• BMB Reports
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• 제37권2호
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• pp.167-176
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• 2004

Although efficient antiviral lamivudine is used for HBV-infected patients, a prolonged treatment with nucleoside analogs often results in lamivudine-resistant variants. In this study, we evaluated the fidelity of the lamivudine-resistant variants. The FLAG-tagged wild-type (FPolE) and Met550 variants (FPolE/M550A, M550V, and M550I) of HBV DNA polymerases were expressed in insect cells then purified. Like many other reverse transcriptases, no $3'{\rightarrow}5'$ exonuclease activity was detected in the HBV DNA polymerase. Since there is no proofreading activity, then the use of the site-specific nucleotide misincorporation method is beneficial. From the $f_{ins}$ value analysis, it is evident that M550I and M550V exhibit higher fidelity values than the wild-type HBV DNA polymerase, while M550A exhibits similar fidelity values. It is therefore suggested that lamivudine resistance comes from the stringency to dNTP binding and the discrimination of dCTP and lamivudine in M550V and M550I.

• Biomolecules & Therapeutics
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• 제7권2호
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• pp.133-137
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• 1999

This study was undertaken to test for anti-Hepatitis B virus (HBV) activity of the aqueous extracts prepared from Eugenia caryophyllate, Ephedra sinica, Cinnamomum cassia. Aqueous extracts were assayed for the inhibition of HBV replication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HePG2 2.2.15 cells. All extracts decreased the levels of extracellular HBV virion DNA at concentrations ranging from 128 to 256 $\mu$g/ml and inhibited the production of HBsAg dose-dependently. Our findings suggest that these three hebal medicinal plants may have potential to develop as specific anti-HBV drugs in the future.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4199-4202
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• 2015

Background: Hepatitis B virus infection is one of the major world health problems. Epigallocatechin-3 gallate is the major component of the polyphenolic fraction of green tea and it has an anti-viral, anti-mutagenic, anti-tumorigenic, anti-angiogenic, anti-proliferative, and/or pro-apoptotic effects on mammalian cells. In this study, our aim was to investigate the inhibition of HBV replication by epigallocatechin-3 gallate in the Hep3B2.1-7 hepatocellular carcinoma cell line. Materials and Methods: HBV-replicating Hep3B2.1-7 cells were used to investigate the preventive effects of epigallocatechin-3 gallate on HBV DNA replication. The expression levels of HBsAg and HBeAg were determined using ELISA. Quantitative real-time-PCR was applied for the determination of the expression level of HBV DNA. Results: Cytotoxicity of epigallocathechin-3-gallate was not observed in the hepatic carcinoma cell line when the dose was lower than $100{\mu}M$. The ELISA method demonstrated that epigallocatechin-3 gallate have strong effects on HBsAg and HBeAg levels. Also it was detected by real-time PCR that epigallocatechin-3 gallate could prevent HBV DNA replication. Conclusions: The obtained data pointed out that although the exact mechanism of HBV DNA replication and related diseases remains unclear, epigallocatechin-3 gallate has a potential as an effective anti-HBV agent with low toxicity.

• Archives of Pharmacal Research
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• 제29권11호
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• pp.1042-1048
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• 2006

Plasmid DNA vaccines encoding the hepatitis B virus (HBV) surface and hepatitis C virus (HCV) envelope antigens, respectively, were constructed, and attempt were made to find the possibility of a divalent vaccine against HBV and HCV. The expression of each plasmid in Cos-1 cells was confirmed using immunocytochemistry. To measure the induced immune response by these plasmids in vivo, female BALB/c mice were immunized intramuscularly with $100\;{\mu}g$ of either both or just one of the plasmids. Anti-HBV and HCV-specific antibodies and related cytokines were evaluated to investigate the generation of both humoral and cellular immune responses. As a result, specific anti-HBV and anti-HCV serum antibodies from mice immunized with these plasmids were observed using immunoblot. The levels of IL-2 and RANTES showing a $Th_{1}$ immune response were significantly increased, but there was no change in the level of IL-4 ($Th_{1}$ immune response) in any of the immunized groups. Compared with each plasmid DNA vaccine, the combined vaccine elicited similar immune responses in both humoral and cell-mediated immunities. These results suggest that the combined DNA vaccine can induce not only comparable immunity experimentally without antigenic interference, but also humoral and $Th_{1}$ dominant cellular immune responses. Therefore, they could serve as candidates for a simultaneous bivalent vaccine against HBV and HCV infections.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9635-9641
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• 2014

Background: This retrospective study was aimed to investigate the efficacy of prophylactic agents in hepatocellular carcinoma (HCC) patients receiving TACE and compare the difference between lamivudine and entecavir. Materials and Methods: A consecutive series of 203 HBV-related HCC patients receiving TACE were analyzed including 91 patients given prophylactic agents. Virologic events, defined as an increase in serum HBV DNA level to more than 1 log10 IU/ml higher than the nadir level, hepatitis flares due to HBV reactivation and progression free survival (PFS) were the main endpoints. Results: Some 48 (69.6%) reached virologic response. Prophylaxis significantly reduced virologic events (8.8% vs 58.0%, p=0.000) and hepatitis flares (1.1% vs 13.4%, p=0.001). Patients presenting undetectable HBV DNA levels displayed a significantly improved PFS as compared to those who never achieved undetectable HBV DNA. Prophylaxis and e-antigen positivity were the only significant variables associated with virologic events. In addition, prophylaxis was the only independent protective factor for hepatitis flares. Liver cirrhosis, more cycles of TACE, HBV DNA negativity, a lower Cancer of the Liver Italian Program score, non-metastasis and no hepatitis flares were protective factors for PFS. Prophylactic lamivudine demonstrated similar efficacy as entecavir. Conclusions: Prophylactic agents are efficacious for prevention of HBV reactivation in HCC patients receiving TACE. Achievement of undetectable HBV DNA levels displayed a significant capability in improving PFS. Moreover, persistent tumor residual lesions, positive HBV DNA and hepatitis B flares might be causes of tumor progression in these patients.

• IMMUNE NETWORK
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• 제5권1호
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• pp.1-10
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• 2005

Background: Chronic infection with hepatitis B virus (HBV) affects about 350 million people worldwide, which have a high risk of development of cirrhosis and hepatocellular carcinoma. Treatment of chronic HBV infection relies on IFN-${\alpha}$ or lamivudine. However, interferon-${\alpha}$ is effective in only about 30% of patients. Also, the occurrence of escape mutations limits the usage of lamivudine. Therefore, the development and evaluation of new compounds or approaches are urgent. Methods: We comparatively evaluated DNA and adenoviral vaccines expressing HBV antigens, either alone or in combined regimens, for their ability to elicit Th1-type immune responses in Balb / c mice which are believed to be suited to resolve HBV infection. The vaccines were tested with or without a genetically engineered IL-12 (mIL-12 N220L) which was shown to enhance sustained Th1-type immune responses in HCV E2 DNA vaccine. Results: Considering the Th1-type cytokine secretion and the IgG2a titers, the strongest Th1-type immune response was elicited by the DNA prime-adenovirus boost regimen in the presence of mIL-12 N220L. In addition, the codelivery of mIL-12 N220L modulated differentially the immune responses by different vaccination regimens. Conclusion: Our results suggest that the DNA prime-adenovirus boost regimen in the presence of mIL-12 N220L may be the best candidate for HBV vaccine therapy of the regimens tested in this study and will be worthwhile being evaluated in chronic HBV patients.

• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.16-24
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• 2021

Hepatitis B virus (HBV) genome P-encoded protein HBV DNA polymerase (Pol) has long been known as a reverse transcriptase during HBV replication. In this study, we investigated the impact of HBV Pol on host cellular processes, mainly apoptosis, and the underlying mechanisms. We showed a marked reduction in apoptotic rates in the HBV Pol-expressed HepG2 cells compared to controls. Moreover, a series of assays, i.e., yeast two-hybrid, GST pull-down, co-immunoprecipitation, and confocal laser scanning microscopy, identified the host factor eEF1A2 to be associated with HBV Pol. Furthermore, knockdown of eEF1A2 gene by siRNA abrogated the HBV Pol-mediated anti-apoptotic effect with apoptosis induced by endoplasmatic reticulum (ER) stress-inducer thapsigargin (TG), thus suggesting that the host factor eEF1A2 is essential for HBV Pol's anti-apoptosis properties. Our findings have revealed a novel role for HBV Pol in its modulation of apoptosis through integrating with eEF1A2.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제13권1호
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• pp.44-50
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• 2010

목 적: 라미부딘에 내성을 보인 소아 청소년 만성 B형 간염에서 엔테카비어 단독요법의 바이러스 억제효과를 확인하고자 하였다. 방 법: 라미부딘에 내성을 보이는 소아 청소년 만성 B형 간염 환자 23명 중 6명(남 4, 나이 15.1~24.6세, 평균 17.5세)에게 엔테카비어 1 mg으로 치료하였으며 (평균 13.4개월, 1~21.1개월) 아데포비어로 치료한 11명과 비교하였다. 치료 시작 후 HBV DNA 역가가 1 $log_{10}$ 이하, 2 $log_{10}$ 이하, 357 IU/mL 이하로 감소하는데 걸리는 기간을 각각 구하여 서로 비교하였다. 결 과: HBV DNA 역가가 2 $log_{10}$ IU/mL 이상 감소하는데 걸린 기간은 각각 2.4${\pm}$2.3개월, 9.2${\pm}$7.3개월로 (p=0.025) 두 군 간에 유의한 차이가 있었다. HBV DNA 역가가 1 $log_{10}$ IU/mL 이상 감소하는데 걸린 기간 및 357 IU/mL 이하로 감소하는데 걸린 기간은 두 군 간에 유의한 차이가 없었다. 결 론: 라미부딘 내성 소아 청소년 만성 B형 간염에서 엔테카비어 단독요법은 아데포비어 단독요법과 비교해 볼 때 HBV DNA 역가가 2 $log_{10}$ IU/mL 이상 감소하는데 걸린 기간이 유의하게 짧았다. 특별한 부작용은 관찰되지 않았다. 엔테카비어의 치료 효과를 알기 위하여 더 많은 환자를 대상으로 한 장기 치료가 필요하다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제2권2호
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• pp.169-177
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• 1999

목 적: 소아 만성 B형 간염 환아에서 알파 인터페론의 치료 효과는 보고자마다 차이가 있으나 30~40%로 알려져 있다. 그러나 만성 지속성 B형 간염, 혈청 ALT치가 낮은 경우나 혈청 HBV DNA치가 높은 소아 만성 B형 간염 환자에서 알파 인터페론 단독 투여 시 그 치료 효과는 더 낮다고 보고되고 있다. 이에 저자들은 알파 인터페론 단독 투여 시 치료 효과가 낮다고 알려진 소아 만성 B형간염 환자에 prednisolone 이탈 요법 후 인터페론 병용 투여 시 그 치료 효과를 알아보고자 본 연구를 시행하였다. 대상 및 방법: 1996년 1월부터 1997년 12월까지 전남대학교병원 소아과에 내원하여 만성 B형 간염으로 진단받은 28명을 대상으로 하였다. 대상 환아 중 간 조직 검사 상 만성 활동성 간염을 보이고 혈청 ALT치가 100 IU/L 이상이고 혈청 HBV-DNA치가 100 pg/$300\;{\mu}L$ 미만인 14명(group 1)은 알파 인터페론을 체표면적($m^2$) 당 5백만 단위를 6개월 동안 주 3회 단독 투여하였다. 조직 검사 상 만성 지속성 간염인 경우와 만성 활동성 간염이면서 혈청ALT치가 100 IU/L 미만 또는 혈청 HBV DNA치가 100 pg/$300\;{\mu}L$ 초과한 14명(group 2)은 prednisolone을 60 mg/$m^2$, 40 mg/$m^2$, 20 mg/$m^2$으로 각각 2주씩 6주간 경구 투여하고 2주간 휴약 기간을 가진 후 알파 인터페론을 group 1과 같은 방법으로 투여하였다. 치료에 대한 반응은 인터페론 투여가 종료되는 시점에서 완전반응(항 HBe 항체의 양전화, 혈청 ALT 정상화 및 혈청 HBV-DNA 음성), 부분반응(혈청 ALT 정상화 또는 혈청 HBV-DNA 음성) 및 무반응으로 평가하였다. 결 과: 1) 대상 환아의 평균 연령은 130.6개월(21~192개월)이었고, 남아는 22례, 여아는 6례이었다. 만성 지속성 간염은 11례, 만성 활동성 간염은 17례이었고, 15명의 환아에서 모친이 B형 간염 바이러스 만성 보유자이었다. 2) Group 1에서 평균 연령은 144.1개월(97~169개월), 남아 9명, 여아 5명, 혈청 ALT $299.9{\pm}215.3$ IU/L, HBV-DNA $49.3{\pm}33.1\;pg/300\;{\mu}L$이었고, group 2에서 평균 연령은 112.1개월(21~192개월), 남아 13명, 여아 1명, 만성 지속성 간염 11명, 만성 활동성 간염 3명, 혈청 ALT $85.6{\pm}71.0$ IU/L, HBVDNA $524.3{\pm}1064\;pg/300\;{\mu}L$이었다. 3) Group 1에서 항 HBe 항체 양전은 10례(71.4%) 에서, 혈청 ALT는 9례(64.3%)에서 정상화되었고, HBV-DNA는 11례(78.6%)에서 음성화되었다. Group 2에서 항 HBe 항체 양전은 7례(50.0%)에서, 비정상 수치를 보인 9명의 환아 중 5명(55.6%)이 ALT 의 정상화를 보였고, HBV-DNA는 9례(64.3%)에서 음성화되었다. 두 군간의 항 HBe 항체의 양전율, ALT치의 정상화율, HBV DNA치의 음성화율에 있어서 통계학적으로 유의한 차이는 없었다. 4) Group 1에서 완전반응은 8례(57.1%), 부분반응은 3례(21.4%), 무반응은 3례(21.4%)이었고, group 2 에서는 완전반응 7례(50.0%), 부분반응 2례(14.3%), 무반응 5례(35.7%)으로 두 군간의 통계학적 유의한 차이는 없었다. 결 론: 소아 만성 B형 간염에 대한 치료로 인터페론 단독 요법으로 반응이 좋지 않을 것으로 예측되는 환자군에 스테로이드 이탈 요법 후 인터페론 병합 투여는 안전하고 효과적인 치료법으로 생각된다. 향후 치료 효과의 지속 여부에 대한 지속적인 관찰과 더 많은 환자를 대상으로 한 전향적인 비교 연구가 필요하리라 사료된다.

• Journal of Preventive Medicine and Public Health
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• 제33권3호
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• pp.323-333
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• 2000

Objectives : Chronic HBsAg carriers are the principal source of infection for other susceptible people, and are themselves at high risk of developing serious liver diseases. In Korea, it has been estimated that 65-75% of the HBsAg positives remained as persistent carriers. Additionally, familial clustering of MBV infection has frequently been observed among carriers. Some would become progressive, chronic hepatitis patients, and others would not. The aim of this study was to evaluate the association between various factors, such as the duration of infection, type of virus, mutation of precore/core region in HBV, major histocompatibility class-I, and developing chronic liver diseases among familial HBV carriers. Methods : Chronic carrier status was identified by repeated serological tests for HBsAg at intervals of six months or more. A familial chronic carrier was defined when the disease was observed in a family member over two generations. Two families were recruited, among which a total of 20 chronic HBsAg carriers(11 carriers in No.1, and 9 in No.2 family) were identified. Data on the general characteristics and liver disease status were collected. Identification of the HBV-DNA was successful only for 13 subjects among the 20 carriers. Analysis of viral DNA in terms of subtype, pre-core and core region mutations was carried out. The type of major histocompatibility class-1 for the 13 subjects was also analysed. Results & Conclusions : Seven of 10 chronic HBV carriers of the 1st generation and one of 10 of the 2nd generation were clinical patients with chronic hepatitis, the others, three of the 1 st and nine of the 2nd generation, were asymptomatic carriers. This data indicates that the duration of HBV carriage is one of the major factors for disease severity. The subtype of HBsAg analysed using MBV-DNA identified in 13 carriers were adr, and the pattern of precore nonsense mutation in HBV-DNA was identical among family members, which meads that the same virus strains were transmitted between the family members. The association between the precore or core mutations in HBV-DNA and the disease severity was not observed. While it was suggested that a specific type of MHC class-I may be related to disease progression.