重组hβc基因的慢病毒颗粒的包装及其在NB4细胞过表达研究

Packaging of Lentivirus Carrying Gene hβc and Overexpression of Gene hβc in NB4 Cells

本研究旨在通过慢病毒介导的基因转移方法,使NB4细胞稳定过表达hβc基因,观察过表达hβc基因的NB4细胞在IL-3或GM-CSF作用下分化行为的改变,探讨hβc基因与NB4细胞分化之间的关系。以本实验室前期构建的携带hβc基因ORF的克隆质粒为模板,用带PmeI和BstBI酶切位点的引物PCR获得目的基因,酶切PCR产物,定向克隆至慢病毒载体pRRLSIN.cPPT.PGK/IRES/GFP.WPRE,构建含hβc基因的慢病毒载体,经酶切及测序鉴定其正确性,将构建好的重组质粒与包装质粒一起共转染293T细胞,收集培养液上清,感染NB4细胞,用Western blot鉴定目的基因在NB4细胞中的表达情况。以转染空载体慢病毒的NB4细胞(简称NB4-blank细胞)为对照,观察过表达hβc基因的NB4细胞(简称NB4-hβc细胞)在IL-3、GM-CSF、全反式维甲酸(ATRA)作用下分化行为的改变。结果表明:含有hβc基因的重组慢病毒载体能高效转染NB4细胞,并使NB4细胞稳定过表达hβc基因。NB4-hβc细胞,在IL-3或GM-CSF作用下CD11b表达水平上调,但上调的幅度均低于ATRA作用下的上调幅度,且未观察到形态学改变。NB4-Blank细胞在IL-3或GM-CSF作用下CD11b表达水平无明显变化。结论 :通过慢病毒介导的基因转移方法,成功地使NB4细胞稳定过表达hβc基因,IL-3或GM-CSF在一定程度上能诱导过表达hβc基因的NB4细胞向中性粒细胞分化,但不能使其完全分化成熟。

This study was amied to overexpress gene hβc in NB4 cells via the method of lentivirus-mediated gene transfer, to observe the differentiation behaviour change of hβc over-expressing NB4 cells treated with IL-3 or GM-CSF, to explore the relationship between hβc gene and the differentiation behaviour of NB4 cells. The targeted hβc gene was amplified by PCR from the cloned vector carrying ORF of hβc. The PCR product containing PmeI and BstBI site introduced by primer was digested, and then cloned into lentivirus vector pRRLSIN, cPPT. PGK/IRES/GFP. WPRE to construct a lentiviral vector carrying hβc, named pLV-hβc. And the pLV-hβc plasmid was confirmed by restriction and se- quencing. The recombinant lentivirus was produced by co-transfecting three plasmids into 293T packing cells. After transfection, the lentiviral supernatant was collected to transfect NB4 cells. GFP expression was examined by fluorescent microscope and the expression of hβc gene was detected by Western blot. Then, the NB4 cells over-expressing hβc were treated with IL-3 （10 ng/ml）, GM-CSF（ 10 ng/ml）, ATRA（ 1 μmol/L） respectively, and the CD1 l b expression, morphology and differentiation behaviour changes of every groups were observed by flow cytometry and microscopy, while NB4 cells transfected with blank leutivirus（ NB4-blank cells） were used as controls. The results showed that the recombinant lentivirus vector carrying hβc gene could efficiently transfect NB4 cells and made NB4 cells to stably over-express hβc gene. The expression of CD1 lb was up-regulated in NB4-hβc cells treated with of IL-3 or GM-CSF, but it was not as obvious as the effect of ATRA, and no morphological change was observed in NB4 hβc cells treated with the IL-3 or GM-CSF. It is concluded that IL-3 or GM-CSF can induce NB4 cells over-expressing hβc to differentiate to neutrophils, but can not make them fully matured.