Combination of small interfering RNA and lamivudine on inhibition of human B virus replication in HepG2.2.15 cells

AIM: To observe the inhibition of hepatitis B virus (HBV) replication and expression by combination of siRNA and lamivudine in HepG2.2.15 cells. METHODS: Recombinant plasmid psil-HBV was constructed and transfected into HepG2.2.15 cells. The transfected cells were cultured in lamivudine-containing medium (0.05 μmol/L) and harvested at 48, 72 and 96 h. The concentration of HBeAg and HBsAg was determined using ELISA. HBV DNA replication was examined by real- time PCR and the level of HBV mRNA was measured by RT-PCR. RESULTS: In HepG2.2.15 cells treated with combination of siRNA and lamivudine, the secretion of HBeAg and HBsAg into the supernatant was found to be inhibited by 91.80% and 82.40% (2.89 ± 0.48 vs 11.73 ± 0.38, P < 0.05; 4.59 ± 0.57 vs 16.25 ± 0.48, P < 0.05) at 96 h, respectively; the number of HBV DNA copies within culture medium was also significantly decreased at 96 h (1.04 ± 0.26 vs 8.35 ± 0.33, P < 0.05). Moreover, mRNA concentration in HepG2.2.15 cells treated with combination of siRNA and lamivudine was obviously lower compared to those treated either with siRNA or lamivudine (19.44 ± 0.17 vs 33.27 ± 0.21 or 79.9 ± 0.13, P < 0.05). CONCLUSION: Combination of siRNA and lamivudine is more effective in inhibiting HBV replication as compared to the single use of siRNA or lamivudine in HepG2.2.15 cells.     

Replication of clinical hepatitis B virus isolate and its application for selecting antiviral agents for chronic hepatitis B patients

AIM： To establish a cell model harboring replicative clinical hepatitis B virus （HBV） isolates and evaluate its application in individualized selection of anti-HBV agents for chronic hepatitis B （CHB） patients.
METHODS： The full-length HBV genomic DNA from 8 CHB patients was amplified by polymerase chain reaction （PCR）. All the patients were treated with lamivudine for at least seven months and finally became resistant to lamivudine. The amplified HBV DNA fragments were inserted into pHY106 vectors by Sap Ⅰ digestion. The recombinant plasmids containing 1.1 copies of HBV genome were transiently transfected into Huh7 cell line, and the levels of HBsAg, HBeAg and intercellular HBV replicative intermediates were determined by ELISA and Southern blot analysis, respectively, with or without lamivudine and adefovir treatment. The antiviral treatment with adefovir was administered to the patients and analyzed in parallel.
RESULTS： A total of 25 independent HBV isolates were obtained from the sera of 8 patients, each patient had at least two isolates. One isolate from each individual was selected and subcloned into pHY106 vector, including 5 isolates with YVDD mutation and 3 isolates with YIDD mutation. All recombinant plasmids harboring HBV isolates were transfected into Huh7 cells. The results indicated that HBV genome carried in HBV replicons of clinical HBV isolates could effectively replicate and express in Huh7 cells. Adefovir, but not lamivudine, inhibited HBV replication both in vitro and in vivo, and in vitro inhibition was dose-dependent.
CONCLUSION： The novel method described herein enables individualized selection of anti-HBV agents in clinic and is useful in future studies of antiviral therapy for CHB.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

Inhibition of hepatitis B virus by a novel L-nucleoside, β-L-D4A and related analogues

AIM: To explore the inhibition of β-L-D4A on hepatitis B virus (HBV) in 2.2.15 cells derived from HepG2 cells transfected with HBV genome.METHODS: 2.2.15 cells were plated at a density of 5&#215;10^4 per well in 12-well tissue culture plates, and treated with various concentrations of β-L-D4A for 6 days. In the end,5μl of medium was used for the estimation of HBsAg and HBeAg, the other medium was processed to obtain virions by a polyethlene glycol precipitation method. At the same time, intracellular DNA was also extracted and digested with HindⅢ. Both DNAs were subjected to Southern blot,hybridized with a ^32P-labeled HBV probe and autoradiophed.Intensity of the autoradiographic bands was quantitated by densitometric scans of computer and ED50 was calculated. Then Hybond-N membrane was washed and rehybridized with a ^32P-labeled mtDNA-specific probe, and effect of β-L-D4A on mitochondrial DNA was studied. 2.2.15 cells were also seeded in 24-well tissue culture plates,and cytotoxicity with different concentrations was examined by MTT method. ID50 was calculated. Structure-activity relationships between D2A and D4A were also studied as above.RESULTS: Autoradiographic bands were similar between supernatant and intracellular HBV DNA. Episomal HBV DNAwas inhibited in a dose-dependent manner. ED50 was 0.2μM. HBsAg or HBeAg was not apparently decreased, and inhibition of mitochondrial DNA was not obvious. The experiment of cytotoxicity gained ID50 at 200 μM.CONCLUSION: β-L-D4A possesses potent inhibitory effects on the replication of HBV in vitro with little cytotoxidty and mitochondrial toxicity, TI value is 1000. It is expected to be developed as a new clinically anti-HBV drug.     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

Inhibition of hepatitis B virus gene expression and replication by artificial microRNA

AIM： To investigate the inhibitory effects of hepatitis B virus （HBV） replication and expression by transfecting artificial microRNA （amiRNA） into HepG2.2.15 cells. METHODS： Three amiRNA-HBV plasmids were constructed and transfected into HepG2.2.15 cells. HBV antigen secretion was detected in the cells with transient and stable transfection by time-resolved fluoroimmunoassays （TRFIA）. HBV DNA replication was examined by ？ uorescence quantitative PCR, and the level of HBV S mRNA was measured by semi- quantitative RT-PCR. RESULTS： The efficiency of transient transfection of the vectors into 2.2.15 cells was 55%-60%. All the vectors had significant inhibition effects on HBsAg and HBeAg at 72 h and 96 h after transfection （P 〈 0.01 for all）. The secretion of HBsAg and HBeAg into the supernatant was inhibited by 49.8% ± 4.7% and 39.9% ± 6.7%, respectively, at 72 h in amiRNA- HBV-S608 plasmid transfection group. The copy of HBV DNA within culture supernatant was also significantly decreased at 72 h and 96 h after transfection （P 〈0.01 for all）. In the cells with stable transfection, the secretion of HBsAg and HBeAg into the supernatant was significantly inhibited in all three transfection groups （P 〈 0.01 for all, vs negative control）. The copies of HBV DNA were inhibited by 33.4% ± 3.0%, 60.8% ± 2.3% and 70.1% ± 3.3%, respectively. CONCLUSION： In HepG2.2.15 cells, HBV replication and expression could be inhibited by artif icial microRNA targeting the HBV S coding region. Vector-based artificial microRNA could be a promising therapeutic approach for chronic HBV infection.     

Lamivudine treatment of decompensated hepatitis B virus-related cirrhosis

BACKGROUND: Patients with decompensated hepatitis B vires (HBV)-related cirrhosis tend to have low or undetectable HBV replication. However, some patients continue to have high levels of HBV replication and effective suppression of HBV replication with antiviral agents may potentially decrease hepatic necroinflammation and improve or stabilize liver function. This review was to under stand the efficacy and safety of lamivudine in the treatment of decompensated HBV cirrhosis. DATA SOURCES: An English-language literature search (MEDLINE January 1988-July 2005) was performed, and a total of 52 articles/abstracts relevant to the issue were selected. After review of the selected papers, the meaningful results and conclusions were extracted using scientific crite ria. The papers reviewed pertained mainly to the efficacy and safety profiles of lamivudine treatment for decompensated HBV cirrhosis. RESULTS: The ultimate treatment of decompensated HBV cirrhosis is liver transplantation, but lamivudine treatment may lead to rapid suppression of viral replication and improvement of biochemical and clinical parameters, reduced morbidity and hospitalization for complications of liver disease, increased pre-transplant survival as well as reduced need for transplantation. However, viral resistance can develop after prolonged treatment with lamivudine, and breakthrough hepatitis may be fatal in few patients. Adefovir is effective for lamivudine-resistant HBV mutants. CONCLUSIONS: Antiviral therapy with lamivudine for decompensated HBV cirrhosis can be effective. However, some patients may experience a hepatitis flare with the emergence of YMDD mutants resulting in progressive worsening of liver disease, and should be referred for "rescue" therapy with other nucleoside/nucleotide analogues such as adefovir dipivoxil.     

HepG2 cells support viral replication and gene expression of hepatitis C virus genotype 4 in vitro

AIM: To establish a cell culture system with long-term replication of hepatitis C virus (HCV) genome and expression of viral antigens in vitro. METHODS: HepG2 cell line was tested for its susceptibility to HCV by incubation with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various time points during the culture. Culture supernatant was tested for its ability to infect naive cells. The presence of minus (antisense) RNA strand, and the detection of core and El antigens in cells were examined by RT-PCR and immunological techniques (flow cytom-etry and Western blot) respectively. RESULTS: The intracellular HCV RNA was first detected on d 3 after infection and then could be consistently detected in both cells and supernatant over a period of at least three months. The fresh cells could be infected with supernatant from cultured infected cells. Flow cytometric analysis showed surface and intracellular HCV antigen expression using in house made polyclonal antibodies (anti-core, and anti-El). Western blot analysis showed the expression of a cluster of immunogenic peptides at molecular weights extended between 31 and 45 kDa in an one month old culture of infected cells whereas this cluster was undetectable in uninfected HepG2 cells. CONCLUSION: HepG2 cell line is not only susceptible to HCV infection but also supports its replication in vitro. Expression of HCV structural proteins can be detected in infected HepG2 cells. These cells are also capable of shedding viral particles into culture media which in turn become infectious to uninfected cells.     

Inhibition of hepatitis B virus replication by APOBEC3G in vitro and in vivo

AIM: To investigate the effect of APOBEC3G mediated antiviral activity against hepatitis B virus (HBV) in cell cultures and replication competent HBV vector-based mouse model. METHODS: The mammalian hepatoma cells Huh7 and HepG2 were cotransfected with various amounts of CMV-driven expression vector encoding APOBEC3G and replication competent 1.3 fold over-length HBV. Levels of HBsAg and HBeAg in the media of the transfected cells were determined by ELISA. The expression of HBcAg in transfected cells was detected by western blot. HBV DNA and RNA from intracellular core particles were examined by Northern and Southern blot analyses. To assess activity of the APOBEC3G in vivo, an HBV vector-based model was used in which APOBEC3G and the HBV vector were co-delivered via high-volume tail vein injection. Levels of HBsAg and HBV DNA in the sera of mice as well as HBV core-associated RNA in the liver of mice were determined by ELISA and quantitative PCR analysis respectively. RESULTS: There was a dose dependent decrease in the levels of intracellular core-associated HBV DNA and extracellular production of HBsAg and HBeAg. The levels of intracellular core-associated viral RNA also decreased, but the expression of HBcAg in transfected cells showed almost no change. Consistent with In vitro results, levels of HBsAg in the sera of mice were dramatically decreased. More than 1.5 log 10 decrease in levels of serum HBV DNA and liver HBV RNA were observed in the APOBEC3G-treated groups compared with the control groups. CONCLUSION: These findings indicate that APOBEC3G could suppress HBV replication and antigen expression both in vivo and in vitro, promising an advance in treatment of HBV infection.     

Interferon-a plus lamivudine vslamivudine reduces breakthroughs, but does not affect sustained response in HBeAg negative chronic hepatitis B

AIM: To investigate the efficacy of combination treatment of IFN-α and lamivudine compared to lamivudine monotherapy, after 24 mo of administration in HBeAgnegative hepatitis B patients. METHODS: Fifty consecutive patients were randomly assigned to receive IFN-α-2b (5MU thrice per week, n=24) plus lamivudine (100mg daily) or lamivudine only (n=26) for 24 mo. Patients were followed up for further 6 mo. The primary outcome was the proportion with sustained virological response (undetectable serum HBV DNA concentrations) and or sustained biochemical response (transaminase levels within normal range) at 30 mo (6 mo after the end of therapy). Secondary end-points were timed from initial virological (biochemical) response to VBR (BBR, respectively) and the emergence of YMDD mutants across the two arms. RESULTS: Five of twenty-four (21%) patients in the combination arm vs 3/26 (12%) in the lamivudine arm had sustained response (i.e., normal serum transaminase levels and undetectable HBV DNA by PCR assay) 6 mo after treatment discontinuation. A reduction in the emergence of YMDD mutants and in the development of virological breakthroughs was observed in patients receiving combination treatment (10% vs 46%, P=0.01 and 14% vs 46%, P=0.03, respectively). Time from initial virologic response to virologic breakthrough (VBR) was greater among initial responders receiving combination treatment compared to those receiving lamivudine (22.9 mo vs 15.9 mo, respectively; P=0.005). CONCLUSION: Our results demonstrate that IFN-α plus lamivudine combination therapy does not increase the sustained response, compared to lamivudine. However, combination therapy reduces the likelihood of VBR due to YMDD mutants and prolongs the time period until the breakthrough development.     

Sequential changes of serum ferritin levels and their clinical significance in lamivudine-treated patients with chronic viral hepatitis B

AIM: To study the sequential changes of serum ferritin levels in lamivudine-treated patients with chronic viral hepatitis B and the clinical implications. METHODS: Thirty-eight patients with chronic viral hepatitis B were prospectively studied during their treatment with lamivudine. Each patient received 100 mg oral lamivudine daily for 12 mo, and was observed and tested for blood biochemistry and hepatitis B virus (HBV) DNA levels and serum ferritin levels at baseline and at 3, 6 and 12 mo during the treatment. Serum HBV DNA levels were quantitatively determined using fluorescent quantitative polymerase chain reaction (FQ-PCR), and serum ferritin levels were measured by radioimmunoassay. The sequential changes of serum ferdtin levels and their relationships with virological, serological and biochemical responses in the patients were analyzed. RESULTS: All the patients had a baseline HBV DNA level higher than 1&#215;10^7 copies/L as determined by FQ-PCR and positive HBsAg and HBeAg and abnormal ALT levels. At the end of the 12-mo treatment, 19 of the 38(50.00%) patients had undetectable serum HBV DNA levels by FQ-PCR, and 12(31.58%) became negative for serum HSeAg and 10(26.32%) had seroconversion from HBeAg to HBeAb. Nineteen out of the 38(50.00%) patients had biochemically normal ALT levels after 12-mo lamivudine treatment. Sequential determination showed bhat lamivudine treatment significantly reduced ferritin levels in chronic hepatitis B patients. When the patients were divided into different groups according to their posttreatment virological, serological and biochemical responses for analysis of the sequential changes of ferritin levels, it was found bhat the decrease of ferritin levels in HBV DNA-negative group was significantly more obvious than that in HBV DNApositive group at 6 mo during the treatment (P=-0.013). Consecutive comparisons showed that ferritin levels at 3 mo of treatment were obviously decreased as compared with the baseline levels (P&lt;0.05) in HBeAg-negative group, and the decrease of serum ferritin levels in patients with normalized ALT was more significant than that in patients with abnormal ALT at the end of the 12-mo treatment (P=0.048). CONCLUSION: Lamivudine treatment can reduce the serum ferritin levels in chronic viral hepatitis B patients and decreases of ferdtin levels can be more significant in patients exhibiting virological, serological and biochemical responses, indicating that dynamic observation of serum ferritin levels in patients with chronic viral hepatitis B during lamivudine treatment might be helpful for monitoring and predicting patients‘ responses to the therapy.