1
|
Ide M, Tabata N, Yonemura Y, Murai K, Wang Y, Ishida A, Honda M, Kaneko S, Ito S, Yanagawa H. Hepatitis B virus evades the immune system by suppressing the NF-κB signaling pathway with DENND2A. Microbiol Spectr 2024; 12:e0378523. [PMID: 38240571 PMCID: PMC10913737 DOI: 10.1128/spectrum.03785-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 12/08/2023] [Indexed: 03/06/2024] Open
Abstract
Overcoming hepatitis B virus (HBV) is a challenging problem because HBV deceives the host immune system. We have found that DENN domain-containing 2A (DENND2A) was essential for HBV maintenance, although its role remains unclear. In this study, we elucidate its function by screening a novel DENND2A-binding peptide, DENP4-3S. DENP4-3S exhibits homology to SAM and SH3 domain-containing protein 1 (SASH1), a scaffold protein involved in Toll-like receptor signaling that promotes proinflammatory cytokine production. We confirmed that DENND2A interacts with SASH1 specifically. Overexpression and knockdown experiments showed that overexpression of DENND2A suppressed the transcriptional activity of NF-κB, and the knockdown of DENND2A promoted it and the production of cytokines and interferons. Here, we constructed a fusion protein (10M-DEN3SN) consisting of an anti-asialoglycoprotein receptor antibody and DENP4-3S to deliver the peptide to hepatocytes specifically. 10M-DEN3SN inhibited the interaction between DENND2A and SASH1, and rescued SASH1 trapped by DENND2A, leading to the upregulation of NF-κB and its downstream signaling. In addition, 10M-DEN3SN suppressed HBV proliferation in PXB chimeric mice. These results with the DENND2A-binding peptide delivered into hepatocytes suggested the involvement of DENND2A, SASH, and NF-κB signaling pathway in the HBV infection and onset of hepatitis. In conclusion, this study indicates that HBV utilizes DENND2A and SASH1 to evade the immune system.IMPORTANCEHepatitis B virus (HBV) is a serious liver infection with no established cure, causing an abnormal host immune response. Here, we identified a novel peptide that interacts with DENN domain-containing 2A (DENND2A), a host factor essential for HBV maintenance. The resulting peptide showed sequence homology, revealing an interaction between DENND2A and the immune system regulator SASH1. This study suggests that DENND2A contributes to HBV infection by suppressing the cellular immune system by inhibiting SASH1. The DENND2A-binding peptide, incorporated into our hepatocyte-specific peptide delivery system, inhibited the DENND2A-SASH1 interaction and promoted the production of cytokines and interferons in cultured hepatocytes. As a consequence, the peptide suppressed HBV proliferation in humanized mice. We report new insights into the role of DENND2A and SASH1 in HBV maintenance and highlight the importance of the immune system.
Collapse
Affiliation(s)
- Mayuko Ide
- Research Department, Purotech Bio Inc, Yokohama, Kanagawa, Japan
| | - Noriko Tabata
- Research Department, Purotech Bio Inc, Yokohama, Kanagawa, Japan
| | - Yuko Yonemura
- Research Department, Purotech Bio Inc, Yokohama, Kanagawa, Japan
| | - Kazuhisa Murai
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, Kanazawa, Ishikawa, Japan
| | - Ying Wang
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, Kanazawa, Ishikawa, Japan
| | - Atsuya Ishida
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, Kanazawa, Ishikawa, Japan
| | - Masao Honda
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, Kanazawa, Ishikawa, Japan
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, Kanazawa, Ishikawa, Japan
| | - Shuichi Kaneko
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, Kanazawa, Ishikawa, Japan
| | - Satoru Ito
- Research Department, Purotech Bio Inc, Yokohama, Kanagawa, Japan
| | - Hiroshi Yanagawa
- Research Department, Purotech Bio Inc, Yokohama, Kanagawa, Japan
| |
Collapse
|
2
|
Zhao X, Wang C, Zhao L, Tian Z. HBV DNA polymerase regulates tumor cell glycogen to enhance the malignancy of HCC cells. Hepatol Commun 2024; 8:e0387. [PMID: 38358372 PMCID: PMC10871796 DOI: 10.1097/hc9.0000000000000387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 12/16/2023] [Indexed: 02/16/2024] Open
Abstract
BACKGROUND The essential function of HBV DNA polymerase (HBV-DNA-Pol) is to initiate viral replication by reverse transcription; however, the role of HBV-DNA-Pol in HBV-associated HCC has not been clarified. Glycogen phosphorylase L (PYGL) is a critical regulator of glycogenolysis and is involved in tumorigenesis, including HCC. However, it is unknown whether HBV-DNA-Pol regulates PYGL to contribute to HCC tumorigenesis. METHODS Bioinformatic analysis, real-time quantitative PCR, western blotting, and oncology functional assays were performed to determine the contribution of HBV-DNA-Pol and PYGL to HCC development and glycolysis. The mechanisms of co-immunoprecipitation and ubiquitination were employed to ascertain how HBV-DNA-Pol upregulated PYGL. RESULTS Overexpression of HBV-DNA-Pol enhanced HCC progression in vitro and in vivo. Mechanistically, HBV-DNA-Pol interacted with PYGL and increased PYGL protein levels by inhibiting PYGL ubiquitination, which was mediated by the E3 ligase TRIM21. HBV-DNA-Pol competitively impaired the binding of PYGL to TRIM21 due to its stronger binding affinity to TRIM21, suppressing the ubiquitination of PYGL. Moreover, HBV-DNA-Pol promoted glycogen decomposition by upregulating PYGL, which led to an increased flow of glucose into glycolysis, thereby promoting HCC development. CONCLUSIONS Our study reveals a novel mechanism by which HBV-DNA-Pol promotes HCC by controlling glycogen metabolism in HCC, establishing a direct link between HBV-DNA-Pol and the Warburg effect, thereby providing novel targets for HCC treatment and drug development.
Collapse
Affiliation(s)
- Xiaoqing Zhao
- Department of Clinical Laboratory, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Chunqing Wang
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Laboratory Medicine, Jinan, China
| | - Liqing Zhao
- Department of Pediatrics, Zaozhuang Municipal Hospital, Zaozhuang, China
| | - Zhongzheng Tian
- Shandong Agricultural Technology Extending Center, Jinan, China
| |
Collapse
|
3
|
Vogel OA, Forwood JK, Leung DW, Amarasinghe GK, Basler CF. Viral Targeting of Importin Alpha-Mediated Nuclear Import to Block Innate Immunity. Cells 2023; 13:71. [PMID: 38201275 PMCID: PMC10778312 DOI: 10.3390/cells13010071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
Cellular nucleocytoplasmic trafficking is mediated by the importin family of nuclear transport proteins. The well-characterized importin alpha (IMPA) and importin beta (IMPB) nuclear import pathway plays a crucial role in the innate immune response to viral infection by mediating the nuclear import of transcription factors such as IRF3, NFκB, and STAT1. The nuclear transport of these transcription factors ultimately leads to the upregulation of a wide range of antiviral genes, including IFN and IFN-stimulated genes (ISGs). To replicate efficiently in cells, viruses have developed mechanisms to block these signaling pathways. One strategy to evade host innate immune responses involves blocking the nuclear import of host antiviral transcription factors. By binding IMPA proteins, these viral proteins prevent the nuclear transport of key transcription factors and suppress the induction of antiviral gene expression. In this review, we describe examples of proteins encoded by viruses from several different families that utilize such a competitive inhibition strategy to suppress the induction of antiviral gene expression.
Collapse
Affiliation(s)
- Olivia A. Vogel
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Jade K. Forwood
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia;
| | - Daisy W. Leung
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA;
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA;
| | - Christopher F. Basler
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| |
Collapse
|
4
|
Tang Q, Meng C, Liu Y, Cheng Y, Liu Y, Long Y, Sun S, Feng F. Silencing SIRT1 promotes the anti-HBV action of IFN-α by regulating Pol expression and activating the JAK-STAT signaling pathway. Int Immunopharmacol 2023; 124:110939. [PMID: 37741128 DOI: 10.1016/j.intimp.2023.110939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 09/01/2023] [Accepted: 09/11/2023] [Indexed: 09/25/2023]
Abstract
PURPOSE The purpose this study is to investigate the impact of SIRT1 on the anti-HBV activity of IFN-α and further elucidate its underlying mechanism. METHODS HepG2.2.15 cells stably transfected with HBV virus were chosen as the primary study subject. IFN-α was used to stimulate the cells and regulate the expression of SIRT1, and the JAK-STAT pathway and HBV-related indices were measured by qRT-PCR, Western blotting and ELISA. Immunofluorescence (IF) was used to detect the nuclear translocation of STAT1 and STAT2. Coimmunoprecipitation (Co-IP) was used to detect the binding of SIRT1 to HBV Polymerase (Pol). RESULTS In HepG2.2.15 cells, we found changes in SIRT1 expression. We show that silencing SIRT1 promotes the IFN-α-triggered Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway and consequently enhances the antiviral effects of IFN-α against HBV replication. Importantly, SIRT1 can interact with Pol and increase JAK-STAT activity by regulating Pol expression. Additionally, the inhibition of SIRT1 activity by treatment with the SIRT1 inhibitor selisistat enhanced the anti-HBV effect of IFN-α and JAK-STAT pathway activity. CONCLUSION In conclusion, our results demonstrate that silencing SIRT1 activates the JAK-STAT pathway and enhances the anti-HBV activity of IFN-α by inhibiting Pol expression. This would be a promising therapeutic target to improve the efficacy of IFN-α in the treatment of CHB.
Collapse
Affiliation(s)
- Qinyan Tang
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei Province, China.
| | - Chunyan Meng
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei Province, China.
| | - Yue Liu
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei Province, China.
| | - Yanlin Cheng
- School of Life Science, North China University of Science and Technology, Tangshan, Hebei Province, China.
| | - Yang Liu
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei Province, China.
| | - Yifei Long
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei Province, China.
| | - Shufeng Sun
- School of Nursing and Rehabilitation, North China University of Science and Technology, Tangshan, Hebei Province, China.
| | - Fumin Feng
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei Province, China.
| |
Collapse
|
5
|
You H, Qin S, Zhang F, Hu W, Li X, Liu D, Kong F, Pan X, Zheng K, Tang R. Regulation of Pattern-Recognition Receptor Signaling by HBX During Hepatitis B Virus Infection. Front Immunol 2022; 13:829923. [PMID: 35251017 PMCID: PMC8891514 DOI: 10.3389/fimmu.2022.829923] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/24/2022] [Indexed: 12/16/2022] Open
Abstract
As a small DNA virus, hepatitis B virus (HBV) plays a pivotal role in the development of various liver diseases, including hepatitis, cirrhosis, and liver cancer. Among the molecules encoded by this virus, the HBV X protein (HBX) is a viral transactivator that plays a vital role in HBV replication and virus-associated diseases. Accumulating evidence so far indicates that pattern recognition receptors (PRRs) are at the front-line of the host defense responses to restrict the virus by inducing the expression of interferons and various inflammatory factors. However, depending on HBX, the virus can control PRR signaling by modulating the expression and activity of essential molecules involved in the toll-like receptor (TLR), retinoic acid inducible gene I (RIG-I)-like receptor (RLR), and NOD-like receptor (NLR) signaling pathways, to not only facilitate HBV replication, but also promote the development of viral diseases. In this review, we provide an overview of the mechanisms that are linked to the regulation of PRR signaling mediated by HBX to inhibit innate immunity, regulation of viral propagation, virus-induced inflammation, and hepatocarcinogenesis. Given the importance of PRRs in the control of HBV replication, we propose that a comprehensive understanding of the modulation of cellular factors involved in PRR signaling induced by the viral protein may open new avenues for the treatment of HBV infection.
Collapse
Affiliation(s)
- Hongjuan You
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, China
| | - Suping Qin
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, China
| | - Fulong Zhang
- Imaging Department, The Second Affiliated Hospital of Shandong First Medical University, Taian, China
| | - Wei Hu
- Nanjing Drum Tower Hospital Group Suqian Hospital, The Affiliate Suqian Hospital of Xuzhou Medical University, Suqian, China
| | - Xiaocui Li
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, China
| | - Dongsheng Liu
- Nanjing Drum Tower Hospital Group Suqian Hospital, The Affiliate Suqian Hospital of Xuzhou Medical University, Suqian, China
| | - Fanyun Kong
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, China
| | - Xiucheng Pan
- Department of Infectious Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Kuiyang Zheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, China.,National Demonstration Center for Experimental Basic Medical Sciences Education, Xuzhou Medical University, Xuzhou, China
| | - Renxian Tang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, China.,National Demonstration Center for Experimental Basic Medical Sciences Education, Xuzhou Medical University, Xuzhou, China
| |
Collapse
|
6
|
Zaki MYW, Fathi AM, Samir S, Eldafashi N, William KY, Nazmy MH, Fathy M, Gill US, Shetty S. Innate and Adaptive Immunopathogeneses in Viral Hepatitis; Crucial Determinants of Hepatocellular Carcinoma. Cancers (Basel) 2022; 14:1255. [PMID: 35267563 PMCID: PMC8909759 DOI: 10.3390/cancers14051255] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/01/2022] [Accepted: 02/04/2022] [Indexed: 02/08/2023] Open
Abstract
Viral hepatitis B (HBV) and hepatitis C (HCV) infections remain the most common risk factors for the development of hepatocellular carcinoma (HCC), and their heterogeneous distribution influences the global prevalence of this common type of liver cancer. Typical hepatitis infection elicits various immune responses within the liver microenvironment, and viral persistence induces chronic liver inflammation and carcinogenesis. HBV is directly mutagenic but can also cause low-grade liver inflammation characterized by episodes of intermittent high-grade liver inflammation, liver fibrosis, and cirrhosis, which can progress to decompensated liver disease and HCC. Equally, the absence of key innate and adaptive immune responses in chronic HCV infection dampens viral eradication and induces an exhausted and immunosuppressive liver niche that favors HCC development and progression. The objectives of this review are to (i) discuss the epidemiological pattern of HBV and HCV infections, (ii) understand the host immune response to acute and chronic viral hepatitis, and (iii) explore the link between this diseased immune environment and the development and progression of HCC in preclinical models and HCC patients.
Collapse
Affiliation(s)
- Marco Y. W. Zaki
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia 61732, Egypt; (A.M.F.); (N.E.); (M.H.N.); (M.F.)
- National Institute for Health Research Birmingham Liver Biomedical Research Unit and Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - Ahmed M. Fathi
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia 61732, Egypt; (A.M.F.); (N.E.); (M.H.N.); (M.F.)
| | - Samara Samir
- Department of Biochemistry, Faculty of Pharmacy, Sohag University, Sohag 82524, Egypt;
| | - Nardeen Eldafashi
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia 61732, Egypt; (A.M.F.); (N.E.); (M.H.N.); (M.F.)
| | - Kerolis Y. William
- Department of Internal Medicine, Faculty of Medicine, Cairo University, Cairo 12613, Egypt;
| | - Maiiada Hassan Nazmy
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia 61732, Egypt; (A.M.F.); (N.E.); (M.H.N.); (M.F.)
| | - Moustafa Fathy
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia 61732, Egypt; (A.M.F.); (N.E.); (M.H.N.); (M.F.)
| | - Upkar S. Gill
- Barts Liver Centre, Centre for Immunobiology, Barts & The London School of Medicine & Dentistry, QMUL, London E1 2AT, UK;
| | - Shishir Shetty
- National Institute for Health Research Birmingham Liver Biomedical Research Unit and Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| |
Collapse
|
7
|
Abstract
Hepatitis B virus (HBV) is a hepatotropic, partially double-stranded DNA virus that replicates by reverse transcription and is a major cause of chronic liver disease and hepatocellular carcinoma. Reverse transcription is catalyzed by the four-domain multifunctional HBV polymerase (P) protein that has protein-priming, RNA- and DNA-dependent DNA synthesis (i.e., reverse transcriptase), and ribonuclease H activities. P also likely promotes the three strand transfers that occur during reverse transcription, and it may participate in immune evasion by HBV. Reverse transcription is primed by a tyrosine residue in the amino-terminal domain of P, and P remains covalently attached to the product DNA throughout reverse transcription. The reverse transcriptase activity of P is the target for the nucleos(t)ide analog drugs that dominate HBV treatment, and P is the target of ongoing efforts to develop new drugs against both the reverse transcriptase and ribonuclease H activities. Despite the unusual reverse transcription pathway catalyzed by P and the importance of P to HBV therapy, understanding the enzymology and structure of HBV P severely lags that of the retroviral reverse transcriptases due to substantial technical challenges to studying the enzyme. Obtaining a better understanding of P will broaden our appreciation of the diversity among reverse transcribing elements in nature, and will help improve treatment for people chronically infected with HBV.
Collapse
Affiliation(s)
- Daniel N Clark
- Department of Microbiology, Weber State University, Ogden, UT, United States
| | - Razia Tajwar
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, United States
| | - Jianming Hu
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, United States.
| |
Collapse
|
8
|
Xu C, Chen J, Chen X. Host Innate Immunity Against Hepatitis Viruses and Viral Immune Evasion. Front Microbiol 2021; 12:740464. [PMID: 34803956 PMCID: PMC8598044 DOI: 10.3389/fmicb.2021.740464] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/29/2021] [Indexed: 11/13/2022] Open
Abstract
Hepatitis viruses are primary causative agents of hepatitis and represent a major source of public health problems in the world. The host innate immune system forms the first line of defense against hepatitis viruses. Hepatitis viruses are sensed by specific pathogen recognition receptors (PRRs) that subsequently trigger the innate immune response and interferon (IFN) production. However, hepatitis viruses evade host immune surveillance via multiple strategies, which help compromise the innate immune response and create a favorable environment for viral replication. Therefore, this article reviews published findings regarding host innate immune sensing and response against hepatitis viruses. Furthermore, we also focus on how hepatitis viruses abrogate the antiviral effects of the host innate immune system.
Collapse
Affiliation(s)
- Chonghui Xu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jizheng Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China.,Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xinwen Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China.,Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| |
Collapse
|
9
|
Altstetter SM, Quitt O, Pinci F, Hornung V, Lucko AM, Wisskirchen K, Jung S, Protzer U. Hepatitis-D Virus Infection Is Not Impaired by Innate Immunity but Increases Cytotoxic T-Cell Activity. Cells 2021; 10:3253. [PMID: 34831475 PMCID: PMC8619298 DOI: 10.3390/cells10113253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/08/2021] [Accepted: 11/18/2021] [Indexed: 11/22/2022] Open
Abstract
Approximately 70 million humans worldwide are affected by chronic hepatitis D, which rapidly leads to liver cirrhosis and hepatocellular carcinoma due to chronic inflammation. The triggers and consequences of this chronic inflammation, induced by co-infection with the hepatitis D virus (HDV) and the hepatitis B virus (HBV), are poorly understood. Using CRISPR technology, we characterized the recognition of HDV mono- and co-infection by intracellular innate immunity and determined its influence on the viral life cycle and effector T-cell responses using different HBV and HDV permissive hepatoma cell lines. We showed that HDV infection is detected by MDA5 and -after a lag phase -induces a profound type I interferon response in the infected cells. The type I interferon response, however, was not able to suppress HDV replication or spread, thus providing a persistent trigger. Using engineered T-cells directed against the envelope proteins commonly used by HBV and HDV, we found that HDV immune recognition enhanced T-cell cytotoxicity. Interestingly, the T-cell effector function was enhanced independently of antigen presentation. These findings help to explain immune mediated tissue damage in chronic hepatitis D patients and indicate that combining innate triggers with T-cell activating therapies might allow for a curative approach.
Collapse
Affiliation(s)
- Sebastian Maximilian Altstetter
- Institute of Virology, School of Medicine, Helmholtz Zentrum München/Technical University of Munich, 81675 Munich, Germany; (S.M.A.); (O.Q.); (A.M.L.); (K.W.)
| | - Oliver Quitt
- Institute of Virology, School of Medicine, Helmholtz Zentrum München/Technical University of Munich, 81675 Munich, Germany; (S.M.A.); (O.Q.); (A.M.L.); (K.W.)
| | - Francesca Pinci
- Gene Center and Department of Biochemistry, Ludwig-Maximilians—University Munich, 81377 Munich, Germany; (F.P.); (V.H.)
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians—University Munich, 81377 Munich, Germany; (F.P.); (V.H.)
| | - Aaron Michael Lucko
- Institute of Virology, School of Medicine, Helmholtz Zentrum München/Technical University of Munich, 81675 Munich, Germany; (S.M.A.); (O.Q.); (A.M.L.); (K.W.)
| | - Karin Wisskirchen
- Institute of Virology, School of Medicine, Helmholtz Zentrum München/Technical University of Munich, 81675 Munich, Germany; (S.M.A.); (O.Q.); (A.M.L.); (K.W.)
| | - Stephanie Jung
- Institute of Virology, School of Medicine, Helmholtz Zentrum München/Technical University of Munich, 81675 Munich, Germany; (S.M.A.); (O.Q.); (A.M.L.); (K.W.)
- Institute of Cardiovascular Immunology, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Ulrike Protzer
- Institute of Virology, School of Medicine, Helmholtz Zentrum München/Technical University of Munich, 81675 Munich, Germany; (S.M.A.); (O.Q.); (A.M.L.); (K.W.)
- German Center for Infection Research (DZIF), Munich Partner Site, 81675 Munich, Germany
| |
Collapse
|
10
|
Goh ZY, Ren EC, Ko HL. Intracellular interferon signalling pathways as potential regulators of covalently closed circular DNA in the treatment of chronic hepatitis B. World J Gastroenterol 2021; 27:1369-1391. [PMID: 33911462 PMCID: PMC8047536 DOI: 10.3748/wjg.v27.i14.1369] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/23/2021] [Accepted: 03/17/2021] [Indexed: 02/06/2023] Open
Abstract
Infection with the hepatitis B virus (HBV) is still a major global health threat as 250 million people worldwide continue to be chronically infected with the virus. While patients may be treated with nucleoside/nucleotide analogues, this only suppresses HBV titre to sub-detection levels without eliminating the persistent HBV covalently closed circular DNA (cccDNA) genome. As a result, HBV infection cannot be cured, and the virus reactivates when conditions are favorable. Interferons (IFNs) are cytokines known to induce powerful antiviral mechanisms that clear viruses from infected cells. They have been shown to induce cccDNA clearance, but their use in the treatment of HBV infection is limited as HBV-targeting immune cells are exhausted and HBV has evolved multiple mechanisms to evade and suppress IFN signalling. Thus, to fully utilize IFN-mediated intracellular mechanisms to effectively eliminate HBV, instead of direct IFN administration, novel strategies to sustain IFN-mediated anti-cccDNA and antiviral mechanisms need to be developed. This review will consolidate what is known about how IFNs act to achieve its intracellular antiviral effects and highlight the critical interferon-stimulated gene targets and effector mechanisms with potent anti-cccDNA functions. These include cccDNA degradation by APOBECs and cccDNA silencing and transcription repression by epigenetic modifications. In addition, the mechanisms that HBV employs to disrupt IFN signalling will be discussed. Drugs that have been developed or are in the pipeline for components of the IFN signalling pathway and HBV targets that detract IFN signalling mechanisms will also be identified and discussed for utility in the treatment of HBV infections. Together, these will provide useful insights into design strategies that specifically target cccDNA for the eradication of HBV.
Collapse
Affiliation(s)
- Zhi Yi Goh
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore 138648, Singapore
- Integrative Sciences and Engineering Programme, NUS Graduate School, National University of Singapore, Singapore 119077, Singapore
| | - Ee Chee Ren
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore 138648, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119260, Singapore
| | - Hui Ling Ko
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore 138648, Singapore
| |
Collapse
|
11
|
Wang G, Guan J, Khan NU, Li G, Shao J, Zhou Q, Xu L, Huang C, Deng J, Zhu H, Chen Z. Potential capacity of interferon-α to eliminate covalently closed circular DNA (cccDNA) in hepatocytes infected with hepatitis B virus. Gut Pathog 2021; 13:22. [PMID: 33845868 PMCID: PMC8040234 DOI: 10.1186/s13099-021-00421-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/01/2021] [Indexed: 12/14/2022] Open
Abstract
Interferon-alpha (IFN-α) and nucleot(s)ide analogs (NAs) are first-line drugs for the treatment of chronic hepatitis B virus (HBV) infections. Generally, NAs target the reverse transcription of HBV pregenomic RNA, but they cannot eliminate covalently-closed-circular DNA (cccDNA). Although effective treatment with NAs can dramatically decrease HBV proteins and DNA loads, and even promote serological conversion, cccDNA persists in the nucleus of hepatocytes due to the lack of effective anti-cccDNA drugs. Of the medications currently available, only IFN-α can potentially target cccDNA. However, the clinical effects of eradicating cccDNA using IFN-α in the hepatocytes of patients with HBV are not proficient as well as expected and are not well understood. Herein, we review the anti-HBV mechanisms of IFN-α involving cccDNA modification as the most promising approaches to cure HBV infection. We expect to find indications of promising areas of research that require further study to eliminate cccDNA of HBV in patients.
Collapse
Affiliation(s)
- Gang Wang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Jun Guan
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Nazif U Khan
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Guojun Li
- Institute for Hepatology, Shenzhen Third People's Hospital, National Clinical Research Center for Infectious Disease, Shenzhen, 518112, Guangdong, China.,The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, 518112, Shenzhen, China
| | - Junwei Shao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Qihui Zhou
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Lichen Xu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Chunhong Huang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Jingwen Deng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Haihong Zhu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Zhi Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, National Clinical Research Center for Infectious Diseases, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China.
| |
Collapse
|
12
|
Chang S, Wang LHC, Chen BS. Investigating Core Signaling Pathways of Hepatitis B Virus Pathogenesis for Biomarkers Identification and Drug Discovery via Systems Biology and Deep Learning Method. Biomedicines 2020; 8:biomedicines8090320. [PMID: 32878239 PMCID: PMC7555687 DOI: 10.3390/biomedicines8090320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/19/2020] [Accepted: 08/21/2020] [Indexed: 12/17/2022] Open
Abstract
Hepatitis B Virus (HBV) infection is a major cause of morbidity and mortality worldwide. However, poor understanding of its pathogenesis often gives rise to intractable immune escape and prognosis recurrence. Thus, a valid systematic approach based on big data mining and genome-wide RNA-seq data is imperative to further investigate the pathogenetic mechanism and identify biomarkers for drug design. In this study, systems biology method was applied to trim false positives from the host/pathogen genetic and epigenetic interaction network (HPI-GEN) under HBV infection by two-side RNA-seq data. Then, via the principal network projection (PNP) approach and the annotation of KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways, significant biomarkers related to cellular dysfunctions were identified from the core cross-talk signaling pathways as drug targets. Further, based on the pre-trained deep learning-based drug-target interaction (DTI) model and the validated pharmacological properties from databases, i.e., drug regulation ability, toxicity, and sensitivity, a combination of promising multi-target drugs was designed as a multiple-molecule drug to create more possibility for the treatment of HBV infection. Therefore, with the proposed systems medicine discovery and repositioning procedure, we not only shed light on the etiologic mechanism during HBV infection but also efficiently provided a potential drug combination for therapeutic treatment of Hepatitis B.
Collapse
Affiliation(s)
- Shen Chang
- Laboratory of Automatic Control, Signal Processing and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan;
| | - Lily Hui-Ching Wang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan;
| | - Bor-Sen Chen
- Laboratory of Automatic Control, Signal Processing and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan;
- Correspondence:
| |
Collapse
|
13
|
Jung S, Altstetter SM, Protzer U. Innate immune recognition and modulation in hepatitis D virus infection. World J Gastroenterol 2020; 26:2781-2791. [PMID: 32550754 PMCID: PMC7284172 DOI: 10.3748/wjg.v26.i21.2781] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 03/30/2020] [Accepted: 05/23/2020] [Indexed: 02/06/2023] Open
Abstract
Hepatitis D virus (HDV) is a global health threat with more than 15 million humans affected. Current treatment options are largely unsatisfactory leaving chronically infected humans at high risk to develop liver cirrhosis and hepatocellular carcinoma. HDV is the only human satellite virus known. It encodes only two proteins, and requires Hepatitis B virus (HBV) envelope protein expression for productive virion release and spread of the infection. How HDV could evolve and why HBV was selected as a helper virus remains unknown. Since the discovery of Na+-taurocholate co-transporting polypeptide as the essential uptake receptor for HBV and HDV, we are beginning to understand the interactions of HDV and the immune system. While HBV is mostly regarded a stealth virus, that escapes innate immune recognition, HBV-HDV coinfection is characterized by a strong innate immune response. Cytoplasmic RNA sensor melanoma differentiation antigen 5 has been reported to recognize HDV RNA replication and activate innate immunity. Innate immunity, however, seems not to impair HDV replication while it inhibits HBV. In this review, we describe what is known up-to-date about the interplay between HBV as a helper and HDV’s immune evasion strategy and identify where additional research is required.
Collapse
MESH Headings
- Carcinoma, Hepatocellular/immunology
- Carcinoma, Hepatocellular/pathology
- Carcinoma, Hepatocellular/virology
- Coinfection/complications
- Coinfection/immunology
- Coinfection/pathology
- Coinfection/virology
- Hepatitis B virus/genetics
- Hepatitis B virus/immunology
- Hepatitis B virus/metabolism
- Hepatitis B, Chronic/complications
- Hepatitis B, Chronic/immunology
- Hepatitis B, Chronic/pathology
- Hepatitis B, Chronic/virology
- Hepatitis D, Chronic/complications
- Hepatitis D, Chronic/immunology
- Hepatitis D, Chronic/pathology
- Hepatitis D, Chronic/virology
- Hepatitis Delta Virus/genetics
- Hepatitis Delta Virus/immunology
- Hepatitis Delta Virus/metabolism
- Hepatitis delta Antigens/immunology
- Hepatitis delta Antigens/metabolism
- Humans
- Immune Evasion
- Immunity, Innate
- Interferon-Induced Helicase, IFIH1/metabolism
- Liver/immunology
- Liver/pathology
- Liver/virology
- Liver Cirrhosis/immunology
- Liver Cirrhosis/pathology
- Liver Cirrhosis/virology
- Liver Neoplasms/immunology
- Liver Neoplasms/pathology
- Liver Neoplasms/virology
- Organic Anion Transporters, Sodium-Dependent/metabolism
- RNA, Viral/immunology
- RNA, Viral/metabolism
- Receptors, Pattern Recognition/immunology
- Receptors, Pattern Recognition/metabolism
- Satellite Viruses/genetics
- Satellite Viruses/immunology
- Satellite Viruses/metabolism
- Symporters/metabolism
- Virus Replication/immunology
Collapse
Affiliation(s)
- Stephanie Jung
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich D-81675, Germany
| | | | - Ulrike Protzer
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich D-81675, Germany
- German Center for Infection Research (DZIF), Munich Partner Site, Munich D-81675, Germany
| |
Collapse
|
14
|
Warner N, Locarnini S, Xu H. The role of hepatitis B surface antibodies in HBV infection, disease and clearance. Future Virol 2020. [DOI: 10.2217/fvl-2019-0147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The clinical sequelae associated with chronic HBV infection is generally regarded as a consequence of an inadequate and inappropriate immune response to active viral replication, predominantly at the T-cell level. However, recent studies on hepatitis B surface antigen (HBsAg)-specific B cells and hepatitis B surface antibody (anti-HB) responses have identified their previously unrecognized role in the pathogenesis of chronic hepatitis B (CHB). These studies have also uncovered novel therapeutic approaches to more effectively target HBsAg loss and seroconversion, an important end point and regarded as a functional cure. Anti-HBs IgG has also been shown to have multiple direct acting antiviral roles with the Fab component directly blocking viral entry, and release while the Fc component has been linked to antibody dependent cellular cytotoxicity. Likewise, the HBsAg-specific B-cell dysfunctionality can be reversed providing new therapeutic opportunities to achieve functional cure in CHB.
Collapse
Affiliation(s)
- Nadia Warner
- Molecular Research & Development, Victorian Infectious Diseases Reference Laboratory, Doherty Institute, Melbourne, Victoria, Australia
| | - Stephen Locarnini
- Molecular Research & Development, Victorian Infectious Diseases Reference Laboratory, Doherty Institute, Melbourne, Victoria, Australia
| | - Hui Xu
- Molecular Research & Development, Victorian Infectious Diseases Reference Laboratory, Doherty Institute, Melbourne, Victoria, Australia
| |
Collapse
|
15
|
The Study of Correlation Between Serum Vitamin D 3 Concentrations and HBV DNA Levels and Immune Response in Chronic Hepatitis Patients. Nutrients 2020; 12:nu12041114. [PMID: 32316365 PMCID: PMC7230547 DOI: 10.3390/nu12041114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 02/07/2023] Open
Abstract
Chronic hepatitis B (CHB) is a common chronic disease. Previous studies have shown a link between 25-hydroxyvitamin D3 (vitamin D3) concentration and liver disease. Hepatitis B virus (HBV) infection has been attributed to the inappropriate functioning of cell-mediated immunity. However, the effects of vitamin D3, immune cell, and HBeAg status on HBV viral load in CHB patients are still unclear. We investigated the relationship between the serum concentration of vitamin D3, percentage of immune cells in peripheral blood, and the HBV viral load of CHB patients. Sixty CHB patients were recruited, and their blood samples were collected and analyzed. Vitamin D level was measured using a chemiluminescence assay. A level of 30 ng/mL or above was defined as a vitamin D3 sufficiency. We assigned vitamin D3 status as either normal (≥30 ng/mL), insufficient (20-30 ng/mL), or deficient (<20 ng/mL). T-lymphocyte and B-lymphocyte surface markers in peripheral blood were detected using flow cytometry. The factors associated with HBV viral load were analyzed using univariate and multivariate-adjusted models. The mean serum vitamin D3 concentration in the subjects was 20.9±5.6 ng/mL. Up to 88.3% of the patients were either deficient in or had insufficient vitamin D3. The gender, BMI, hepatitis B surface antigen levels, and ALT levels were significantly related to serum vitamin D3 levels. Serum vitamin D3 concentration, HBe status, HBs levels, ALT, and AST levels showed a statistically significant correlation with the HBV DNA levels. Serum vitamin D3 concentrations and hepatitis B surface antigen levels were strongly correlated with HBV DNA levels. Vitamin D3 levels were significantly associated with CD19 numbers (β:-6.2, 95% CI: -10.5). In multivariate analysis, vitamin D3 levels in the deficient and insufficient groups, and the CD8, HBeAg, and WBC counts were significantly associated with HBV DNA levels. In the immune tolerance phase of HBeAg-negative chronic HBV infection, vitamin D3 may be a modulator of immune function via CD8, CD19, and HBV DNA.
Collapse
|
16
|
Megahed FAK, Zhou X, Sun P. The Interactions between HBV and the Innate Immunity of Hepatocytes. Viruses 2020; 12:v12030285. [PMID: 32151000 PMCID: PMC7150781 DOI: 10.3390/v12030285] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 02/05/2023] Open
Abstract
Hepatitis B virus (HBV) infection affects ~350 million people and poses a major public health problem worldwide. HBV is a major cause of cirrhosis and hepatocellular carcinoma. Fewer than 5% of HBV-infected adults (but up to 90% of HBV-infected infants and children) develop chronic HBV infection as indicated by continued, detectable expression of hepatitis B surface antigen (HBsAg) for at least 6 months after the initial infection. Increasing evidence indicates that HBV interacts with innate immunity signaling pathways of hepatocytes to suppress innate immunity. However, it is still not clear how HBV avoids monitoring by the innate immunity of hepatocytes and whether the innate immunity of hepatocytes can be effective against HBV if re-triggered. Moreover, a deep understanding of virus-host interactions is important in developing new therapeutic strategies for the treatment of HBV infection. In this review, we summarize the current knowledge regarding how HBV represses innate immune recognition, as well as recent progress with respect to in vitro models for studying HBV infection and innate immunity.
Collapse
Affiliation(s)
- Fayed Attia Koutb Megahed
- Stem Cell Research Center, Research Center for Reproductive Medicine, Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, China;
- Department of Nucleic Acid Researches, Genetic Engineering and Biotechnology Research Institute, General Autority-City of Scientific Researches and Technological Applications, Alexandria 21934, Egypt
| | - Xiaoling Zhou
- Stem Cell Research Center, Research Center for Reproductive Medicine, Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, China;
- Correspondence: (X.Z.); (P.S.)
| | - Pingnan Sun
- Stem Cell Research Center, Research Center for Reproductive Medicine, Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, China;
- Correspondence: (X.Z.); (P.S.)
| |
Collapse
|
17
|
Host Transcription Factors in Hepatitis B Virus RNA Synthesis. Viruses 2020; 12:v12020160. [PMID: 32019103 PMCID: PMC7077322 DOI: 10.3390/v12020160] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 02/06/2023] Open
Abstract
The hepatitis B virus (HBV) chronically infects over 250 million people worldwide and is one of the leading causes of liver cancer and hepatocellular carcinoma. HBV persistence is due in part to the highly stable HBV minichromosome or HBV covalently closed circular DNA (cccDNA) that resides in the nucleus. As HBV replication requires the help of host transcription factors to replicate, focusing on host protein–HBV genome interactions may reveal insights into new drug targets against cccDNA. The structural details on such complexes, however, remain poorly defined. In this review, the current literature regarding host transcription factors’ interactions with HBV cccDNA is discussed.
Collapse
|
18
|
Moreno-Altamirano MMB, Kolstoe SE, Sánchez-García FJ. Virus Control of Cell Metabolism for Replication and Evasion of Host Immune Responses. Front Cell Infect Microbiol 2019; 9:95. [PMID: 31058096 PMCID: PMC6482253 DOI: 10.3389/fcimb.2019.00095] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/22/2019] [Indexed: 12/11/2022] Open
Abstract
Over the last decade, there has been significant advances in the understanding of the cross-talk between metabolism and immune responses. It is now evident that immune cell effector function strongly depends on the metabolic pathway in which cells are engaged in at a particular point in time, the activation conditions, and the cell microenvironment. It is also clear that some metabolic intermediates have signaling as well as effector properties and, hence, topics such as immunometabolism, metabolic reprograming, and metabolic symbiosis (among others) have emerged. Viruses completely rely on their host's cell energy and molecular machinery to enter, multiply, and exit for a new round of infection. This review explores how viruses mimic, exploit or interfere with host cell metabolic pathways and how, in doing so, they may evade immune responses. It offers a brief outline of key metabolic pathways, mitochondrial function and metabolism-related signaling pathways, followed by examples of the mechanisms by which several viral proteins regulate host cell metabolic activity.
Collapse
Affiliation(s)
- María Maximina B Moreno-Altamirano
- Laboratorio de Inmunorregulación, Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Simon E Kolstoe
- School of Health Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Francisco Javier Sánchez-García
- Laboratorio de Inmunorregulación, Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| |
Collapse
|
19
|
Gotlieb N, Tachlytski I, Lapidot Y, Sultan M, Safran M, Ben-Ari Z. Hepatitis B virus downregulates vitamin D receptor levels in hepatoma cell lines, thereby preventing vitamin D-dependent inhibition of viral transcription and production. Mol Med 2018; 24:53. [PMID: 30326825 PMCID: PMC6192355 DOI: 10.1186/s10020-018-0055-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 09/28/2018] [Indexed: 02/06/2023] Open
Abstract
Background Vitamin D is a key immune-modulator that plays a role in the innate and adaptive immune systems. Certain pathogens impair the immune defense by downregulating the vitamin D receptor (VDR) pathway. Low serum levels of vitamin D are associated with increased hepatitis B virus (HBV) replication. Our study aimed to assess the in-vitro relationship between HBV production and Vitamin D signaling pathway and to explore the associated mechanism(s). Methods HBV transcription and replication was evaluated by qRT-PCR of the HBV-RNA and covalently closed circular DNA (cccDNA). Furthermore, we have transfected the 1.3 X HBV-Luc plasmid to the cells and measured the Luciferase activity using Luminometer. Vitamin D signaling pathway activation was evaluated by measuring the expression levels of VDR, CYP24A1, Tumor necrosis factor α (TNFα) and cathelicidin (CAMP) by qRT-PCR. All assays were performed on HepG2.2.15, HepG2, and HepAD38 cells treated with or without Vitamin D active metabolite: calcitriol. Results Calcitriol did not suppress HBV transcription, cccDNA expression or HBV RNA levels in HepG2.2.15 cells. However, VDR transcript levels in HepG2.215 cells were significantly lower compared to HepG2 cells. Similar results were obtained in HepAD38 cell where VDR expression was down-regulated when HBV transcript level was up-regulated. In addition, calcitriol induced VDR-associated signaling, resulting in upregulation of CYP24A1, TNFα and CAMP expression level in HepG2 cells but not in the HepG2.2.15 cells. Conclusions These findings indicate that VDR expression is downregulated in HBV-transfected cells, thereby preventing vitamin D from inhibiting transcription and translation of HBV in vitro. HBV might use this mechanism to avoid the immunological defense system by affecting both TNFα and CAMP signaling pathways. Electronic supplementary material The online version of this article (10.1186/s10020-018-0055-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Neta Gotlieb
- Liver Reaserch Laboratory, Sheba Medical Center, Tel Hashomer, 52620, Ramat Gan, Israel
| | - Irena Tachlytski
- Liver Reaserch Laboratory, Sheba Medical Center, Tel Hashomer, 52620, Ramat Gan, Israel
| | - Yelena Lapidot
- Liver Reaserch Laboratory, Sheba Medical Center, Tel Hashomer, 52620, Ramat Gan, Israel.,The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Maya Sultan
- Liver Reaserch Laboratory, Sheba Medical Center, Tel Hashomer, 52620, Ramat Gan, Israel
| | - Michal Safran
- Liver Reaserch Laboratory, Sheba Medical Center, Tel Hashomer, 52620, Ramat Gan, Israel
| | - Ziv Ben-Ari
- Liver Reaserch Laboratory, Sheba Medical Center, Tel Hashomer, 52620, Ramat Gan, Israel. .,Liver Disease Center, Sheba Medical Center, Tel Hashomer, 52620, Ramat Gan, Israel. .,The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| |
Collapse
|
20
|
Mani SKK, Andrisani O. Interferon signaling during Hepatitis B Virus (HBV) infection and HBV-associated hepatocellular carcinoma. Cytokine 2018; 124:154518. [PMID: 30126685 DOI: 10.1016/j.cyto.2018.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/09/2018] [Accepted: 08/11/2018] [Indexed: 02/06/2023]
Abstract
Chronic Hepatitis B Virus (HBV) infection is linked to hepatocellular carcinoma (HCC) pathogenesis. The World Health Organization estimates that globally 257 million people are chronic HBV carriers at risk of developing liver cancer. Current therapies for prevention and treatment of HCC are inadequate. Although interferon-based treatment strategies hold great promise for combating chronic infection and HCC, many patients do not respond to the IFN-based drugs for reasons not completely understood. Interferon signaling plays key roles in activation of innate and adaptive immunity. However, HBV has evolved various mechanisms to suppress IFN signaling. In this review, we present the basics about HBV infection and interferon signaling. Next, we discuss mechanisms through which HBV downregulates the function -activity and transcription- of the transcription factor STAT1 during acute and chronic infection. STAT1 is activated in response to all types (I/II/III) of interferon signaling and is essential in mediating all types (I/II/III) of interferon responses. Lastly, we discuss emerging evidence from different human cancers linking loss of interferon signaling to aggressive cancer and cancer stem cells. Whether the same occurs during HBV-associated hepatocarcinogenesis is discussed and currently under investigation.
Collapse
Affiliation(s)
- Saravana Kumar Kailasam Mani
- Department of Basic Medical Sciences and Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
| | - Ourania Andrisani
- Department of Basic Medical Sciences and Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
| |
Collapse
|
21
|
Abstract
Hepatitis B virus (HBV) is a hepatotropic virus that can establish a persistent and chronic infection in humans through immune anergy. Currently, 3.5% of the global population is chronically infected with HBV, although the incidence of HBV infections is decreasing owing to vaccination and, to a lesser extent, the use of antiviral therapy to reduce the viral load of chronically infected individuals. The course of chronic HBV infection typically comprises different clinical phases, each of which potentially lasts for decades. Well-defined and verified serum and liver biopsy diagnostic markers enable the assessment of disease severity, viral replication status, patient risk stratification and treatment decisions. Current therapy includes antiviral agents that directly act on viral replication and immunomodulators, such as interferon therapy. Antiviral agents for HBV include reverse transcriptase inhibitors, which are nucleoside or nucleotide analogues that can profoundly suppress HBV replication but require long-term maintenance therapy. Novel compounds are being actively investigated to achieve the goal of HBV surface antigen seroclearance (functional cure), a serological state that is associated with a higher remission rate (thus, no viral rebound) after treatment cessation and a lower rate of cirrhosis and hepatocellular carcinoma. This Primer addresses several aspects of HBV infection, including epidemiology, immune pathophysiology, diagnosis, prevention and management.
Collapse
|
22
|
Mutz P, Metz P, Lempp FA, Bender S, Qu B, Schöneweis K, Seitz S, Tu T, Restuccia A, Frankish J, Dächert C, Schusser B, Koschny R, Polychronidis G, Schemmer P, Hoffmann K, Baumert TF, Binder M, Urban S, Bartenschlager R. HBV Bypasses the Innate Immune Response and Does Not Protect HCV From Antiviral Activity of Interferon. Gastroenterology 2018; 154:1791-1804.e22. [PMID: 29410097 DOI: 10.1053/j.gastro.2018.01.044] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Hepatitis C virus (HCV) infection is sensitive to interferon (IFN)-based therapy, whereas hepatitis B virus (HBV) infection is not. It is unclear whether HBV escapes detection by the IFN-mediated immune response or actively suppresses it. Moreover, little is known on how HBV and HCV influence each other in coinfected cells. We investigated interactions between HBV and the IFN-mediated immune response using HepaRG cells and primary human hepatocytes (PHHs). We analyzed the effects of HBV on HCV replication, and vice versa, at the single-cell level. METHODS PHHs were isolated from liver resection tissues from HBV-, HCV-, and human immunodeficiency virus-negative patients. Differentiated HepaRG cells overexpressing the HBV receptor sodium taurocholate cotransporting polypeptide (dHepaRGNTCP) and PHHs were infected with HBV. Huh7.5 cells were transfected with circular HBV DNA genomes resembling viral covalently closed circular DNA (cccDNA), and subsequently infected with HCV; this served as a model of HBV and HCV coinfection. Cells were incubated with IFN inducers, or IFNs, and antiviral response and viral replication were analyzed by immune fluorescence, reverse-transcription quantitative polymerase chain reaction, enzyme-linked immunosorbent assays, and flow cytometry. RESULTS HBV infection of dHepaRGNTCP cells and PHHs neither activated nor inhibited signaling via pattern recognition receptors. Incubation of dHepaRGNTCP cells and PHHs with IFN had little effect on HBV replication or levels of cccDNA. HBV infection of these cells did not inhibit JAK-STAT signaling or up-regulation of IFN-stimulated genes. In coinfected cells, HBV did not prevent IFN-induced suppression of HCV replication. CONCLUSIONS In dHepaRGNTCP cells and PHHs, HBV evades the induction of IFN and IFN-induced antiviral effects. HBV infection does not rescue HCV from the IFN-mediated response.
Collapse
Affiliation(s)
- Pascal Mutz
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany; HBIGS graduate school, Heidelberg, Germany
| | - Philippe Metz
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Florian A Lempp
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; German Centre for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany
| | - Silke Bender
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Bingqian Qu
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Katrin Schöneweis
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; German Centre for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany
| | - Stefan Seitz
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Thomas Tu
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Agnese Restuccia
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jamie Frankish
- Research Group "Dynamics of early viral infection and the innate antiviral response", Division Virus-associated carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christopher Dächert
- Research Group "Dynamics of early viral infection and the innate antiviral response", Division Virus-associated carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Benjamin Schusser
- Reproductive Biotechnology, School of Life Sciences Weihenstephan, Technical University of Munich, Munich, Germany
| | - Ronald Koschny
- Department of Gastroenterology, Infection and Intoxication, University Hospital Heidelberg, Heidelberg, Germany
| | - Georgios Polychronidis
- Department of General-, Visceral- and Transplant Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Peter Schemmer
- Department of General-, Visceral- and Transplant Surgery, University Hospital Heidelberg, Heidelberg, Germany; Division of Transplant Surgery, Medical University of Graz, Graz, Austria
| | - Katrin Hoffmann
- Department of General-, Visceral- and Transplant Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Thomas F Baumert
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Université de Strasbourg, Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Nouvel Hôpital Civil, Strasbourg, France
| | - Marco Binder
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; Research Group "Dynamics of early viral infection and the innate antiviral response", Division Virus-associated carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; German Centre for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany; HBIGS graduate school, Heidelberg, Germany; German Centre for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany.
| |
Collapse
|
23
|
Suslov A, Boldanova T, Wang X, Wieland S, Heim MH. Hepatitis B Virus Does Not Interfere With Innate Immune Responses in the Human Liver. Gastroenterology 2018; 154:1778-1790. [PMID: 29408639 DOI: 10.1053/j.gastro.2018.01.034] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 01/17/2018] [Accepted: 01/20/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Most viruses are detected at early stages of cell infection and induce an innate immune response mediated by production of interferons (IFNs). IFNs induce expression of hundreds of IFN-stimulated genes (ISGs). Infection of chimpanzees with hepatitis C virus, but not hepatitis B virus (HBV), induces ISG expression in the liver. HBV might not induce an innate immune response because it is not detected by pattern recognition receptors (the stealth properties of HBV) or because HBV suppresses IFN production or signaling despite detection by pattern recognition receptors. We studied innate immune signaling in liver biopsies from patients with different stages of chronic HBV infection and uninfected individuals (controls). METHODS We obtained liver within 10 minutes after collection from 30 patients with chronic HBV infection (hepatitis B e antigen-positive or -negative, with or without hepatitis) and 42 controls (most with fatty liver disease). The liver tissues were analyzed by histology, immunohistochemistry, quantitative reverse-transcription polymerase chain reaction, in situ hybridization, HBV RNA quantification, and HBV genotyping; some specimens were incubated with toll-like receptor (TLR) ligands (polyinosinic-polycytidylic acid) or infected with Sendai virus and then analyzed. RESULTS Liver specimens from patients with HBV infection were not expressing more IFN or ISGs than those from control patients, indicating that chronic HBV infection did not activate an innate immune response. However, liver specimens from patients with HBV infection did produce IFN and induce expression of ISGs following activation of TLR3 with poly(I:C) or Sendai virus infections, so the innate immune response is not suppressed in these tissues. CONCLUSION Liver tissues from patients with chronic HBV infection do not have induction of an innate immune response, but this response can be activated by other factors (TLR3 binding, Sendai virus infection) in HBV-infected liver tissue. These findings support the hypothesis that HBV is invisible to pattern recognition receptors.
Collapse
Affiliation(s)
- Aleksei Suslov
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Tujana Boldanova
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland; Division of Gastroenterology and Hepatology, University Hospital Basel, Basel, Switzerland
| | - Xueya Wang
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Stefan Wieland
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland.
| | - Markus H Heim
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland; Division of Gastroenterology and Hepatology, University Hospital Basel, Basel, Switzerland.
| |
Collapse
|
24
|
Cavallari I, Scattolin G, Silic-Benussi M, Raimondi V, D'Agostino DM, Ciminale V. Mitochondrial Proteins Coded by Human Tumor Viruses. Front Microbiol 2018; 9:81. [PMID: 29467726 PMCID: PMC5808139 DOI: 10.3389/fmicb.2018.00081] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/12/2018] [Indexed: 12/26/2022] Open
Abstract
Viruses must exploit the cellular biosynthetic machinery and evade cellular defense systems to complete their life cycles. Due to their crucial roles in cellular bioenergetics, apoptosis, innate immunity and redox balance, mitochondria are important functional targets of many viruses, including tumor viruses. The present review describes the interactions between mitochondria and proteins coded by the human tumor viruses human T-cell leukemia virus type 1, Epstein-Barr virus, Kaposi's sarcoma-associated herpesvirus, human hepatitis viruses B and C, and human papillomavirus, and highlights how these interactions contribute to viral replication, persistence and transformation.
Collapse
Affiliation(s)
| | - Gloria Scattolin
- Department of Surgery, Oncology, and Gastroenterology, University of Padova, Padova, Italy
| | | | | | | | - Vincenzo Ciminale
- Veneto Institute of Oncology IOV-IRRCS, Padova, Italy.,Department of Surgery, Oncology, and Gastroenterology, University of Padova, Padova, Italy
| |
Collapse
|
25
|
Cheng X, Xia Y, Serti E, Block PD, Chung M, Chayama K, Rehermann B, Liang TJ. Hepatitis B virus evades innate immunity of hepatocytes but activates cytokine production by macrophages. Hepatology 2017; 66:1779-1793. [PMID: 28665004 PMCID: PMC5706781 DOI: 10.1002/hep.29348] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 06/23/2017] [Accepted: 06/26/2017] [Indexed: 12/12/2022]
Abstract
UNLABELLED Hepatitis B virus (HBV) infects hepatocytes specifically and causes immune-mediated liver damage. How HBV interacts with the innate immunity at the early phase of infection, either with hepatocytes or other cells in the liver, remains controversial. To address this question, we utilized various human cell-culture models and humanized Alb-uPA/SCID mice. All these models were unable to mount an interferon (IFN) response despite robust HBV replication. To elucidate the mechanisms involved in the lack of IFN response, we examined whether HBV actively inhibits innate immune functions of hepatocytes. By treating HBV-infected cells with known inducers of the IFN signaling pathway, we observed no alteration of either sensing or downstream IFN response by HBV. We showed that the DNA innate sensing pathways are poorly active in hepatocytes, consistent with muted innate immune recognition of HBV. Upon exposure to high-level HBV, human macrophages could be activated with increased inflammatory cytokine expressions. CONCLUSION HBV behaves like a "stealth" virus and is not sensed by, nor actively interferes with, the intrinsic innate immunity of infected hepatocytes. Macrophages are capable of sensing HBV, but require exposure to high HBV titers, potentially explaining the long "window period" during acute infection and HBV's propensity to chronic infection. (Hepatology 2017;66:1779-1793).
Collapse
Affiliation(s)
- Xiaoming Cheng
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Yuchen Xia
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Elisavet Serti
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Peter Daniel Block
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Michelle Chung
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Kazuaki Chayama
- Department of Gastroenterology and Metabolism, Hiroshima University, Hiroshima, Japan
| | - Barbara Rehermann
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - T. Jake Liang
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| |
Collapse
|
26
|
Dandri M, Petersen J. Mechanism of Hepatitis B Virus Persistence in Hepatocytes and Its Carcinogenic Potential. Clin Infect Dis 2017; 62 Suppl 4:S281-8. [PMID: 27190317 DOI: 10.1093/cid/ciw023] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Liver disease associated with persistent infection with hepatitis B virus (HBV) continues to be a major health problem of global impact. Despite the existence of an effective vaccine, at least 240 million people are chronically infected worldwide, and are at risk of developing liver cirrhosis and hepatocellular carcinoma. Although chronic HBV infection is considered the main risk factor for liver cancer development, the molecular mechanisms determining persistence of infection and long-term pathogenesis are not fully elucidated but appear to be multifactorial. Current therapeutic regimens based on the use of polymerase inhibitors can efficiently suppress viral replication but are unable to eradicate the infection. This is due both to the persistence of the HBV genome, which forms a stable minichromosome, the covalently closed circular DNA (cccDNA), in the nucleus of infected hepatocytes, as well as to the inability of the immune system to efficiently counteract chronic HBV infection. In this regard, the unique replication strategies adopted by HBV and viral protein production also appear to contribute to infection persistence by limiting the effectiveness of innate responses. The availability of improved experimental systems and molecular techniques have started to provide new information about the complex network of interactions that HBV establishes within the hepatocyte and that may contribute to disease progression and tumor development. Thus, this review will mostly focus on events involving the hepatocyte: the only target cell where HBV infection and replication take place.
Collapse
Affiliation(s)
- Maura Dandri
- I Department of Internal Medicine, University Medical Center Hamburg-Eppendorf German Center for Infection Research, Hamburg-Lübeck-Borstel site
| | - Joerg Petersen
- IFI Institute for Interdisciplinary Medicine, Asklepios Clinic St Georg, Hamburg, Germany
| |
Collapse
|
27
|
Romani S, Hosseini SM, Mohebbi SR, Boonstra A, Sharifian A. Differential expression of innate immune response genes in clinical phases of chronic hepatitis B infection. J Viral Hepat 2017; 24:776-788. [PMID: 28218976 DOI: 10.1111/jvh.12699] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 02/01/2017] [Indexed: 12/16/2022]
Abstract
We investigated innate immune gene expression in clinical phases of chronic hepatitis B infection, including immune tolerant (IT), immune active (IA), inactive carrier (IC) and hepatitis B e antigen (HBeAg)-negative phases, as well as healthy controls. Expression levels of interferon types I, II and III, their receptor subunits, IRFs, TLRs and other IFN-induced genes in peripheral blood mononuclear cells were compared. Forty HBsAg-positive treatment-naïve subjects without co-infection with HIV, HCV or HDV were enrolled. To complement the viral load, the expression levels of 37 innate immune genes were measured by qPCR. The highest response of the innate immune system was observed in the IT and HBeAg-negative phases, and the IC phase had the lowest response; 31 of the 37 studied genes reached their maximum mRNA expression levels in the IT and HBeAg-negative phases, and the minimum expression levels of 23 genes were found in the IC phase. The highest mRNA expression levels of IFNs, IFN receptor subunits, IRFs and TLRs genes in all clinical phases were IFN-λ2 and 3, IFN-γR2, IRF7 and TLR7, and the lowest levels of mRNA expression were observed for IFN-α, IFN-λR1, IRF8 and TLR2. We conclude that innate immune response genes are expressed differentially among chronic HBV phases, and this difference may help to develop new precise and noninvasive methods to determine the progression of disease in chronic HBV patients.
Collapse
Affiliation(s)
- S Romani
- Department of Microbiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran
| | - S M Hosseini
- Department of Microbiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran
| | - S R Mohebbi
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - A Boonstra
- Department of Gastroenterology and Hepatology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - A Sharifian
- Basic and Molecular Epidemiology of gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| |
Collapse
|
28
|
Yu Y, Wan P, Cao Y, Zhang W, Chen J, Tan L, Wang Y, Sun Z, Zhang Q, Wan Y, Zhu Y, Liu F, Wu K, Liu Y, Wu J. Hepatitis B Virus e Antigen Activates the Suppressor of Cytokine Signaling 2 to Repress Interferon Action. Sci Rep 2017; 7:1729. [PMID: 28496097 PMCID: PMC5431827 DOI: 10.1038/s41598-017-01773-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/31/2017] [Indexed: 12/18/2022] Open
Abstract
Hepatitis B virus (HBV) infection causes acute hepatitis B (AHB), chronic hepatitis B (CHB), liver cirrhosis (LC), and eventually hepatocellular carcinoma (HCC). The presence of hepatitis B e antigen (HBeAg) in the serum generally indicates ongoing viral replication and disease progression. However, the mechanism by which HBeAg regulates HBV infection remains unclear. Interferons (IFNs) are pleiotropic cytokines that participate in host innate immunity. After binding to receptors, IFNs activate the JAK/STAT pathway to stimulate expression of IFN-stimulated genes (ISGs), leading to induction of antiviral responses. Here, we revealed that HBeAg represses IFN/JAK/STAT signaling to facilitate HBV replication. Initially, HBeAg stimulates the expression of suppressor of cytokine signaling 2 (SOCS2). Subsequently, SOCS2 impairs IFN/JAK/STAT signaling through reducing the stability of tyrosine kinase 2 (TYK2), downregulating the expression of type I and III IFN receptors, attenuating the phosphorylation and nucleus translocation of STAT1. Finally, SOCS2 inhibits the expression of ISGs, which leads to the repression of IFN action and facilitation of viral replication. These results demonstrate an important role of HBeAg in the regulation of IFN action, and provide a possible molecular mechanism by which HBV resists the IFN therapy and maintains persistent infection.
Collapse
Affiliation(s)
- Yi Yu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China.,Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Pin Wan
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Yanhua Cao
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Wei Zhang
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Junbo Chen
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Li Tan
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Yan Wang
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Zhichen Sun
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Qi Zhang
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Yushun Wan
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Ying Zhu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Fang Liu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Kailang Wu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China.
| | - Yingle Liu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China.
| | - Jianguo Wu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan, 430071, China.
| |
Collapse
|
29
|
Mondello P, Brea EJ, De Stanchina E, Toska E, Chang AY, Fennell M, Seshan V, Garippa R, Scheinberg DA, Baselga J, Wendel HG, Younes A. Panobinostat acts synergistically with ibrutinib in diffuse large B cell lymphoma cells with MyD88 L265P mutations. JCI Insight 2017; 2:e90196. [PMID: 28352655 DOI: 10.1172/jci.insight.90196] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Diffuse large B cell lymphoma (DLBCL) frequently harbors genetic alterations that activate the B cell receptor (BCR) and TLR pathways, which converge to activate NF-κB. While selective inhibition of BTK with ibrutinib causes clinical responses in relapsed DLBCL patients, most responses are partial and of a short duration. Here, we demonstrated that MyD88 silencing enhanced ibrutinib efficacy in DLBCL cells harboring MyD88 L265P mutations. Chemical downregulation of MyD88 expression with HDAC inhibitors also synergized with ibrutinib. We demonstrate that HDAC inhibitor regulation of MyD88 expression is mediated by STAT3. In turn, STAT3 silencing caused a decrease in MyD88 mRNA and protein levels, and enhanced the ibrutinib antilymphoma effect in MyD88 mutant DLBCL cells. Induced mutations in the STAT3 binding site in the MyD88 promotor region was associated with a decrease in MyD88 transcriptional activity. We also demonstrate that treatment with the HDAC inhibitor panobinostat decreased phosphorylated STAT3 binding to the MyD88 promotor. Accordingly, combined treatment with panobinostat and ibrutinib resulted in enhanced inhibition of NF-κB activity and caused regression of DLBCL xenografts. Our data provide a mechanistic rationale for combining HDAC inhibitors and ibrutinib for the treatment of DLBCL.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Hans-Guido Wendel
- Cancer Biology & Genetics Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | | |
Collapse
|
30
|
Lamb C, Arbuthnot P. Activating the innate immune response to counter chronic hepatitis B virus infection. Expert Opin Biol Ther 2016; 16:1517-1527. [PMID: 27603796 DOI: 10.1080/14712598.2016.1233962] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Chronic infection with hepatitis B virus (HBV) is endemic to several populous parts of the world, where resulting complicating cirrhosis and hepatocellular carcinoma occur commonly. Licensed drugs to treat the infection have limited curative efficacy, and development of therapies that eliminate all replication intermediates of HBV is a priority. Areas covered: The recent demonstration that the activation of the innate immune response may eradicate HBV from infected hepatocytes has a promising therapeutic application. Small molecule stimulators of Toll-like receptors (TLRs) inhibit replication of woodchuck hepatitis virus in woodchucks and HBV in chimpanzees and mice. Early stage clinical trials using GS-9620, a TLR7 agonist, indicate that this candidate antiviral is well tolerated in humans. Using an alternative approach, triggering the innate immune response with agonists of lymphotoxin-β receptor caused efficient APOBEC-mediated deamination and degradation of viral covalently closed circular DNA. Expert opinion: Eliminating HBV cccDNA from infected individuals would constitute a cure, and has become the focus of intensive research that employs various therapeutic approaches, including gene therapy. Immunomodulation through innate immune activation shows promise for the treatment of chronic infection of HBV (CHB) and, used in combination with other therapeutics, may contribute to the global control of infections and ultimately to the eradication of HBV.
Collapse
Affiliation(s)
- Camilla Lamb
- a Wits/SAMRC Antiviral Gene Therapy Research Unit, School of Pathology, Faculty of Health Sciences , University of the Witwatersrand , Johannesburg , South Africa
| | - Patrick Arbuthnot
- a Wits/SAMRC Antiviral Gene Therapy Research Unit, School of Pathology, Faculty of Health Sciences , University of the Witwatersrand , Johannesburg , South Africa
| |
Collapse
|
31
|
Hepatitis B Virus Polymerase Localizes to the Mitochondria, and Its Terminal Protein Domain Contains the Mitochondrial Targeting Signal. J Virol 2016; 90:8705-19. [PMID: 27440888 DOI: 10.1128/jvi.01229-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 07/13/2016] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED To understand subcellular sites of hepatitis B virus (HBV) replication, we visualized core (Cp), polymerase (Pol), and pregenomic RNA (pgRNA) in infected cells. Interestingly, we found that the majority of Pol localized to the mitochondria in cells undergoing viral replication. The mitochondrial localization of Pol was independent of both the cell type and other viral components, indicating that Pol contains an intrinsic mitochondrial targeting signal (MTS). Neither Cp nor pgRNA localized to the mitochondria during active replication, suggesting a role other than DNA synthesis for Pol at the mitochondria. The Pol of duck hepatitis B virus (DHBV) also localized to the mitochondria. This result indicates that localization of Pol to mitochondria is likely a feature of all hepadnaviruses. To map the MTS within HBV Pol, we generated a series of Pol-green fluorescent protein (Pol-GFP) fusions and found that a stretch spanning amino acids (aa) 141 to 160 of Pol was sufficient to target GFP to the mitochondria. Surprisingly, deleting aa 141 to 160 in full-length Pol did not fully ablate Pol's mitochondrial localization, suggesting that additional sequences are involved in mitochondrial targeting. Only by deleting the N-terminal 160 amino acids in full-length Pol was mitochondrial localization ablated. Crucial residues for pgRNA packaging are contained within aa 141 to 160, indicating a multifunctional role of this region of Pol in the viral life cycle. Our studies show an unexpected Pol trafficking behavior that is uncoupled from its role in viral DNA synthesis. IMPORTANCE Chronic infection by HBV is a serious health concern. Existing therapies for chronically infected individuals are not curative, underscoring the need for a better understanding of the viral life cycle to develop better antiviral therapies. To date, the most thoroughly studied function of Pol is to package the pgRNA and reverse transcribe it to double-stranded DNA within capsids. This study provides evidence for mitochondrial localization of Pol and defines the MTS. Recent findings have implicated a non-reverse transcription role for Pol in evading host innate immune responses. Mitochondria play an important role in controlling cellular metabolism, apoptosis, and innate immunity. Pol may alter one or more of these host mitochondrial functions to gain a replicative advantage and persist in chronically infected individuals.
Collapse
|
32
|
Molecular dissection of HBV evasion from restriction factor tetherin: A new perspective for antiviral cell therapy. Oncotarget 2016; 6:21840-52. [PMID: 26334101 PMCID: PMC4673130 DOI: 10.18632/oncotarget.4808] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 08/17/2015] [Indexed: 02/07/2023] Open
Abstract
Viruses have evolved various strategies to escape from the innate cellular mechanisms inhibiting viral replication and spread. Extensive evidence has highlighted the ineffectiveness of interferon (IFN) therapy against chronic hepatitis B virus (HBV) infection, implying the existence of mechanisms by which HBV evades IFN-induced antiviral responses. In our current study, we demonstrate that HBV surface protein (HBs) plays a crucial role in counteracting the IFN-induced antiviral response mediated by tetherin (also known as BST-2). The type I IFN treatment of HBV-producing cells marginally but significantly inhibited the release of HBsAg and viral DNA, but this release was recovered by the knockdown of tetherin. HBs can interact with tetherin via its fourth transmembrane domain thereby inhibiting its dimerization and antiviral activity. The expression of a tetherin mutant devoid of the HBs-binding domain promoted a prominent restriction of HBV particle production that eventually resulted in the alleviation of caspase-1-mediated cytotoxicity and interleukin-1β secretion in induced pluripotent stem cell (iPSC)-derived hepatocytes. Our current results thus reveal a previously undescribed molecular link between HBV and tetherin during the course of an IFN-induced antiviral response. In addition, strategies to augment the antiviral activity of tetherin by impeding tetherin-HBs interactions may be viable as a therapeutic intervention against HBV.
Collapse
|
33
|
Sepehri Z, Kiani Z, Alavian SM, Arababadi MK, Kennedy D. The link between TLR7 signaling and hepatitis B virus infection. Life Sci 2016; 158:63-9. [PMID: 27373425 DOI: 10.1016/j.lfs.2016.06.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 06/12/2016] [Accepted: 06/27/2016] [Indexed: 01/04/2023]
Abstract
Toll-Like Receptors (TLRs) play crucial roles in recognition and induction of appropriate immune responses against viral infections, including hepatitis B. TLR7 detects intracellular viral single strand RNA which leads to the activation of several pro-inflammatory transcription factors via the MYD88 dependent pathway. Patients with prolonged infectious forms of hepatitis B, including active and inactive chronic forms, are unable to clear HBV from hepatocytes completely. It is believed that the differences in genetic and immunological parameters of the patients and clearance subjects, who successfully clear HBV infections, are the main factors responsible for allowing the long term infections to persist. It appears that defective expression of TLR7 may result in impaired immune responses against HBV. The aim of this review is to address the recent information regarding the crucial roles played by TLR7 in hepatitis B infection and also the main mechanisms used by HBV to escape from recognition by TLR7 in prolonged HBV infected patients. Considering that chronic hepatitis B infection is not yet curable, it could be possible to activate TLR7-related immunological pathways as a therapy directed towards persistent HBV infection. Hence, another aim of this study is to present recent developments of TLR7 agonists as a therapeutic strategy for chronic hepatitis B.
Collapse
Affiliation(s)
- Zahra Sepehri
- Department of Internal Medicine, Zabol University of Medical Sciences, Zabol, Iran
| | - Zohre Kiani
- Zabol Medicinal Plant Research Center, Zabol University of Medical Sciences, Zabol, Iran; Kerman University of Medical Sciences, Kerman, Iran
| | - Seyed Moayed Alavian
- Baqiyatollah Research Center for Gastroenterology and Liver Diseases, Baqiyatollah University of Medical Sciences, Tehran, Iran
| | - Mohammad Kazemi Arababadi
- Department of Laboratory Sciences, Faculty of Paramedicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
| | - Derek Kennedy
- School of Natural Sciences, Eskitis Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| |
Collapse
|
34
|
Zou ZQ, Wang L, Wang K, Yu JG. Innate immune targets of hepatitis B virus infection. World J Hepatol 2016; 8:716-725. [PMID: 27330680 PMCID: PMC4911505 DOI: 10.4254/wjh.v8.i17.716] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 04/29/2016] [Accepted: 06/03/2016] [Indexed: 02/06/2023] Open
Abstract
Approximately 400 million people are chronically infected with hepatitis B virus (HBV) globally despite the widespread immunization of HBV vaccine and the development of antiviral therapies. The immunopathogenesis of HBV infection is initiated and driven by complexed interactions between the host immune system and the virus. Host immune responses to viral particles and proteins are regarded as the main determinants of viral clearance or persistent infection and hepatocyte injury. Innate immune system is the first defending line of host preventing from virus invasion. It is acknowledged that HBV has developed active tactics to escape innate immune recognition or actively interfere with innate immune signaling pathways and induce immunosuppression, which favor their replication. HBV reduces the expression of pattern-recognition receptors in the innate immune cells in humans. Also, HBV may interrupt different parts of antiviral signaling pathways, leading to the reduced production of antiviral cytokines such as interferons that contribute to HBV immunopathogenesis. A full comprehension of the mechanisms as to how HBV inactivates various elements of the innate immune response to initiate and maintain a persistent infection can be helpful in designing new immunotherapeutic methods for preventing and eradicating the virus. In this review, we aimed to summarize different branches the innate immune targeted by HBV infection. The review paper provides evidence that multiple components of immune responses should be activated in combination with antiviral therapy to disrupt the tolerance to HBV for eliminating HBV infection.
Collapse
|
35
|
Hepatitis B virus spliced variants are associated with an impaired response to interferon therapy. Sci Rep 2015; 5:16459. [PMID: 26585041 PMCID: PMC4653653 DOI: 10.1038/srep16459] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/14/2015] [Indexed: 02/08/2023] Open
Abstract
During hepatitis B virus (HBV) replication, spliced HBV genomes and splice-generated proteins have been widely described, however, their biological and clinical significance remains to be defined. Here, an elevation of the proportion of HBV spliced variants in the sera of patients with chronic hepatitis B (CHB) is shown to correlate with an impaired respond to interferon-α (IFN-α) therapy. Transfection of the constructs encoding the three most dominant species of spliced variants into cells or ectopic expression of the two major spliced protein including HBSP and N-terminal-truncated viral polymerase protein result in strong suppression of IFN-α signaling transduction, while mutation of the major splicing-related sites of HBV attenuates the viral anti-IFN activities in both cell and mouse models. These results have associated the productions of HBV spliced variants with the failure response to IFN therapy and illuminate a novel mechanism where spliced viral products are employed to resist IFN-mediated host defense.
Collapse
|
36
|
Giersch K, Dandri M. Hepatitis B and Delta Virus: Advances on Studies about Interactions between the Two Viruses and the Infected Hepatocyte. J Clin Transl Hepatol 2015; 3:220-9. [PMID: 26623269 PMCID: PMC4663204 DOI: 10.14218/jcth.2015.00018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/11/2015] [Accepted: 07/12/2015] [Indexed: 12/14/2022] Open
Abstract
The mechanisms determining persistence of hepatitis B virus (HBV) infection and long-term pathogenesis of HBV-associated liver disease appear to be multifactorial. Although viral replication can be efficiently suppressed by the antiviral treatments currently available, viral clearance is generally not achieved since HBV has developed unique replication strategies, enabling persistence of its genome within the infected hepatocytes. Moreover, no direct antiviral therapy exists for the more than 15 million people worldwide that are also coinfected with the hepatitis delta virus (HDV), a defective virus that needs the HBV envelope proteins for propagation. The limited availability of robust HBV and HDV infection systems has hindered the understanding of the complex network of virus-virus and virus-host interactions that are established in the course of infection and slowed down progress in drug development. Since chronic HBV/HDV coinfection leads to the most severe form of chronic viral hepatitis, elucidation of the molecular mechanisms regulating virus-host interplay and pathogenesis are urgently needed. This article summarizes the current knowledge regarding the interactions among HBV, HDV, and the infected target cell and discusses the dependence of HDV on HBV activity and possible future therapeutic approaches.
Collapse
Affiliation(s)
- Katja Giersch
- Department of Internal Medicine, Center for Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maura Dandri
- Department of Internal Medicine, Center for Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel site, Germany
- Correspondence to: Maura Dandri, Department of Internal Medicine, Center for Internal Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany. Tel: +49-40741052949, Fax: +49-40741057232, E-mail:
| |
Collapse
|
37
|
Yi Z, Chen J, Kozlowski M, Yuan Z. Innate detection of hepatitis B and C virus and viral inhibition of the response. Cell Microbiol 2015; 17:1295-303. [PMID: 26243406 DOI: 10.1111/cmi.12489] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/07/2015] [Accepted: 07/17/2015] [Indexed: 12/23/2022]
Abstract
Viral hepatitis caused by hepatitis B virus (HBV) and hepatitis C virus (HCV) infections poses a significant burden to the public health system. Although HBV and HCV differ in structure and life cycles, they share unique characteristics, such as tropism to infect hepatocytes and association with hepatic and extrahepatic disorders that are of innate immunity nature. In response to HBV and HCV infection, the liver innate immune cells eradicate pathogens by recognizing specific molecules expressed by pathogens via distinct cellular pattern recognition receptors whose triggering activates intracellular signalling pathways inducing cytokines, interferons and anti-viral response genes that collectively function to clear infections. However, HBV and HCV evolve strategies to inactivate innate signalling factors and as such establish persistent infections without being recognized by the innate immunity. We review recent insights into how HBV and HCV are sensed and how they evade innate immunity to establish chronicity. Understanding the mechanisms of viral hepatitis is mandatory to develop effective and safe therapies for eradication of viral hepatitis.
Collapse
Affiliation(s)
- Zhigang Yi
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jieliang Chen
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Maya Kozlowski
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhenghong Yuan
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Institutes of Medical Microbiology and Biomedical Sciences, Fudan University, Shanghai, China
| |
Collapse
|
38
|
Tan A, Koh S, Bertoletti A. Immune Response in Hepatitis B Virus Infection. Cold Spring Harb Perspect Med 2015; 5:a021428. [PMID: 26134480 DOI: 10.1101/cshperspect.a021428] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatitis B virus (HBV) can replicate within hepatocytes without causing direct cell damage. The host immune response is, therefore, not only essential to control the spread of virus infection, but it is also responsible for the inflammatory events causing liver pathologies. In this review, we discuss how HBV deals with host immunity and how we can harness it to achieve virus control and suppress liver damage.
Collapse
Affiliation(s)
- Anthony Tan
- Program Emerging Infectious Diseases, Duke-NUS Graduate Medical School, Singapore 169857
| | - Sarene Koh
- Viral Hepatitis Laboratory, Singapore Institute for Clinical Sciences, A*STAR, Singapore 117609
| | - Antonio Bertoletti
- Program Emerging Infectious Diseases, Duke-NUS Graduate Medical School, Singapore 169857 Viral Hepatitis Laboratory, Singapore Institute for Clinical Sciences, A*STAR, Singapore 117609 School of Immunity and Infection, College of Medical and Dental Science, University of Birmingham, Edgbaston, Birmingham B16 2TT, United Kingdom
| |
Collapse
|
39
|
Abstract
Hepatitis B virus (HBV) infection acquired in adult life is generally self-limited while chronic persistence of the virus is the prevalent outcome when infection is acquired perinatally. Both control of infection and liver cell injury are strictly dependent upon protective immune responses, because hepatocyte damage is the price that the host must pay to get rid of intracellular virus. Resolution of acute hepatitis B is associated with functionally efficient, multispecific antiviral T-cell responses which are preceded by a poor induction of intracellular innate responses at the early stages of infection. Persistent control of infection is provided by long-lasting protective memory, which is probably sustained by continuous stimulation of the immune system by trace amounts of virus which are never totally eliminated, persisting in an occult episomic form in the nucleus of liver cells even after recovery from acute infection. Chronic virus persistence is instead characterized by a lack of protective T-cell memory maturation and by an exhaustion of HBV-specific T-cell responses. Persistent exposure of T cells to high antigen loads is a key determinant of functional T-cell impairment but also other mechanisms can contribute to T-cell inhibition, including the tolerogenic effect of the liver environment. The degree of T-cell impairment is variable and its severity is related to the level of virus replication and antigen load. The antiviral T-cell function is more efficient in patients who can control infection either partially, such as inactive HBsAg carriers with low levels of virus replication, or completely, such as patients who achieve HBsAg loss either spontaneously or after antiviral therapy. Thus, understanding the features of the immune responses associated with control of infection is needed for the successful design of novel immune modulatory therapies based on the reconstitution of efficient antiviral responses in chronic HBV patients.
Collapse
Affiliation(s)
- Carlo Ferrari
- Unit of Infectious Disease and Hepatology, Laboratory of Viral Immunopathology, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
| |
Collapse
|
40
|
Zhang E, Lu M. Toll-like receptor (TLR)-mediated innate immune responses in the control of hepatitis B virus (HBV) infection. Med Microbiol Immunol 2014; 204:11-20. [PMID: 25550115 PMCID: PMC4305100 DOI: 10.1007/s00430-014-0370-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 10/01/2014] [Indexed: 12/19/2022]
Abstract
The role of adaptive immune responses in the control of hepatitis B virus (HBV) infection is well accepted. The contribution of innate immune responses to the viral control is recognized but yet not fully understood. Toll-like receptors (TLRs) sense pathogen-associated molecule patterns and activate antiviral mechanisms including the intracellular antiviral pathways and the production of antiviral effectors like interferons (IFNs) and pro-inflammatory cytokines. Activation of the TLR3 pathway and the production of IFN-β represent one of the major mechanisms leading to the suppression of HBV replication in the liver, as shown in different in vitro and in vivo models. TLR4 signaling and TLR2 signaling result in the activation of intracellular pathways including MAPK and PI-3 K/Akt in hepatocytes and reduce HBV replication in an IFN-independent manner. HBV is able to counteract the actions of TLR3 and TLR2/4 through downregulation of TLR expression and attenuation of the cellular signaling pathways. Thus, TLR ligands are promising candidates as immunomodulators and therapeutics for the treatment of chronic HBV infection. Specific antiviral treatment against HBV could recover the TLR functions in chronic HBV infection and increase the effectiveness of therapeutic approaches based on TLR activation.
Collapse
Affiliation(s)
- Ejuan Zhang
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45122, Essen, Germany
| | | |
Collapse
|
41
|
Hepatitis B virus polymerase disrupts K63-linked ubiquitination of STING to block innate cytosolic DNA-sensing pathways. J Virol 2014; 89:2287-300. [PMID: 25505063 DOI: 10.1128/jvi.02760-14] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED The cellular innate immune system recognizing pathogen infection is essential for host defense against viruses. In parallel, viruses have developed a variety of strategies to evade the innate immunity. The hepatitis B virus (HBV), a DNA virus that causes chronic hepatitis, has been shown to inhibit RNA helicase RIG-I-mediated interferon (IFN) induction. However, it is still unknown whether HBV could affect the host DNA-sensing pathways. Here we report that in transiently HBV-transfected Huh7 cells, the stably HBV-producing cell line HepAD38, and HBV-infected HepaRG cells and primary human hepatocytes, HBV markedly interfered with IFN-β induction and antiviral immunity mediated by the stimulator of interferon genes (STING), which has been identified as a central factor in foreign DNA recognition and antiviral innate immunity. Screening analysis demonstrated that the viral polymerase (Pol), but not other HBV-encoded proteins, was able to inhibit STING-stimulated interferon regulatory factor 3 (IRF3) activation and IFN-β induction. Moreover, the reverse transcriptase (RT) and the RNase H (RH) domains of Pol were identified to be responsible for the inhibitory effects. Furthermore, Pol was shown to physically associate with STING and dramatically decrease the K63-linked polyubiquitination of STING via its RT domain without altering the expression level of STING. Taken together, these observations suggest that besides its inherent catalytic function, Pol has a role in suppression of IFN-β production by direct interaction with STING and subsequent disruption of its K63-linked ubiquitination, providing a new mechanism for HBV to counteract the innate DNA-sensing pathways. IMPORTANCE Although whether and how HBV infection induces the innate immune responses are still controversial, it has become increasingly clear that HBV has developed strategies to counteract the pattern recognition receptor-mediated signaling pathways. Previous studies have shown that type I IFN induction activated by the host RNA sensors could be inhibited by HBV. However, it remains unknown whether HBV as a DNA virus utilizes evasion mechanisms against foreign DNA-elicited antiviral signaling. In recent years, the cytosolic DNA sensor and key adaptor STING has been demonstrated to be essential in multiple foreign DNA-elicited innate immune signalings. Here, for the first time, we report STING as a new target of HBV to antagonize IFN induction and identify the viral polymerase responsible for the inhibitory effect, thus providing an additional molecular mechanism by which HBV evades the innate immunity; this implies that in addition to its inherent catalytic function, HBV polymerase is a multifunctional immunomodulatory protein.
Collapse
|
42
|
Pei RJ, Chen XW, Lu MJ. Control of hepatitis B virus replication by interferons and Toll-like receptor signaling pathways. World J Gastroenterol 2014; 20:11618-11629. [PMID: 25206268 PMCID: PMC4155354 DOI: 10.3748/wjg.v20.i33.11618] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/23/2013] [Accepted: 04/16/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV) infection is one of the major causes of liver diseases, affecting more than 350 million people worldwide. The interferon (IFN)-mediated innate immune responses could restrict HBV replication at the different steps of viral life cycle. Indeed, IFN-α has been successfully used for treatment of patients with chronic hepatitis B. However, the role of the innate immune response in HBV replication and the mechanism of the anti-HBV effect of IFN-α are not completely explored. In this review, we summarized the currently available knowledge about the IFN-mediated anti-HBV effect in the HBV life cycle and the possible effectors downstream the IFN signaling pathway. The antiviral effect of Toll-like receptors (TLRs) in HBV replication is briefly discussed. The strategies exploited by HBV to evade the IFN- and TLR-mediated antiviral actions are summarized.
Collapse
|
43
|
Zhang P, Li F, Li N, Zhu Q, Yang C, Han Q, Chen J, Lv Y, Yu L, Wei P, Liu Z. Genetic variations of SOCS1 are associated with chronic hepatitis B virus infection. Hum Immunol 2014; 75:709-14. [PMID: 24768946 DOI: 10.1016/j.humimm.2014.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/19/2014] [Accepted: 04/06/2014] [Indexed: 10/25/2022]
|
44
|
The carboxy terminal region of the human cytomegalovirus immediate early 1 (IE1) protein disrupts type II inteferon signaling. Viruses 2014; 6:1502-24. [PMID: 24699362 PMCID: PMC4014707 DOI: 10.3390/v6041502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 03/07/2014] [Accepted: 03/07/2014] [Indexed: 12/21/2022] Open
Abstract
Interferons (IFNs) activate the first lines of defense against viruses, and promote innate and adaptive immune responses to viruses. We report that the immediate early 1 (IE1) protein of human cytomegalovirus (HCMV) disrupts signaling by IFNγ. The carboxyl-terminal region of IE1 is required for this function. We found no defect in the initial events in IFNγ signaling or in nuclear accumulation of signal transducer and activator of transcription 1 (STAT1) in IE1-expressing cells. Moreover, we did not observe an association between disruption of IFNγ signaling and nuclear domain 10 (ND10) disruption. However, there is reduced binding of STAT1 homodimers to target gamma activated sequence (GAS) elements in the presence of IE1. Co-immunoprecipitation studies failed to support a direct interaction between IE1 and STAT1, although these studies revealed that the C-terminal region of IE1 was required for interaction with STAT2. Together, these results indicate that IE1 disrupts IFNγ signaling by interfering with signaling events in the nucleus through a novel mechanism.
Collapse
|
45
|
Liu D, Wu A, Cui L, Hao R, Wang Y, He J, Guo D. Hepatitis B virus polymerase suppresses NF-κB signaling by inhibiting the activity of IKKs via interaction with Hsp90β. PLoS One 2014; 9:e91658. [PMID: 24618592 PMCID: PMC3950214 DOI: 10.1371/journal.pone.0091658] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 02/13/2014] [Indexed: 01/04/2023] Open
Abstract
Nuclear factor-κB (NF-κB) plays a central role in the regulation of diverse biological processes, including immune responses, development, cell growth, and cell survival. To establish persistent infection, many viruses have evolved strategies to evade the host’s antiviral immune defenses. In the case of hepatitis B virus (HBV), which can cause chronic infection in the liver, immune evasion strategies used by the virus are not fully understood. It has recently been reported that the polymerase of HBV (Pol) inhibits interferon-β (IFN-β) activity by disrupting the interaction between IKKε and the DDX3. In the current study, we found that HBV Pol suppressed NF-κB signaling, which can also contribute to IFN-β production. HBV Pol did not alter the level of NF-κB expression, but it prevented NF-κB subunits involved in both the canonical and non-canonical NF-κB pathways from entering the nucleus. Further experiments demonstrated that HBV Pol preferentially suppressed the activity of the IκB kinase (IKK) complex by disrupting the association of IKK/NEMO with Cdc37/Hsp90, which is critical for the assembly of the IKK complex and recruitment of the IKK complex to the tumor necrosis factor type 1 receptor (TNF-R1). Furthermore, we found that HBV Pol inhibited the NF-κB-mediated transcription of target genes. Taken together, it is suggested that HBV Pol could counteract host innate immune responses by interfering with two distinct signaling pathways required for IFN-β activation. Our studies therefore shed light on a potential therapeutic target for persistent infection with HBV.
Collapse
Affiliation(s)
- Dan Liu
- National Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan City, P. R. China
| | - An’dong Wu
- National Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan City, P. R. China
| | - Lei Cui
- National Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan City, P. R. China
| | - Ruidong Hao
- National Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan City, P. R. China
| | - Yuan Wang
- National Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan City, P. R. China
| | - Jing He
- National Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan City, P. R. China
| | - Deyin Guo
- National Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan City, P. R. China
- * E-mail:
| |
Collapse
|
46
|
Guo P. Suppression of interferon-mediated antiviral immunity by hepatitis B virus: an overview of research progress. Scand J Immunol 2013; 78:230-7. [PMID: 23790137 DOI: 10.1111/sji.12086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 06/04/2013] [Indexed: 01/30/2023]
Abstract
Interferon (IFN)-α is an indispensable drug for hepatitis B treatment in clinical settings. However, hepatitis B virus (HBV) can attenuate IFN-mediated antiviral responses to avoid being inhibited or cleared. Much progress has been made in exploring how the IFN-induced anti-HBV effect is inhibited. This review examines and summarizes new advances regarding the molecular mechanism underlying the HBV-induced suppression of type I IFN-mediated antiviral immunity.
Collapse
Affiliation(s)
- P Guo
- West Campus Hospital of Shandong University, Jinan, China
| |
Collapse
|
47
|
Jones SA, Hu J. Hepatitis B virus reverse transcriptase: diverse functions as classical and emerging targets for antiviral intervention. Emerg Microbes Infect 2013; 2:e56. [PMID: 26038488 PMCID: PMC3820986 DOI: 10.1038/emi.2013.56] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 07/21/2013] [Indexed: 12/12/2022]
Abstract
Hepatitis B virus (HBV) infection remains a global health problem with over 350 million chronically infected, causing an increased risk of cirrhosis and hepatocellular carcinoma. Current antiviral chemotherapy for HBV infection include five nucleos(t)ide analog reverse transcriptase inhibitors (NRTIs) that all target one enzymatic activity, DNA strand elongation, of the HBV polymerase (HP), a specialized reverse transcriptase (RT). NRTIs are not curative and long-term treatment is associated with toxicity and the emergence of drug resistant viral mutations, which can also result in vaccine escape. Recent studies on the multiple functions of HP have provided important mechanistic insights into its diverse roles during different stages of viral replication, including interactions with viral pregenomic RNA, RNA packaging into nucleocapsids, protein priming, minus- and plus-strand viral DNA synthesis, RNase H-mediated degradation of viral RNA, as well as critical host interactions that regulate the multiple HP functions. These diverse functions provide ample opportunities to develop novel HP-targeted antiviral treatments that should contribute to curing chronic HBV infection.
Collapse
Affiliation(s)
- Scott A Jones
- Department of Microbiology and Immunology, The Penn State University College of Medicine, Hershey , PA 17033, USA
| | - Jianming Hu
- Department of Microbiology and Immunology, The Penn State University College of Medicine, Hershey , PA 17033, USA
| |
Collapse
|
48
|
Li J, Liu K, Liu Y, Xu Y, Zhang F, Yang H, Liu J, Pan T, Chen J, Wu M, Zhou X, Yuan Z. Exosomes mediate the cell-to-cell transmission of IFN-α-induced antiviral activity. Nat Immunol 2013; 14:793-803. [DOI: 10.1038/ni.2647] [Citation(s) in RCA: 383] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 05/17/2013] [Indexed: 12/21/2022]
|
49
|
Meng Z, Zhang X, Wu J, Pei R, Xu Y, Yang D, Roggendorf M, Lu M. RNAi induces innate immunity through multiple cellular signaling pathways. PLoS One 2013; 8:e64708. [PMID: 23700487 PMCID: PMC3659100 DOI: 10.1371/journal.pone.0064708] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 04/17/2013] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AIMS Our previous results showed that the knockdown of woodchuck hepatitis virus (WHV) by RNA interference (RNAi) led to upregulation of interferon stimulated genes (ISGs) in primary hepatocytes. In the present study, we tested the hypothesis that the cellular signaling pathways recognizing RNA molecules may be involved the ISG stimulation by RNAi. METHODS Primary murine hepatocytes (PMHs) from wild type mice and WHV transgenic (Tg) mice were prepared and treated with defined siRNAs. The mRNA levels of target genes and ISGs were detected by real-time RT-PCR. The involvement of the signaling pathways including RIG-I/MDA5, PKR, and TLR3/7/8/9 was examined by specific inhibition and the analysis of their activation by Western blotting. RESULTS In PMHs from WHV Tg mice, specific siRNAs targeting WHV, mouse β-actin, and GAPDH reduced the levels of targeted mRNAs and increased the mRNA expression of IFN-β, MxA, and IP-10. The enhanced ISG expression by siRNA transfection were abolished by siRNA-specific 2'-O-methyl antisense RNA and the inhibitors 2-AP and chloroquine blocking PKR and other TLR-mediated signaling pathways. Furthermore, Western blotting revealed that RNAi results in an increase in PKR phosphorylation and nuclear translocation of IRF3 and NF-êB, indicating the possible role of IRF3 in the RNAi-directed induction of ISGs. In contrast, silencing of RIG-I and MDA5 failed to block RNAi-mediated MxA induction. CONCLUSIONS RNAi is capable of enhancing innate immune responses through the PKR- and TLR-dependent signaling pathways in primary hepatocytes. The immune stimulation by RNAi may contribute to the antiviral activity of siRNAs in vivo.
Collapse
Affiliation(s)
- Zhongji Meng
- Institute of Virology, University Hospital of Essen, University Duisburg-Essen, Essen, Germany
- Department of Infectious Diseases, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Xiaoyong Zhang
- Institute of Virology, University Hospital of Essen, University Duisburg-Essen, Essen, Germany
| | - Jun Wu
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rongjuan Pei
- Institute of Virology, University Hospital of Essen, University Duisburg-Essen, Essen, Germany
| | - Yang Xu
- Department of Microbiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dongliang Yang
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Michael Roggendorf
- Institute of Virology, University Hospital of Essen, University Duisburg-Essen, Essen, Germany
| | - Mengji Lu
- Institute of Virology, University Hospital of Essen, University Duisburg-Essen, Essen, Germany
- * E-mail:
| |
Collapse
|
50
|
Chen J, Wu M, Zhang X, Zhang W, Zhang Z, Chen L, He J, Zheng Y, Chen C, Wang F, Hu Y, Zhou X, Wang C, Xu Y, Lu M, Yuan Z. Hepatitis B virus polymerase impairs interferon-α-induced STA T activation through inhibition of importin-α5 and protein kinase C-δ. Hepatology 2013; 57:470-82. [PMID: 22996189 DOI: 10.1002/hep.26064] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 08/30/2012] [Indexed: 12/24/2022]
Abstract
UNLABELLED Treatment with exogenous interferon (IFN)-α is not effective in the majority of patients with chronic hepatitis B virus (HBV) infection. Recent evidence suggests that HBV has evolved strategies to block the nuclear translocation of signal transducer and activator of transcription (STAT) 1 to limit IFN-α-induced cellular antiviral responses. However, it remains unclear whether STAT1 translocation is impaired in chronic hepatitis B patients and what mechanisms are involved. Here we report that the expression of HBV polymerase (Pol) in human hepatic cell lines inhibited induction of IFN-stimulated genes and resulted in a weakened antiviral activity of IFN-α. Ectopic expression of Pol suppressed IFN-α-induced STAT1 serine 727 phosphorylation and STAT1/2 nuclear accumulation, whereas STAT1 tyrosine 701 phosphorylation, and STAT1-STAT2 heterodimer formation were not affected. Further studies demonstrated that Pol interacted with the catalytic domain of protein kinase C-δ (PKC-δ) and perturbed PKC-δ phosphorylation and its association with STAT1, which resulted in the suppression of STAT1 Ser727 phosphorylation. Moreover, Pol was found to interfere with nuclear transportation of STAT1/2 by competitively binding to the region of importin-α5 required for STAT1/2 recruitment. Truncation analysis suggested that the terminal protein and RNase H domains of Pol were able to bind to PKC-δ and importin-α5, respectively, and were responsible for the inhibition of IFN-α signaling. More importantly, the inhibition of STAT1 and PKC-δ phosphorylation were confirmed in a hydrodynamic-based HBV mouse model, and the blockage of IFN-α-induced STAT1/2 nuclear translocation was observed in HBV-infected cells from liver biopsies of chronic HBV patients. CONCLUSIONS These results demonstrate a role for Pol in HBV-mediated antagonization of IFN-α signaling and provide a possible molecular mechanism by which HBV resists the IFN therapy and maintains its persistence.
Collapse
Affiliation(s)
- Jieliang Chen
- Key Laboratory of Medical Molecular Virology, Ministry of Education and HealthShanghai Medical College of Fudan University, Shanghai, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|