-SIGN)启动子活性的影响,探讨DC-SIGN表达的机制.方法 从人外周血中提取全基因组DNA,设计DC-SIGN启动子序列上下游引物、转录因子结合位点两侧的引物及其相应的连接引物,利用PCR方法,通过不同的引物组合扩增出转录因子结合位点两侧的片段,再用连接引物连接两片段,得到转录因子结合位点缺失的DC-SIGN启动子序列,通过双酶切、连接的方法,将得到的DC-SIGN启动子序列定向克隆入荧光素酶报告质粒,将上述质粒通过脂质体转染Hacat和293细胞,48 h后检测荧光素酶的活性.结果 体外扩增得到的转录因子结合位点缺失的DC-SIGN启动子序列以及重组的荧光素酶报告质粒经双酶切、基因测序鉴定正确,荧光素酶活性检测结果显示AP-1位点缺失使DC-SIGN启动子活性下降20%(293细胞)和10%(Hacat细胞),带增强子的DC-SIGN启动子活性下降了40%～50%;ETS-1位点缺失的普通型和带增强子型DC-SIGN启动子的活性几乎消失.结论 ETS-1转录因子结合位点在DC-SIGN启动子活性表达中起重要作用,AP-1转录因子结合位点作用不大.
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