OBJECTIVETo highly express TAT-HBX-EGFP fusion protein and study its distribution in mouse liver.

METHODSTAT-HBX-EGFP recombinant vector was constructed and fusion protein was induced by IPTG and expression in BL21; fusion protein was purified by Ni-NTA argarose, then injected into the peritoneal cavity of the mice. Distribution of fusion protein was observed by immunofluorescence.

RESULTSTAT-HBX-EGFP was highly expression in E. coli; HBX could be induced into mouse liver by TAT.

CONCLUSIONHBX protein could be induced into mouse liver by TAT induced peptide.

Animals ; Cell Membrane ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Female ; Gene Expression ; Green Fluorescent Proteins ; genetics ; isolation & purification ; metabolism ; Hepatitis B ; metabolism ; virology ; Humans ; Liver ; metabolism ; Male ; Mice ; Mice, Inbred ICR ; Protein Transport ; Recombinant Fusion Proteins ; genetics ; isolation & purification ; metabolism ; Trans-Activators ; genetics ; isolation & purification ; metabolism ; Viral Regulatory and Accessory Proteins ; genetics ; isolation & purification ; metabolism ; tat Gene Products, Human Immunodeficiency Virus ; genetics ; isolation & purification ; metabolism

Amino Acid Sequence ; Blood Donors ; Gene Deletion ; Gene Products, nef ; chemistry ; genetics ; Humans ; Molecular Sequence Data ; nef Gene Products, Human Immunodeficiency Virus

Carcinoma, Hepatocellular ; pathology ; virology ; Cisplatin ; pharmacology ; Drug Synergism ; Flavonoids ; pharmacology ; Humans ; Liver Neoplasms ; pathology ; virology ; Trans-Activators ; Tumor Cells, Cultured ; Viral Regulatory and Accessory Proteins ; drug effects

Gene therapy offers the promise of curing the HIV-infected patients. Specific, potent, and sustained short hairpin RNA (shRNA)-mediated gene silencing is crucial for the successful application of RNA interference technology to therapeutic interventions. To reduce the probability of viral escape mutants, in this study, we constructed lentiviral vector containing vpr and tat shRNA, respectively, furthermore the bispecific lentiviral vector harboring vpr and tat shRNA expression cassettes from U6 promotor and H1 promotor was cotransfected with recombinant plasmid expressing the vpr and tat gene. The result showed that the bispecific lentiviral vector plvx-vpr-tatshRNA could inhibit the vpr and tat effectively,with ratios of 89.20% and 62.00% respectively. When cotransfected with pNL4-3 in 293T cell, plvx-vpr-tatshRNA showed higher efficacy in down regulating the HIV NL4-3 packaging production than the plvx-vprshRNA or plvx-tatshRNA individually. MT4 cell clones transduced with recombinant lentiviral vectors were screened and challenged with HIV NL4-3. P24 ELISA test showed that MT4 transduced with the combinational lentiviral vector could inhibit virus replication efficiently.
Cell Line ; Down-Regulation ; Genetic Therapy ; Genetic Vectors ; genetics ; metabolism ; HIV Infections ; therapy ; virology ; HIV-1 ; genetics ; metabolism ; Humans ; Lentivirus ; genetics ; metabolism ; RNA Interference ; RNA, Small Interfering ; genetics ; metabolism ; therapeutic use ; tat Gene Products, Human Immunodeficiency Virus ; genetics ; metabolism ; vpr Gene Products, Human Immunodeficiency Virus ; genetics ; metabolism

BACKGROUNDThe correlation between HIV-1 Nef-specific CD8 T-cell responses and markers of HIV-1 disease progression still remains unclear. This study analysed and compared the role of HIV-1 Nef-specific CD8 T-cell responses in patients with different disease status.

METHODSTwo groups of patients with HIV-1 subtype B infection were selected according to CD4 count and clinical manifestations: long-term nonprogressors (LTNPs, n = 20) and advanced progressors (APs, CD4 count < 500 cells/microl, n = 34). Nef-specific CD8 T-cell responses were studied by interferon-gamma ELISpot assay against 3 pools of HIV-Nef peptides.

RESULTSNef-specific CD8 T-cell responses did not correlate with viral load or CD4 count in all patients and no significant differences were found in the magnitude of Nef-specific CD8 T-cell responses between groups LTNPs and APs (670 SFC/10(6) peripheral blood mononuclear cells vs 1107 SFC/10(6) peripheral blood mononuclear cells, P = 0.255). Further comparisons showed that there were also no significant correlations observed in group LTNPs, but Nef-specific CD8 T cells correlated negatively with viral load (r = -0.397, P = 0.020) and positively with CD4 count (r = 0.364, P = 0.034) in group APs.

CONCLUSIONThese data suggest that different correlation patterns between Nef-specific CD8 T-cell responses and disease progression exist in LTNPs and APs. Although a negative association was observed with concurrent plasma HIV RNA in APs, Nef-specific CD8 T-cell responses might fail to play a protective role in different stages of HIV-1 infection.

Acquired Immunodeficiency Syndrome ; immunology ; Adult ; CD4 Lymphocyte Count ; CD8-Positive T-Lymphocytes ; immunology ; Disease Progression ; Female ; Gene Products, nef ; immunology ; HIV-1 ; classification ; Humans ; Male ; Middle Aged ; RNA, Viral ; blood ; nef Gene Products, Human Immunodeficiency Virus

Xeroderma pigmentosum group D (XPD) gene is the second subunit of basic transcript factor TFII H; it plays an important role in transcription and nucleotide excision repair. In this study, using the total RNA extracted from HeLa cells, we cloned the human full length XPD by RT-PCR and inserted it into the pEGFP-N2 plasmid vector which expressed the green fluorescence protein (GFP). Then the recombinant plasmid pEGFP-N2/XPD was transfected into the human hepatoma carcinoma cell Hep3B integrated with HBx protein,and we analysed the expression of HBx and the proliferative ability of recombinant cells. The data collected from this study could serve as a physical basis on which to further investigate the biological activities of XPD.
Cloning, Molecular ; DNA Repair ; Female ; HeLa Cells ; Humans ; Liver Neoplasms ; genetics ; Recombinant Proteins ; genetics ; metabolism ; Trans-Activators ; genetics ; Transcription Factor TFIIH ; genetics ; Transcription, Genetic ; Transfection ; Viral Regulatory and Accessory Proteins ; genetics ; Xeroderma Pigmentosum Group D Protein ; genetics ; metabolism

BACKGROUNDHepatitis B virus (HBV) x protein (HBx) in HepG2 cells causes a moderate decrease in proteolysis activity of the proteasome. A highly conserved Kunitz-type serine protease inhibitor domain within 154 amino acid residues of HBx has been identified. In this study, a peptide chain derived from the Kunitz domain (PKD) was used to study its effect on the cell cycle and apoptosis of HepG2 cells, and investigated the function of PKD on the activities of proteasomes and AAA-ATPase p97, which involves in the ubiquitin-proteasome protein degradation pathway.

METHODSThe PKD peptide (Phe-Val-Leu-Gly-Gly-Cys-Arg-His-Lys) was chemically synthesized. MTT assays were used to determine the effects of PKD on HepG2 cell growth. Mouse anti-p97 antibody was developed for Western blotting to detect the expression of p97. ATPase activity of proteasomes was measured using a colorimetric assay. Peptidase activities of proteasomes were analyzed with various peptidase-specific fluorogenic peptide substrates. Flow cytometry was used to determinate cell cycle phase and apoptosis.

RESULTSViability of HepG2 cells decreased in a PKD-dose-dependent manner. Cells exhibited significant cytotoxicity in the presence of 15 mmol/L of PKD. Western blotting analysis showed that expression of p97 was suppressed in HepG2 cells treated with PKD compared to untreated cells. The ATPase activity of proteasomes from immunoprecipitates of HepG2 cells pretreated with PKD was apparently decreased. Chymotryptic activity of proteasomes in HepG2 cells was significantly inhibited by 10 mmol/L PKD; tryptic activity and peptidylglutamyl peptide hydrolase activity of proteasomes were less inhibited by PKD than chymotryptic activity. The cell cycle phase of HepG2 cells treated with PKD for 36 hours was blocked largely at the G(0)-G(1) phase, while untreated control cells were mainly in S phase. PKD also significantly induced apoptosis.

CONCLUSIONSThe peptide derived from Kunitz domain of HBx protein induces HepG2 cell growth arrest and apoptosis, which may result from down-regulation of p97 expression, and decrease of both the ATPase and chymotryptic activities of proteasomes.

Adenosine Triphosphatases ; metabolism ; Animals ; Apoptosis ; drug effects ; Blotting, Western ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Enzyme Activation ; drug effects ; Humans ; Lipopeptides ; chemistry ; pharmacology ; Mice ; Nuclear Proteins ; metabolism ; Trans-Activators ; chemistry ; Viral Regulatory and Accessory Proteins ; chemistry

OBJECTIVETo study the function of nuclear factor-kappaB (NF-kappaB) signaling pathway in regulating vascular endothelial growth factor (VEGF) by hepatitis B virus X protein (HBx).

METHODSAfter the establishment of L02-HBx cell line with stable transfected HBx gene, NF-kappaB signaling pathway blocker PDTC was introduced to cut off its signal transduction. Double immunofluorescent staining and laser scanning confocal microscopy were applied to study the activation and deactivation of NF-kappaB signaling pathway. Real-time PCR and Western blot were used to observe the expression of VEGF gene before and after the HBx transfection, as well as the treatment with PDTC.

RESULTSThe NF-kappaB signaling pathway of L02-HBx cells was activated after transfection with HBx gene as compared to the control L02 cells without treatment. The mRNA and protein levels of VEGF in L02-HBx cells increased 4.07 +/- 0.31 and 4.34 +/- 0.64 times respectively. The difference was of statistical significance (P < 0.05) in comparison with the control cells. The mRNA levels of VEGF decreased to 2.33 +/- 0.22 and 1.86 +/- 0.18(P < 0.05) and at the same time the expression of VEGF also reduced to 2.52 +/- 0.29 and 2.17 +/- 0.34 (P < 0.05), after treatment with 25.0 micromol/L and 50.0 micromol/L PDTC for 24 h respectively when the NF-kappaB signaling pathway was blocked. There was no significant difference in VEGF mRNA and protein levels when treated with 12.5 micromol/L PDTC for 24 h.

CONCLUSIONNF-kappaB signaling pathway maybe one of the routes through which HBx up-regulate the expression of VEGF to promote angiogenesis in hepatocellular carcinoma.

Cell Line ; NF-kappa B ; genetics ; metabolism ; Proline ; analogs & derivatives ; pharmacology ; RNA, Messenger ; genetics ; Signal Transduction ; Thiocarbamates ; pharmacology ; Trans-Activators ; genetics ; Transfection ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; Viral Regulatory and Accessory Proteins ; genetics

BACKGROUNDHepatitis B virus encoded X protein (HBx) is a trans-activating protein that may be involved in hepatocarcinogenesis, although few natural effectors of HBx that participate in this process have been identified. We screened, by comparative proteomics method, effectors of HBx associated with hepatocarcinogenesis.

METHODSHBx positive and negative HepG2 cells were constructed and expression patterns of cellular proteins were obtained by high resolution, two dimensional electrophoresis. Comprehensive analyses of proteins associated with hepatocellular carcinoma (HCC) were focused on the differently expressed proteins (more than two-fold increase or decrease, P < 0.05) from HBx positive and negative HepG2 cells. For peptide mass fingerprinting, protein spots with different intensity between HBx positive and negative HepG2 cells were directly cut out of gels and processed for matrix assisted, laser desorption/ionization, time of flight mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) analysis.

RESULTSThe mean number of protein spots for HBx negative and HBx positive HepG2 cells were 2095 +/- 137 and 2188 +/- 105, respectively. The analysis of paired cells showed 75 spots with significant differences in expression between HBx negative and HBx positive cells: 37 spots corresponding to 32 different proteins; 25 proteins were upregulated, 7 downregulated. We found 7 proteins not previously reported differentially expressed in HBx positive HepG2 cells. Variations in protein accumulation were confirmed for four (HSP90AB1, BCL2 associated athanogene 2, nucleophosmin and chloride intracellular channel 1) by Western blotting in HBx positive HepG2 cells.

CONCLUSIONSNumerous effectors of HBx that may promote the development of HCC are identified, of which 7 are newly noted in HepG2 cells. Several of these effectors of HBx may help in elucidating the roles of HBx in hepatocarcinogenesis and diagnostics or targets for therapeutic intervention.

Blotting, Western ; Carcinoma, Hepatocellular ; genetics ; metabolism ; Cell Line, Tumor ; Electrophoresis, Gel, Two-Dimensional ; Humans ; Polymerase Chain Reaction ; Proteomics ; methods ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Trans-Activators ; genetics ; metabolism ; Viral Regulatory and Accessory Proteins ; genetics ; metabolism

Adult ; Female ; Gene Expression ; Glomerulonephritis, Membranous ; etiology ; genetics ; pathology ; Hepatitis B ; complications ; Hepatitis B virus ; genetics ; metabolism ; Humans ; Male ; Middle Aged ; Mutation ; Receptors, Phospholipase A2 ; genetics ; metabolism ; Trans-Activators ; genetics ; metabolism ; Viral Regulatory and Accessory Proteins ; genetics ; metabolism