• Korean Journal of Microbiology
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• v.47 no.4
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• pp.342-347
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• 2011

T cells play a key role in viral infection. However, in patients with chronic hepatitis C virus (HCV) infection, HCV-specific T cells are dysfunctional and impaired in the liver, which is the primary site for HCV replication. There are multiple potential mechanisms for HCV-specific T cell dysfunction including induction of immune inhibitory pathways (program death-1; PD-1, cytotoxic t lymphocyte associated antigen-4; CTLA-4) and immune tolerance induced specific for the liver. However, the interaction between hepatocytes and HCV-specific CD8 T cells has not clearly established. In this study, we confirmed huh (human hepatoma) 7.5 cells expressing HLA (human leukocyte antigen) A2 presented antigen to activate HCV-specific CD8 T cells in HLA A2-restricted manner and expression of PD-L (program death ligand) 1 on huh7.5 cells reduced HCV-specific CD8 T cell activation, suggesting an immune modulatory activity. Loss of HCV-specific tetramer responses following antigenic stimulation correlated with increased caspase-3 activity. In addition, PD-L1 on huh7.5 cells rescued HCV-specific CD8 T cells from apoptosis. Our results suggest that the interaction between PD-L1 and PD-1 can recover the function of HCV-specific CD8 T cells in the liver, which could be applied in therapy of HCV chronic infection.

• Journal of Preventive Medicine and Public Health
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• v.37 no.3
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• pp.253-259
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• 2004

Objectives : To investigate the prevalence of hepatitis B and C virus infections and determine the associated risk factors among young adults in Busan, Korea, which is known to have a high incidence of liver cancer. Methods : The study population consisted of volunteer participants in a health survey during 2002, which included 1,350 students (515 males and 835 females) aged between 16 and 24 years, from three different schools in Busan. The participating students were asked to fill in a self-administered questionnaire which included lifestyle habits and risk factors of hepatitis. Sera obtained from the participants were studied for HBsAg, anti-HBs, and Anti-HCV by enzyme immunoassay (EIA) method and for liver function tests. Results : Among the study subjects (N=1,350), the seropositivities of HBsAg 7.9%(95% CI=7.8-8.0), 7.6%(95% CI=7.6-7.7) in male and 8.1%(95% CI=8.0-8.2) in female. And the seropositivity of Anti-HBs was 69.7%(95% CI=69.0-70.4), 70.5%(95% CI=69.8-71.2) in male and 69.2%(95% CI=68.5-69.9) in female. The seropositivity of Anti-HCV was 0.4%, 0.2% in male and 0.5% in female. The seropositivity for HBsAg in the subjects not having a hepatitis B vaccination history was twice(95% CI=1.0-4.4) that of those that did. Also, the seropositivity for HBsAg in subjects having experienced sexual intercourse was 1.7 times (95% CI=0.9-3.0) that of the subjects who had not. Conclusions : The present study confirmed the high prevalence of HBsAg seropositivity and sexual transmission of HBV among adolescents and young adults may occur. Further studies to evaluate the relationship between HBV vaccination and sexual transmission are required for the young population in Korea.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.660-664
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• 2005

We have previously isolated specific RNA aptamers with high affinity against the helicase domain of hepatitis C virus (HCV) nonstructural protein 3 (NS3). The RNA aptamers competitively and efficiently inhibited the helicase activity, partially impeding HCV replicon replication in human hepatocarcinoma cells. In this study, the RNA aptamers were tested for binding to the HCV NS3 proteins in eukaryotic cells, using a yeast three-hybrid system. The aptamers were then recognized by the HCV NS3 proteins when expressed in the cells, while the antisense sequences of the aptamers were not. These results suggest that the in vitro selected RNA aptamers can also specifically bind to the target proteins in vivo. Consequently, they could be potentially utilized as anti-HCV lead compounds.

• Journal of Life Science
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• v.28 no.9
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• pp.1007-1015
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• 2018

The E6-associated protein (E6AP) is known to induce the ubiquitination and proteasomal degradation of HCV core protein and thereby directly impair capsid assembly, resulting in a decline in HCV replication. To counteract this anti-viral host defense system, HCV core protein has evolved a strategy to inhibit E6AP expression via DNA methylation. In the present study, we further explored the mechanism by which HCV core protein inhibits E6AP expression. HCV core protein upregulated both the protein levels and enzyme activities of DNA methyltransferase 1 (DNMT1), DNMT3a, and DNMT3b to inhibit E6AP expression via promoter hypermethylation in HepG2 cells but not in Hep3B cells, which do not express p53. Interestingly, p53 overexpression alone in Hep3B cells was sufficient to activate DNMTs in the absence of HCV core protein and thereby inhibit E6AP expression via promoter hypermethylation. In addition, upregulation of p53 was absolutely required for the HCV core protein to inhibit E6AP expression via promoter hypermethylation, as evidenced by both p53 knockdown and ectopic expression experiments. Accordingly, levels of the ubiquitinated forms of HCV core protein were lower in HepG2 cells than in Hep3B cells. Based on these observations, we conclude that HCV core protein evades ubiquitin-dependent proteasomal degradation in a p53-dependent manner.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7213-7218
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• 2014

Background: Egypt has one of the highest prevalences of hepatitis C virus (HCV) infection worldwide. Although the IL28B gene polymorphism has been shown to modify the course of chronic HCV infection, this has not been properly assessed in the Egyptian population. Materials and Methods: The IL28B rs12979860 single nucleotide polymorphism (SNP) was therefore examined in 256 HCV-infected Egyptian patients (group II) at different stages of disease progression and in 48 healthy volunteers (group I). Group II was subdivided into GII-A (chronic hepatitis patients, n=119), GII-B (post hepatitis cirrhosis, n=66) and GII-C (HCC on top of cirrhosis, n=71). Results: The C/T genotype was the commonest in all groups. It was more frequent in GI (52%) than in GII (48%). There was no significant difference in the frequency of C/T and C/C or T/T genotypes between groups and subgroups (p=0.82). Within the subgroups; the C/C genotype was more common in GII-B while C/T and T/T genotypes were more common in GII-C, though with no significant difference (p=0.59 and p=0.80). There was no significant association between IL28B rs12979860 SNP and viral load, ALT, AFP level, METAVIR scores for necro-inflammation and fibrosis, and Child-Pugh classification. Conclusions: 1) IL28Brs12979860 C/T genotype is the commonest genotype in HCV-associated CH and HCC in Egypt. 2) IL28Brs12979860 polymorphisms are not associated with disease progression or aggression (histological staging, severity of fibrosis in CH or the incidence of post-HCV HCC). 3) Differences in IL28Brs12979860 genotypes could be a consequence of environmental or ethnic variation.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2699-2703
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• 2016

Background: Primary hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. MicroRNAs (miRNAs) have great HCC diagnostic potential and circulating miRNAs have been reported as promising biomarkers for various pathologic conditions. Aim: To explore the potential benefit of serum miR-126, miR-129, miR-155, miR-203 and miR-223 as non-invasive diagnostic markers of hepatitis C virus (HCV)-related HCC. Materials and Methods: The expression of miRNA was evaluated using real-time quantitative RT-PCR in 78 serum samples (30 $treatment-na{\ddot{i}}ve$ chronic HCV, 25 post-HCV compensated cirrhosis and 23 $treatment-na{\ddot{i}}ve$ HCC cases). Results: Comparing miRNA fold changes in the HCC group vs the non HCC groups, there was significant fold decrease in miR-126 (P= 0.034), miR-129 (P= 0.006), miR-155 (P= 0.011), miR-203 (P<0.001) and miR-223 (P= 0.013). The highest AUC to differentiate HCC patients from non-HCC was 0.76 for miR-203. Conclusions: Among studied miRNAs, serum miR-203 has the highest potential as a non-invasive biomarker of HCC.

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.285-291
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• 2005

The nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) is the viral RNA-dependent RNA polymerase (RdRp), which is the essential catalytic enzyme for the viral replication and is an appealing target for the development of new therapeutic agents against HCV infection. A small amount of serum from a single patient with hepatitis C was used to get the genome of a Korean HCV isolate. Sequence analysis of NS5B 1701 nucleotides showed the genotype of a Korean isolate to be subtype 1b. The soluble recombinant HCV NS5B polymerase lacking the C-terminal 24 amino acids was expressed and purified to homogeneity. With the highly purified NS5B protein, we established in vitro systems for RdRp activity to identify potential polymerase inhibitors. The rhodanine family compounds were found to be potent and specific inhibitors of NS5B from high throughput screening (HTS) assay utilizing the scintillation proximity assay (SPA) system. The binding mode of an inhibitor was analyzed by measuring various kinetic parameters. Lineweaver-Burk plots of the inhibitor suggested it binds not to the active site of NS5B polymerase, but to an allosteric site of the enzyme. The activity of NS5B in in vitro polymerase reactions with homopolymeric RNA requires interaction with multiple substrates that include a template/primer and ribonucleotide triphosphate. Steady-state kinetic parameter, such as Km, was determined for the ribonucleotide triphosphate. One of compounds found interacts directly with the viral polymerase and inhibits RNA synthesis in a manner noncompetitively with respect to UTP. Furthermore, we also investigated the ability of the compound to inhibit NS5B-directed viral RNA replication using the Huh7 cell-based HCV replicon system. The investigation is potentially very useful for the utility of such compounds as anti-hepatitic agents.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3595-3604
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• 2015

Hepatocellular carcinoma (HCC) has been one of the most fatal malignant tumors worldwide and its associated morbidity and mortality remain of significant concern. Based on in-depth reviews of serological diagnosis of HCC, in addition to AFP, there are other biomarkers: Lens culinaris agglutinin-reactive AFP (AFP-L3), descarboxyprothrombin (DCP), tyrosine kinase with Ig and eprdermal growth factor (EGF) homology domains 2 (TIE2)-espressing monocytes (TEMs), glypican-3 (GPC3), Golgi protein 73 (GP73), interleukin-6 (IL-6), and squamous cell carcinoma antigen (SCCA) have been proposed as biomarkers for the early detection of HCC. The diagnosis of HCC is primarily based on noninvasive standard imaging methods, such as ultrasound (US), dynamic multiphasic multidetector-row CT (MDCT) and magnetic resonance imaging (MRI). Some experts advocate gadolinium diethyl-enetriamine pentaacetic acid (Gd-EOB-DTPA) MRI and contrast-enhanced US as the promising imaging madalities of choice. With regard to recent advancements in tissue markers, many cuting-edge technologies using genome-wide DNA microarrays, qRT-PCR, and proteomic and inmunostaining studies have been implemented in an attempt to identify markers for early diagnosis of HCC. Only less than half of HCC patients at initial diagnosis are at an early stage treatable with curative options: local ablation, surgical resection, or liver transplant. Transarterial chemoembolization (TACE) is considered the standard of care with palliation for intermediate stage HCC. Recent innovative procedures using drug-eluting-beads and radioembolization using Yttrium-90 may exhibit beneficial effects in HCC treatment. During the past few years, several molecular targeted agents have been evaluated in clinical trials in advanced HCC. Sorafenib is currently the only approved systemic treatment for HCC. It has been approved for the therapy of asymptomatic HCC patients with well-preserved liver function who are not candidates for potentially curative treatments, such as surgical resection or liver transplantation. In the USA, Europe and particularly Japan, hepatitis C virus (HCV) related HCC accounts for most liver cancer, as compared with Asia-Pacific regions, where hepatitis B virus (HBV) may play a more important role in HCC development. HBV vaccination, while a vaccine is not yet available against HCV, has been recognized as a best primary prevention method for HBV-related HCC, although in patients already infected with HBV or HCV, secondary prevention with antiviral therapy is still a reasonable strategy. In addition to HBV and HCV, attention should be paid to other relevant HCC risk factors, including nonalcoholic fatty liver disease due to obesity and diabetes, heavy alcohol consumption, and prolonged aflatoxin exposure. Interestingly, coffee and vitamin K2 have been proven to provide protective effects against HCC. Regarding tertiary prevention of HCC recurrence after surgical resection, addition of antiviral treatment has proven to be a rational strategy.

• Journal of Yeungnam Medical Science
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• v.33 no.2
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• pp.150-154
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• 2016

Hepatitis C virus (HCV) infection is present in a high proportion of patients with kidney transplantation. Compared with uninfected kidney transplant recipients, HCV infected kidney recipient have higher prevalence of liver disease and worse allograft survival after transplantation. Interferon monotherapy before transplantation is standard therapy for HCV-infected kidney transplant candidates. If HCV infection is discovered after transplantation, interferon monotherapy is considered due to the limited critical situation. However, in this patient, who was a kidney recipient, HCV infection was treated after kidney transplantation with peginterferon-${\alpha}$ and rivabirin. As a result, the patient achieved sustained virologic response.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.261-266
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• 2018

To determine the clinical utility of an immunoblot test and RT-PCR-hybridization test, 160 samples from patients with a chronic HCV infection were analyzed by two tests. A total of 133 samples out of 150 positive samples were positive by RT-PCR-hybridization. The true positive rate of the immunoblot tests and the concordance rate of the two tests was 88.6% and 89.3%, respectively. Serotyping and genotyping were performed to evaluate the distribution of the HCV subtype in Korean isolates. HCV serotypes 1 and 2, and genotypes 1b and 2a were the most common sources of HCV infections in this group. In 49 cases studied with the serotypes and genotypes, serotypes 1 and 2 were 57.1% and 42.9%, respectively. Genotypes 1b, 1b/2b, 2a, 2a/2c, and 2b were 51.0%, 2.0%, 34.7%, 8.2%, and 4.1%, respectively. This study shows that immunoblot tests are more useful for screening HCV infections. The RT-PCR-hybridization test confirmed the HCV infection in patients with positive immunoblot test results. The serotype test is preferred over the genotype test for monitoring the progression or response to treatment. On the other hand, there were no significant differences in the response to an ${\alpha}$-interferon treatment of HCV infection with serotype type 1 or type 2 in Korea.