The inhibitory effects on hepatitis B virus replication by stable expression of DN mutants of hepatitis B virus X gene pRev X-GFP / 中华肝脏病杂志

<p><b>OBJECTIVE</b>Persistent replication of hepatitis B virus (HBV) is one of the major obstacles in HBV infection treatment. Reduction or clearance of HBV propagation would be one of the aims of HBV therapy. The drugs approved in clinical used such as nucleotide analogs or interferon, were limited effects on HBV replication. The newly developing gene therapy method, dominant negative mutants, were be used as new promising HBV therapy strategy, and a dominant negative mutant of HBVX gene pRev X-GFP which we have reported in our previous study has some effects both on HBV replication and expression in transient expression, but the effects were interfered by persistent secretion of HBV in HepG2 2.2.15 cells without transfection pRev X-GFP in the experiment. To make sure the effects of dominant negative mutant of pRev X-GFP, we established a HBX DN stable express cell clone, and evaluated the effects of HBX dominant negative mutant on HBV replication.</p><p><b>METHODS</b>The X gene mutant, in which a specific point mutation of 3'-end ATG to AAG and fused with human green fluorescence protein (GFP) were cloned into pRev TRE vector, assigned to pRev HBX-GFP dominant mutant (pRev X-GFP). And the plasmid contains the wild type X gene or GFP gene was cloned into the same vector to construct pRev Xwt, pRev GFP constructs. All the constructs then transfected into HepG2 2.2.15 cells by liposome. After 7 days resistance selection of hygromycin (300 microg/ml), and cell clones which stable expression HBX-GFP, HBXwt, GFP were obtained. After reseeding of 106 cells of each clones in 12 wells with a 12 well cell plate and another 12 wells 2.2.15 cell were serve as blank control. The cells and media were harvested after cultured in DMEM with 10% FBS for 3 days. HBV-related DNA was assayed by dot blot and Southern blot.</p><p><b>RESULTS</b>The 100% expression of pRev HBX-GFP, GFP and wild type X constructs were obtained. The stable expressed HBX-GFP can significantly reduce HBV DNA level both in cell media and cells by dot blot and Southern blot analysis, but not for pRev Xwt and pRev GFP.</p><p><b>CONCLUSION</b>The dominant negative mutant pRev HBX-GFP can significantly inhibit the HBV gene expression. It also suggested that X gene might be one of promising target for HBV gene therapy.</p>

Clinical study of lamivudine and interferon combinate administration to inhibit hepatitis B virus replication / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore a new strategy for effective and economical anti-virus therapy for HBV infection, we conducted a sequence administration of lamivudine and interferon alpha 1b to evaluate its effects on HBV replication and rebound as well as YMDD mutation induced by lamivudine.</p><p><b>METHODS</b>150 HBV patients having at least 6 months history of infection were assigned randomly into 5 groups. Each group of these patients was either treated with lamivudine, interferon alpha 1b, lamivudine combined with interferon, sequence administration of lamivudine and interferon (sequence group) or no anti-virus therapy (control group) for 12 months. The serum samples were collected at 0, 3, 6, 9, 12 and 18th months and were assayed for ALT, AST, HBeAg, HBV DNA (quantitive PCR) as well as YMDD mutation types by microarray.</p><p><b>RESULTS</b>The anti-virus replication effects were shown as early as the 3rd month in the sequence group but not in the IFN and control groups. The significant and persistent inhibition effect of it on HBV replication and improvement of liver function was shown. It was more effective than lamivudine or IFN treatments at the end of the drug administration and 6 months later after the drug was withdrawn. We also found that this sequence administration pattern can significantly shorten the period of treatment of lamivudine as well as reduce the rate of YMDD mutation and rebound of HBV replication after lamivudine withdrawal. It is also more economical than a combined therapy of lamivudine with IFN.</p><p><b>CONCLUSION</b>This sequence administration of lamivudine and IFN pattern can significantly improve the anti-virus effect on HBV replication, shorten the period of treatment with lamivudine, reduce the mutation rate of YMDD and prevent the rebound of HBV after drug withdrawal.</p>

Clinical study of oligonucleotide microarray on monitoring the lamivudine-resistance mutations in hepatitis B virus / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the mutations of lamivudine-resistance using oligonucleotide microarray in hepatitis B virus (HBV) infected patients.</p><p><b>METHODS</b>A randomized clinical trial was conducted on 20 lamivudine-treated patients for 18 months and 10 patients as controls. The serum HBV DNA was amplified by PCR and the lamivudine-resistance mutations in YMDD region were assayed by 4 sites microarray developed before.</p><p><b>RESULTS</b>This microarray could clearly differentiate the wide-type from mutated-type HBV with lamivudine-resistance mutations. The rate of mutations in YMDD region increased with the time of lamivudine treatment (chi2=6.69, P<0.01). The most common mutated type was M539V+L515M and next M539I. Continuous administration of lamivudine was no benefit for inhibiting the replication of HBV with YMDD mutation but helpful for wide-type HBV.</p><p><b>CONCLUSION</b>The routine serum HBV DNA assay by PCR may introduce prejudice in monitoring HBV inhibitory effect by lamivudine, while the microarray technique can avoid this and is one of the best ways to monitor the lamivudine-resistance mutations in HBV. There is no effect of lamivudine on HBV with YMDD mutation in clinical practice.</p>