人多形上皮黏蛋白与巨噬细胞集落刺激因子基因融合构建双基因多表位抗原的真核共表达质粒

背景：一些实验已经证明在同一载体上构建含多个基因的共表达载体，可提高转染和表达效率。目的：利用多形上皮黏蛋白（polymorphic epithelial mucin，MUC1）多肽骨架中含有许多连续重复系列，构建人MUC1重复序列串联体基因与巨噬细胞集落刺激因子（Granulocyte macrophagehage colony stimulating factor，GM-CSF）基因重组的真核共表达质粒pcDNA3．1（＋）．MUC1-GM-CSF，并观察重组质粒在COS-7细胞中的表达。设计、时间及地点：基因重组体设计实验，于2005—09，2006-12在解放军第四军医大学动物中心实验室完成。材料：真核表达载体pcDNA3．1（＋）由英国Taylor-Papadimitriou教授惠赠，pGEM-3zf（-）-GM-CSF质粒、COS-7细胞、pUC18载体及E．coli DH5α为自备，雌性BALB／c小鼠由解放军第四军医大学实验动物中心提供。方法：将信号肽及编码MUC1基因片段合成、合成的片断经退火等方法获得MUC1基因重复序列串联体，酶叨鉴定及序列分析后，与GM—CSF基因克隆入pcDNA3．1（＋）真核表达载体中，构建真核共表达质粒pcDNA3．1（＋）-MUC1-GM—CSF。以重组质粒转染COS-7细胞。主要观察指标：通过间接免疫荧光法及ELISA检测目的基因的表达。结果：酶切鉴定及序列分析表明，重绍质粒含育人MUC1重复序列串联体与GM-CSF的融合基因，在COS-7细胞中可检测到MUC1表达，重组质粒免疫小鼠可诱导产生抗GM—CSF抗体。结论：成功构建了人MUC1基因重复序列串联体与免疫佐剂GM—CSF基因重组成为双基因多表位抗原的真核共表达质粒。

Construction of eukaryotic expression plasmid containing human polymorphic epithelial mucin and granulocyte macrophage colony stimulating factor

BACKGROUND: Previous studies demonstrated that construction of eoexpression plasmid containing multiple genes on the same vector could improve transfection and expression rates.OBJECTIVE: To construct eukaryotic expression plasmid pcDNA3.1 (+)-MUC1 -GM-CSF by human polymorphic epithclial mucin (MUC 1) and granulocyte macrophage colony stimulating factor.(GM-CSF) and to observe expression of recombinant plasmid in COS-7 cells.DESIGN,TIME AND SETTING: Gene recombination design,which was carried out in the Animal Central Laboratory,the Fourth Military University of Chinese PLA from September 2005 to December 2006.MATERIALS: Eukaryotic expression vector pcDNA3.1 (+) was presented by Pro.Taylor-Papadimitriou;pGEM-3zf()-GM-CSF plasmid,COS-7 cells,pUCI 8 vector,and E.coli DH5α were made in the center; female BALB/c mice were provided by Experimental Animal Center of the Fourth Military University of Chinese PLA.METHODS: Signal peptide was synthesized with encoded MUCI gene sections to obtain repeated sequence coneatemer after renaturation.Next,the accepted concatemer was cloned with GM-CSF following enzyme identification and sequencing analysis,and then they were put in eukaryotic expression vector pcDNA3.1(+) to construct eukaryotic coexpression plasmid pcDNA3.1 (+)-MUCI -GM-CSF in order to transform COS-7 cells.MAIN OUTCOME MEASURES: Gene expression was detected by indirect immunofluorescence and enzyme linked immunosorbent assay (ELISA).RESULTS: Enzyme identification and sequencing analysis showed that recombinant plasmid contained a fusion gene encompassing human MUC1 repeated sequence concatemer and GM-CSF; moreover,MUC1 expression was detected in COS-7 cells,while recombinant plasmid could induce the production of anti-GM-CSF antibody.CONCLUSION: The recombination between human MUC1 repeated sequence concatemer and GM-CSF gene successfully constructs eukaryotic coexpression plasmid.