pEGFP-N1-omp25荧光真核表达载体的构建及鉴定

目的克隆布鲁氏杆菌外膜蛋白omp25基因并构建荧光真核表达载体p EGFP-N1-omp25,检测其在大鼠脑内的表达。方法根据Genebank中omp25基因的核苷酸序列,设计并合成1对引物,以布鲁氏杆菌总基因组DNA为模板,进行PCR扩增得到omp25基因片段,并将omp25基因片段及质粒p EGFP-N1分别进行进行酶切、体外连接,使其定向重组,构建其重组质粒。将制备的重组质粒经侧脑室注射至大鼠,检测p EGFP-N1-omp25在大鼠脑内的表达。结果 PCR扩增出642bp大小的片段,挑取的LB固体培养基上的单菌落经菌液PCR、酶切、测序表明成功构建了p EGFP-N1-omp25荧光真核表达载体。质粒经大鼠侧脑室注射后,脑组织冰冻切片可见荧光表达。结论采用体外重组技术,成功构建了布鲁氏杆菌外膜蛋白omp25基因的真核表达载体,且重组质粒在大鼠脑组织内成功表达。

Construction of DNA Vaccine for FMDV P1 Gene and Immunization Experiment

[Objective] This study aimed to construct DNA vaccine of foot-and-mouth disease （FMD）.[Method] Plasmid carriers plESZP1 and pUTK3CP1 with PRV were constructed for FMDV P1 gene expression.Mice were immunized,and their antibody level was detected.The two eukaryotic expression plasmids constructed were transfected into Vero cells.PCR,IFA and Westem-blot were carried out to detect the transcription and expression of the objective gene.Balb/C mice were intramuscularly inoculated with the DNA plasmid which expressed the target gene correctly,and the antibody level in mice was detected by the means of ELISA and serum neutralization （SN）.[Result] DNA plasmid carrying P1 gene which encodes FMDV capsid protein caused specific body fluid immunoreaction in mice,and the antibody level of anti-FMDV had no difference in the mice induced by the two recombinant plasmids.[Conclusion] This study lays a foundation for evaluating the genetically modified vaccine by immunizing animals with recombinant PRV containing the FMDV P1 gene and recombinant virus.

Effect of p27Kip1 Inhibition on Proliferation of Bovine Corneal Endothelial Cells by RNA Interference

Three plasmids （pGenesil-P1, pGenesil-P2, pGenesil-P3） with different p27Kip1-shRNA sequences were designed and synthesized. Their effects on the proliferation of bovine corneal endothelial cells （bCEC） were investigated. Plasmid expressing irrelevant shRNA with a random combination was used as negative control （pGenesil-HK）. The recombination of four plamids was confirmed by restrictive enzyme digestion and sequence analysis. The expression of mRNA and protein of p27Kip1 was detected by RT-PCR and Western blotting after stable transfection. The expressions of p27Kip1 mRNA and p27Kip1 protein of pGenesil-P1 group, pGenesil-P2 group and pGenesil-P3 group were all lower than those in the pGenesil-HK group and the blank group （non-transfected group）, pGenesil-P3 had the strongest inhibitory effect and was selected for the next steps. The proliferation rates of the pGenesil-P3 group, the pGenesil-HK group and the blank group were assessed by MTT. The influence of shRNA-p27Kip1 on bCEC cell cycle was detected by flow cytometry （FCM）. Compared with the control groups, the proliferation rate of the pGenesil-P3 group was increased significantly, and the ratio of S-phase also increased. It is concluded that shRNA-p27Kip1 could down-regulate the expression of p27Kip1 effectively and increase the proliferation of bCEC. RNA interference （RNAi） may be an effective means to promote the proliferation of CEC.

原代猪成纤维细胞电转染条件的探索

用绿色荧光蛋白基因的DNA(p EGFP-N1)作为目的基因,对原代猪成纤维细胞电转染条件进行探索。结果表明,在电压1 200 V/cm、脉冲时间3 ms、p EGFP-N1添加量4 mg/m L时电转染效率最好。

线粒体转录复合物各因子质粒标准品的构建

目的:构建大鼠线粒体转录因子TFAM(A)、线粒体转录因子TFB1M(B1)、线粒体转录TFB2M(B2)及线粒体RNA聚合酶(POLRMT)的质粒标准品,为检测内耳细胞线粒体TFAM、TFB1M、TFB2M、POLRMT的mRNA表达水平做基础。方法:设计特异性引物和探针,提取大鼠内耳组织总mRNA逆转录成c DNA,PCR扩增、纯化目的片段,将纯化产物与p Zero Back/blunt载体重组,提取重组质粒,经测序鉴定后,用实时荧光绝对定量PCR建立标准曲线。结果:测序结果与各目的序列一致,获得良好的标准曲线(R2>0.99)。结论:成功构建了各目的基因的质粒标准品。

携带绿色荧光报告基因的EBV-LMP1真核表达载体构建与鼻咽癌细胞中的表达

潜伏膜蛋白1(LMP1)是由EB病毒编码的致瘤蛋白,众多研究表明LMP1蛋白可通过NF-κB、p38 MAPK、c-JNK等多条重要信号通路引起鼻咽癌细胞的生物学行为改变。我们从EB病毒阳性的B95-8狨猴淋巴瘤细胞中克隆EB病毒LMP1 c DNA,构建携带绿色荧光基因的真核表达质粒p IRES2-Zs-Green1-LMP1,通过脂质体转染的方法将质粒导入鼻咽癌细胞株CNE1、CNE2中,利用质粒所携带的绿色荧光蛋白表达粗略计算转染的效率,通过免疫细胞化学(ICC)、RT-PCR、Western-Blot检测该质粒的表达。本实验室所构建的p IRES2-Zs-Green1-LMP1表达质粒能在鼻咽癌细胞内表达LMP1蛋白,为后续的实验研究奠定基础。

广西巴马小型猪TRβ1基因真核表达载体的构建及鉴定

本试验为了克隆广西巴马小型猪甲状腺激素受体β1(TRβ1)基因编码序列并构建该基因的真核表达载体,取广西巴马小型猪肝脏组织作为材料,采用RT-PCR技术扩增出TRβ1基因编码序列,与pMD19-T-Simple载体连接,测序正确的重组质粒双酶切后,连接pEGFP-N1载体,构建pEGFP-N1-TRβ1真核表达载体。经双酶切和测序鉴定后,重组质粒pEGFP-N1-TRβ1转染293T细胞,培养48 h后,在荧光显微镜下观察细胞荧光蛋白的表达情况。结果表明,本试验成功克隆了广西巴马小型猪的TRβ1基因cDNA序列,序列长度为1 368 bp,编码455个氨基酸,与参考序列的同源性为99.6%,有5处位点突变,且全为同义突变。阳性重组质粒pEGFP-N1-TRβ1转染293T细胞48 h后,在荧光显微镜下观测出绿色荧光表达。

具有双层结构和负电荷屏障载体的构建及其基因转染

用组氨酸分别修饰聚乙烯亚胺（PEI）和透明质酸,得到了聚乙烯亚胺-组氨酸（PEI-His）和透明质酸-组氨酸（HA-His）。然后将PEI-His与增强型绿色荧光蛋白质粒DNA（p EGFP-N1）复合形成PEI-His/DNA复合物（PD复合物）,并进一步在其表面吸附HA-His形成具有双层结构和负电屏障的（PEI-His/DNA）/HA-His复合物（HPD复合物）,用于基因传递研究。透射电镜观察到HPD复合物为球形纳米粒子,水化后平均粒径约为142 nm,ζ电位为-28.9 m V。HPD复合物中加入10%胎牛血清后平均粒径为135 nm,ζ电位为-25.8 m V,提示其具有良好的血清稳定性。HPD复合物对p EGFP-N1的包载效率为（91.9±1.15）%,并可有效保护DNA不被DNase I降解。在PEI浓度5~20μg/ml范围内,HPD复合物的细胞毒性明显低于PEI/DNA复合物,前者细胞存活率可维持在80%以上;同时,它可介导DNA进入细胞实现基因转染,转染效率为2.88%。