重组小鼠干细胞逆转录病毒载体高效基因转染CD41^+、UT7、U937和MDA-MB-435细胞

High-efficient genetic transfection of CD41^+,UT7,U937 and MDA-MB-435 cells with a recombined murine stem cell retroviral vector

目的 :研究重组小鼠干细胞逆转录病毒载体介导基因转染 ,探索一条高效基因转染的途径 ,为重组小鼠干细胞逆转录病毒载体在基因转染中的应用提供理论依据和奠定实验基础。方法 :①逆转录病毒载体的构建 :EC1- 4 (repeats 1- 4ofcadherin - 5extracellulardomains)基因克隆产物和mutant(Ser2 2 2A)MEK 1基因克隆产物 ,Bg1Ⅱ和EcoRⅠ限制性内切核酸酶切割后 ,克隆进入逆转录病毒表达载体pMSCV。②CD4 1+ 细胞的获取和细胞培养 :从脐带血分离的CD34+ 细胞通过TPO诱导表达CD4 1,FACS分离CD4 1+ 细胞。高糖DMEM培养液培养NIH 3T3和MDA -MB - 4 35细胞 ,U937细胞培养在RPMI- 16 4 0培养液 ,UT7细胞是细胞因子依赖性细胞株 ,Iscove’smodifiedDulbeco’s培养液中加入GM -CSF。③测定病毒滴度 :逆转录病毒载体转入包装细胞 2 93,36h后收集病毒上清液 ,感染NIH3T3细胞 ,流式细胞仪测定病毒滴度。④Westernblot:基因转染CD4 1+ 、UT7、U937和MDA -MB - 4 35细胞 ,Westernblot检测基因产物的表达。结果 :2 93细胞产生高滴度MEK1pMSCV病毒 :3 1× 10 7,高滴度EC1- 4pMSCV病毒 :1 0×10 8。用稀释 8倍的病毒转染基因 ,重组逆转录病毒MEK1pMSCV转染白血病细胞株UT7和U973,GFP阳性细胞 (转染阳性细胞 )分别是 6 0 73%、

AIM: Gene transduction with a recombined murine stem cell retroviral vector has been investigated to find an effective way of gene transduction and to offer theory and experimental basis for the recombined murine stem cell retroviral vector used for gene transduction. METHODS: 1. Construction of retrovirus vector: EC1-4 gene (repeats 1-4 of cadherin-5 extracellular domain) and mutant (Ser 222A) MEK1 gene were cloned into retrovirus vector pMSCV after cut by Bgl Ⅱ and EcoR 1 restriction endonuclease. 2. Obtaining CD41 + cells and cell culture: Cells expressing CD34 + from cord blood were isolated. The inducement of cells expressing CD41 from CD34 + cells was performed by using TPO and cells CD41 + were selected by FACS. NIH 3T3 cells were cultured in high sugar DMEM medium and U937 in RPMI 1640 medium. UT7 cells which is cytokine-dependent cell line were grown in Iscove's modified Dulbeco's medium supplemented by GM-CSF. 3. Determination of viral titers: Retroviral vectors were transferred to packaging cell line 293. Retroviral containing supenatant was collected after transfection. The viral titers was tested on infection of NIH 3T3 cells by FACS analysis. 4. Western blot: Transduced CD41 +,UT7,U937 and MDA-MB-435 cells were analyzed by western blot to examine expression of transduced genes. RESULTS: A packaging cell line 293 produces high-titer MEK1 pMSCV retroviruses (3.1×10 7) and EC1-4 pMSCV retroviruses (1.0×10 8). With 8-folds dilution retroviruses,60.73% GFP positive cells have been obtained in MEK1 pMSCV transduced UT7 cells,72.56% in U937 cells and 30.57% in CD41 + cells,respectively. GFP positive cells have reached up 97.54 % in EC1-4 pMSCV transducted MDA-MB-435 cells. Phosphorylated MEK1 has been decreased in experiment group when TPO has stimulated CD41 + and UT7 cells or serum has stimulated U973 cells. This indicates that is a dominant negative effect of mutation MEK gene. EC1-4 gene transduced MDA-MB-435 cells have expressed EC1-4. CONCLUSION: The recombined murine stem cell retrovirus can effectively mediate gene transduction of CD41 +,UT7,U937 and MDA-MB-435 cells,and transduced genes can be stably expressed.