OBJECTIVESTo transfer 1.3-fold-overlength genome of HBV expression plasmid into HepG2 cells, and observe the dynamic changes of viral replication as well as expression in the transfected cells.

METHODS4.1 kb fragment of HBV genome, derived from pGEM-HBV, was cloned into Hind III site of the eukaryotic expression vector pCDNA3.1 to construct the recombinant plasmid pHBV. Then HepG2 hepatoma, cells were transfected with pHBV, using Lipofectamine2000 transfection reagent. After 24, 48, 72 hours, the levels of HBsAg and HBeAg in the supernatant of HepG2 cells were determined with Abbott MEIA Kit. Intracellular viral DNA and RNA were analyzed by Southern and northern blot hybridization. In addition, viral-specific proteins (HBsAg and HBcAg) were assayed by immunofluorescence staining.

RESULTSThe expression vector pCDNA3.1 was constructed successfully. The levels of HBsAg were 5.36+-0.25, 13.42+-1.24, 7.52+-0.43, and the values of HBeAg were 9.16+-0.32, 22.75+-1.49, 15.96+-1.03 after 24, 48, 72 hours, respectively. All expected HBV replicative intermediates and specific transcripts were verified by Southern and northern blot analysis. The HBsAg-positive cells peaked after 24 hours, and then dropped slowly. HBsAg positive staining scattered in the cytoplasm, whereas HBcAg lied maily in the cytoplasm apart from nuclears.

CONCLUSIONSThis recombinant plasmid, which initiates viral replication efficiently in infected cells, is expected as a novel tool for investigating HBV replication in vitro.

Carcinoma, Hepatocellular ; pathology ; virology ; DNA, Viral ; genetics ; Eukaryotic Cells ; virology ; Gene Expression Regulation, Viral ; Genome, Viral ; Hepatitis B virus ; genetics ; physiology ; Humans ; Liver Neoplasms ; pathology ; virology ; Plasmids ; genetics ; Transfection ; Tumor Cells, Cultured ; Virus Replication

Adult ; Aged ; Fatty Liver ; metabolism ; pathology ; Female ; Humans ; Male ; Middle Aged ; Platelet-Derived Growth Factor ; metabolism ; Protein-Serine-Threonine Kinases ; metabolism ; Receptors, Platelet-Derived Growth Factor ; metabolism ; Receptors, Transforming Growth Factor beta ; metabolism ; Young Adult

OBJECTIVETo establish a stable cell line that can replicate hepatitis B virus (HBV) DNA carrying the reverse transcriptase sequence derived from a clinical isolate.

METHODSNested PCR was used to amplify the HBV DNA fragment from the serum. The fragment was cloned into a plasmid that can support HBV replication in vitro by fragment substitution reaction (FSR), followed by the cloning of the neomycin expressing fragment downstream from HBV DNA. G418 selection was conducted after the transfection of HepG2 cells with the recombinant DNA. Real-time PCR and enzyme linked immunosorbent assay (ELISA) were used to screen stable cell lines that can replicate HBV DNA, and the replication of HBV DNA by the cell line was confirmed by using Southern blot analysis.

RESULTSFragment nt55-1654 amplified from the serum DNA was substituted to the plasmid pLL, generating the plasmid p11. The neomycin fragment was cloned into p11, leading to the plasmid p11-neo, and p11-neo was confirmed to be HBV-replication-competent. A stable cell line named 3-10 that can replicate HBV DNA was obtained.

CONCLUSIONSA stable cell line was established that can replicate HBV DNA carrying the reverse transcriptase sequence derived from a clinical isolate. Real-time PCR plus ELISA may help to rapidly screen out stable cell lines replicating HBV DNA.

Cell Line ; Cloning, Molecular ; DNA Replication ; DNA, Viral ; biosynthesis ; Genetic Vectors ; Hep G2 Cells ; Hepatitis B virus ; genetics ; Hepatocytes ; cytology ; virology ; Humans ; Plasmids ; RNA-Directed DNA Polymerase ; genetics ; Virus Replication ; genetics

BACKGROUND/AIMS: The recognition of a correlation between patatin-like phospholipase domain containing-protein 3 (PNPLA3) rs738409 (C>G) and the severity of liver steatosis or fibrosis in chronic hepatitis C (CHC) has not reached a consensus. This meta-analysis sought to investigate with accuracy the association between the PNPLA3 rs738409 (C>G) polymorphism and liver steatosis and advanced fibrosis in CHC patients. METHODS: We performed a comprehensive literature search from the PubMed, Embase, Web of Science, and Google Scholar databases up to December 31, 2014. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Statistical analyses were performed using Stata 12.0 software. RESULTS: The meta-analysis revealed the severity of liver fibrosis was significantly higher in CHC patients with PNPLA3 rs738409 GG in Caucasians (versus CC+CG: OR, 2.29; 95% CI, 1.57 to 3.35; p<0.05) but not Asian populations. In Caucasians, liver steatosis was also more severe in CHC patients with rs738409 GG (versus CC+CG; OR, 4.33; 95% CI, 2.59 to 7.22; p<0.05). The sensitivity analysis indicated the results of this meta-analysis were stable and no publication bias was detected. CONCLUSIONS: PNPLA3 rs738409 (C>G) was associated with the risk of both advanced liver fibrosis and steatosis in patients with CHC, especially among Caucasian populations.
Asian Continental Ancestry Group ; Consensus ; Fatty Liver ; Fibrosis* ; Hepatitis C, Chronic* ; Hepatitis, Chronic* ; Humans ; Liver Cirrhosis ; Odds Ratio ; Phospholipases ; Publication Bias