慢性乙型肝炎病毒感染树鼩Kupffer细胞TLR2和TLR4的表达及其意义

目的探索慢性乙型肝炎病毒(HBV)感染树鼩Kupffer细胞Toll样受体(TLR)家族中的TLR2和TLR4在mRNA水平的表达情况及其对Kupffer细胞功能的影响。方法树鼩分为确定慢性感染HBV的树鼩、疑似慢性感染HBV的树鼩和未接种HBV的正常对照树鼩。全部动物定期抽血和进行肝活检手术,采用实时荧光定量PCR(qRT-PCR)分析血清和肝组织的HBV DNA水平;对手术切取的树鼩肝组织进行Kupffer细胞的分离、纯化和原代培养,采用qRT-PCR检测TLR2、TLR4以及TNF-α的mRNA表达水平;采用迁移实验及溶酶体荧光探针等方法分析TLR2和TLR4对Kupffer细胞迁移能力及溶酶体数量的影响。结果确定慢性感染HBV的树鼩TLR2 mRNA和TLR4 mRNA表达水平均低于疑似慢性感染HBV的树鼩和未接种HBV的正常对照树鼩(P0.05),表达水平均与动物肝组织的HBV DNA拷贝数呈负相关(P0.05),与Kupffer细胞的细胞迁移数、溶酶体密度及TNF-αmRNA表达水平呈正相关(P0.05)。结论 Kupffer细胞中的TLR2和TLR4可能通过影响Kupffer细胞功能而参与树鼩HBV感染后肝脏病变的慢性化发展过程。     

树鼩、熊猴感染人乙型肝炎病毒肝细胞内感染指征的研究

目的 对树鼩、熊猴感染人乙型肝炎病毒(HHBV)后对肝细胞病变进行动态观察。方法 10只成年树鼩，28只熊猴接种含人乙型肝炎病毒(HBV)血清后，定期肝活检，采用HE染色、免疫组化、原位杂交对实验动物肝组织进行研究分析。结果 80％树鼩感染HHBV后，通过免疫组化在肝组织内可找到乙型肝炎病毒表面抗原(HBsAg)，50％通过原位杂交可检测到HBV DNA。有25％熊猴的肝组织内可检测到HBsAg，但信号较弱，而肝组织内未发现HBV DNA。结论 树鼩感染HHBV后，肝细胞内出现病理改变，适用于对人乙型肝炎的研有．     

HBV体外感染卵巢颗粒细胞

目的建立HBV体外感染颗粒细胞模型,研究HBV在颗粒细胞中的复制情况,为深入研究HBV经卵细胞母婴垂直传播提供研究平台。方法原代颗粒细胞体外培养后用HBV阳性血清感染。收集培养上清,在不同时点检测HBsAg、HBeAg定量,实时定量PCR检测HBVDNA。免疫组化检测培养细胞中的HBsAg和HBcAg。巢式PCR检测细胞中的HBVDNA及HBV-mRNA。原位杂交检测细胞内的HBVDNA。结果成功建立了HBV体外感染颗粒细胞模型,在培养上清中可以持续96h检测到HBsAg和HBV DNA,在细胞内检测到HBsAg和HBcAg的阳性信号,PCR扩增显示细胞内有HBVD-NA及HBV-mRNA的存在,原位杂交证实细胞内HBVDNA阳性。结论 HBV能够在体外感染颗粒细胞,并在其内复制,该结果为深入研究HBV经卵细胞传播机制提供了很好的研究平台。     

丙型肝炎病毒体外感染原代人胎肝细胞的研究

目的　研究丙型肝炎病毒 (HCV)体外细胞培养方法。方法　原代人胎肝细胞与HCV感染血清共孵育后 ,用逆转录 聚合酶链反应、原位杂交、免疫组化分别检测细胞和培养上清中的HCVRNA和HCV抗原表达。结果　从感染血清和细胞共同孵育后的 2～ 2 5d ,细胞内和 /或培养上清中可间断检出HCV正、负链RNA ;HCVNS3抗原在细胞内能稳定表达 ;原位杂交显示HCV负链RNA阳性物质多位于细胞浆。结论　原代人胎肝细胞对HCV易感 ,可用作HCV体外感染和复制的靶细胞     

MXA蛋白抑制HBV复制的体外研究

目的研究MXA蛋白抑制HBV复制的活性。方法将pcDNA3．1-MXA重组质粒和PU19-1．24HBV重组质粒分别按1：1、2：1共转染HepG2细胞（MXA组），对照组使用空pcDNA3．1、Salon DNA和PU19-1．24HBV重组质粒共转染，3d后Western blot检测MXA蛋白表达，Abbott法检测细胞上清HBeAg和HBsAg分泌量，定量PCR检测上清和胞内HBV DNA水平，统计学分析结果。pcDNA3．1-MXA与PU19-1．24HBV重组质粒共转染HepG2细胞，对照组为pcDNA3．1-MXA重组质粒、PU19空质粒和Salon DNA共转染．3d后裂解细胞Western blot检测MXA蛋白表达。结果Western blot显示MXA组有MXA蛋白表达：与对照组相比，pcDNA3．1-MXA和PU19—1．24HBV重组质粒按1：1转染时，MXA组HBeAg下降27％．上清HBV DNA和细胞内HBV DNA分别下降1个log值和0．6个log值；按2：1比例转染时MXA组HBeAg较对照组下降66％，上清HBV DNA和细胞内HBV DNA水平分别下降1．9个和1．7个log值，差异均具有统计学意义（P〈0．05）。Western blot检测显示MXA蛋白抑制HBV组与对照组MXA蛋白表达没有明显差别。结论MXA蛋白在HepG2细胞具有抑制HBV复制活性，抑制活性与蛋白的表达量相关；在抑制HBV复制过程中MXA蛋白自身可能不发生降解。     

HBV adr亚型体外感染肝细胞模型的建立

目的:构建1.1倍乙型肝炎病毒(HBV)全基因的真核表达载体,稳定转染L-02细胞,建立HBVadr亚型体外感染的细胞模型。方法:以pVUⅡ酶切质粒p3.6Ⅱ获得1.1倍HBV DNA片段,用牛小肠碱性磷酸酶将经EcoRV线性化的pcDNA3去磷酸化,以T4DNA连接酶连接1.1倍HBV DNA片段和线性化的pcDNA3,将构建的pcDNA3-1.1HBV以脂质体转染L-02肝癌细胞,经G418稳定筛选。ELISA检测转染细胞培养上清中HB-sAg、HBeAg的表达。RT-PCR检测转染细胞中HBpreS2、HBX的表达。结果:成功构建了1.1倍HBV全基因真核表达载体,稳定转染L-02后,建立了新的肝细胞系L-02.1Z,其培养上清中可检测到HBsAg、HBeAg的稳定表达,并可检测到HBpreS2、HBX RNA在转染细胞中表达。结论:该表达载体可介导病毒复制,其稳定转染的细胞可作为一种新型的HBV体外感染模型。     

MiR-340-5p调控乙型肝炎病毒复制的机制

目的阐释miR-340-5p对HBV复制的影响及其调控机制, 并为HBV感染后的生物标志物和治疗用药提供新的策略。方法在肝癌细胞HepG2.2.15中转染miR-340-5p的模拟物(340-mimic)和抑制剂(340-inhibitor)及其对应的阴性对照。通过ELISA检测上清中HBeAg和HBsAg的水平变化。同时收取细胞, 提取RNA和壳体化DNA, 并采用qRT-PCR分别检测HBV总RNA和pgRNA的水平及HBV DNA拷贝数的变化;分子克隆构建STAT3的过表达质粒pEF-flag-stat3, 通过qRT-PCR和western blot对STAT3的mRNA和蛋白表达加以验证;此外, 共转染miR-340-5p的模拟物和pEF-flag-stat3后通过northern blot, qPCR和ELISA对HBV的复制情况进行检测。结果 miR-340-5p过表达后, HBV转录生成总RNA和逆转录模板pgRNA的水平明显下降至对照组的45.89%、61.46% (P=0.001、P=0.003);壳体化DNA的合成及HBeAg和HBsAg的分泌水平分别受到72.4...     

丙型肝炎病毒阳性血清体外感染人肝细胞的研究

目的 研究丙型肝炎病毒(HCV)抗体(Ab)阴性,HCV-RNA阳性血清建立体外感染肝细胞模型.方法 HCV Ab阴性,HCV-RNA阳性的窗口期血清与人肝细胞共同培养,用反转录-聚合酶链反应(RT-PCR)、免疫荧光染色、Western blot、共聚焦显微镜和透射电镜等方法检测细胞内HCV核酸复制、蛋白质表达及超微结构改变.结果 细胞与病毒共同培养7～45 d,细胞内和/或培养上清中可间断检出HCV正、负链RNA;细胞浆内有HCV 核心和NS3抗原的表达;细胞超微结构有改变,并于感染后第24天时观察到类似病毒样颗粒.结论 窗口期血清中的HCV能在人肝细胞7701中复制一段时间.     

HBV感染人胎盘滋养层细胞机制的初步探讨

目的 采用透射电镜观察HBV体外感染人胎盘滋养层细胞的超微结构变化.方法 HBV体外感染人胎盘滋养层细胞.ELISA检测培养上清中HBsAg,PCR检测细胞培养上清和滋养层细胞中的HBV DNA.HBV荧光定量PCR检测细胞培养上清中HBV DNA量(拷贝/ml).透射电镜观察滋养层细胞的超微结构.结果 感染组滋养层细胞培养上清中HBsAg在PBS清洗后12 h时A值为0.942,96 h时上升为1.264.PCR检测感染组细胞培养上清和感染组细胞HBV DNA均为阳性.PBS彻底清洗后0、12、36、60、84 h感染组细胞培养上清的HBV DNA分别为:＜103,3×104,6×105,5×105,3×105拷贝/ml.透射电镜观察到感染组滋养层细胞膜附近存在包涵素(Clathrin)形式的内吞小体形成,并且发现内吞小体内存在病毒颗粒样结构.在感染组细胞粗面内质网内发现HBsAg特异性的纤维丝状结构.结论 HBV可能经包涵素依赖的细胞内吞形式进入滋养层细胞,进而实现感染细胞或通过胞释作用将病毒排至细胞的对侧而实现穿越滋养层细胞屏障.     

树鼩慢性感染乙肝病毒过程中枯否细胞变化的意义*

 目的：探索枯否细胞在树鼩感染乙肝病毒（HBV）慢性化过程中的意义。方法：树鼩分为3组：A组6只,为前期实验已确定慢性感染HBV的树鼩;B组3只,为疑似慢性感染HBV的树鼩;C组4只,为未接种HBV的正常对照树鼩。全部动物定期抽血和进行肝活检手术;对手术切取的树鼩肝组织进行枯否细胞的分离、纯化和原代培养,采用流式细胞术、细胞免疫组化、溶酶体荧光探针及实时荧光定量RT-PCR等方法检测CD163+细胞数量、溶酶体数量、溶菌酶的表达及肿瘤坏死因子α（TNF-α） mRNA表达水平。结果：（1）慢性感染HBV的树鼩肝脏枯否细胞比例及肝组织内CD163+细胞数量显著高于其它2组（均P<0.05）;（2）慢性感染HBV的树鼩肝脏枯否细胞的溶酶体荧光强度、肝组织内溶菌酶阳性细胞计数和TNF-α mRNA的表达水平均显著低于其它2组（均P<0.05）。结论：枯否细胞在宿主感染HBV的慢性化过程中可能起一定的调节作用。     

成年树鼩实验感染丁型肝炎病毒的初步研究

在证实成年树可感染人乙型肝炎病毒（ＨＢＶ）的基础上，进行了丁型肝炎病毒－乙型肝炎病毒（ＨＤＶ／ＨＢＶ）实验感染的探索。ＨＤＶ／ＨＢＶ阳性人血清经同时和重叠感染方式接种于成年树后，定期留取感染树血清及肝组织，检测血清中ＨＢｓＡｇ、ＨＤＡｇ、抗－ＨＤ、ＨＢＶＤＮＡ及ＨＤＶＲＮＡ，初步探讨成年树实验感染ＨＤＶ的可能性。研究发现：①成年树对人ＨＢＶ易感，ＨＢｓＡｇ阳性率为７５％，其血清学反应及肝组织病理改变与文献报道一致；②ＨＤＶ可通过同时和重叠两种方式感染成年树，感染树血清中可出现ＨＤＡｇ及抗－ＨＤ，经分子杂交证实其血清及肝内均有ＨＤＶＲＮＡ和ＨＢＶＤＮＡ存在，且可导致明显的肝细胞损伤。结果提示：成年树既可感染人ＨＢＶ也可感染ＨＤＶ，可作为研究ＨＤＶ人工感染的实验动物；成年树感染ＨＤＶ后的特点与人及黑猩猩感染时十分相似，能较好地反映人丁型肝炎的真实情况。     

Replication of hepatitis B virus in culture systems with adult human hepatocytes

We developed a technique for isolation and primary culture of adult human hepatocytes from surgical liver biopsy specimens by in situ perfusion and a shaking method. Cultured hepatocytes were maintained in monolayers for more than three weeks and showed morphological and functional characteristics in vivo. The cultured human hepatocytes were inoculated with hepatitis B virus (HBV). Hepatitis B surface antigen (HBsAg) in the medium was detected for about three weeks after inoculation, which was longer than that reported in previous studies. In one case of high attachment efficiency, hepatitis B e antigen (HBeAg) was detected in the medium five to eight days after inoculation. HBsAg and HBeAg were also detected in the extracts of inoculated human hepatocytes. Immunofluorescence study revealed HBsAg in 20-30% of hepatocytes and hepatitis B core antigen (HBcAg) in 2-3% of the cultured human hepatocytes four days after inoculation. Free HBV DNA was identified in the human hepatocytes for at least two weeks after inoculation, although single-stranded HBV DNA was not detected. These studies suggest that HBsAg was actively produced and that HBV replicated in a small number of inoculated adult human hepatocytes in primary culture. However, further improvement of culture systems is needed for active replication of HBV in vitro.     

Detection of HBV-DNA by in situ hybridization using a biotin-labeled probe

A biotin-labeled DNA probe specific for hepatitis B virus (HBV) nucleotide sequences was hybridized in situ to liver tissue of 20 patients; 16 were chronic carriers of hepatitis B surface antigen (HBsAg) and 4 had no markers of HBV infection. HBV-DNA was also analyzed in the serum and the liver of these patients by spot and Southern blot hybridization, respectively. Liver specimens from six carriers were positive for HBV-DNA both by in situ and Southern blot hybridization; ten carriers were negative by in situ hybridization, and two of these were positive by Southern blot technique. The staining was granular, mainly cytoplasmic, limited to liver specimens containing replicative forms of HBV-DNA, and associated with detection of HBcAg in hepatocytes by immunofluorescence. The sensitivity of this technique was not sufficient to detect few copies of integrated HBV-DNA. The hybridization procedure was specific, as results were constantly negative in liver specimens of patients without markers of HBV infection, and no reaction was observed using DNA probes lacking HBV-DNA sequences. Detection of HBV-DNA by in situ hybridization, using a biotinylated probe, is a rapid, reproducible, and specific histochemical method. Currently available biotinylated probes are advantageous when absolute sensitivity is not the limiting factor, and they also facilitate studies of the cellular and subcellular distribution of HBV nucleic acids.     

Distribution of hepatitis B virus in the liver of chronic hepatitis C patients with occult hepatitis B virus infection

Although occult hepatitis B virus (HBV) infection (HBV-DNA in serum in the absence of hepatitis B surface antigen [HBsAg]) is common in chronic hepatitis C, its characteristics are not well known. In this work, the presence of HBV-DNA (by polymerase chain reaction; PCR) and its distribution (by in situ hybridization) in liver biopsies and peripheral blood mononuclear cells (PBMCs) from 32 patients with chronic hepatitis C and occult HBV infection and in 20 HBsAg chronic carriers were determined. The results showed that serum HBV-DNA levels were statistically lower (P = 0.001) in patients with occult HBV infection than in HBsAg chronic carriers. The HBV infection pattern in liver cells was identical between patients with occult HBV infection and those with chronic hepatitis B. However, the mean percentage of HBV-infected hepatocytes was significantly lower (P = 0.001) in patients with occult HBV infection (5 +/- 4.44%) than in HBsAg chronic carriers (17.99 +/- 11.58%). All patients with chronic hepatitis B have HBV-DNA in their PBMCs while this occurred in 50% of the cases with occult HBV infection. In conclusion, patients with occult HBV infection have a low number of HBV-infected hepatocytes and this fact could explain the lack of HBsAg detection and low viremia levels found in these cases.     

Different expression of hepatitis B surface antigen between hepatocellular carcinoma and its surrounding liver tissue,studied using a tissue microarray

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and is highly associated with chronic liver disease, including hepatitis B viral infection. In order to study the association between hepatitis B virus (HBV) infection and HCC development, tissue microarrays were used to detect the expression of hepatitis B surface antigen (HBsAg) in 194 HCCs and their surrounding liver tissues, using anti-HBsAg monoclonal antibody. The results showed that the expression of HBsAg is significantly lower in tumour tissue than in non-tumour tissue. Among the 138 cases with positive serum HBsAg, expression of HBsAg was more frequently detected in non-tumour tissue (103 cases, 75%) than in tumour tissue (11 cases, 8%). RT-PCR and Southern blot analysis were performed to explore the mechanism of the decreased expression of HBsAg in tumour cells. The RT-PCR results showed that absence or decreased expression of the HBV S gene was detected in 3/15 (20%) and 6/15 (40%) HCCs, respectively. Integration of HBV in 23 pairs of HCCs and their matched non-tumour liver tissues was studied by Southern blot. The results showed that the integrated HBV S gene sequence was detected in 19/23 tumours (83%) and 1/23 non-tumour tissues (4%), whereas the free replicative virus form was observed in 3/23 tumours (13%) and 14/23 non-tumour tissues (61%). These findings suggest that HBsAg-negative results in tumour tissues were directly related to HBV DNA insertion and provide new insights into the involvement of HBsAg in hepatocarcinogenesis.     

Hepatitis B virus (HBV) infections in turtles

Thirty turtles (15 Clemys mutica and 15 Geoclemys reevesii) which were inoculated with human sera those were positive for hepatitis B surface antigen (HBsAg) and hepatitis B "e" antigen (HBeAg) were found to be infected with hepatitis B virus (HBV). The levels of HBV infection markers, such as HBsAg and antibody to HBsAg (anti-HBsAg), were retinely monitored in the turtles' serum for 46 weeks. Within two weeks of the inoculation, 42% of the turtles tested were positive for HBsAg, and their reciprocal titers as measured by reverse passive hemagglutination (RPHA) and enzyme linked immunoabsorbance assay (ELISA) ranged from 16 to 96. Within 20 weeks, the remaining turtles tested HBsAg positive, as confirmed by ELISA. At 20 weeks, all but one of the turtles exhibited changes in HBV blood marker from HBsAg to anti-HBs; the one exception was positive for both HBsAg and anti-HBs. At the 47th week, 7 animals were killed and their organs were examined for HBV infected cells utilizing an immunofluorescent technique. Numerous fluorescent cells which reacted with human anti-HBs nad anti-HBc were observed in the following organs: pancreas, liver, kidney, and brain. Histopathologically, edematous changes in hepatocytes and minor cellular infiltration attributed to an inflammatory response were noted. Liver and kidney cells from the infected animals were cultured, and HBV antigen positive cells for HBsAg and HBcAg were detected in the cultures. Throughout the experiment, HBsAg was detected in the supernatant by ELISA. Virus particles which were indistinguishable from Dane particles were seen in the cytoplasmic vacuoles of the cultured cells by electron microscopy. Finally, the presence of HBV DNA was established by molecular hybridization techniques in the culture supernatants of kidney cells from the infected turtles.     

霉酚酸对HepG2.2.15细胞中乙型肝炎病毒复制的影响

目的:探讨霉酚酸（MPA）在体外对乙型肝炎病毒(HBV)复制的影响。 方法:将不同浓度的MPA（1-20 mg/L）作用于HepG2.2.15细胞，在外加或不加鸟嘌呤核苷（简称鸟苷）的情况下，分别收集第4 d细胞培养上清，采用酶联免疫吸附试验（ELISA）检测上清中乙型肝炎病毒表面抗原（HBsAg）和e抗原（HBeAg），采用逆转录多聚酶链反应（RT-PCR）检测细胞内乙型肝炎病毒核心蛋白mRNA（HBV core mRNA）,狭缝印迹杂交法定量分析细胞内 HBV DNA。 结果:在不外加鸟苷情况下，MPA对HBV复制具有抑制作用，随着浓度增加，对HBsAg和HBeAg的抑制率逐渐上升，细胞内HBV DNA复制水平下降。外加鸟苷后能逆转MPA对HBV复制的抑制作用。 结论:MPA对HepG2.2.15细胞HBsAg和HBeAg的分泌及HBV DNA复制具有抑制作用。MPA可能通过减少细胞内鸟苷酸的合成来实现对HBV复制的抑制。     

In vitro infection of primary cultures of cryopreserved adult human hepatocytes with hepatitis B virus

Infection with HBeAg and HBV DNA positive serum in primary cultures of cryopreserved human hepatocytes in the presence of human whole blood in the medium was performed in 8 consecutive experiments. HBsAg and HBV DNA release into the medium was increased in the second week after infection. Via immunostaining, HBcAg was first observed in the nucleus of hepatocytes approximately 3 days after infection. A maximal percentage of HBcAg positive cells in 0.1% of cultured hepatocytes was detected on the 7th day. HBsAg was also first demonstrated on the 3rd day, and predominantly localized in the cytoplasm. About 5% of hepatocytes were HBsAg positive on the 12th day after infection. The percentage of positive cells did not appear to increase after this time. Using in situ cytohybridization and agarose gel electrophoresis and Southern blot analysis, HBV DNA was first detected on the 4th day. In addition, electron microscopic studies revealed the presence of 42 nm virus-like particles in the cytoplasm of infected cells in the second week after infection. This in vitro system provides a model for studying the mechanism of HBV infection, viral replication and maturation. However, further improvement of culture systems is needed, to increase the number of infected cells and for active HBV replication.