OBJECTIVETo investigate the effect of protein transduction domain-hepatitis B virus core antigen (CTP-HBcAg18-27)-Tapasin fusion protein-induced specific cytotoxic T lymphocyte (CTL) response on hepatitis B virus (HBV) replication in HBV transgenic mice.

METHODSTwenty HBV-transgenic mice were randomly divided into two groups for a 3-week course of once weekly subcutaneous immunizations with either CTP-HBcAg18-27-Tapasin fusion protein or CTP-HBcAg18-27. Mice administered isotonic saline served as blank controls. Expressions of cytokines in splenocytes were analyzed by flow cytometry. Serum levels of hepatitis B surface antigen (HBsAg) and HBV DNA were determined by microparticle enzyme immunoassay and real-time fluorescent PCR assay, respectively. Expression of HBsAg in hepatic tissues was detected by immunohistochemistry.

RESULTSImmunization with 100 mug of CTP-HBcAg18-27-Tapasin fusion protein led to a significant increase in proportions of CTLs in spleen (2.70%+/-0.20% vs. 50 mug of CTP-HBcAg18-27-Tapasin: 1.66%+/-0.53%, 50 mug of CTP-HBcAg18-27: 1.26%+/-0.56%, and blank controls: 0.75%+/-0.71%; F = 741.45, P = 0.000) and up-regulation of inflammatory cells in hepatic tissue. In addition, both immunizations of CTP-HBcAg18-27-Tapasin led to significant decreases in serum HBsAg and HBV DNA levels compared to those in the CTP-HBcAg18-27 group.

CONCLUSIONHBV-related modification of the expression of the molecular chaperone Tapasin may affect its interaction with intracellular antigen peptides, thereby leading to increases the number of specific CTLs in the spleen, decreases in serum HBsAg and HBV DNA levels, and down-regulation of HBsAg expression in hepatic tissue. These results obtained in HBV-transgenic mice suggest that the CTP-HBcAg18-27-Tapasin fusion protein has anti-HBV activity.

Animals ; DNA, Viral ; blood ; Female ; Hepatitis B ; immunology ; Hepatitis B Core Antigens ; genetics ; Hepatitis B Surface Antigens ; blood ; Hepatitis B virus ; physiology ; Male ; Membrane Transport Proteins ; genetics ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Recombinant Fusion Proteins ; genetics ; immunology ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Virus Replication

In order to study the proliferation inhibition effect of H5N1 subtype avian influenza virus (AIV) with small interfere RNA (siRNA), a total of 4 siRNAs were designed in accordance with the NP and PA genes of H5N1 subtype AIV, the siRNAs were then transfected to chicken embryo fibroblast(CEF), CEF was infected with H5N1 subtype AIV after 6 hrs. Virus titer of cell supernatant was tested at 16-56hrs post infection, and pathological changes of the cells was observed; mRNA levels of NP, PA, HA and p13-actin gene were tested at 36hrs post infection. The results showed that these 4 siRNAs could inhibit the prolif-eration of H5N1 subtype AIV in CEF in varying degrees, and one siRNA targeting PA was best per-formed. The experimental results also showed that the inhibition effect was decreased with the time prolonged. This research provides a basis for further studying RNAi on AIV prevention and control.
Actins ; genetics ; Animals ; Chick Embryo ; DNA Primers ; genetics ; Fibroblasts ; virology ; Hemagglutination ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Hemagglutinins ; genetics ; Humans ; Influenza A Virus, H5N1 Subtype ; genetics ; growth & development ; physiology ; RNA Interference ; RNA Replicase ; genetics ; RNA, Small Interfering ; chemical synthesis ; genetics ; RNA-Binding Proteins ; genetics ; Real-Time Polymerase Chain Reaction ; Specific Pathogen-Free Organisms ; Transfection ; Viral Core Proteins ; genetics ; Viral Proteins ; genetics ; Virus Replication

Avian influenza virus subtype H9N2 has been circulating in multiple terrestrial birds and repeatedly infecting mammals, including swines and humans to pose a significant threat to public health. The cross-species infection of human, replication activity and tissue tropism of avian influenza virus H9N2 was evaluated in this study. The results showed that surgically removed human lung tissue samples were infected ex vivo by avian influenza virus subtype H9N2 (Ck/GX/1875/04, Ck/GX/187/05) and seasonal human influenza virus H3N2 (A/ST/602/05). Examination of nucleoprotein expression replication in the infected human lung tissue samples showed that the replication of avian influenza virus H9N2 and seasonal human influenza virus H3N2 were mainly prevalent in alveolar epithelial cells, respiratory bronchiole epithelial cells and bronchial epithelial cells. Double-immunostaining for viral antigens and cellular markers indicated that avian influenza virus subtype H9N2 replicated in type 2 alveolar epithelial cells. These findings suggest that the H9N2 virus may be better adapted to the human host and replicates efficiently in human lung epithelial cells. Moreover, H9N2 avian influenza virus repeatedly infecting human, may favor gene evolution and the potential emergence of pandemic influenza virus.
Animals ; Epithelial Cells ; virology ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; physiology ; Influenza A Virus, H9N2 Subtype ; genetics ; isolation & purification ; physiology ; Influenza, Human ; virology ; Lung ; cytology ; virology ; RNA-Binding Proteins ; genetics ; metabolism ; Viral Core Proteins ; genetics ; metabolism ; Virus Replication

Hepatitis C virus (HCV), one of the major pathogens of viral hepatitis, causes significant hazards in humans. Interferon treatment in combination with ribavirin is used as the first line clinical treatment for HCV infection. However, good response to this treatment has only been observed in few patients and repeated recurrence has also been reported frequently. Therefore, new antiviral agents and therapies are in urgent demand. Here, we report a newly constructed Escherichia coli RNase P based M1GS ribozyme that can specifically and efficiently target the core gene of HCV. The guide sequence (GS) of this M1IGS was designed according to the sequence of the core coding region of HCV genome. The GS was then covalently linked to the 3' terminus of M1 RNA, the catalytic subunit of RNase P from Escherichia coli. The specification of this sequence-specific ribozyme, M1GS, was then examined using an in vitro cleavage assay. The cytotoxicity and its activity in inhibition of HCV gene expression and viral proliferation were further studied in vivo. Our results show that the reconstructed M1GS ribozyme displayed obvious catalytic activity in cleaving target mRNAs fragment in vitro. Notable reduction in the expression of HCV core protein and a 1 000-fold reduction in viral growth were also observed in cultured HCV infected Huh7.5.1 cells expressing the functional M1GS ribozyme. This study demonstrated a direct evidence for the antiviral activity of the customized M1GS-HCV/C141 ribozyme, and thus provided a promising new strategy for clinical treatment of HCV infection.
Antiviral Agents ; pharmacology ; Escherichia coli ; genetics ; Genetic Engineering ; Hepacivirus ; genetics ; physiology ; RNA, Catalytic ; genetics ; pharmacology ; RNA, Guide ; genetics ; Ribonuclease P ; genetics ; Viral Core Proteins ; genetics

OBJECTIVESThe hepatitis B virus core protein has been found in nuclei, cytoplasm, or both of hepatocytes transfected with HBV DNA. It is still unclear whether intact core particles could pass through nuclear pores and what could be the mechanism regulating the subcellular localization of the core protein. This study on the distribution of core protein in hepatocytes and its translocation has a potential advantage to learn more about the HBV life cycle.

METHODSDimethyl sulphoxide (DMSO, 2%), which effects hepatic differentiation, and/or 1 micro mol/L heteroaryldihydropyrimidine Bay41-4109, which interferes with the assembly of core particles, were added into HepG2.2.15 cell culture system for 4 days. The hepatitis B virus core antigen (HBcAg) and hepatitis B virus surface antigen (HBsAg) were stained with fluorescent immunocytochemistry and then observed under a confocal microscope. HBcAg in cytoplasm and nuclei were respectively extracted and analyzed using Western blot. HBV covalently closed circular DNA (cccDNA) was detected by using selective PCR method.

RESULTSThe HBcAg was mostly expressed in the cytoplasm and weak signals of cccDNA were detected in the control HepG2.2.15 cells. After DMSO treatment, the expression of HBcAg in cytoplasm was increased about 2.5-fold; the expression of HBcAg and cccDNA in nuclei also increased. With the use of Bay41-4109, the signal of HBcAg in cytoplasm decreased 2/3, but it increased in the nuclei, and cccDNA decreased in the nuclei. When the HepG2.2.15 cells were treated both with DMSO and Bay41-4109, cord-liked distribution of HBsAg was observed in the cytoplasm. HBcAg in cytoplasm was decreased 1/2 but the HBcAg in the nuclei increased about 5-fold, whereas the cccDNA was almost negative.

CONCLUSIONIn HepG2.2.15 cells, the core protein is mainly assembled as a formation of core particles in the cytoplasm and they are blocked by the nuclear membrane. Bay41-4109 interferes with the assembly of core particles and the dissociated core proteins are able to enter the nuclei. DMSO promotes the nuclear entry of core protein/core particles and facilitates the formation of cccDNA.

Chromosome Positioning ; Dimethyl Sulfoxide ; pharmacology ; Hep G2 Cells ; Hepatitis B Core Antigens ; metabolism ; Hepatitis B virus ; physiology ; Humans ; Neoplasm Metastasis ; Pyridines ; pharmacology ; Pyrimidines ; pharmacology ; Viral Core Proteins ; metabolism ; Virus Assembly

OBJECTIVETo explore the role of hepatitis C virus core protein on the infiltration and metastasis of cholangiocarcinoma tissues.

METHODSFrom January 2001 to November 2006, 34 patients with cholangiocarcinoma who had intact follow-up data randomly were chosen. The expression of HCVc protein, epithelium markers and mesenchymal markers in cholangiocarcinoma tissues were examined by SP methods of immunohistochemistry, clinical-pathological data were recorded and analyzed.

RESULTSThe positive expression rate was observed in 47.1% for HCVc protein, 50% for N-cadherin, 44.1% for Vimentin, 55.9% for Fibronectin and the decreased expression rate was E-cadherin for 55.9%, alpha-catenin for 70.6%, beta-catenin for 55.9%. The positive expression of HCVc protein was associated with the decreased expression of E-cadherin, alpha-catenin and the positive expression of N-cadherin, Vimentin, Fibronectin (chi(2) = 4.480, 4.163, 4.250, 7.438, 12.260, P < 0.05). A positive-correlation between the expression of HCVc protein and metastasis of lymph nodes and other organs were found (chi(2) = 5.708, 4.163, P < 0.05).

CONCLUSIONHCVc protein might promote cholangiocarcinoma tissues' infiltration and metastasis by inducing it's epithelial-mesenchymal transition.

Adult ; Aged ; Cell Transformation, Neoplastic ; Cholangiocarcinoma ; metabolism ; pathology ; virology ; Epithelium ; metabolism ; pathology ; virology ; Female ; Hepacivirus ; metabolism ; Hepatitis C ; metabolism ; pathology ; virology ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Viral Core Proteins ; metabolism ; physiology

To study the effect of HCV core protein on the interferon-induced antiviral genes expression and its mechanisms. Methods HepG2 cells were transiently transfected with HCV core protein expression plasmid and the blank plasmid respectively. RT-PCR was used to analyze the effect of HCV core protein on PKR and 2'-5'OAS expression. The effect of HCV core protein on ISRE-medicated gene expression was detected by luciferase activity assay. Western-blot assay was performed to observe the change of mRNA and protein levels of SOCS3, STAT1 and p-STAT1 following HCV core expression. In the presence of HCV core protein, the transcription of PKR and 2'-5' OAS are down-regulated. ISRE-medicated reporter gene expression and STAT1 phosphorylation were inhibited. The transcription and expression of SOCS3 were induced compared with blank plasmid-transfected group. In HepG2 cells, HCV core protein can down-regulate the expression of some interferon-induced antiviral genes, which involves the induction of SOCS3 and the inhibition of STAT1 phosphorylation.
2',5'-Oligoadenylate Synthetase ; genetics ; metabolism ; Carcinoma, Hepatocellular ; pathology ; Down-Regulation ; Hepacivirus ; genetics ; metabolism ; Humans ; Interferon-Stimulated Gene Factor 3 ; genetics ; metabolism ; Interferon-alpha ; genetics ; immunology ; Liver Neoplasms ; pathology ; Protein Kinases ; genetics ; metabolism ; STAT1 Transcription Factor ; genetics ; metabolism ; STAT2 Transcription Factor ; genetics ; metabolism ; Transcription, Genetic ; Transfection ; Tumor Cells, Cultured ; Viral Core Proteins ; genetics ; metabolism ; physiology

Adult ; DNA, Viral ; genetics ; Hepatitis B virus ; genetics ; physiology ; Hepatitis B, Chronic ; virology ; Humans ; Liver ; virology ; Male ; Severity of Illness Index ; Viral Core Proteins ; genetics ; Virus Replication

Adult ; Female ; Hepatitis C, Chronic ; virology ; Humans ; Liver Cirrhosis ; virology ; Male ; Middle Aged ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics ; Viral Core Proteins ; physiology

OBJECTIVETo study the effect of hepatitis C virus core protein (HCV-C) on human normal biliary epithelial cells (BEC) transformation and tumor development.

METHODSBEC cells were transfected with plasmid pcDNA HCV-C (expressing HCV-C) by lipofectamine and selected in G418. The expression of HCV-C gene and protein was determined by PCR and immunohistochemical staining, respectively. Biological effect of transfected cells was observed through cell proliferation assay, anchor independent growth, and tumor development in nude mice. The expression of HCV-C protein in the induced tumor was evaluated by immunohistochemistry.

RESULTSHCV-C was strongly expressed in BEC cells transfected with plasmid pcDNA HCV-C and the positive signal was located in cytoplasm. The HCV-C expression protein in the induced cytoplasm. Cell proliferation assay showed that the population doubling time in the pcDNA HCV-C transfected cells was much shorter than that in the pcDNA3 and non-transfected cells (14 h, 28 h, 30 h respectively). The cloning efficiencies of transfected cells with pcDNA HCV-C, pcDNA3 and non-transfected cells were 36%, 2.5% and 1.5%, respectively (P < 0.01). Tumor developed in nude mice inoculated with pcDNA HCV-C transfected cells after the inoculation. HE staining showed bile duct carcinoma character and immunohistochemistry confirmed HCV-C expression in the tumor tissue. The positive control group also showed tumor development, while no tumor mass obtained in the nude mice inoculated with pcDNA3 and non-transfected cells even 36 days after the injection.

CONCLUSIONHCV-C protein showed human normal biliary epithelial cells transformation and tumorigenic features.

Animals ; Bile Duct Neoplasms ; etiology ; Bile Ducts ; cytology ; Cell Transformation, Neoplastic ; Cell Transformation, Viral ; Cells, Cultured ; Epithelial Cells ; pathology ; Female ; Hepacivirus ; Humans ; Mice ; Mice, Nude ; Plasmids ; Transfection ; Viral Core Proteins ; physiology