携带hIL-4逆转录病毒重组体的构建及在类风湿关节炎中体外表达的研究

目的 构建携带人白介素4（hIL-4）表达序列的重组逆转录病毒pLXSN—hIL-4并检测目的基因的表达。方法 2004年6月至12月在中国医科大学基础医学院设计带有酶切位点的引物，含有目的基因的DNA进行聚合酶链反应扩增并纯化目的基因片段。pLXSN与目的基因片段hIL-4进行定向克隆连接，筛出阳性克隆并进行鉴定。扩增重组逆转录病毒载体pLXSN—hIL-4，并转染体外培养的人滑膜成纤维样细胞。Western blotting法测定目的基因蛋白表达水平。结果 成功构建了携带治疗基因的逆转录病毒重组体：rRV—hIL-4。Western blotting法检测到了hIL-4的表达。结论 成功构建了携带治疗基因的逆转录病毒重组体：rRv—hIL-4。以逆转录病毒为载体可以将hIL-4基因导入体外培养的人滑膜成纤维样细胞，转染后的细胞可以表达hIL-4蛋白。     

人白细胞介素-1受体拮抗剂或白细胞介素-10逆转录病毒载体的构建与体外实验

目的 构建携带人白细胞介素-1受体拮抗剂(hIL-1Ra)或人白细胞介素-10(hIL-10)基因的重组逆转录病毒(rRv)，体外转染免滑膜成纤维样细胞，检测目的基因的表达水平与持续时间。方法 提取人外周血单个核细胞总RNA，反转录聚合酶链反应(RT-PCR)扩增目的基因；酶切、连接目的基因与逆转录病毒载体pLXSN，筛出阳性克隆，经GP2-293细胞包装，收集病毒并鉴定；rRV-hlL-1Ra、rRV-hlI-10分别体外转染兔滑膜成纤维样细胞，RT-PcR测定目的基因mRNA表达水平与时间的关系。免疫组织化学与免疫印迹测定蛋白水平的表达与持续时间。结果 成功构建了携带hIL-1Ra或hIL-10基因的重组逆转录病毒，rRv-hIL-1Ra与rRV-hIL-10均能有效转染体外培养的兔滑膜成纤维样细胞，RT-PcR测定目的基因mRNA高峰均出现于转染后第5天左右。免疫组织化学和免疫印迹均检测到hIL-lRa、hlL-10的表达。经G418筛选后的细胞中，hIL-1Ra的表达在转染后第30天内达高峰，至少持续60d：hIL-10的表达至少持续40d。结论 以重组逆转录病毒为载体可以成功地将hIL-lRa或hIL-10基因导人体外培养的兔滑膜成纤维样细胞并实现稳定表达。     

HSV1-tk基因逆转录病毒载体构建、病毒包装及稳定细胞株建立

目的构建携带HSV1-tk基因的逆转录病毒载体pDON-AI-HSV1-tk,包装后产生携带相应基因的逆转录病毒并稳定感染T47D乳腺癌细胞。方法用PCR方法扩增HSV1-tk基因,利用基因重组技术构建逆转录病毒载体pDON-AI-HSV1-tk,经PCR及BamHI、SalI双酶切鉴定后与gag-pol和env表达载体用脂质体法共同转染293T包装细胞,产生含有HSV1-tk基因的逆转录病毒并用其感染T47D细胞,经G418筛选获得稳定表达株,命名为tk/T47D。结果构建了携带HSV1-tk基因的逆转录病毒载体pDON-AI-HSV1-tk,并通过PCR及BamHI、SalI双酶切证实。包装产生的逆转录病毒提取病毒基因组后PCR扩增出目的基因HSV1-tk,并成功地建立稳定表达HSV1-tk基因的T47D细胞。结论成功的构建了含有HSV1-tk基因的逆转录病毒载体并包装出携带相应基因的逆转录病毒,建立稳定表达HSV1-tk基因的乳腺癌T47D细胞株。     

介导人硫氧还蛋白基因转移的重组腺病毒构建

目的应用基因重组方法构建携带人硫氧还蛋白(hTRX)基因的复制缺陷型重组腺病毒。方法用内切酶、RT-PCR、测序方法获得目的基因片段,然后将其cDNA克隆至表达载体pShuttle构建hTRX的重组真核细胞表达载体pShuttle-hTRX,在HeLa细胞中进行瞬时表达检测。从真核表达载体pShuttle-hTRX切下目的基因,并插入至腺病毒载体构建hTRX的重组腺病毒载体Adeno-hTRX,经PCR方法亦证明了成功构建腺病毒重组体。重组腺病毒在293细胞中扩增、纯化。结果成功构建了携带人硫氧还蛋白基因的复制缺陷型重组腺病毒,并以多种方法证实了构建载体的正确性。结论正确构建的人硫氧还蛋白重组腺病毒载体,可为基因治疗心血管系统疾病打下良好基础。     

人Tum-5基因逆转录病毒载体及包装细胞株的构建

目的 构建携带Tum-5基因的逆转录病毒载体并对其进行包装,获得稳定的产毒细胞系.方法 采用RT-PCR法从胎肾组织中扩增Tum-5基因片断,并将其定向克隆到逆转录病毒载体pLXSN中进行PCR、双酶切和测序鉴定.利用电穿孔方法 将获得的重组质粒转染PA317细胞,经G418 筛选抗性克隆,收集病毒上清后感染NIH3T3 细胞测定病毒滴度.结果 PCR、酶切证实Tum-5基因克隆至逆转录病毒载体pLXSN,Tum-5基因测序结果 和原始序列相同.重组逆转录病毒载体转染PA317 包装细胞,RT-PCR证实转染后的PA317细胞上清液中存在携带人Tum-5基因的病毒RNA,病毒滴度为2.05×104cfu/ml.结论 成功的构建了携带人Tum-5基因的逆转录病毒载体,获得了稳定的产毒细胞系.     

重组人GDNF基因逆转录病毒真核表达载体的构建及表达

目的 构建含有胶质细胞源性神经营养因子(GDNF)和加强型绿色荧光蛋白基因(EGFP)的逆转录病毒载体,将其导入包装细胞PT67,检测基因在细胞中的表达.方法 PCR法扩增GDNF基因及IRES2-EGFP基因,测序验证正确后与逆转录病毒载体pLXSN连接,构建重组逆转录病毒质粒pLXSN-IRES2-EGFP-GDNF.EcoR I酶切鉴定重组质粒.脂质体Lipofectamine 2000介导下转染包装细胞PT67,G418筛选并检测病毒滴度.流式细胞仪和荧光显微镜分别检测转染效率和基因表达.结果 PCR扩增得到大小约558 bp和1 308 bp的特异性条带,测序证实,获得正确的人GDNF序列和EGFP序列.经EcoR I酶切鉴定,成功构建重组质粒pLXSN-IRES2-EGFP-GDNF.荧光显微镜检测显示GDNF基因获得良好表达,流式细胞仪检测转染效率为24.4%.结论 正确克隆了人GDNF基因全序列并构建重组逆转录病毒pLXSN-IRES2-EGFP-GDNF质粒.基因转染包装细胞PT67获良好表达.     

人白细胞介素10真核表达载体的构建及表达

目的 建立人白细胞介素10(hIL-10)真核表达系统并观察其在HeLa细胞中的表达。方法 用RT-PCR方法自活化的人外周血淋巴细胞扩增hIL-10 cDNA，将其克隆至pMDl8-T中，测序正确后，再定向插入真核表达载体pCIneo中，经脂质体介导转染HeLa细胞，检测其在细胞内外的表达和分泌。结果 RT-PCR扩增的hIL-10 cDNA序列与GenBank中hIL-10 cDNA序列一致；构建了真核重组表达载体pCIneo-hIL-10；转染HeLa细胞后可检测到hIL-10的转录和表达。结论 成功构建了hIL-10真核表达系统，为今后的临床研究及基因工程药物的生产奠定基础。     

人白细胞介素-10真核表达载体的构建及其在兔滑膜细胞中的表达

目的 构建人白细胞介素-10(hIL-10)高效真核表达载体,观察其在家兔滑膜细胞(RSCs)中表达.方法 提取人外周血单个核细胞(PBMCs)总RNA作为模板,根据基因库(NM 000572)中hIL-10全长开放读框设计特异性引物,反转录-聚合酶链反应(RT-PCR)一步法扩增hIL-10 mRNA全长开放读框,扩增产物定向克隆人真核表达载体pcDNA4/HisMaxA,并对克隆人真核表达载体的扩增产物进行酶切及DNA测序鉴定,构建的真核表达载体pcDNA4/HisMaxA-hIL-10经阳离子脂质体介导转染兔滑膜细胞RSCs.酶联免疫吸附试验(ELISA)检测转染后12、24、48、72 h和7、14 d RSCs培养上清中hIL-10水平.结果 RT-PCR产物约0.54 kb,克隆人真核表达载体pcDNA4/HisMaxA的扩增产物经酶切及DNA测序鉴定与读码框架序列无差别.转染后12 h到第7天细胞培养上清检测出hIL-10,且水平显著性高于对照组(F=21.878,P＜0.01).结论 hIL-10真核高效表达载体pcDNA4/HisMaxA-hIL-10构建成功.     

人硫氧还蛋白真核载体的构建及表达

目的构建人硫氧还蛋白基因的重组真核表达载体。方法人硫氧还蛋白的cDNA克隆至pGEM-TEasy载体,经DNA测序证明后,将其克隆至真核表达载体pShttle构建重组pShttle-hTRX,pShttle-hTRX转染Hela细胞系进行瞬时表达,通过Westernblot、免疫组化、活性测定、酶切、PCR扩增等方法证实构建载体的正确性。结果构建携带人硫氧还蛋白基因的真核表达载体pShttle-hTRX,转染HeLa细胞后可检测到hTRX的转录和表达。结论正确构建了携带人硫氧还蛋白基因的真核表达载体,本结果可用于探讨硫氧还蛋白的生物学作用。     

人Kiss-1真核表达荧光载体的构建

[目的]构建并鉴定人Kiss-1真核表达荧光质粒。[方法]按照Genebank中人Kiss-1序列设计引物,以EC109细胞cDNA为模板,扩增基因片段与载体pIRES2-EGFP连接,得到人Kiss-1真核表达荧光载体并测序鉴定,通过脂质体体外转染至EC-109细胞,根据转染情况分为2组:空载体组(转染pIRES2-EGFP空载体)、转染组(转染pIRES2-EGFP-Kiss-1重组质粒)。裂解细胞分别提取RNA和蛋白样品用于检测Kiss-1表达水平。[结果]构建的pIRES2-EGFP-Kiss-1荧光重组质粒,经PCR、酶切、测序结果完全达到预期设计,转染组细胞中Kiss-1mRNA和蛋白表达水平均显著高于空载体组。[结论]成功重组质粒pIRES2-EGFP-Kiss-1和瞬时表达Kiss-1基因的食管癌细胞,为后续建立Kiss-1高表达阳性细胞克隆奠定了基础,为研究Kiss-1对人食管癌细胞增殖、侵袭和转移能力提供了实验基础。     

IL—6基因转导大肠癌细胞的表达

目的:IL-6基因导入大肠癌细胞,建立能有效表达IL-6的转导株HT-29IL-6.方法:采用酶切与连接技术构建重组IL-6基因逆转录病毒载体,基因转染包装细胞,C418筛选克隆,常规制备重组病毒液并感染HT-29细胞,筛选抗性细胞,Southern blot和Northem blot分析基因的整合与mRNA转录水平,MTT显色法及ELISA法检测表达产物的量与活性.结果:成功地构建了重组载体pZIPIL-6cDNA,制备了高滴度的重组病毒液(5.1×10~5cft/ml),其感染率达80%以上,建立了HT-29IL-6表达株,杂交结果证实具有目的基因的稳定整合和相应mRNA的有效转录,表达IL-6的量与活性分别为1132.5pg/ml和15OU/ml.结论:逆转录病毒载体介导的IL-6基因通过转染及筛选能稳定整合在大肠癌细胞染色体,并进行有效的转录与表达,为IL-6转基因治疗大肠癌的研究奠定了基础.     

Efficient screening of retroviral cDNA expression libraries.

Expression cloning of cDNAs was first described a decade ago and was based on transient expression of cDNA libraries in COS cells. In contrast to transient transfection of plasmids, retroviral gene transfer delivers genes stably into a wide range of target cells. We utilize a simple packaging system for production of high-titer retrovirus stock from cDNA libraries to establish a cDNA expression cloning system. In two model experiments, murine interleukin (IL)-3-dependent Ba/F3 cells were infected with libraries of retrovirally expressed cDNA derived from human T-cell mRNA or human IL-3-dependent TF-1 cell line mRNA. These infected Ba/F3 cells were selected for the expression of CD2 by flow cytometry or for the alpha subunit of the human IL-3 receptor (hIL-3R alpha) by factor-dependent growth. CD2 (frequency, 1 in 10(4)) and hIL-3R alpha (frequency, 1 in 1.5 x 10(5)) cDNAs were readily detected in small-scale experiments, indicating this retroviral expression cloning system is efficient enough to clone low-abundance cDNAs by their expression or function.     

Gene transfer and expression of enhanced green fluorescent protein in variant HT-29c cells

AIM: To study the expression of enhanced green fluorescent protein (EGFP) gene in retrovirally transduced variant HT-29 cells. METHODS: The retroviral vector prkat EGFP/neo was constructed and transfected into the 293T cell using a standard calcium phosphate precipitation method. HT-29c cells (selected from HT-29 cells) were transduced by a retroviral vector encoding the GEFP gene. The fluorescence intensity of colorectal carcinoma HT-29c cells after transduced with the EGFP bearing retrovirus was visualized using fluorescence microscope and fluorescence activated cell sorter (FACS) analysis. Multiple biological behaviors of transduced cells such as the proliferating potential and the expression of various antigens were comparatively analyzed between untransduced and transduced cells in vitro. EGFP expression of the fresh tumor tissue was assessed in vivo. RESULTS: After transduced, HT-29c cells displayed a stable and long-term EGFP expression under the nonselective conditions in vitro. After cells were successively cultured to passage 50 in vitro, EGFP expression was still at a high level. Their biological behaviors, such as expression of tumor antigens, proliferation rate and aggregation capability were not different compared to untransduced parental cells in vitro. In subcutaneous tumors, EGFP was stable and highly expressed. CONCLUSION: An EGFP expressing retroviral vector was used to transduce HT-29c cells. The transduced cells show a stable and long-term EGFP expression in vitro and in vivo. These cells with EGFP are a valuable tool for in vivo research of tumor metastatic spread.     

Clonal analysis of stably transduced human epidermal stem cells in culture.

We have transduced normal human keratinocytes with retroviral constructs expressing a bacterial beta-galactosidase (beta-gal) gene or a human interleukin-6 (hIL-6) cDNA under control of a long terminal repeat. Efficiency of gene transfer averaged approximately 50% and 95% of clonogenic keratinocytes for beta-gal and hIL-6, respectively. Both genes were stably integrated and expressed for more than 150 generations. Clonal analysis showed that both holoclones and their transient amplifying progeny expressed the transgene permanently. Southern blot analysis on isolated clones showed that many keratinocyte stem cells integrated multiple proviral copies in their genome and that the synthesis of the exogenous gene product in vitro was proportional to the number of proviral integrations. When cohesive epidermal sheets prepared from stem cells transduced with hIL-6 were grafted on athymic animals, the serum levels of hIL-6 were strictly proportional to the rate of secretion in vitro and therefore to the number of proviral integrations. The possibility of specifying the level of transgene expression and its permanence in a homogeneous clone of stem cell origin opens new perspectives in the long-term treatment of genetic disorders.     

多房棘球绦虫pBCG-Em14-3-3重组质粒的构建及其在BCG中的表达

目的构建多房棘球绦虫重组质粒pBCG-Em14-3-3,并转化BCG进行表达。方法超声粉碎泡球蚴组织提取总RNA,通过RT-PCR扩增Em14-3-3抗原编码基因;将该扩增产物定向克隆到大肠杆菌-分枝杆菌穿梭表达载体pBCG,构建重组质粒pBCG-Em14-3-3;电穿孔法转化BCG,构建多房棘球绦虫重组BCG-Em14-3-3。免疫印迹分析pBCG-Em14-3-3的表达产物。结果RT-PCR成功扩增出779bp的Em14-3-3抗原编码基因;双酶切证实Em14-3-3抗原编码基因成功插入pBCG中;PCR证实rBCG-Em14-3-3构建成功;免疫印迹分析发现pBCG-Em14-3-3的表达产物在相对分子质量(Mr)约为27×103处有明显的目的蛋白表达条带,且能被活动性泡球蚴病鼠血清特异识别。结论成功构建了多房棘球绦虫重组BCG-Em14-3-3。     

尘螨变应原Der f 2编码基因重组pCold TF体系构建及可溶性表达

目的建立尘螨变应原Der f 2编码基因重组pCold TF体系并诱导表达。方法以质粒pMD19-T-Der f 2为模板扩增目的基因Der f 2,克隆至pCold TF DNA载体,转化BL21细菌,用IPTG诱导表达,用SDS-PAGE和West-ern blot鉴定表达产物。结果 PCR扩增获得Der f 2编码基因,成功构建表达质粒pCold TF-Der f 2。SDS-PAGE检测表明该质粒在大肠埃希菌中正常表达,且基本为可溶性表达,表达产物分子质量单位为69ku,Western blot检测该蛋白能被鼠抗Penta-His抗体识别。结论成功建立尘螨变应原Der f 2编码基因重组pCold TF体系,并实现其可溶性原核表达。     

Direct gene delivery to synovium: An evaluation of potential vectors in vitro and in vivo

Objective. To assess the abilities of various vectors to transfer genes to the synovial lining of joints. Methods. Vectors derived from retrovirus, adenovirus, and herpes simplex virus as well as cationic liposomes and naked plasmid DNA were evaluated. Each construct contained the lac Z marker gene; and one retroviral construct, and one plasmid also contained a gene encoding human interleukin-1 receptor antagonist. Gene expression was under the control of the human cytomegalovirus promoter in all vectors except the retrovirus, where the endogenous 5′ long terminal repeat was retained as the promoter. Cultures of rabbit synovial fibroblasts were exposed to these vectors and stained with X-gal to identify lac Z+ cells. Vectors were then injected directly into rabbits' knee joints, and gene transfer and expression were assessed by X-gal staining and polymerase chain reaction (PCR). Results. Adenovirus was a highly effective vector both in vitro and in vivo, with lac Z gene expression persisting for at least 28 days. However, an inflammatory response was noted in vivo. Cells infected in vitro and in vivo with herpes simplex virus also expressed the lac Z gene at high levels, but expression was limited by cytotoxicity. Retroviruses, in contrast, were effective only under in vitro conditions, permitting cell division. Liposomes gave variable in vitro results; when injected into joints in vivo, gene expression was low and was detectable for only a few days, even though a PCR signal persisted for at least 28 days. Unexpectedly, plasmid DNA was captured by the synoviocytes and expressed transiently following intraarticular injection. Conclusion. None of the vectors was ideal for in vivo gene delivery to synovium, although adenovirus was clearly the most effective of those tested. Retroviruses, although poor vectors for in vivo gene delivery, are well suited for ex vivo gene transfer to the synovial lining of joints.