重组腺相关病毒介导内皮抑素的表达及体外活性研究

OBJECTIVE: To construct the recombinant adeno-associated viral vector containing human endostatin gene (rAAV-hEndo) and observe the biological activity of the expressed human endostatin in vitro. METHODS: rAAV-hEndo was prepared using a helper virus-free packaging system. The rAAV viral genome titer was quantified by Taqman real-time PCR, and the endostatin expressed in human umbilical vein endothelial cell line ECV304 was detected by immunofluorescence staining. The effects of endostatin on ECV340 cells were evaluated by MTT cell proliferation assay, cell cycle analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling (TUNEL) technique. RESULTS: The viral titer of rAAV-hEndo prepared was 2 x 10(12) vg/ml and the vector had an infection efficiency of 98%. Immunofluorescence staining showed that the human endostatin protein was expressed mainly in the cytoplasm of ECV304 cells, and the proliferation of the cells was obviously inhibited by the supernatant of rAAV-hEndo, with a inhibition rate of 67.3% 72 h after the addition of the supernatant. ECV304 cells infected with rAAV-hEndo were obviously arrested in G(1) phase, and the G(1)-phase cell percentage of treatment group were significantly higher than that of control group [(72.5+/-4.0)% vs (52.1+/-2.1)%, P<0.01]. ECV304 cells infected with rAAV-hEndo demonstrated markedly enhanced apoptosis, with a significantly greater apoptotic index than that of the control cells [(32.6+/-3.2)% vs (4.2+/-1.9)%, P<0.01]. CONCLUSION: rAAV-hEndo can effectively mediate the expression of biologically active human endostatin, which may facilitate further study of antiangiogenic gene therapy with endostatin for cancers.     

腺相关病毒衣壳蛋白修饰的研究进展

腺相关病毒(adeno-associated virus,AAV)介导的基因治疗在单基因遗传性疾病的临床治疗中取得了突破性进展.通过衣壳蛋白修饰来优化AAV载体,获得具有细胞靶向性、高转导能力和低或无免疫原性的AAV载体成为当前基因治疗研究的重点之一.目前,研究者主要通过合理设计、定向进化和化学修饰方法对AAV衣壳进行...     

腺相关病毒介导增强型绿色荧光蛋白基因体外转染兔结膜上皮细胞

目的:研究2型重组腺相关病毒( recombinant adeno-associated virus 2,rAAV2)载体介导增强型绿色荧光蛋白基因(enhanced green fluorescent protein,EGFP) 对体外培养兔结膜上皮细胞的转染和表达情况,为后续研究提供依据。方法:体外培养兔结膜上皮细胞,rAAV2-EGFP 按感染复数(multiplicity of infection ,MOI)为104、105、106 转染第2代兔结膜上皮细胞,转染后第1 、3 、5 、7日倒置荧光显微镜下观察细胞中EGFP表达情况,计算转染率。MTT方法检测rAAV2-EGFP转染对细胞增殖的影响。结果:随着MOI值增大及转染时间延长,EGFP 表达效率逐渐增高,转染后第7～8日达到高峰并维持。MTT检测各MOI组与对照组差别无统计学意义。结论:rAAV2载体可以介导EGFP 基因高效稳定转染兔结膜上皮细胞,并且对细胞增殖无影响。     

重组腺相关病毒介导内皮抑素的表达及体外活性研究

目的 构建携带人内皮抑素基因的重组腺相关病毒rAAV-hEndo,介导其体外表达并检测其生物活性。方法 采用无需包装辅助病毒的双质粒共转染方法制备rAAV-hEndo,测定其滴度及感染效率。免疫荧光染色检测内皮抑素蛋白在体外感染细胞中的表达,并通过MTT法、细胞周期检测及TUNEL法检测细胞凋亡指数,观察其对人脐静脉内皮细胞ECV304的影响。结果 所制备的重组腺相关病毒滴度为2×10¹²vg/ml,感染效率达98%。免疫荧光染色显示内皮抑素蛋白主要表达于细胞胞质。rAAV-hEndo感染细胞培养上清对ECV304细胞72h增殖抑制率为67.3%。内皮细胞转染内皮抑素基因后细胞周期明显阻滞于G₁期,其G₁期占(72.5±4.0)%,与对照组(52.1±2.1)%比较有显著差异(P<0.01)。TUNEL法检测实验组内皮细胞凋亡指数为(32.6±3.2)%,与对照组(4.2±1.9)%比较有显著差异(P<0.01)。结论 所制备的重组腺相关病毒rAAV-hEndo能有效介导具有生物活性的内皮抑素表达,为进一步肿瘤抗血管生成基因治疗动物实验奠定了基础。     

氧相关HRE启动子控制下表达hVEGF165基因重组2型腺相关病毒的获得及鉴定

目的包装及鉴定低氧反应元件（HRE）启动子控制下缺氧诱导目的基因hVEGF165基因表达的2型重组腺相关病毒。方法磷酸钙三质粒共转染方法将pAAV—HRE9-VEGF165、pAAV—Rep／cap、pHelper质粒转染HEK293T细胞，制备2型重组腺病毒相关病毒（rAAV2）。分离培养S—D大鼠心肌细胞，转染rAAV，细胞固定后做免疫细胞荧光染色，检测细胞内血管内皮细胞生长因子（VEGF165）蛋白的表达。结果pAAV—HRE9-VEGF165质粒经测序鉴定，结果与NCBIGenBank公布的人VEGF165 eDNA核苷酸序列（AB021221）完全一致，含HRE启动子及目的基因hVEGF165的2型重组非复制型腺相关病毒包装成功，可感染原代培养的大鼠心肌细胞，缺氧可诱导VEGF165蛋白表达。结论成功包装并鉴定了rAAV—HRE9-hVEGF165载体，可有效转染心肌细胞，VEGF165基因的适时表达，为缺血性心肌疾病的“分子搭桥”治疗提供了更可能的安全性。     

含乙型肝炎表面抗原基因重组腺相关病毒的构建及其基因的表达和功能初步研究

目的构建含乙型肝炎表面抗原(HBsAg)基因的重组腺相关病毒(rAAV)并观察目的基因的表达和功能。方法采用PCR法从PTHBV-1质粒中扩增HBsAg基因(ayw 亚型);将PCR扩增产物插入腺相关病毒(AAV)表达质粒pSNAV中,构建重组质粒pSNAV-HBsAg;用脂质体转染的方法将重组质粒转入BHK-21细胞中,G418筛选得到转入重组质粒并能表达目的基因的细胞系BHK-HBsAg;用具有rAAV包装功能的HSV-1- HSV1-rc/△UL2感染BHK-HBsAg,纯化后得到rAAV-HBsAg;ELISA检测重组病毒表面抗原基因在BHK-21细胞和293细胞中的表达;用rAAV-HBsAg免疫BalB/C小鼠,RIA法检测血清中表面抗体的滴度。结果ELISA法检测到混合细胞系BHK-HBsAg中HBsAg的表达量为(28.6±6.7)ng/5×106细胞;rAAV-HBsAg感染BHK-21细胞和293细胞后均能检测到HBsAg的表达,表达量随感染复数的增加而升高;rAAV-HBsAg免疫的BalB/C小鼠能产生表面抗体(抗-HBs抗体)。结论rAAV-HBsAg在体外能表达,免疫动物能诱导体液免疫反应的产生。rAAV-HBsAg有希望成为乙型肝炎候选疫苗,也可以进一步用于探索慢性乙型肝炎的免疫治疗。     

HSV1-TK基因重组腺相关病毒载体的构建及表达

目的:构建含单纯疱疹病毒Ⅰ型胸苷激酶(HSV1-TK)基因的重组腺相关病毒载体质粒pSNAV2.0-TK,制备重组腺相关病毒rAAV2/HSV1-TK,并检测HSV1-TK基因在转染晶状体上皮细胞中的整合和表达,为后囊膜混浊的基因治疗奠定基础.方法:用基因重组技术构建含HSV1-TK基因的重组腺相关病毒载体质粒pSNAV2.0-TK,并通过PCR和酶切鉴定;将该质粒转染BHK-21细胞,经G418筛选出携带该质粒的载体细胞株BHK-21/TK,在辅助病毒的参与下包装成重组病毒rAAV2/HSV1-TK;用SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)法和高效液相色谱(HPLC)法检测重组病毒rAAV2/HSV1-TK的纯度,用斑点杂交法检测重组病毒的滴度;重组病毒rAAV2/HSV1-TK转染兔晶状体上皮细胞N/N1003A,用PCR和RT-PCR检测HSV1-TK基因的整合和表达.结果:经PCR和酶切鉴定重组质粒pSNAV2.0-TK构建成功;成功制备了重组病毒rAAV2/HSV1-TK,病毒滴度达1×1012v.g./mL;重组病毒转染N/N1003A细胞后,PCR和RT-PCR检测显示HSV1-TK基因在细胞中整合并且有效表达.结论:成功构建了含HSV1-TK基因的重组腺相关病毒载体质粒,制备了高滴度重组病毒rAAV2/HSV1-TK,HSV1-TK基因在转染该病毒的晶状体上皮细胞中可有效表达.     

Aβ单链抗体基因腺相关病毒载体的构建

阿尔茨海默病(Alzheimer's disease, AD)的发生、发展和β淀粉样肽(amyloid β peptide, Aβ)在大脑组织的过载和神经毒性密切相关~([1]).动物实验和临床测试结果均表明Aβ疫苗免疫接种或Aβ抗体的外周注射有助于清除大脑组织内过载的Aβ~([2-3]).     

含乙型肝炎表面抗原基因重组腺相关病毒的构建及其基因的表达和功能初步研究

OBJECTIVE: To construct recombinant adeno-associated virus (rAAV) carrying hepatitis B surface antigen (HBsAg) gene and study the function of the expressed HBsAg. METHODS: HBsAg gene (subtype ayw) was amplified from PTHBV-1 by PCR and cloned into the adeno-associated virus vector pSNAV to form the recombinant pSNAV-HBsAg, which was transfected into BHK-21 cells by means of lipofectamine. Using G418 selection, a mixed cell line, BHK-HBsAg, was isolated, which was capable of HBsAg expression and was subsequently infected with HSV-1-HSV1-rc/Delta UL2 that was able to package the rAAV. After purification, rAAV-HBsAg was obtained. The expression of HBsAg in BHK-21 cells and 293 cells infected with rAAV-HBsAg were detected by enzyme-linked immunosorbent assay (ELISA), and the HBsAg antibodies in the sera of rAAV-HBsAg-immunized BalB/C mice were assayed by radio immunoassay. RESULTS: As detected by ELISA, the expressed HBsAg in mixed cell line mounted to 28.6+/-6.72 ng per 5 x 10(6) cells. The BHK-21 cells and 293 cells infected with rAAV-HBsAg were both capable of HBsAg expression, the amount of which augmented with the increase of multiplicity of infection (MOI). BalB/C mice immunized with rAAV-HBsAg produced anti-HBsAg antibodies. CONCLUSIONS: rAAV-HBsAg can induce humoral immune response against HBsAg and therefore can be a promising candidate hepatitis B vaccine, and in addition, it may serve the purpose of exploring possible immunotherapy for chronic HBV infection.     

Her2/neu蛋白基因重组腺相关病毒转染树突状细胞的初步探讨

目的 用Her2／neu蛋白基因重组腺相关病毒(rAAV-Her-2／neu)转染人外周血中树突状细胞(dendritic cell,DC),并鉴定其表面分子的表达,及同种混合淋巴细胞反应。方法 采用Fieol分离人外周血中的单个核细胞,在6孔板上培养。细胞分2组,分别加入病毒液和293细胞冻溶液。流式细胞仪检测DC表面标志。应用MTT法检测同种混合淋巴细胞反应。结果 两组细胞均高表达CD80,CD83,CD86,HLA-DR,较低表达CDla,CD40,两组无明显差异(P＞0．05)。结论 rAAV-Her-2／neu转染DC刺激T细胞增殖能力明显高于非转染组DC(P＞0．05)。     

Hepatitis B Virus X Protein Upregulates Intracellular Calcium Signaling by Binding C-terminal of Orail Protein

Hepatitis B virus X (HBx) protein plays a pivotal role in the development of hepatitis B virus (HBV)-associated hepatocellular carcinoma. Although regulation of cytosolic calcium is essential for HBV replication and is mediated by HBx protein, the mechanism of HBx protein regulating intracellular calcium level remains poorly understood. The present study examined whether HBx protein elevated the intracellular calcium through interacting with storeoperated calcium entry (SOCE) components, Orail and stromal interaction molecule 1, and then identified the targets of HBx protein, with an attempt to understand the mechanism of HBx protein upsetting intracellular calcium homeostasis. By employing co-immunoprecipitation and GST-pull-down assay, we found that Orail protein interacted with HBx protein, and the C-terminus of Orail was implicated in the interaction. Confocal microscopy also revealed that HBx protein could co-localize with full-length Orail protein in HEK293 cells. Moreover, live cell calcium imaging exhibited that HBx protein elevated intracellular calcium, possibly by binding to SOCE components. Our results suggest that HBx protein binds to STIM1-Orail complexes to positively regulate the activity of plasma membrane store-operated calcium channels.     

hDaxx与乙型肝炎病毒X蛋白的相互作用

目的采用酵母双杂交法研究HBVX蛋白与hDaxx蛋白的相互作用，为探讨HBVX蛋白的致癌机制奠定实验基础。方法构建pGBKT7-hDaxx和pGADT7-HBX重组质粒，分四组转化酵母AHl09，A组为pGADT7和pGBKT7，B组为pGBKT7-hDaxx和pGADT7-HBX，C组为pGADT7-T和pG-BKT7-Lam，D组为pGADT7-T和pGBKT7-p53。将转化菌落接种于SD／-Tip-ku（二缺）固体平板，长出克隆后再接种于SD／-Tip-Leu-His（三缺）和SD／-Tip-Leu-His-Ade（四缺）平板，30℃培养36～72h。裂解酵母菌，提取蛋白，经SDS-PAGE、Western blot检测hDaxx和X蛋白在酵母中的表达。结果仅有共转化pGBKT7-hDaxx和pGADT7-HBx的AHl09可以在三缺及四缺平板上生长。Western blot检测到hDaxx和X蛋白均能在酵母中表达。结论HBV X蛋白与hDaxx能在酵母细胞内发生相互作用。     

乙型肝炎病毒X基因蛋白诱导人类白细胞抗原DR表达

乙型肝炎病毒(HBV)所致的肝细胞坏死,被认为是与人类白细胞抗原(HLA)有关的MHC限制的T细胞为主的免疫应答的结果。本研究证实,转染HBV基因组或X基因后的人肝癌细胞系可诱导HLAⅡ(即HLA DR)表达。核转录及RNA杂交分析提示表达X基因的细胞其HLA DR mRNA水平增加,X蛋白增加该基因的转录。氯霉索乙酰基转移酶(CAT)基因分析进一步提示,X蛋白通过作用于HLA DR基因上游的调节序列诱导HLA DR表达。结果表明:X蛋白可能通过调节HLA DR表达参与HBV感染的免疫发病机理。     

儿童感染的乙型肝炎病毒X基因的分子特征分析

目的 初步调查儿童感染的乙型肝炎病毒(HBV)X基因的分子特征.方法 收集20例儿童慢性乙型肝炎(乙肝)患者的血清标本,抽提血清中的HBV DNA,采用PCR扩增HBV X基因并测序,利用Clustal X、Bioedit软件对PCR产物序列进行X基因的突变分析.结果 20例HBV X基因突变区主要集中在羧基端aa120-150,氨基酸序列突变点分别为I127T、K130M、V131I、P145R、A146G/C、C148R/H和N149G/D;核苷酸序列突变点分别为T1753C、A1762T、G1764A、T1800C、C1807G、C1810G、A1811T、A1814C、T1815C、C1817T、A1819G和C1820A.结论 儿童感染的HBV X存在突变,集中在羧基端aa120-150,对儿童乙肝的演变会产生重要影响.     

靶向X基因shRNA特异抑制HBV基因表达和复制

目的:研究针对HBV X基因小发夹RNA(shRNA)对HBV基因表达和复制的抑制作用。方法:利用分子克隆方法构建了4个HBV X基因特异性shRNA的表达质粒pshHBx1-4,与HBV复制性质粒共转染HepG2细胞,Northern和Southern印迹法检测HBV的mRNA和病毒复制中间体,化学发光微粒免疫分析方法检测细胞培养上清中的HBsAg和HBeAg,免疫荧光染色分析细胞HBcAg的表达水平。结果:共转染pshHBx1-4显著抑制HBV mRNA表达、降低细胞培养上清中HBsAg和HBeAg的水平和细胞内HBcAg的表达水平、并有效抑制HBV的病毒复制中间体的合成。结论:HBV X基因特异性的shRNA可以有效抑制HBV的基因表达和病毒复制,有可能发展成为新的抗HBV制剂。     

乙型肝炎病毒基因型别及X基因变异的研究进展

乙型肝炎病毒是一个以RNA为中间体的反转录复制病毒,由于RNA聚合酶缺乏校正功能,这使其突变率明显高于一般的DNA病毒,随着分子生物学研究技术的进展,不断有新的HBV基因型和亚型被发现。对和疾病进程、治疗相关的HBV基因型和X基因变异进行研究,有助于对疾病的控制和治疗提供更好的理论依据,在控制HBV感染上具有重要的意义。     

血清乙肝病毒X基因的检测方法及意义

目的 探讨血清乙肝病毒（ＨＢＶ）Ｘ基因的检测方法及肝病患者Ｘ基因检测的意义。方法 通过ＰＣＲ扩增法探讨ＨＢＶ Ｘ基因的检测方法,对扩增产物的序列进行测序分析,并对３０例肝癌及３２例肝硬化患者血清ＨＢｓＡｇ、ＨＢｅＡｇ与Ｘ基因进行检测。结果经琼脂糖电泳与序列分析表明,扩增产物与Ｘ基因序列一致。血清学检测显示,２例肝癌与２例肝硬化患者血清中Ｘ基因检测阳性,但ＨＢｓＡｇ检测阴性。结论 应用ＰＣＲ法能在血清中扩增出完整Ｘ基因片段,为研究Ｘ基因的序列变化与肝癌发生的关系提供了一个有效途径。部分肝病患者血清ＨＢｓＡｇ阴性,但在血清中能检出Ｘ基因,提示肝组织中存在Ｘ基因整合。     

乙肝病毒X基因慢病毒载体的构建和鉴定

目的 构建乙型肝炎病毒(HBV)X蛋白的重组慢病毒载体pRRLsincPPT-hPGK-X-IRES-eGFP-WPRE(pRRL-X),并感染正常组织来源的人肝细胞HL-7702,以验证其在体外的感染效率.方法 采用PCR技术扩增出HBV X基因的DNA片段,用IN-Fusion技术构建表达载体pRRL-X并鉴定,j...     

Extract from Phyllanthus urinaria L. Inhibits Hepatitis B Virus Replication and Expression in Hepatitis B Virus Transfection Model in Vitro

Objective: To explore the effects of the extract from Phyllanthus urinaria L. on hepatitis B virus (HBV) replication and expression in HBV transient transfection model in vitro. Methods: The eukaryotic expression plasmid pHBV1.1, which contains 1.1-fold-overlength genome of HBV, was transfected into the human hepatoma cell line, HepG2, to establish and assess the HBV transient transfection model. The extract from Phyllanthus urinaria L. was prepared in different concentrations and methyl thiazolyl tetrazolium was used to detect the maximum nontoxic concentration of the drug. The extract from Phyllanthus urinaria L. were added into the transfected cell, at the concentrations of 0.8, 0.2 and 0.05 g/L, respectively. Four days after drug application, enzyme-linked immuno sorbent assay was used to detect the concentration of HBsAg in the supernatants, Southern blot was applied to analyze HBV DNA level, and Western blot was used to detect the expression of HBcAg in cells. Results: After the transfection of plasmid pHBV1.1 into HepG2 cells, the concentration of HBsAg in supernatants was increased obviously as compared with that of the normal cells (P<0.05), and all expected HBV replicative intermediates were confirmed by Southern blot analysis, which ensured the successful establishment of the HBV transient transfection model. After the application of drugs at the concentrations of 0.8 and 0.2 g/L, the level of HBsAg was obviously decreased in the supernatants, as compared with that of the virus group (P<0.05); Southern blot showed that the level of HBV rc DNA, ds DNA, ss DNA was obviously reduced compared with that of the virus group (P<0.01); Western blot revealed that the expression of HBcAg in the drug group was obviously inhibited, as compared with that of the virus group (P<0.01). Conclusions: The extract from Phyllanthus urinaria L. obviously inhibited replication and expression of HBV in HBV transfected cell lines in vitro, thus exerting distinctive anti-HBV effects.     

深圳地区慢性HBV感染者血清中HBx基因多态性分析

目的:研究HBV感染者血清学模式与HBx基因多态性的关系。方法:采用聚合酶链反应、单链构象多态性和异源双链分析的方法对HBV感染者血清中HBx基因进行多态性分析。结果:在HBsAg(+)/HBeAg(+)/HBcAb(+)、HBsAg(+)/HBeAb(+)/HBcAb(+)和HBsAg(+)/HBcAb(+)血清学模式中,HBx基因双链区(nt1595-1881)多态性不明显(P(0.05),带形基本一致;HBx基因单链区(nt1365-1625)多态性明显,HBsAg(+)/HBeAg(+)/HBcAb(+)模式PCR扩增产物条带数与HBsAg(+)/HBcAb(+)模式相比,差异显著(P(0.05)。结论:慢性HBV感染者不同血清学模式HBx基因存在多态性,其多态性主要表现在HBx基因单链区。