逆转录病毒介导人VEGF在兔皮肤成纤维细胞中的表达

本文以人VEGFcDNA为目的基因,构建成逆转录病毒质粒载体,并进一步包装成重组缺陷型逆转录病毒,以此感染原代兔皮肤成纤维细胞,经G418筛选,获得了具有分泌VEGF能力的抗性细胞克隆,经Southern、PCR、Northern、RT-PCR等检测,证实了外源基因已整合至原代兔皮肤成纤维细胞基因组中,无重排和产生野生型病毒之患。整合的VEGF可在修饰细胞中转录,经内皮细胞增殖实验和血管通透性实验证实其表达产物具有强大的生物活性。为进一步研究VEGF的生物学功能和生理效应提供有用的工具。     

人IL-12重组逆转录病毒载体在HeLa细胞中的表达

目的:包装携带人白细胞介素12(IL-12)的逆转录病毒,用于宫颈癌的治疗研究.方法:携带IL-12的逆转录病毒重组质粒pL35P40SN经PA317细胞包装,G418筛选.在NIH3T3细胞进行病毒滴度测定.然后用病毒感染人宫颈癌细胞HeLa.PCR、RT-PCR方法检测IL-12基因在HeLa中的整合和表达情况.结果:重组质粒pL35P40SN经PA317细胞包装后收获病毒上清,感染HeLa细胞,检测发现IL-12基因整合到细胞基因组DNA中,并且能有效的转录.结论:成功包装了携带IL-12基因的逆转录病毒,该病毒能有效感染HeLa细胞,并使携带的基因IL-12在细胞中表达,为今后IL-12基因治疗宫颈癌的研究奠定基础.     

转录病毒载体介导的稳定表达口蹄疫病毒3D基因的BHK21细胞系的建立

[目的]研究口蹄疫病毒RNA聚合酶在BHK-21细胞中的稳定表达状况,为研究RNA聚合酶生物学活性及其基囚工程疫苗研制提供科学依据.[方法]从重组质粒pMD18-T-3D扩增口蹄疫病毒3D基因,通过分子克隆技术构建莺组逆转录病毒表达载体pBPSTR1-3D.用pBPSTR1-3D和pVSV-G双质粒瞬时转染GP2-293包装细胞,收获重组逆转录病毒,然后感染BHK-21细胞,嘌呤霉素持续筛选12 d后获得阳性克隆,并用有限稀释法挑选单个阳性细胞克隆.[结果]应用PCR、RT-PCR技术可从体外反复传代的阳性细胞中扩增到3D基因,证实目的外源基因能转录并被稳定整合进宿主细胞基因组中.经SDS-PAGE、Western blot、间接免疫荧光检测到在不同代次的阳性细胞中有目的蛋白表达.[结论]本试验利用逆转录病毒载体介导的基因转移技术,将外源基因插入到靶细胞的基因组中,构建了稳定表达口蹄疫病毒RNA聚合酶的包装细胞系,为研究3D基因表达及其蛋白定位提供了方便,也为下一步研究RNA聚合酶生物学功能和疫苗研制提供了科学依据.     

神经营养素-3基因的人工合成及其在毕赤酵母中的分泌性表达

根据人神经营养素3（Human neurotrohin3,hNT3）的基因序列,把编码氨基酸的密码子转换成毕赤酵母（Pichia pastoris）偏爱的形式,设计了10条36～59nt的寡聚核苷酸引物,通过5次连续PCR反应,获得了人工合成的NT3 cDNA片段（简称NT3b基因）。将合成的NT3b基因克隆到pPIC9K质粒上,获得重组表达载体pPIC9KNT3b。将重组表达载体pPIC9KNT3b和pPIC9KhNT3分别电击转化宿主毕赤酵母GS115菌株,经筛选得到重组转化子。不同转化子经甲醇诱导,表达产物进行SDSPAGE检测、Western blot检测和ELISA分析,结果表明,NT3b基因和hNT3基因成功获得分泌性表达,从整体水平上,使用偏爱密码子的NT3b基因在毕赤酵母GS115菌株中的表达明显优越于hNT3基因(x2=4.334,P<0.05),表达量在诱导后72～96h最高,达到31mg/L左右。     

组织特异性启动子介导的反义FGF8b RNA对前列腺癌细胞生长增殖能力的影响

利用启动子的组织特异性和治疗基因组织特异表达的特点 ,设计出前列腺癌靶向基因治疗的新方案 .利用DNA重组技术将前列腺组织特异性启动子 (probasin基因启动子 )和在前列腺癌细胞中高表达成纤维细胞生长因子 (FGF) 8b反义cDNA克隆到逆转录病毒载体pSIR中构建成重组体PB 反义FGF8b pSIR .经转染包装细胞PT 6 7后将产生的复制缺陷型逆转录病毒体外感染前列腺癌细胞系PC 3M ,体外检测其生长增殖和侵袭转移能力的变化 .结果表明 ,与对照组相比 ,前列腺癌细胞感染产生反义FGF8bRNA的逆转录病毒后生长速度减慢 ,集落形成能力下降 ,体外侵袭转移能力降低 (P <0 0 1) .体外试验表明 ,前列腺组织特异性启动子介导的反义FGF8bRNA可有效降低前列腺癌细胞的体外生长增殖和转移能力 ,这为体内靶向前列腺癌基因治疗奠定了可靠的基础 .     

小鼠T-bet逆转录病毒载体的构建与功能验证

为在小鼠细胞中表达并研究T-bet功能,首先构建了含有报告基因Thy1.1的小鼠T-bet逆转录病毒载体,并将构建的载体质粒转染病毒包装细胞系包装成重组病毒,再利用重组病毒分别感染NIH-3T3和D9细胞系检测其感染能力。之后,使用该重组病毒感染T-bet敲除小鼠的CD4+T淋巴细胞,流式细胞术检测T-bet及其下游靶基因Ifng的表达情况。经验证,重组的逆转录病毒感染T-bet敲除小鼠T淋巴细胞后可以在细胞中表达T-bet,并进一步引起下游靶基因Ifng的表达上调,证明本研究中外源表达的转录因子T-bet具有正常功能。综上所述,本实验成功构建了含有报告基因的小鼠T-bet重组逆转录病毒载体,为进一步在小鼠细胞中研究T-bet功能奠定了基础。     

携带人NFBD1基因shRNA重组逆转录病毒载体的构建及鉴定

建立逆转录病毒介导的NFBD1基因RNA干扰表达体系,并观察其在宫颈癌SiHa细胞中对NFBD1表达的影响.将人NFBD1基因RNA干扰双链DNA片段重组到pSUPER Retro质粒中,构建携带人NFBD1基因RNA干扰的逆转录病毒载体pSUPER-shRNA-NFBD1,经PT67细胞包装后,产生的重组逆转录病毒感染宫颈癌细胞株SiHa细胞,并用嘌呤霉素筛选产生稳定的细胞克隆,用实时荧光定量PCR和Westernblotting检测细胞中NFBD1 mRNA和蛋白表达的变化.重组逆转录病毒质粒经测序鉴定正确;逆转录病毒感染SiHa细胞后用嘌呤霉素筛选出稳定的细胞克隆;实时荧光定量PCR和Westernblotting检测人NFBD1 mRNA和蛋白表达水平明显低于阴性对照组和未干扰组.携带人NFBD1基因RNA干扰双链DNA片段的逆转录病毒感染SiHa细胞后能明显抑制NFBD1 mRNA和蛋白表达,为进一步研究NFBD1在宫颈癌中的作用奠定了基础.     

重组anti－CD20 scFv／CD80／CD28/ζ非复制型逆转录病毒的构建及其在Jurkat细胞株中的表达

目的:构建表达anti-CD20 scFv/CD80/CD28/ζ重组非复制型逆转录病毒,转染Jurkat细胞株使其表达目的蛋白.方法:采用DNA重组技术把pBULLET上的CD28-ζcDNA插入到已含anti-CD20 scFv/CD80的真核逆转录病毒载体pLNCX质粒上,转染PA 317细胞株,收获上清液获非复制型逆转录病毒,感染NIH 3T3细胞株,用PCR、流式细胞术检测目的基因在NIH 3T3细胞的表达情况,确定病毒滴度.挑取高滴度的包装细胞株收获病毒,感染Jurkat细胞,经G418筛选细胞,用RT-PCR检测目的基因表达情况.结果:经酶切及测序鉴定均证实pLNCX/anti-CD20 scFv/CD80/CD28/ζ的成功构建; 用PCR能够从逆转录病毒感染的NIH 3T3细胞中扩增出一条与目的基因大小一致的DNA片段; 流式细胞术检测显示该目的基因能够在NIH 3T3细胞中表达目的蛋白; 经RT-PCR,能够从转染的Jurkat细胞株中扩增出1条与目的基因大小一致的DNA片段.结论:成功构建高滴度表达anti-CD20 scFv/CD80/CD28/ζ非复制型逆转录病毒,并能在Jurkat细胞中表达目的蛋白.     

FATE/BJ-HCC-2基因表达促进细胞增殖及肿瘤形成

FATE/BJ-HCC-2是本实验室鉴定的一个新的肿瘤-睾丸抗原基因,定位于Xq28染色体.为探讨FATE/BJ-HCC-2 对细胞生物学行为的影响及裸鼠体内肿瘤形成能力的改变,分别采用脂质体转染真核表达载体及逆转录病毒感染两种方式,获得了FATE/BJ-HCC-2 表达的Bel-7402单克隆细胞株及NIH-3T3细胞克隆,并通过RT-PCR和Western 印迹在基因和蛋白水平鉴定了FATE/BJ-HCC-2 表达情况.通过3H-TdR参入法,检测细胞的增殖能力;通过稀释铺板克隆形成率测定和soft agar克隆形成实验,检测细胞的克隆形成能力;通过裸鼠体内细胞注射成瘤,检测细胞成瘤性和肿瘤生长速度.结果表明,FATE/BJ-HCC-2基因表达能明显提高细胞体外增殖、克隆形成能力和成瘤性.提示其对肿瘤的发生发展起到促进作用.     

FLT3配基在人骨髓基质细胞系中的基因转移与表达

目的：研究逆转录病毒介导的FL在骨髓基质细胞系HFCL中的表达。方法：采用脂质体法将重组质粒pLF-SN/HFCL和空载体pLXSN/HFCL转染包装细胞PA317,G418筛选抗性克隆,用抗性克隆上清液感染HFCL。RT－PCR和基因组DNA－PCR检测外源基因mRNA水平的表达及染色体的整合,小鼠CFU－GM集落法检测FL生物学活性。结果：在mRNA水平上有FL的表达,染色体基因组中整合有标记neo基因和FL基因。活性测试结果显示转染的骨髓基质细胞分泌FL。结论：提示骨髓基质细胞可作为基因治疗的靶细胞。     

白细胞介素6重组逆转录病毒载体的构建及鉴定

目的 构建特异性过表达大鼠IL-6基因的重组逆转录病毒载体,并在大鼠嗜铬细胞瘤PC12细胞和人胚肾HEK293细胞中检测IL-6的表达。方法以大鼠骨髓间充质干细胞mRNA为模板,经PCR获得目的基因IL-6,将其定向克隆到逆转录病毒载体pSEB-3H中,构建重组逆转录病毒质粒pSEB—IL-6,经脂质体分别转染到PC12细胞和HEK293细胞中,应用Real—timePCR和ELISA的方法在mRNA和蛋白质水平检测IL-6的表达变化。继而用HEK293细胞中包装获得的含有pSEB—IL-6的病毒颗粒进一步感染PC12细胞,Real—timePCR检测,IL-6mRNA的表达水平变化。结果PCR电泳及酶切鉴定证实目的基因正确克隆至逆转录病毒载体中,其基因序列与Genbank报道一致;Real—timePCR和ELISA结果均显示,逆转录病毒质粒pSEB—IL-6转染PC12细胞和HEK293细胞后,IL-6的表达水平较对照组显著上调;经pSEB—IL-6逆转录病毒颗粒感染的PC12细胞中,IL-6mRNA表达水平较对照组提高4倍。结论成功构建了特异性表达大鼠儿-6基因的重组逆转录病毒载体pSEB—IL-6,并获得了具有感染能力的逆转录病毒颗粒,感染真核细胞后可高表达IL-6,为进一步研究IL-6的功能及其在多种疾病中的免疫调节机制提供重要的分子手段。     

人神经元素3基因重组逆转录病毒表达载体的构建及其包装细胞株的建立

为构建表达人神经元素3基因(neurogenin 3,ngn3)的重组逆转录病毒载体,建立稳定表达ngn3的包装细胞株,本研究以流产人胎儿胰腺组织为材料,通过RT-PCR方法克隆出人ngn3基因,将其连接到pMD18-T载体上并测序,结果表明,测序得到的基因序列与发表的人ngn3基因序列(GenBank Accession No.BC126468)完全一致。将EcoRI和HpaI双酶切后的基因片段构建到pMSCV-neo逆转录病毒载体中,酶切鉴定结果表明,pMSCV-ngn3重组逆转录病毒载体构建成功。脂质体法将pMSCV-ngn3重组载体导入PT67包装细胞,G418筛选后,对得到的细胞株进行RT-PCR和免疫组化检测,结果显示,该细胞株在mRNA水平和蛋白水平均稳定表达Ngn3;收集该细胞株的培养上清液,进行RT-PCR检测及电镜观察,结果表明,该细胞株将导入的重组逆转录病毒载体pMSCV-ngn3包装成了具有感染性的病毒颗粒,并将其释放到了培养上清液中。以上结果表明PT67-ngn3包装细胞株建立成功。该细胞株的成功建立,为下一步将ngn3基因应用于提高人胎儿胰腺祖细胞诱导分化效率方面的研究奠定了基础。     

Ultrasound enhances retrovirus-mediated gene transfer

Viral vector systems are efficient for transfection of foreign genes into many tissues. Especially, retrovirus based vectors integrate the transgene into the genome of the target cells, which can sustain long term expression. However, it has been demonstrated that the transduction efficiency using retrovirus is relatively lower than those of other viruses. Ultrasound was recently reported to increase gene expression using plasmid DNA, with or without, a delivery vehicle. However, there are no reports, which show an ultrasound effect to retrovirus-mediated gene transfer efficiency. Retrovirus-mediated gene transfer systems were used for transfection of 293T cells, bovine aortic endothelial cells (BAECs), rat aortic smooth muscle cells (RASMCs), and rat skeletal muscle myoblasts (L6 cells) with beta-galactosidase (beta-Gal) genes. Transduction efficiency and cell viability assay were performed on 293T cells that were exposed to varying durations (5 to 30 seconds) and power levels (1.0 watts/cm(2) to 4.0 watts/cm(2)) of ultrasound after being transduced by a retrovirus. Effects of ultrasound to the retrovirus itself was evaluated by transduction efficiency of 293T cells. After exposure to varying power levels of ultrasound to a retrovirus for 5 seconds, 293T cells were transduced by a retrovirus, and transduction efficiency was evaluated. Below 1.0 watts/cm(2) and 5 seconds exposure, ultrasound showed increased transduction efficiency and no cytotoxicity to 293T cells transduced by a retrovirus. Also, ultrasound showed no toxicity to the virus itself at the same condition. Exposure of 5 seconds at the power of 1.0 watts/cm(2) of an ultrasound resulted in significant increases in retrovirus-mediated gene expression in all four cell types tested in this experiment. Transduction efficiencies by ultrasound were enhanced 6.6-fold, 4.8-fold, 2.3-fold, and 3.2-fold in 293T cells, BAECs, RASMCs, and L6 cells, respectively. Furthermore, beta-Gal activities were also increased by the retrovirus with ultrasound exposure in these cells. Adjunctive ultrasound exposure was associated with enhanced retrovirus-mediated transgene expression in vitro. Ultrasound associated local gene therapy has potential for not only plasmid-DNA-, but also retrovirus-mediated gene transfer.     

腺病毒介导的BDNF及NT3基因对体外培养听神经元的营养作用研究

在听力损伤过程中有一大类的损伤是由于各种外界因素对于听神经的损伤而引起的。为了观察脑源性神经营养因子（ＢＤＮＦ）和神经营养素－３（ＮＴ３）对听神经元的营养作用,并研究基因治疗在听神经损伤治疗中的可行性。在体外建立了听神经元的培养系统,利用ＬａｃＺ重组腺病毒感染培养的听神经元来研究重组腺病毒介导的外源基因的转染效率,通过Ｘ－Ｇａｌ染色来显示被感染的阳性细胞,在加入１００病毒感染复数（ＭＯＩ）的Ａｄ－     

Expression of human urokinase in inoculated rodent cells. Loss of introns during gene transfer using a retroviral vector]

Expression of urokinase in murine and rat cells was performed by two recombinant constructs, one containing cDNA and the other--hybrid (cDNA/genome) variant of human urokinase gene conserving 7 introns of 10, in the eukaryotic retrovirus vector pPS-3-neo. DNA of both constructs was introduced into packaging cell line psi 2 by a standard Ca-phosphate transfection technique. Infection of mouse and rat fibroblasts BALB/c 3T3 and Rat I with virus particles, produced by transfected psi 2 cells, led to an integration into the host genome of one or two recombinant proviral copies. Stable expression and secretion into the culture medium of glycosylated high molecular weight human urokinase was observed for both cell types. For the hybrid gene construct, precise excision of intervening sequences was shown during transferring of genetic material from packaging to recipient cells.     

Ultrasound Enhances Retrovirus‐Mediated Gene Transfer

Abstract

Viral vector systems are efficient for transfection of foreign genes into many tissues. Especially, retrovirus based vectors integrate the transgene into the genome of the target cells, which can sustain long term expression. However, it has been demonstrated that the transduction efficiency using retrovirus is relatively lower than those of other viruses. Ultrasound was recently reported to increase gene expression using plasmid DNA, with or without, a delivery vehicle. However, there are no reports, which show an ultrasound effect to retrovirus‐mediated gene transfer efficiency.

Retrovirus‐mediated gene transfer systems were used for transfection of 293T cells, bovine aortic endothelial cells (BAECs), rat aortic smooth muscle cells (RASMCs), and rat skeletal muscle myoblasts (L6 cells) with β‐galactosidase (β‐Gal) genes. Transduction efficiency and cell viability assay were performed on 293T cells that were exposed to varying durations (5 to 30 seconds) and power levels (1.0 watts/cm² to 4.0 watts/cm²) of ultrasound after being transduced by a retrovirus. Effects of ultrasound to the retrovirus itself was evaluated by transduction efficiency of 293T cells. After exposure to varying power levels of ultrasound to a retrovirus for 5 seconds, 293T cells were transduced by a retrovirus, and transduction efficiency was evaluated.

Below 1.0 watts/cm² and 5 seconds exposure, ultrasound showed increased transduction efficiency and no cytotoxicity to 293T cells transduced by a retrovirus. Also, ultrasound showed no toxicity to the virus itself at the same condition. Exposure of 5 seconds at the power of 1.0 watts/cm² of an ultrasound resulted in significant increases in retrovirus‐mediated gene expression in all four cell types tested in this experiment. Transduction efficiencies by ultrasound were enhanced 6.6‐fold, 4.8‐fold, 2.3‐fold, and 3.2‐fold in 293T cells, BAECs, RASMCs, and L6 cells, respectively. Furthermore, β‐Gal activities were also increased by the retrovirus with ultrasound exposure in these cells.

Adjunctive ultrasound exposure was associated with enhanced retrovirus‐mediated transgene expression in vitro. Ultrasound associated local gene therapy has potential for not only plasmid‐DNA‐, but also retrovirus‐mediated gene transfer.     

反转录病毒MSCV介导汉坦病毒核蛋白基因在NIH3T3细胞中整合和表达

汉坦病毒是引起肾综合征出血热(HFRS)和汉坦病毒型肺炎综合征(HPS)的主要病原体.由S基因编码的核蛋白(NP)主要与机体的细胞免疫有关,并调节病毒的复制及诱导细胞程序性死亡.构建了汉坦病毒Z10株核蛋白cDNA与含有pac基因的反转录病毒鼠干细胞病毒(MSCV)重组体MSCV-FlagNP,通过磷酸钙转录法导入产病毒的包装细胞系BOSC23中,产生完整的重组MSCV-FlagNP病毒.然后以重组病毒感染NIH 3T3细胞,利用Puromycin的选择特性(pac基因)对感染细胞进行连续压力筛选,获得了转核蛋白抗性细胞.利用Southern blot和PCR方法分别对核蛋白基因在抗性细胞染色体整合情况及其完整性进行了鉴定.并且用Western blot在抗性细胞中可检测到核蛋白的表达.进一步以Flag单克隆抗体介导的免疫荧光染色联合共聚焦激光扫描荧光显微镜,分析了内源性Flag融合核蛋白在抗性细胞内分布,发现核蛋白主要分布于胞浆及胞核周围区,并且部分核蛋白可聚集形成胞浆包涵体.转核蛋白基因细胞模型的建立,对进一步研究汉坦病毒核蛋白功能以及病毒复制机制有重要意义.     

移植神经营养素-4基因工程细胞对脊髓前角神经元的保护作用

用重组逆转录病毒介导的体外神经营养素－４（ＮＴ－４）基因转移的方法,制备高表达ＮＴ－４基因工程细胞并移植大鼠坐骨神经离断处,尼氏染色和ＣｈＥ染色的结果表明,移植ＮＴ－４基因工程细胞对外周神经损伤所造成的运动神经元的退变有显著的改善作用,而且这种作用可以维持三个月。