Hepatitis c virus (HCV) infection has become one of the global public health problem,while there is no vaccine to prevent HCV infection, the so-called "cocktail" therapy that use a combination of drugs targeting multiple steps in the HCV infection cycle could achieve better curative effect. the process of HCV entering into host cell is the important step of drug intervention, in which HCV envelope protein El and E2, Host cell factors including Heparan sulfate(HS), CD81, scavenger receptor class B type I (SR-BI), Occludin (OCLD), Claudin (CLDN), low densitity lipoprotein receptor (LDLR), dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN), Liver/lymph node specific ICAM-3-grabbing integrin(L-SIGN), trans- ferrin receptor 1 (TfR1) and so on play a important role. The virus and the host factors can be used as targets of hcv entry inhibitors many studies have shown that as novel and promising compounds, HCV entry inhibitors combinating with other drugs can be more effective in the treatment of HCV, this paper have re- viewed targets and inhibitors of HCV enterring into host cell since 1990s.
Animals ; Antiviral Agents ; pharmacology ; Hepacivirus ; drug effects ; physiology ; Hepatitis C ; genetics ; metabolism ; virology ; Humans ; Receptors, Virus ; genetics ; metabolism ; Viral Envelope Proteins ; genetics ; metabolism ; Virus Internalization ; drug effects

APOBEC3 is a class of cytidine deaminase, which is considered as a new member of the innate immune system, and APOBEC3G belongs to this family. The research about APOBEC3G is a new direction of innate immune defense mechanism against virus. APOBEC3G has the restrictive activity on many viral replications, which deaminates dC to dU in the viral genome and then induces extensive hypermutation. APOBEC3G can also interrupt viral replication at several phases such as reverse transcription, replication, nucleocapsid and so on by non-deamination mechanisms. However, virus can encode viral proteins to counteract the restriction activity of APOBEC3G. Elucidation of the antagonistic interaction between APOBEC3G and the virus will be contributed to development of new antiviral drugs in the future.
APOBEC-3G Deaminase ; Animals ; Cytidine Deaminase ; genetics ; metabolism ; DNA Replication ; Deamination ; HIV-1 ; physiology ; Hepacivirus ; genetics ; physiology ; Hepatitis B virus ; genetics ; physiology ; Humans ; Paramyxoviridae ; genetics ; physiology ; Retroviridae ; physiology ; Virus Replication ; vif Gene Products, Human Immunodeficiency Virus ; metabolism

OBJECTIVETo investigate the clinical features and rate of natural viral clearance in patients with hepatitis C virus (HCV) infection acquired by blood transfusion from a single donor.

METHODSNinety-six patients who acquired HCV infection between January 1998 and December 2002, upon receipt of donated blood from a single infected individual in Guizhou,were included in this retrospective cross-sectional study. Patients were clinically assessed to determine levels of anti-HCV antibodies, HCV RNA and biochemical indicators of liver function,as well as features of liver structure (by abdominal B ultrasonography and elastography). HCV genetic testing was used to determine the virus genotype. Measurement data were expressed as mean ± standard deviation. Count data were analyzed by the x² test,with P less than 0.05 indicating statistical significance.

RESULTSAll 96 patients tested positive for antiHCV antibodies. The majority of patients (70%; 34:33 male:female) had HCV RNA more than or equal to 1.0 * 103 copies/ml. All patients carried the same HCV genotype as the single blood donor:genotype lb. The overall rate of natural HCV clearance was 30.2%. but males had a significantly lower rate (19.0% (8/42) vs. females:38.9% (21/54);x²=4.41,P=0.023) as did older patients (more than 40 years-old:16.1% (5/31) vs .less than or equal to 40 years-old:36.9% (24/65);x²=4.30,P=0.028). The overall rate of chronic HCV infection (CHC) was 69.8%,but the rate was significantly lower in younger patients (less than or equal to 40 years-old:63.1% (41/65) vs. more than 40 years-old:83.9% (26/31);x²=6.67,P=0.028). Among the 67 patients with CHC,12 had symptoms of mild weakness,anorexia and abdominal distention,11 had elevated serum alanine aminotransferase (116.25 +/- 24.65 U/L) and stage 3 or 4 fibrosis (liver elasticity values more than or equal to 5.1 kPa),and three had mildly abnormal serum bilirubin (32.56 ± 5.28 mumol/L). Fifteen patients showed signs of chronic hepatitis and one patient showed signs of cirrhosis by abdominal B ultrasonography. None of the patients showed signs of hepatocellular carcinoma.

CONCLUSIONThe course of blood transfusion acquired HCV infection is largely unknown and natural viral clearance rate may be associated with sex-and age-related factors.

Adolescent ; Adult ; Aged ; Blood Donors ; Child ; Cross-Sectional Studies ; Female ; Genotype ; Hepacivirus ; genetics ; physiology ; Hepatitis C ; epidemiology ; virology ; Hepatitis C Antibodies ; blood ; Hepatitis C, Chronic ; epidemiology ; virology ; Humans ; Male ; Middle Aged ; RNA, Viral ; blood ; Remission, Spontaneous ; Retrospective Studies ; Transfusion Reaction ; Young Adult

OBJECTIVETo construct a full-genome hepatitis C virus (HCV) replicon that will allow for direct initiation of replication and generation of infectious viral particles in an in vitro and in vivo cell system.

METHODSSelf-cleaving ribozyme sequences were added to each side of the HCV cDNA clone JFH1 and the replication-deficient clone JFH1/GND, then inserted into the pcDNA3.1 vector downstream of the CMV promoter. The resultant recombinant plasmids, pcDNA3.1-RZ-JFH1 and pcDNA3.1-RZ-JFH1/GND, were tested for activity in vitro and in vivo by transiently transfecting into Huh7.5 cells (5 mug/100 mm culture dish) and injecting by high-pressure tail vein injection into Kunming mice (10 - 30 mug/mouse). Quantitative reverse transcription-PCR, immunofluorescence, immunohistochemistry, and serological testing were performed to determine the replication ability and assess the properties of the recombinant plasmids in the two systems.

RESULTSHCV RNA (1 - 3 * 10(6) copies/ml) was detected in the supernatant of transfected Huh7.5 cells up to 16 weeks after transfection. In addition, the viral particles from the supernatant were able to infect nave Huh7.5 cells. However, only transient viremia was achieved upon tail vein injection of the plasmid, and no HCV antigen-positive cells were detected by immunohistochemistry nor HCV-specific antibodies by serological testing.

CONCLUSIONThe constructed HCV replicon was capable of stable expression in cultured cells and of efficiently generating infectious viral particles in the in vitro system over a long period. However, the HCV replicon did not show infective characteristics in an in vivo mouse system. The full-length HCV replicon may represent a useful tool for in vitro study of HCV pathological mechanisms, possibly including anti-HCV drug screening.

Animals ; Base Sequence ; Cell Line ; Genetic Vectors ; Genome, Viral ; Hepacivirus ; genetics ; physiology ; Humans ; Male ; Mice ; Mice, Inbred Strains ; RNA, Catalytic ; genetics ; Recombination, Genetic ; Replicon ; Virus Replication ; genetics

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

Hepatitis C virus (HCV) is a positive sense, single-stranded RNA virus in the Flaviviridae family. It causes acute hepatitis with a high propensity for chronic infection. Chronic HCV infection can progress to severe liver disease including cirrhosis and hepatocellular carcinoma. In the last decade, our basic understanding of HCV virology and life cycle has advanced greatly with the development of HCV cell culture and replication systems. Our ability to treat HCV infection has also been improved with the combined use of interferon, ribavirin and small molecule inhibitors of the virally encoded NS3/4A protease, although better therapeutic options are needed with greater antiviral efficacy and less toxicity. In this article, we review various aspects of HCV life cycle including viral attachment, entry, fusion, viral RNA translation, posttranslational processing, HCV replication, viral assembly and release. Each of these steps provides potential targets for novel antiviral therapeutics to cure HCV infection and prevent the adverse consequences of progressive liver disease.
Antigens, CD81/metabolism ; Genome, Viral ; Hepacivirus/genetics/*physiology ; Humans ; RNA, Viral/metabolism ; Scavenger Receptors, Class B/metabolism ; Viral Envelope Proteins/chemistry/metabolism ; Viral Nonstructural Proteins/chemistry/metabolism ; Virus Assembly ; Virus Internalization ; Virus Replication

OBJECTIVETo investigate the in vivo functional roles of the La autoantigen (La), the human homologue of the 33-kDa vesicle-associated membrane protein-associated protein (hVAP-33), and the subunit gamma of the human eukaryotic initiation factors 2B (eIF2Bgamma) as co-infection factors supporting chronic infection with hepatitis C virus (HCV).

METHODSSmall interfering (si)RNAs were designed against the HCV internal ribosome entry site (IRES) and transfected into Huh7 cells chronically infected with the HCV pseudovirus (designated as Huh7-HCV cells). The IRES siRNA producing the most effective silencing was selected for further analysis by fluorescence quantitative polymerase chain reaction (qPCR). siRNAs designed against La, hVAP-33, and eIF2Bgamma and the IRES-specific siRNA were then transfected, respectively or in various combinations, into the Huh7-HCV cell line for 48 h. The delta CT values were calculated and used to compare the HCV inhibitive efficacies of the siRNAs in isolation or in combination. Western blotting analysis was used to compare the quantity of core protein expression in each group.

RESULTSThe four gene-specific siRNAs, in isolation or in combination, caused inhibition of HCV replication and gene and protein expressions to varying degrees. The combination of La + IRES siRNAs produced the strongest inhibition of HCV core antigen expression. The combinations of hVAP-33 + IRES siRNAs and eIF2Bgamma + IRES siRNAs produced stronger inhibitions of HCV replication and gene and protein expressions than either hVAP-33 siRNA or eIF2Bgamma siRNA alone.

CONCLUSIONLa, hVAP-33, and eIF2Bgamma act as co-infection factors of HCV chronic infection in vivo. HCV replication and gene and protein expression can be inhibited significantly by RNA interference of these co-infection factors and/or HCV IRES.

Autoantigens ; genetics ; Cell Line ; Eukaryotic Initiation Factor-2B ; genetics ; Hepacivirus ; immunology ; physiology ; Humans ; RNA, Small Interfering ; genetics ; Ribonucleoproteins ; genetics ; Vesicular Transport Proteins ; genetics ; Virus Replication

OBJECTIVETo investigate the influence of miR-122 on IFN-α treatment for HCV infection.

METHODSHuh7.5.1 cells infected with HCV were treated with miR-122 mimics (20 nmol/L, 100 nmol/L, 400 nmol/L) and/or IFN-α (1000 IU/ml). The relative expression of HCV RNA was detected by real-time polymerase chain reaction (PCR). Huh7.5.1 cells were treated with different amounts of HCV (107 copies, 106 copies and 105 copies) and/or IFN-α (1000 IU/ml).

RESULTSIFN-α suppressed the replication of HCV in a time-dependent manner, resulting in a ≊ 83% reduction of HCV at 48 h. MiR-122 mimics facilitated replication of HCV RNA in a dose-dependent manner (P<0.05). The antiviral effect of IFN-α was inverted to levels of miR-122 mimics (20 nmol/L, 100 nmol/L, 400 nmol/L), (73.3% ± 3.5% compared with 84% ± 4.5%, P>0.05; 64.67% ± 5.5% compared with 84% ± 4.5%, P>0.05; 56.33% ± 5.1% compared with 84% ± 4.5%, P<0.05). The antiviral effect of IFN-α was inverted to HCV load (105 copies group compared with 107 copies group, P<0.05).

CONCLUSIONMiR-122 facilitates replication of HCV RNA in the cell culture system; and the expression of miR-122 may partly counteract the anti-HCV effect of IFN-α.

Antiviral Agents ; pharmacology ; Cell Line, Tumor ; Hepacivirus ; drug effects ; genetics ; physiology ; Humans ; Interferon-alpha ; pharmacology ; MicroRNAs ; genetics ; RNA, Viral ; genetics ; Transfection ; Virus Replication ; drug effects ; genetics

OBJECTIVETo investigate the inhibitive effects of small interfering RNA (siRNA) on hepatitis C virus (HCV) replication in cells infected by HCV in vitro.

METHODSThe HCV RNA transcripts prepared by pFL-JC1 were transfected into Huh-7.5.1 cells. Na ve Huh-7.5.1 cells were incubated with the supernatants of transfected cells and the expression of HCV core protein in infected cells was detected by indirect immunofluorescence. The infected cells were transfected with 4, 40 and 200 nmol/L of NS5B siRNA for 24 h, 48 h and 72 h, respectively. The normal Huh-7.5.1 cells were transfected with 4, 40 and 200 nmol/L of NS5B siRNA. Group of blank, lipofectamine 2000, unrelated siRNA and IFNα-2b (1000 IU/ml) served as controls. The HCV RNA and PKR mRNA levels were examined by quantitative RT-PCR.

RESULTSThe HCV core protein in HCV infected cells was detected. Compared with control groups, the HCV RNA levels in infected cells significantly decreased when transfected with 40 and 200 nmol/L of siRNA for 24 h; 4, 40 and 200 nmol/L of siRNA for 48 h and 72 h (P<0.05). The HCV RNA levels in infected cells treated with IFNα-2b (1000 IU/ml) for 24 h, 48 h and 72 h were significantly lower than those in control groups (P<0.05 or P<0.01). The PKR mRNA levels in Huh-7.5.1 cells transfected with siRNA of three concentrations did not have significant difference, as compared with control groups (P>0.05).

CONCLUSIONsiRNA against HCV NS5B region can effectively inhibit HCV replication in HCV infected cells, but can not activate the dsRNA-dependent protein kinase (PKR).

Cell Line, Tumor ; Hepacivirus ; drug effects ; genetics ; physiology ; Humans ; RNA, Small Interfering ; pharmacology ; Transfection ; Viral Nonstructural Proteins ; genetics ; Virus Replication ; drug effects

Amyotrophic Lateral Sclerosis ; genetics ; Animals ; Biological Transport, Active ; Bipolar Disorder ; genetics ; Glucose Transporter Type 4 ; metabolism ; Hepacivirus ; physiology ; Humans ; Neoplasm Metastasis ; Neoplasms ; metabolism ; Point Mutation ; Polymorphism, Single Nucleotide ; R-SNARE Proteins ; metabolism ; Tissue Distribution ; Transport Vesicles ; physiology ; Vesicular Transport Proteins ; chemistry ; genetics ; metabolism ; physiology ; Virus Replication