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Song Z, Lin S, Wu X, Ren X, Wu Y, Wen H, Qian B, Lin H, Huang Y, Zhao C, Wang N, Huang Y, Peng B, Li X, Peng H, Shen S. Hepatitis B virus-related intrahepatic cholangiocarcinoma originates from hepatocytes. Hepatol Int 2023; 17:1300-1317. [PMID: 37368186 PMCID: PMC10522522 DOI: 10.1007/s12072-023-10556-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/27/2023] [Indexed: 06/28/2023]
Abstract
BACKGROUND Hepatitis B virus (HBV) infection is one of the most common risk factors for intrahepatic cholangiocarcinoma (ICC). However, there is no direct evidence of a causal relationship between HBV infection and ICC. In this study, we attempted to prove that ICC may originate from hepatocytes through a pathological study involving ICC tissue-derived organoids. METHOD The medical records and tumor tissue samples of 182 patients with ICC after hepatectomy were collected. The medical records of 182 patients with ICC were retrospectively analyzed to explore the prognostic factors. A microarray of 182 cases of ICC tumor tissue and 6 cases of normal liver tissue was made, and HBsAg was stained by immunohistochemistry (IHC) to explore the factors closely related to HBV infection. Fresh ICC tissues and corresponding adjacent tissues were collected to make paraffin sections and organoids. Immunofluorescence (IF) staining of factors including HBsAg, CK19, CK7, Hep-Par1 and Albumin (ALB) was performed on both fresh tissues and organoids. In addition, we collected adjacent nontumor tissues of 6 patients with HBV (+) ICC, from which biliary duct tissue and normal liver tissue were isolated and RNA was extracted respectively for quantitative PCR assay. In addition, the expression of HBV-DNA in organoid culture medium was detected by quantitative PCR and PCR electrophoresis. RESULTS A total of 74 of 182 ICC patients were HBsAg positive (40.66%, 74/182). The disease-free survival (DFS) rate of HBsAg (+) ICC patients was significantly lower than that of HBsAg (-) ICC patients (p = 0.0137). IF and IHC showed that HBsAg staining was only visible in HBV (+) ICC fresh tissues and organoids, HBsAg expression was negative in bile duct cells in the portal area. Quantitative PCR assay has shown that the expression of HBs antigen and HBx in normal hepatocytes were significantly higher than that in bile duct epithelial cells. Combined with the IF and IHC staining, it was confirmed that HBV does not infect normal bile duct epithelial cells. In addition, IF also showed that the staining of bile duct markers CK19 and CK7 were only visible in ICC fresh tissue and organoids, and the staining of hepatocyte markers Hep-Par1 and ALB was only visible in normal liver tissue fresh tissue. Real-time PCR and WB had the same results. High levels of HBV-DNA were detected in the culture medium of HBV (+) organoids but not in the culture medium of HBV (-) organoids. CONCLUSION HBV-related ICC might be derived from hepatocytes. HBV (+) ICC patients had shorter DFS than HBV (-) ICC patients.
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Affiliation(s)
- Zimin Song
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Shuirong Lin
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Xiwen Wu
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
- Department of Clinical Nutrition, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Xiaoxue Ren
- Department of Oncology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Yifan Wu
- Department of Oncology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Haoxiang Wen
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Baifeng Qian
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Haozhong Lin
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Yihao Huang
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Chenfeng Zhao
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Nian Wang
- Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510030, China
| | - Yan Huang
- Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510030, China
| | - Baogang Peng
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China
| | - Xiaoxing Li
- Institute of Precision Medicine, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China.
| | - Hong Peng
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China.
| | - Shunli Shen
- Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510030, China.
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Zhang Y, Cao KX, Niu QJ, Deng J, Zhao L, Khalil MM, Karrow NA, Kuča K, Sun LH. Alpha-class glutathione S-transferases involved in the detoxification of aflatoxin B 1 in ducklings. Food Chem Toxicol 2023; 174:113682. [PMID: 36813151 DOI: 10.1016/j.fct.2023.113682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023]
Abstract
The objective of this study was to identify the key glutathione S-transferase (GST) isozymes involved in the detoxification of Aflatoxin B1 (AFB1) in ducks' primary hepatocytes. The full-length cDNA encoding the 10 GST isozymes (GST, GST3, GSTM3, MGST1, MGST2, MGST3, GSTK1, GSTT1, GSTO1 and GSTZ1) were isolated/synthesized from ducks' liver and cloned into the pcDNA3.1(+) vector. The results showed that pcDNA3.1(+)-GSTs plasmids were successfully transferred into the ducks' primary hepatocytes and the mRNA of the 10 GST isozymes were overexpressed by 1.9-3274.7 times. Compared to the control, 75 μg/L (IC30) or 150 μg/L (IC50) AFB1 treatment reduced the cell viability by 30.0-50.0% and increased the LDH activity by 19.8-58.2% in the ducks' primary hepatocytes. Notably, the AFB1-induced changes in cell viability and LDH activity were mitigated by overexpression of GST and GST3. Compared to the cells treated with AFB1, exo-AFB1-8,9-epoxide (AFBO)-GSH, as the major detoxified product of AFB1, was increased in the cells overexpression of GST and GST3. Moreover, the sequences, phylogenetic and domain analysis revealed that the GST and GST3 were orthologous to Meleagris gallopavo GSTA3 and GSTA4. In conclusion, this study found that the ducks' GST and GST3 were orthologous to Meleagris gallopavo GSTA3 and GSTA4, which were involved in the detoxification of AFB1 in ducks' primary hepatocytes.
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Affiliation(s)
- Yu Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China; Newhope Liuhe Co. Ltd., Beijing, 100102, China
| | - Ke-Xin Cao
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Qin-Jian Niu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Jiang Deng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
| | - Ling Zhao
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Mahmoud Mohamed Khalil
- Monogastric Research Center, School of Agriculture and Environment, Massey University, Palmerston North, 4442, New Zealand
| | | | - Kamil Kuča
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic
| | - Lv-Hui Sun
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
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Li M, Du M, Cong H, Gu Y, Fang Y, Li J, Gan Y, Tu H, Gu J, Xia Q. Characterization of hepatitis B virus DNA integration patterns in intrahepatic cholangiocarcinoma. Hepatol Res 2021; 51:102-115. [PMID: 33037855 DOI: 10.1111/hepr.13580] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/19/2020] [Accepted: 09/24/2020] [Indexed: 12/13/2022]
Abstract
AIM Hepatitis B virus (HBV) integration is one of the mechanisms contributing to hepatocellular carcinoma (HCC) development. However, the status of HBV integration in intrahepatic cholangiocarcinoma (ICC) is poorly understood. This study aims to characterize the viral integration in HBV-related ICC. METHODS The presence of HBV S and C gene in ICCs and the paratumor tissue was determined by polymerase chain reaction direct sequencing. Hepatitis B virus integration was detected by a high-throughput capture sequencing method. The expression analysis of the genes targeted by HBV in ICC was undertaken in The Cancer Genome Atlas dataset. RESULTS Hepatitis B virus S and/or C gene fragments were detected in 71.43% (10/14) ICCs and 57.14% (8/14) paratumor tissues. Using the high-throughput capture sequencing approach, 139 and 183 HBV integration breakpoints were identified from seven ICC and seven paired paratumor tissues, respectively. Seven genes (TERT, CEACAM20, SPATA18, TRERF1, ZNF23, LINC01449, and LINC00486) were recurrently targeted by HBV-DNA in different ICC tissues or different cell populations of the same tissue. TERT, which is the most preferential HBV target gene in HCC, was found to be repeatedly interrupted by HBV-DNA in three different ICC tissues. Based on The Cancer Genome Atlas dataset, TERT, as well as three other HBV recurrently targeted genes (SPATA18, TRERF1, and ZNF23), showed differential expression levels between ICC and para-ICC tissues. CONCLUSIONS Taken together, HBV integration is a common event in HBV-related ICC. The HBV recurrent integration genes identified from this study, such as TERT, provide new clues for further research on the causative link between HBV infection and ICC.
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Affiliation(s)
- Mengge Li
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Min Du
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hui Cong
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuanyuan Gu
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Emergency, Nanjing First Hospital, Nanjing, China
| | - Yuan Fang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Organ Transplantation Center, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Jin Li
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu Gan
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong Tu
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jinyang Gu
- Department of Transplantation, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiang Xia
- Department of Liver Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Kim JW, Lee SH, Park YS, Hwang JH, Jeong SH, Kim N, Lee DH. Replicative activity of hepatitis B virus is negatively associated with methylation of covalently closed circular DNA in advanced hepatitis B virus infection. Intervirology 2011; 54:316-25. [PMID: 21242658 DOI: 10.1159/000321450] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 09/20/2010] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES The aim of this study was to examine the methylation status of intrahepatic hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and to elucidate the possible relationship between the cccDNA methylation and viral replicative activity in patients with HBV-related liver cirrhosis (HBV-LC). METHODS The methylation status of HBV cccDNA was investigated by bisulfite sequencing in nonneoplastic tissues from 12 patients with HBV-LC who underwent surgical resection for combined hepatocellular carcinoma. Clinical, biochemical and virologic factors were evaluated with respect to the degrees of cccDNA methylation. We also examined the effect of methylation of cccDNA on viral transcription by an in vitro transcription assay. RESULTS Variable degrees of CpG methylation were present in the HBV cccDNA from patients with HBV-LC. Old age, low serum HBV DNA levels and low virion productivity were significantly associated with elevated cccDNA methylation. Virion productivity of cccDNA was also lower in HepAD38 cells with a higher degree of cccDNA methylation. In vitro transcription assays showed that the transcriptional activity of HBV cccDNA was suppressed by increased methylation of cccDNA. CONCLUSIONS Increased CpG methylation of cccDNA is associated with old age, low serum HBV DNA levels and suppressed replicative activity in HBV-LC.
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Affiliation(s)
- Jin-Wook Kim
- Department of Medicine, Seoul National University Bundang Hospital, Seongnam, South
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Chen ZY, Cheng AC, Wang MS, Xu DW, Jia R, Guo YF, Zeng W. Viral load in 1-day-old ducklings acutely infected with duck hepatitis B virus by different doses and routes of inoculation. Avian Pathol 2009; 38:129-34. [PMID: 19322711 DOI: 10.1080/03079450902737862] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In order to define clearly the conditions leading to the outcome of acute duck hepatitis B virus (DHBV) infection, 1-day-old Pekin ducklings were infected with DHBV by different routes and given different doses of inoculum. Groups of 24 ducklings were inoculated either intravenously via the vena cruralis, or intraperitoneally with pooled serum containing either 1.6 x 10(7) or 1.6 x 10(4) DHBV genomes. One control duck from each group was inoculated with an equal volume of normal duck serum. A sensitive and reproducible real-time polymerase chain reaction assay based on TaqMan technology was developed for the detection and quantitation of DHBV DNA in the serum and liver. DHBAg was observed in the hepatocytes by immunohistochemistry. Histological changes in the liver tissue were also observed. The results demonstrate that ducklings at each time point and in all groups developed detectable viraemia. In each group, DHBV DNA in the liver was at a lower level than in serum and the peak DNA titre was found in serum earlier than in the liver. In the low-dose groups it was always at a lower level than in the high-dose groups. The DHBV replication levels appeared to be directly related to the number of DHBAg-positive hepatocytes. The variation trends of DHBAg-positive hepatocytes were similar in the high-dose groups. Histological changes were associated with liver viral DNA levels. We suggest that this dose and route of inoculation can be used as a model to study acute DHBV infections.
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Affiliation(s)
- Zong-yan Chen
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Yaan, China
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Maenz C, Chang SF, Iwanski A, Bruns M. Entry of duck hepatitis B virus into primary duck liver and kidney cells after discovery of a fusogenic region within the large surface protein. J Virol 2007; 81:5014-23. [PMID: 17360753 PMCID: PMC1900202 DOI: 10.1128/jvi.02290-06] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hepatitis B viruses exhibit a narrow host range specificity that is believed to be mediated by a domain of the large surface protein, designated L. For duck hepatitis B virus, it has been shown that the pre-S domain of L binds to carboxypeptidase D, a cellular receptor present in many species on a wide variety of cell types. Nonetheless, only hepatocytes become infected. It has remained vague which viral features determine host range specificity and organotropicity. By using chymotrypsin to treat duck hepatitis B virus, we addressed the question of whether a putative fusogenic region within the amino-terminal end of the small surface protein may participate in viral entry and possibly constitute one of the determinants of the host range of the virus. Addition of the enzyme to virions resulted in increased infectivity. Remarkably, even remnants of enzyme-treated subviral particles proved to be inhibitory to infection. A noninfectious deletion mutant devoid of the binding region for carboxypeptidase D could be rendered infectious for primary duck hepatocytes by treatment with chymotrypsin. Although because of the protease treatment mutant and wild-type viruses may have become infectious in an unspecific and receptor-independent manner, their host range specificity was not affected, as shown by the inability of the virus to replicate in different hepatoma cell lines, as well as primary chicken hepatocytes. Instead, the organotropicity of the virus could be reduced, which was demonstrated by infection of primary duck kidney cells.
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Affiliation(s)
- Claudia Maenz
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, Martinistrasse 52, D-20251 Hamburg, Germany
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Foster WK, Miller DS, Marion PL, Colonno RJ, Kotlarski I, Jilbert AR. Entecavir therapy combined with DNA vaccination for persistent duck hepatitis B virus infection. Antimicrob Agents Chemother 2003; 47:2624-35. [PMID: 12878529 PMCID: PMC166090 DOI: 10.1128/aac.47.8.2624-2635.2003] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2002] [Revised: 12/20/2002] [Accepted: 05/23/2003] [Indexed: 01/14/2023] Open
Abstract
This study was designed to test the efficacy of antiviral treatment with entecavir (ETV) in combination with DNA vaccines expressing duck hepatitis B virus (DHBV) antigens as a therapy for persistent DHBV infection in ducks. Ducks were inoculated with 10(9) DHBV genomes at 7 days of age, leading to widespread infection of the liver and viremia within 7 days, and were then treated orally with either ETV (0.1 mg/kg of body weight/day) or distilled water from 21 days posthatch for 244 days. Treatment with ETV caused a 4-log drop in serum DHBV DNA levels within 80 days and a slower 2- to 3-log drop in serum DHBV surface antigen (DHBsAg) levels within 120 days. Following withdrawal of ETV, levels of serum DHBV DNA and DHBsAg rebounded to match those in the water-treated animals within 40 days. Sequential liver biopsy samples collected throughout the study showed that ETV treatment reduced DHBV DNA replicative intermediates 70-fold in the liver, while the level of the stable, template form, covalently closed circular DNA decreased only 4-fold. ETV treatment reduced both the intensity of antigen staining and the percentage of antigen-positive hepatocytes in the liver, but the intensity of antigen staining in bile duct cells appeared not to be effected. Intramuscular administration of five doses of a DNA vaccine expressing the DHBV presurface, surface, precore, and core antigens, both alone and concurrently with ETV treatment, on days 50, 64, 78, 127, and 141 did not result in any significant effect on viral markers.
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MESH Headings
- Animals
- Antiviral Agents/therapeutic use
- Combined Modality Therapy
- DNA, Viral/blood
- DNA, Viral/metabolism
- Ducks/virology
- Guanine/analogs & derivatives
- Guanine/therapeutic use
- Hepatitis B Surface Antigens/blood
- Hepatitis B Virus, Duck/immunology
- Hepatitis, Viral, Animal/drug therapy
- Hepatitis, Viral, Animal/immunology
- Hepatitis, Viral, Animal/therapy
- Hepatocytes/metabolism
- Hepatocytes/virology
- Liver/metabolism
- Liver/pathology
- Liver/virology
- Liver Function Tests
- Vaccination
- Vaccines, DNA/therapeutic use
- Viral Hepatitis Vaccines/therapeutic use
- Virus Replication/drug effects
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Affiliation(s)
- Wendy K Foster
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5005, Australia
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Schilling R, Ijaz S, Davidoff M, Lee JY, Locarnini S, Williams R, Naoumov NV. Endocytosis of hepatitis B immune globulin into hepatocytes inhibits the secretion of hepatitis B virus surface antigen and virions. J Virol 2003; 77:8882-92. [PMID: 12885906 PMCID: PMC167249 DOI: 10.1128/jvi.77.16.8882-8892.2003] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hepatitis B immunoglobulin is used for prophylaxis against hepatitis B virus (HBV) and is thought to act by neutralization of virions and hepatitis B virus surface antigen (HBsAg)-containing particles in circulation. Using a panel of hepatocyte-derived cell lines, the present study investigated in vitro whether HBs-specific immunoglobulin G (IgG) is internalized in hepatocytes and whether it interacts with HBsAg in the cells. By immunoelectron microscopy and immunoblotting, human IgG and FcRn receptor for IgG were demonstrated on cellular membranes and in cytoplasmic extracts, irrespective of the HBsAg status of the cells. Furthermore, HBsAg and anti-HBs were shown to be colocalized in the same cellular compartment by two-color confocal microscopy. Endocytosis of HBs-specific IgG caused intracellular accumulation of HBsAg in a dose-dependent manner and inhibited the secretion of HBsAg and HBV virions from the cells. These effects were not observed with F(ab)(2) fragments or nonimmune IgG as controls. The specificity of intracellular HBsAg- anti-HBs interaction was further investigated in cells transfected with HBV genomes expressing wild-type HBsAg or immune escape HBsAg (with a G145R mutation). Monoclonal anti-HBs markedly reduced the secretion of wild-type HBsAg, while the secretion of mutant HBsAg was not affected. These results suggest that HBs-specific IgG binds to hepatocytes and interacts with HBsAg within the cells. This may be relevant for the selection of surface antibody escape mutations.
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Affiliation(s)
- Ralf Schilling
- Institute of Hepatology, Department of Medicine, University College London, London WC1E 6HX, United Kingdom
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Chin R, Locarnini S. Treatment of chronic hepatitis B: current challenges and future directions. Rev Med Virol 2003; 13:255-72. [PMID: 12820187 DOI: 10.1002/rmv.393] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The clinical management of chronic hepatitis B infection has entered a new era with the introduction and widespread use of oral nucleoside analogues such as lamivudine and nucleotides such as adefovir dipivoxil. From this, new challenges have now emerged in terms of preventing antiviral drug resistance, promoting viral clearance and improving long-term survival. For example, the natural history of nucleoside or nucleotide analogue-associated hepatitis B virus resistant mutants has yet to be determined. Furthermore, the increasing prevalence of HBeAg negative disease with its reduced response to current therapies represents an ongoing challenge to attempts to improve standard of care. There is increasing recognition of the pivotal role that viral load and genotype, and their complex interactions with the host immune response, play in determining the outcome of these treatment interventions. The purpose of this paper is to highlight several key factors that should be considered in the context of future clinical research and management of chronic hepatitis B.
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Affiliation(s)
- Ruth Chin
- Victorian Infectious Diseases and Centre for Clinical Research Excellence in Infectious Diseases, Royal Melbourne Hospital, Victoria 3051, Australia
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Lewin S, Walters T, Locarnini S. Hepatitis B treatment: rational combination chemotherapy based on viral kinetic and animal model studies. Antiviral Res 2002; 55:381-96. [PMID: 12206877 DOI: 10.1016/s0166-3542(02)00071-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Hepatitis B virus (HBV) causes a generally non-cytopathic infection in the liver. Even though HBV is a DNA virus, it replicates via reverse transcription which is coordinated within the viral nucleocapsid by the virus-specific polymerase. The major transcriptional template is the viral mimichromosome from which the viral DNA exists as a covalently closed circular (ccc) molcule. The virus infects hepatocytes but can also be found in non-hepatocyte reservoirs such as bile-duct epithelium, mesangial cells of the kidney, pancreatic islet cells and lymphoid cells. When patients infected with HBV are treated with either interferon alpha or lamivudine, responses are variable and unpredictable. Sophisticated mathematical models analysing the dynamics of viral clearance during antiviral therapy have recently been applied to chronic hepatitis B. Typically complex profiles, rather than the usual biphasic responses seen with other diseases have been observed, indicating that antiviral efficacy requires substantila improvement. This may be achieved with combination chemotherapy. However, chronic hepatitis B is a complex and heterogeneous disease entity, and the challenge for the future is to define measurable end-points of treatment and address key virological issues such as the role of cccDNA and extra-hepatocyte replication in treatment failure. Clearly, new therapies and effective combination therapy protocols are urgently required in order to improve the present poor response rates in patients undergoing treatment.
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Affiliation(s)
- Sharon Lewin
- Victorian Infectious Diseases Service, Royal Melbourne Hospital, Department of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
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