目的:构建大鼠CD80基因的RNAi慢病毒载体并在大鼠NRK和IEC6细胞上鉴定其沉默效率.方法:将筛选获得的大鼠CD80基因特异性siRNA靶点,合成短发卡结构shRNA并退火成双链DNA,与pGCSIL-GFP慢病毒载体重组形成shRNA表达载体,利用PCR和测序鉴定获得连接正确的克隆.经由293T细胞包装shRNA慢病毒颗粒,随后将其感染大鼠NRK细胞、IEC6细胞和大鼠DC细胞(树突状细胞,Dentritic cell),分别采用Real-time PCR和Western blot方法检测靶基因在mRNA和蛋白质水平的沉默效率.结果:构建的慢病毒载体shRNA的PCR鉴定和测序正确,包装病毒后滴度达到4×10~8 TU/ml.shRNA慢病毒颗粒感染NRK和IEC6细胞后CD80基因的 mRNA表达量较阴性对照载体慢病毒感染组分别下降了66.9%和63.5%.结论:成功构建了大鼠CD80基因的shRNA慢病毒表达载体,能够在细胞水平有效沉默靶基因.%Objective:To construct a RNAi lentiviral vector targeting rat CD80 gene and detect its effect of gene silencing in NRK and IEC6 cells.Methods:The effective sequence of siRNA targeting rat CD80 gene was confirmed in our previous work.Oligo-DNA fragment containing short hairpin frame was synthesized and reannealed,and then cloned into pGCSIL-GFP lentiviral expression vector.PCR and sequencing analysis were made for verifying the positive clones.The virus packaging plasmids were transfected into 293T cells to harvest shRNA lentivirus.After infection in NRK and IEC6 cells,Real-time PCR was performed to determine the expressing level of CD80.Results:PCR and sequencing revealed that shRNA plasmids was correctly constructed.Virus with a titer of 4×10~8 TU/ml was successfully packaged.CD80 expression in NRK and IEC6 cells could be knockdown by virus infection as characterized by 66.9% and 63.5% decrease of CD80 mRNA in NRK and IEC6 cells respectively,compared with negative control lentivirus.Conclusion:The recombinant lentiviral shRNA expressing vector targeting rat CD80 gene has been successfully constructed and packaged.CD80 mRNA could be down-regulated availably in NRK and IEC6 cells.
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