乙型肝炎病毒X基因对痉挛性截瘫蛋白21表达的影响

目的 探讨HBV X基因对痉挛性截瘫蛋白(SPG)21表达的影响.方法 采用RT-PCR和Western blot检测HepG2和HepG2.2.15细胞mRNA和蛋白表达的差异,将带有SPG21基因启动子的报告质粒pGL3-SPG21分别与表达HBV基因组的单个基因的质粒共转染HepG2细胞,测定荧光色素酶的活性,以相对光单元(RUL)表达;RT-PCR和Western blot分别检测SPG21 mRNA和蛋白表达的变化.组间比较采用t检验.结果 HepG2.2.15细胞中SPG21 mRNA和蛋白的表达水平明显高于HepG2细胞,相对表达量(与β-肌动蛋白的灰度比值)为0.36±0.06对比0.21±0.05,P＜0.05.转染pCMV-S、pCMV-E、pCMV-C、pCMV-X、pCMV-P和pCMV-ag2B后的HepG2细胞中,荧光素酶的活性分别为每微克蛋白(86±12)RUL、(75±12)RUL、(69±11)RUL、(875±27)RUL、(104±16)RUL和(67±12)RUL;与转染pCMV-tag2B组细胞相比,转染X基因者荧光素酶活性明显升高(P＜0.01).HBV X基因在mRNA和蛋白水平上调SPG21的表达,这种激活作用随着X基因浓度的增加而增强.结论 HBV X基因能特异性地激活SPG21的表达.     

拉米夫定抑制乙型肝炎病毒X基因的转录与表达

目的 乙型肝炎病毒(HBV)X蛋白在HBV相关性肝癌的发生中有着重要作用,本研究旨在探讨拉米夫定对HBV X基因复制、转录及表达水平的影响。 方法 用聚合酶链反应法检测拉米夫定对转染X基因复制的影响,用逆转录-聚合酶链反应法检测拉米夫定对转染X基因mRNA的影响,用生物分子相互作用系统检测拉米夫定对X蛋白表达的影响,探讨了拉米夫定作用的量效和时效关系。 结果 拉米夫定组与对照组HBV X基因复制的目的基因条带吸光度(A)值分别是151.4±3.5和144.0±11.4,差异无统计学意义。4.36×104mol/L拉米夫定持续作用24 h能完全抑制X基因的转录,对照组与治疗组(16 h)目的条带的A值分别为243.9±9.0和133.2±7.8,P<0.01,其抑制效应随药物浓度增加和作用时间延长而增强。4.36×104mol/L拉米夫定持续作用16 h,使代表X蛋白表达的最大结合量值从353.3±15.9降至252.3±18.8,P<0.01。结论 拉米夫定不影响HepG2x中转染的X基因复制,但对X基因的转录和蛋白表达有明显抑制作用。     

甲胎蛋白启动子介导反义乙型肝炎病毒X基因在肝癌细胞中的表达及其作用

目的 构建含甲胎蛋白(AFP)启动子和增强子的反义乙型肝炎病毒X基因(HBX)真核表达载体，研究其特异性和有效性，为开发肝癌细胞特异性HBX反义RNA基因治疗乙型肝炎病毒(HBV)奠定基础。方法 聚合酶链反应(PCR)扩增HBX(1370—1872nt)基因，克隆至EB病毒表达载体，双轮PCR筛选、鉴定基因插入方向。脂质体转染肝癌细胞和ECV304细胞，Northernblot检测HBX mRNA的表达，酶联免疫试验(ELISA)检测HBV抗原，荧光定量PCR检测HBV DNA。结果 成功构建正、反义RNA表达载体pEBAF—s—HBX、pEBAF—as—HBX。Northernblot证实反义RNA仅在AFP阳性的肝癌细胞中表达。pEBAF—as—HBX转染3d后，可显著抑制2．2．15细胞HBV复制和抗原表达，其HBsAg、HBeAg抗原表达较正义对照分别下降37．9％和36．8％，HBV DNA降低25％。结论 反义RNA表达载体pEBAF—as—HBX仅在肝癌细胞中特异表达、并可有效抑制HBV，有良好的开发应用前景。     

乙型肝炎病毒X基因促进肝癌组织血管内皮生长因子的表达

乙型肝炎病毒(HBV)感染与肝癌的发生密切相关，而乙型肝炎病毒X蛋白(HBx)在肝癌的发生和进展中起重要作用。血管内皮生长因子(VEGF)在肝癌细胞中普遍表达，与肝癌的生长和浸润有关。本研究通过建立表达HBx的肝癌动物模型，探讨HBx与肝癌组织VEGF表达的关系。     

乙型肝炎病毒X蛋白反式调节基因11剪切体的京核表达及蛋白纯化

目的克隆乙型肝炎病毒X蛋白反式调节基因11（XTP11）剪切体,构建其原核表达载体,表达并纯化该蛋白。方法应用逆转录聚合酶链反应及生物信息学技术从HepG2细胞中提取cDNA为模板并扩增,意外获得XTP11基因的剪切体基因,选用pGEM—T载体进行T—A克隆,通过限制性酶切分析及测序鉴定,再将其亚克隆到原核表达载体pET-32a（＋）中,转化BL21（DE3）宿主菌,经异丙基-B—D-硫代半乳糖苷（IPTG）诱导XTP11剪切体融合蛋白的表达,表达产物进行SDS—PAGE分析,考马斯亮蓝染色,以鼠Hisprobe单克隆抗体进行Western blot分析鉴定证实表达蛋白的特异性,并纯化蛋白。结果成功扩增出XTP11剪切体基因,构建了pET-32a（＋）XTP11剪切体原核表达载体,经IPTG诱导获得了大小约为69kD的重组蛋白。结论发现的HBV XTP11剪切体及其融合蛋白,为进一步研究其生物学功能奠定了基础。     

乙型肝炎病毒X基因的原核表达及血清抗HBx抗体的检测

目的 应用表达蛋白检测乙型肝炎患者血清抗-HBx抗体水平并探讨其临床意义。方法 通过PCR扩增获得HBVX基因，与原核表达载体Pet32a＋连接构建PET32a-HBX原核表达载体，转化E．coli BL21表达获得重组融合蛋白。经切胶透析纯化后，应用重组蛋白HBx建立检测血清中抗-HBx抗体的间接ELISA方法，分别检测正常人组、急性肝炎组、慢性肝炎组、肝硬化组和肝细胞癌组患者血清中的抗-HBx抗体。结果 获得具有免疫原性的HBx融合蛋白；ELISA检测表明，慢性肝炎组、肝硬化组和肝细胞癌组的抗-HBx抗体的水平均高于急性肝炎组，差异具有显著性；在三组之问，慢性肝炎组高于肝硬化组和肝细胞癌组，差异具有显著性，肝硬化组和肝细胞癌组的抗-HBx抗体水平无显著性差异。结论 HBV患者血清中抗-HBX抗体是乙型肝炎病毒感染的一种特异性抗体，是HBV感染的血清学指标之一，可以反映乙型肝炎肝炎患者病情的变化。     

乙型肝炎病毒preS1基因真核表达载体的构建及表达

目的：构建含preS1基因真核表达质粒，探讨乙型肝炎病毒preS1基因在HBV入胞机制中的作用。方法：PCR法扩增含EcoR I与Pst I酶切点的preS1基因序列，PAS2-1载体及preS1基因PCR产物双酶切，经T4DNA连接酶将两者连接并转化到大肠杆菌JM105，对重组质粒经序列测定，命名为PAS 2—1—preS1。经乙酸锂转化法将重组质粒转化入酵母茵AH109，Western Blot法证实重组质粒在酵母细胞中的表达。结果：已构建的质粒PAS2—1-preS1经序列测定合有完整的preS1基因片段，转入酵母后经Western Blot证实酵母细胞正确表达preS1-BD融合蛋白。结论：PAS2—1—preS1的构建为通过酵母双杂交体系筛选体内与preS1蛋白相互作用的preS1相关蛋白，为进一步深入探讨preS1在HBV致病机制中的作用奠定了基础。     

原发性肝细胞癌乙型肝炎病毒X抗原表达的分析

我们前已报道了抗ＨＢＶＸ抗原（ＨＢｘＡｇ）三种不同肽段的抗体检出肝癌细胞中ＨＢｘＡｇ的存在，我们用ＰＣＲ技术扩增肝癌组织中，ｘ基因，用重组ＨＢｘＡｇ及其抗体中的抗ＨＢｘ和ＨＢｘＡｇ并用免疫组织化学的方法分析肝组织中ＨＢｘＡｇ的表达及其分布，我们发现ＨＢｘＡｇ在肝癌肝组织中阳性率高达９２．６％，而且分布广泛，主要表达在细胞浆，但细胞核内亦有见到，癌旁组织检出率也很高，而在小胆管上皮细胞内亦见有ＨＢｘ     

乙型肝炎病毒X蛋白在不同肝细胞定位及表达的特性

目的探讨乙型肝炎病毒X蛋白(HBx)在肝细胞的分布特点及蛋白表达的规律。方法常规分子克隆技术构建HBx及其各种突变体的表达载体,Western blot验证HBx蛋白的表达;荧光共聚集扫描技术观察HBx蛋白在肝细胞中的分布特点;谷光甘肽S转移酶(GST)-Sepharose 4B亲和层析方法纯化GST-HBx融合蛋白。结果成功构建了全长HBx及其各种缺失突变体表达载体;HBx蛋白在肝细胞核内均匀分布,在细胞质内呈颗粒状聚集分布; 在优化蛋白表达及纯化条件下,突变体HBx(73～120 aa)的GST融合蛋白极易降解。结论为从蛋白水平探讨HBx 的生物学功能提供了有利的材料。     

中老年肝细胞癌患者乙型肝炎病毒X基因检测与分析

目的检测慢性乙型肝炎病毒(HBV)感染后肝细胞癌(HCC)患者血清HBVX基因,并与慢性乙型肝炎、肝硬化患者HBVX基因检出率对比分析。方法在微孔板上包被HBVX基因片段的捕获探针;PCR扩增被检标本中目的片段,其引物用Bio-Ⅱ-dUTP修饰,在微孔板上杂交后用链霉亲和素碱性磷酸酶系统显色。结果该方法检测HBVX基因灵敏,特异;乙型肝炎后HCC患者HBVX基因检出率明显高于慢性乙型肝炎组和肝硬化组。结论检测HBVX基因对HCC具有辅助诊断价值。     

乙型肝炎病毒核心质粒的构建及原核表达

目的构建乙型肝炎病毒核心区原核表达质粒并进行原核蛋白表达、纯化和鉴定。方法应用基因工程技术将编码截短型乙型肝炎病毒核心蛋白(HBcAg1～144aa)的基因片段装入原核表达载体pRSET-B内，在宿主菌B121(DE3)plysS内进行诱导表达，运用Ni—NTA方法纯化日的蛋白。采用酶联免疫吸附实验(ELISA)及Western blot检测蛋白的灵敏度和特异性。结果成功地构建了含截短型乙型肝炎病毒核心区基因的质粒，并纯化得到了分子量约为19．5kD的目的蛋白：结论本方法所获得的重组截短型乙型肝炎病毒核心抗原(1～144a)纯度高，免疫反应性强：     

重组人乙型肝炎病毒S基因表达的体内外评价

目的 构建能表达乙型肝炎病毒（HBV）S基因的DNA疫苗，并在离体与活体条件下评价重组S基因的表达。方法 将克隆的S-X基因片段插入真核细胞表达载体。获得重组质粒，在离体转录系统与转染细胞系中表达重组S基因。并在小鼠中评价HBsAg激发抗-HBs的效果。结果 S基因的表达已通过Northern印迹杂交，Western印迹杂交和ELISA（抗原及抗体检测）予以证实。结论 S基因已成功地实现体外重组与表达。     

HBx-GFP DN突变子长期稳定表达抑制2.2.15细胞乙型肝炎病毒基因的表达

目的　探索和寻找更有效的乙型肝炎治疗新的靶点和新的治疗方法 ,研究其抗病毒基因表达作用。方法　运用基因工程技术 ,建立了HBx GFP及其作对照的表达野生X蛋白、绿色荧光蛋白 (GFP)的长期稳定表达细胞克隆 ,Northernblot检测细胞内的乙型肝炎病毒相关基因RNA转录 ,应用RIA检测细胞上清液中HBsAg和HBeAg表达 ,观察对乙型肝炎病毒基因表达的影响。 结果所构建的X GFP突变子 ,Xwt,GFP质粒均能在 2 .2 .15细胞株中稳定高效表达并使细胞上清液中HBsAgHBeAg表达水平分别较 2 .2 .15组的 ( 10 1± 5.5)ng/ml、 ( 12 1± 8.6)ng/ml显著降低为平均( 7.6± 11.5)ng/ml、 ( 3 5± 3 .5)ng/ml (P <0 .0 1) ,细胞内的病毒 3 .5kb ,2 .1kb及 2 .4kb的RNA与各对照组比较均有显著降低 ,以 2 .1kb及 2 .4kb的mRNA下降最为显著。结论　乙型肝炎X基因DN突变子X GFP能显著抑制乙型肝炎病毒基因转录和S ,C基因的表达。提示 ,X基因亦是乙型肝炎治疗的一个靶基因     

Characterization of hepatitis B virus X gene quasispecies complexity in mono-infection and hepatitis delta virus superinfection

Hepatitis delta virus(HDV) seems to strongly suppress hepatitis B virus(HBV)replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, resulting in viral quasispecies. Next-generation sequencing is a viable approach for analyzing the composition of these mutant spectra. As the regulatory hepatitis B X protein(HBx) is essential for HBV replication, determination of HBV X gene(HBX)quasispecies complexity in HBV/HDV infection compared to HBV monoinfection may provide information on the interactions between these two viruses.AIM To compare HBV quasispecies complexity in the HBX 5' region between chronic hepatitis delta(CHD) and chronic HBV mono-infected patients.METHODS Twenty-four untreated patients were included: 7/24(29.2%) with HBeAgnegative chronic HBV infection(CI, previously termed inactive carriers), 8/24(33.3%) with HBeAg-negative chronic hepatitis B(CHB) and 9/24(37.5%) with CHD. A serum sample from each patient was first tested for HBV DNA levels.The HBX 5' region [nucleotides(nt) 1255-1611] was then PCR-amplified for subsequent next-generation sequencing(MiSeq, Illumina, United States). HBV quasispecies complexity in the region analyzed was evaluated using incidencebased indices(number of haplotypes and number of mutations), abundancebased indices(Hill numbers of order 1 and 2), and functional indices(mutation frequency and nucleotide diversity). We also evaluated the pattern of nucleotide changes to investigate which of them could be the cause of the quasispecies complexity.RESULTS CHB patients showed higher median HBV-DNA levels [5.4 logIU/mL,interquartile range(IQR) 3.5-7.9] than CHD(3.4 logIU/mL, IQR 3-7.6)(P = n.s.)or CI(3.2 logIU/mL, IQR 2.3-3.5)(P < 0.01) patients. The incidence and abundance indices indicated that HBV quasispecies complexity was significantly greater in CI than CHB. A similar trend was observed in CHD patients, although only Hill numbers of order 2 showed statistically significant differences(CHB2.81, IQR 1.11-4.57 vs CHD 8.87, 6.56-11.18, P = 0.038). There were no significant differences in the functional indices, but CI and CHD patients also showed a trend towards greater complexity than CHB. No differences were found for any HBV quasispecies complexity indices between CHD and CI patients. G-to-A and C-to-T nucleotide changes, characteristic of APOBEC3 G, were higher in CHD and CI than in CHB in genotype A haplotypes, but not in genotype D. The proportion of nt G-to-A vs A-to-G changes and C-to-T vs T-to-C changes in genotype A and D haplotypes in CHD patients showed no significant differences. In CHB and CI the results of these comparisons were dependent on HBV genotype.CONCLUSION The lower-replication CHD and CI groups show a trend to higher quasispecies complexity than the higher-replication CHB group. The mechanisms associated with this greater complexity require elucidation.     

乙型肝炎病毒前S2基因酵母表达载体的构建及表达

目的：探讨乙型肝炎病毒（HBV）前S2蛋白的功能。方法：以质粒pCP10 (含有HBV ayw亚型全长序列)为模板，多聚酶链反应（PCR）扩增HBV前S2基因，克隆到pGEM-T载休整 ，测序鉴定、酶切后回收，与酵母表达质粒pGBKT7连接。将重组载体转化酵母细胞AH109，提取酵母蛋白质，进行十二烷基磺酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）和Western免疫印迹分析。结果：成功构建HBV前S2基因酵母表达载体，Western免疫印迹显示HBV前S2蛋白在酵母细胞中表达，表达产物在胞内存在，分子量24kD左右。结论：HBV前S2蛋白在酵母细胞中表达成功。     

Biological impact of hepatitis B virus X-hepatitis C virus core fusion gene on

AIM: To investigate the biological impact of hepatitis B virus X- hepatitis C virus core (HBV X-HCV C) fusion gene on hepatoma cells.METHODS: The recombinant adenoviruses AdXC,Ad-X and Ad-C expressing HBV X-HCV C fusion gene,HBVX gene and HCV C gene were constructed,respectively.Hepatoma cells were infected with different recombinant adenoviruses.MTT,colonyforming experiment,FCM,TUNEL assay were performed to observe the biological impact of the HBV X-HCV C fusion gene on liver cells.RESULTS: MTT showed that the Ad-XC group cells grew faster than the other group cells.Colony-forming experiment showed that the colony-forming rate for the Ad-XC group cells was significantly higher than that for the other group cells.FCM analysis showed that Ad-XC/Ad-X/Ad-C infection enhanced the progression of GIS phase in the HepG2 cell cycle.The apoptosis index of the Ad-XC,Ad-X,Ad-C group cells was significantly lower than that of the AdO and control group cells.Semi-quantitative RT-PCR showed that the expression level of c-myc was the highest in AdXC infected cells.Tumor formation was found at the injected site of mice inoculated with Ad-XC-infected LO2 cells,but not in control mice.CONCLUSION: Ad-XC,Ad-X and Ad-C facilitate the proliferation activity of HepG2 cells and inhibit their apoptosis in vitro.The effect of Ad-XC is significantly stronger than that of Ad-X and Ad-C.Up-regulation of c-myc may be one of the mechanisms underlying the synergism of HBVX and HCV C genes on hepatocarcinogenesis in athymic nude mice.     

Construction of a replication-competent hepatitis B virus vector carrying secreted luciferase transgene and establishment of new hepatitis B virus replication and expression cell lines

BACKGROUND Previously, we have successfully constructed replication-competent hepatitis B virus(HBV) vectors by uncoupling the P open reading frame(ORF) from the preC/C ORF to carefully design the transgene insertion site to overcome the compact organization of the HBV genome and maintain HBV replication competence. Consequently, the replication-competent HBV vectors carrying foreign genes, including pCH-BsdR, carrying blasticidin resistance gene(399 bp),and pCH-hrGFP, carrying humanized renilla green fluorescent protein gene(720 bp), were successfully obtained. However, the replication efficiency of the former is higher but it is tedious to use, while that of the latter is poor and cannot be quantified. Hence, we need to search for a new reporter gene that is convenient and quantifiable for further research.AIM To establish a helpful tool for intracellular HBV replication and anti-viral drugs screening studies.METHODS We utilized the replication-competent HBV viral vectors constructed by our laboratory, combined with the secreted luciferase reporter gene, to construct replication-competent HBV vectors expressing the reporter gene secretory Nanoluc Luciferase(SecNluc). HepG2.TA2-7 cells were transfected with this vector to obtain cell lines with stably secreted HBV particles carrying sec Nluc reporter gene.RESULTS The replication-competent HBV vector carrying the SecNluc reporter gene p CHs NLuc could produce all major viral RNAs and a full set of envelope proteins and achieve high-level secreted luciferase expression. HBV replication intermediates could be produced from this vector. Via transfection with pTRE-sNLuc and selection by hygromycin, we obtained isolated cell clones, named HBV-NLuc-35 cells, which could secrete sec NLuc recombinant viruses, and were sensitive to existing anti-HBV drugs. Using differentiated Hepa RG cells, it was verified that recombinant HBV possessed infectivity.CONCLUSION Our research demonstrated that a replication-competent HBV vector carrying a secreted luciferase transgene possesses replication and expression ability, and the established HBV replication and expression cell lines could stably secrete viral particles carrying sec Nluc reporter gene. More importantly, the cell line and the secreted recombinant viral particles could be used to trace HBV replication or infection.     

Possible mechanism for hepatitis B virus X gene to induce apoptosis of hepatocytes

AIM: To investigate the possible mechanism for HBV X gene to induce apoptosis of hepatocyte HL-7702 cells. METHODS: HBV X gene eukaryon expression vector pcDNA3-X was established and transfected into HL-7702 cells by Iipid-mediated transfection, including transient and stable transfection. Positive clones were screened by incubating in the selective medium with 600 μg/mL G418 and named HL-7702/HBV-encoded X protein (HBx) cells. The expressions of Fas/FasL, Bax/Bcl-2, and c-myc mRNA were measured by semi-quantitative RT-PCR in HL-7702/HBx and control group, respectively. RESULTS: RT-PCR analysis confirmed that HBV X gene was transfected into HL-7702 cells successfully. By semi-quantitative RT-PCR analysis, Bax and c-myc mRNA levels in HL-7702/HBx cells of transient transfection were significantly higher than those in control, FasL and c-myc mRNA levels in HL-7702/HBx cells of stable transfection were significantly higher than those in control, whereas the Bcl-2 mRNA levels in HL-7702/HBx cells of transient and stable transfection were significantly lower than those in control. CONCLUSION: HBV X gene may promote the apoptosis of hepatocytes by regulating the expressions of Fas/FasL, Bax/Bcl-2, and c-myc gene in a dose-dependent manner.     

pRevX-GFP DN突变体抑制HepG2 2.2.15细胞乙型肝炎病毒复制的实验研究

目的 建立pRev X-GFP及其作对照的表达野生X蛋白、绿色荧光蛋白的长期稳定表达细胞克隆，进一步研究以乙型肝炎病毒(HBV)X基因作为治疗靶，运用DN突变体技术，进行抗HBV的稳定表达对抗HBV复制的作用。方法 运用基因工程技术，分别以逆转录病毒载体pRev TRE为载体，构建表达野生型HBV X蛋白，GFP蛋白和X与GFP融合的X-GFP融合蛋白的质粒，并分别导入乙型肝炎的转基因细胞株HepG2 2．2．15细胞(简称2．2．15细胞)中，并通过长期的潮霉素抗性选择，获得能稳定表达DN蛋白的2．2．15细胞克隆。应用dot blot检测细胞上清液及细胞中HBV DNA，Southern blot检测细胞内HBV复制中间体，以观察其表达对HBV病毒复制的影响。结果 所构建的pRev X-GFP突变体、pRev Xwt、pRev GFP质粒均能在2．2．15细胞株中稳定高效表达。PRev X-GFP高效表达后，能有效地抑制或阻断细胞内HBV核酸合成及其分泌入细胞上清液。定量聚合酶链反应结果显示，pRev X-GFP组的平均每毫升HBV DNA浓度较2．2．15细胞组分别下降1．0～1．81g值，对细胞内外dot blot结果进行图像分析，其灰度值仪为对照2．2．15细胞组的7．9％，Southern blot分析则发现，X基因DN突变体对HBV复制中间体rcDNA、ssDNA及dsDNA的形成有全面抑制作用。结论 pRev X-GFP DN突变体具有显著抑制HBV复制作用。初步证实X基因是HBV治疗的一个新靶点。针对X基因的治疗，有望为HBV治疗提供一些新的思路。