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McCoullough LC, Fareh M, Hu W, Sozzi V, Makhlouf C, Droungas Y, Lee CL, Takawy M, Fabb SA, Payne TJ, Pouton CW, Netter HJ, Lewin SR, Purcell DF, Holmes JA, Trapani JA, Littlejohn M, Revill PA. CRISPR-Cas13b-mediated suppression of HBV replication and protein expression. J Hepatol 2024:S0168-8278(24)00360-X. [PMID: 38815932 DOI: 10.1016/j.jhep.2024.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 04/19/2024] [Accepted: 05/16/2024] [Indexed: 06/01/2024]
Abstract
BACKGROUND & AIMS New antiviral approaches that target multiple aspects of the HBV replication cycle to improve rates of functional cure are urgently required. HBV RNA represents a novel therapeutic target. Here, we programmed CRISPR-Cas13b endonuclease to specifically target the HBV pregenomic RNA and viral mRNAs in a novel approach to reduce HBV replication and protein expression. METHODS Cas13b CRISPR RNAs (crRNAs) were designed to target multiple regions of HBV pregenomic RNA. Mammalian cells transfected with replication competent wild-type HBV DNA of different genotypes, a HBV-expressing stable cell line, a HBV infection model and a hepatitis B surface antigen (HBsAg)-expressing stable cell line were transfected with PspCas13b-BFP (blue fluorescent protein) and crRNA plasmids, and the impact on HBV replication and protein expression was measured. Wild-type HBV DNA, PspCas13b-BFP and crRNA plasmids were simultaneously hydrodynamically injected into mice, and serum HBsAg was measured. PspCas13b mRNA and crRNA were also delivered to a HBsAg-expressing stable cell line via lipid nanoparticles and the impact on secreted HBsAg determined. RESULTS Our HBV-targeting crRNAs strongly suppressed HBV replication and protein expression in mammalian cells by up to 96% (p <0.0001). HBV protein expression was also reduced in a HBV-expressing stable cell line and in the HBV infection model. CRISPR-Cas13b crRNAs reduced HBsAg expression by 50% (p <0.0001) in vivo. Lipid nanoparticle-encapsulated PspCas13b mRNA reduced secreted HBsAg by 87% (p = 0.0168) in a HBsAg-expressing stable cell line. CONCLUSIONS Together, these results show that CRISPR-Cas13b can be programmed to specifically target and degrade HBV RNAs to reduce HBV replication and protein expression, demonstrating its potential as a novel therapeutic option for chronic HBV infection. IMPACT AND IMPLICATIONS Owing to the limitations of current antiviral therapies for hepatitis B, there is an urgent need for new treatments that target multiple aspects of the HBV replication cycle to improve rates of functional cure. Here, we present CRISPR-Cas13b as a novel strategy to target HBV replication and protein expression, paving the way for its development as a potential new treatment option for patients living with chronic hepatitis B.
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Affiliation(s)
- Laura C McCoullough
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Department of Microbiology and Immunology, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Mohamed Fareh
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Australia
| | - Wenxin Hu
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Australia
| | - Vitina Sozzi
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Christina Makhlouf
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Yianni Droungas
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Department of Microbiology and Immunology, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Chee Leng Lee
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Mina Takawy
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Stewart A Fabb
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Thomas J Payne
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Colin W Pouton
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Hans J Netter
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Sharon R Lewin
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Victorian Infectious Diseases Service, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Department of Infectious Diseases, Alfred Hospital and Monash University, Melbourne, Australia
| | - Damian Fj Purcell
- Department of Microbiology and Immunology, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Jacinta A Holmes
- Department of Gastroenterology, St. Vincent's Hospital, Melbourne, Victoria, Australia
| | - Joseph A Trapani
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Australia
| | - Margaret Littlejohn
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Peter A Revill
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
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McCoullough LC, Sadauskas T, Sozzi V, Mak KY, Mason H, Littlejohn M, Revill PA. The in vitro replication phenotype of hepatitis B virus (HBV) splice variants Sp3 and Sp9 and their impact on wild-type HBV replication. J Virol 2024; 98:e0153823. [PMID: 38501924 PMCID: PMC11019940 DOI: 10.1128/jvi.01538-23] [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: 10/02/2023] [Accepted: 02/22/2024] [Indexed: 03/20/2024] Open
Abstract
Prior to nuclear export, the hepatitis B virus (HBV) pregenomic RNA may be spliced by the host cell spliceosome to form shorter RNA sequences known as splice variants. Due to deletions in the open reading frames, splice variants may encode novel fusion proteins. Although not essential for HBV replication, the role of splice variants and their novel fusion proteins largely remains unknown. Some splice variants and their encoded novel fusion proteins have been shown to impair or promote wild-type HBV replication in vitro, and although splice variants Sp3 and Sp9 are two of the most common splice variants identified to date, their in vitro replication phenotype and their impact on wild-type HBV replication are unclear. Here, we utilize greater than genome-length Sp3 and Sp9 constructs to investigate their replication phenotype in vitro, and their impact on wild-type HBV replication. We show that Sp3 and Sp9 were incapable of autonomous replication, which was rescued by providing the polymerase and core proteins in trans. Furthermore, we showed that Sp3 had no impact on wild-type HBV replication, whereas Sp9 strongly reduced wild-type HBV replication in co-transfection experiments. Knocking out Sp9 novel precore-surface and core-surface fusion protein partially restored replication, suggesting that these proteins contributed to suppression of wild-type HBV replication, providing further insights into factors regulating HBV replication in vitro. IMPORTANCE The role of hepatitis B virus (HBV) splice variants in HBV replication and pathogenesis currently remains largely unknown. However, HBV splice variants have been associated with the development of hepatocellular carcinoma, suggesting a role in HBV pathogenesis. Several in vitro co-transfection studies have shown that different splice variants have varying impacts on wild-type HBV replication, perhaps contributing to viral persistence. Furthermore, all splice variants are predicted to produce novel fusion proteins. Sp1 hepatitis B splice protein contributes to liver disease progression and apoptosis; however, the function of other HBV splice variant novel fusion proteins remains largely unknown. We show that Sp9 markedly impairs HBV replication in a cell culture co-transfection model, mediated by expression of Sp9 novel fusion proteins. In contrast, Sp3 had no effect on wild-type HBV replication. Together, these studies provide further insights into viral factors contributing to regulation of HBV replication.
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Affiliation(s)
- Laura C. McCoullough
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Tomas Sadauskas
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Vitina Sozzi
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Kai Yan Mak
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Hugh Mason
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Margaret Littlejohn
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Department of Infectious Diseases, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Peter A. Revill
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Department of Infectious Diseases, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
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3
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Sozzi V, McCoullough L, Mason H, Littlejohn M, Revill P. The in vitro replication phenotype of hepatitis B virus (HBV) splice variant Sp1. Virology 2022; 574:65-70. [DOI: 10.1016/j.virol.2022.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 11/30/2022]
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Bannister E, Sozzi V, Mason H, Locarnini S, Hardikar W, Revill PA. Analysis of the in vitro replication phenotype of African hepatitis B virus (HBV) genotypes and subgenotypes present in Australia identifies marked differences in DNA and protein expression. Virology 2019; 540:97-103. [PMID: 31765921 DOI: 10.1016/j.virol.2019.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/01/2019] [Accepted: 11/01/2019] [Indexed: 02/06/2023]
Abstract
Hepatitis B virus infection in Africa is characterised by distinct genotypes with observed differences in natural history and clinical outcomes. Replication-competent cDNA clones of African genotypes were generated from patient-derived sequences identified in African children with chronic hepatitis B infection living in Australia: A1 (wild-type and basal core promotor (BCP) mutant), D2, D6, and E, comparing the replication phenotype to an established D3 cDNA clone in a transient transfection cell culture model. All clones replicated efficiently although less than the European D3 reference clone, and demonstrated marked differences in replication capacity, highest for subgenotypes A1 and D2. The BCP mutation increased the replication levels of the A1 subgenotype compared to wild-type. Intracellular and secreted surface antigen and HBeAg protein expression also varied across genotypes. We observed differences in functional activity in the upstream regulatory region across the genotypes that may contribute to the replication and protein differences observed.
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Affiliation(s)
- E Bannister
- Department of Gastroenterology and Clinical Nutrition, The Royal Children's Hospital, Melbourne, Victoria, Australia; Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - V Sozzi
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - H Mason
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - S Locarnini
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - W Hardikar
- Department of Gastroenterology and Clinical Nutrition, The Royal Children's Hospital, Melbourne, Victoria, Australia; Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - P A Revill
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria, Australia.
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Sozzi V, Shen F, Chen J, Colledge D, Jackson K, Locarnini S, Yuan Z, Revill PA. In vitro studies identify a low replication phenotype for hepatitis B virus genotype H generally associated with occult HBV and less severe liver disease. Virology 2018; 519:190-196. [PMID: 29734042 DOI: 10.1016/j.virol.2018.04.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/27/2018] [Accepted: 04/19/2018] [Indexed: 01/05/2023]
Abstract
Hepatitis B virus (HBV) exists as 9 major genotypes and multiple subtypes, many of which exhibit differences in pathogenicity and treatment response. Genotype H identified in Central America is associated with low incidence of liver disease and HCC, but higher incidence of occult HBV (low level HBV DNA positivity, HBsAg negative). The replication phenotype of genotype H associated with less severe forms of liver disease is unknown. We hypothesized that the reduced pathogenesis associated with this genotype may be due to by lower rates of viral replication and/or secretion compared to other characterised strains. We used transient transfection and infection cell culture models to characterise the replication phenotype, compared to our D3 reference strain. Genotype H exhibited reduced viral replication and altered envelope protein expression compared to genotype D, with functional studies showing that low replication was in part likely due to sequence differences in the major transcriptional regulatory region.
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Affiliation(s)
- Vitina Sozzi
- Victorian Infectious Diseases Reference Laboratory, The Royal Melbourne Hospital, Peter Doherty Institute of Infection and Immunity, 792 Elizabeth St, Melbourne, 3000 Victoria, Australia
| | - Fang Shen
- Key Laboratory of Medical Molecular Virology, School of Basic and Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, China
| | - Jieliang Chen
- Key Laboratory of Medical Molecular Virology, School of Basic and Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, China
| | - Danni Colledge
- Victorian Infectious Diseases Reference Laboratory, The Royal Melbourne Hospital, Peter Doherty Institute of Infection and Immunity, 792 Elizabeth St, Melbourne, 3000 Victoria, Australia
| | - Kathy Jackson
- Victorian Infectious Diseases Reference Laboratory, The Royal Melbourne Hospital, Peter Doherty Institute of Infection and Immunity, 792 Elizabeth St, Melbourne, 3000 Victoria, Australia
| | - Stephen Locarnini
- Victorian Infectious Diseases Reference Laboratory, The Royal Melbourne Hospital, Peter Doherty Institute of Infection and Immunity, 792 Elizabeth St, Melbourne, 3000 Victoria, Australia
| | - Zhenghong Yuan
- Key Laboratory of Medical Molecular Virology, School of Basic and Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, China
| | - Peter A Revill
- Victorian Infectious Diseases Reference Laboratory, The Royal Melbourne Hospital, Peter Doherty Institute of Infection and Immunity, 792 Elizabeth St, Melbourne, 3000 Victoria, Australia.
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Qin B, Zhou Y, Zhou G, Xu X, Wang Y, Chen J. Substitutions of rtL228 and/or L229 are involved in the regulation of replication and HBsAg secretion in hepatitis B virus, and do not affect susceptibility to nucleos(t)ide analogs. Mol Med Rep 2017; 16:9678-9684. [PMID: 29039614 DOI: 10.3892/mmr.2017.7778] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 08/22/2017] [Indexed: 11/05/2022] Open
Abstract
Nucleos(t)ide analogs (NAs) are widely used in the treatment of hepatitis B virus (HBV) and human immunodeficiency virus (HIV). The mutation L210W of HIV‑1 reverse transcriptase (RT) is one of the six principal mutations which confer in vivo resistance to zidovudine. Due to the similar 3D‑structure and high conservation between HIV‑RT and HBV‑RT, the present study aimed to clarify whether corresponding mutations in HBV may decrease its susceptibility to relevant NAs. Mutations including rtL228C/W, rtL229W and rtL228W/L229W were introduced into a HBV replication competent plasmid by fusion polymerase chain reaction. Replication capacity, HBs/e antigen (Ag) levels and susceptibility to NAs were subsequently analyzed in vitro. Single or combination mutations of rtL228 and rtL229 impaired HBV replication. Decreased HBsAg secretion in the supernatant and production in the cell lysate wasobserved with single rtL229W or in combination with rtL228W, while there was no significant difference between wild‑type and mutant HBV with regard to the level of HBeAg in the supernatant and susceptibility to commonly‑used NAs. Substitution mutations of rtL228 and/or L229 in HBV did not alter the susceptibility of the virus to NAs, although replication and HBsAg secretion were affected.
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Affiliation(s)
- Bo Qin
- Department of Clinical Laboratory Center, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang 312000, P.R. China
| | - Yechao Zhou
- Department of Clinical Laboratory Center, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang 312000, P.R. China
| | - Guozhong Zhou
- Department of Clinical Laboratory Center, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang 312000, P.R. China
| | - Xiuping Xu
- Department of Clinical Laboratory Center, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang 312000, P.R. China
| | - Yanan Wang
- Department of Clinical Laboratory Center, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang 312000, P.R. China
| | - Jinkun Chen
- Shaoxing Center for Disease Control and Prevention, Shaoxing, Zhejiang 312000, P.R. China
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In Vitro Studies Show that Sequence Variability Contributes to Marked Variation in Hepatitis B Virus Replication, Protein Expression, and Function Observed across Genotypes. J Virol 2016; 90:10054-10064. [PMID: 27512071 DOI: 10.1128/jvi.01293-16] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/02/2016] [Indexed: 01/05/2023] Open
Abstract
The hepatitis B virus (HBV) exists as 9 major genotypes (A to I), one minor strain (designated J) and multiple subtypes. Marked differences in HBV natural history, disease progression and treatment response are exhibited by many of these genotypes and subtypes. For example, HBV genotype C is associated with later hepatitis B e antigen (HBeAg) seroconversion and high rates of liver cancer compared to other HBV genotypes, whereas genotype A2 is rarely associated with HBeAg-negative disease or liver cancer. The reasons for these and other differences in HBV natural history are yet to be determined but could in part be due to sequence differences in the HBV genome that alter replicative capacity and/or gene expression. Direct comparative studies on HBV replication and protein expression have been limited to date due largely to the absence of infectious HBV cDNA clones for each of the HBV genotypes present in the same genetic arrangement. We have produced replication-competent infectious cDNA clones of the most common subtypes of genotypes A to D, namely, A2, B2, C2, D3, and the minor strain J, and compared their HBV replication phenotype using transient-transfection models. We identified striking differences in HBV replicative capacity as well as HBeAg and surface (HBsAg) protein expression across genotypes, which may in part be due to sequence variability in regulatory regions of the HBV genome. Functional analysis showed that sequence differences in the major upstream regulatory region across genotypes impacted promoter activity. IMPORTANCE There have been very few studies directly comparing the replication phenotype of different HBV genotypes, for which there are marked differences in natural history and disease progression worldwide. We have generated replication-competent 1.3-mer cDNA clones of the major genotypes A2, B2, C2, and D3, as well as a recently identified strain J, and identified striking differences in replicative capacity and protein expression that may contribute to some of the observed differences in HBV natural history observed globally.
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Revill P, Locarnini S. The Basis for Antiviral Therapy: Drug Targets, Cross-Resistance, and Novel Small Molecule Inhibitors. MOLECULAR AND TRANSLATIONAL MEDICINE 2016. [DOI: 10.1007/978-3-319-22330-8_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Vaccher E, Serraino D, Carbone A, De Paoli P. The evolving scenario of non-AIDS-defining cancers: challenges and opportunities of care. Oncologist 2014; 19:860-7. [PMID: 24969164 PMCID: PMC4122480 DOI: 10.1634/theoncologist.2014-0024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 05/13/2014] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The impact of highly active antiretroviral therapies (HAART) on the risk of non-AIDS-defining cancers (NADCs) and the role of biological and clinical factors in their pathogenesis are debated issues. The purpose of this review is to examine the epidemiology, etiology, and not-yet-defined pathogenic characteristics of NADCs and discuss topics such as treatment strategies, comorbidity, and multidrug interactions. Four types of NADCs that deserve special attention are examined: anal cancer, Hodgkin lymphoma (HL), hepatocellular carcinoma, and lung cancer. METHODS The PubMed database and the Cochrane Library were searched by focusing on NADCs and on the association among NADCs, HAART, aging, and/or chronic inflammation. All articles were reviewed to identify those reporting variables of interest. RESULTS NADC incidence is twofold higher in patients with HIV/AIDS than in the corresponding general population, and this elevated risk persists despite the use of HAART. The mechanisms that HIV may use to promote the development of NADCs are presently unclear; immunological mechanisms, either immunodeficiency and/or immunoactivation, may play a role. CONCLUSION Recent clinical studies have suggested that equivalent antineoplastic treatment is feasible and outcome can be similar in HIV-infected patients on HAART compared with uninfected patients for the treatment of HL and anal and lung cancers. However, patients with advanced HIV disease and/or aging-related comorbidities are likely to experience worse outcomes and have poorer tolerance of therapy compared with those with less advanced HIV disease.
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Affiliation(s)
- Emanuela Vaccher
- Division of Medical Oncology, Unit of Epidemiology and Biostatistics, Division of Pathology, Scientific Directorate, Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientifico, Aviano, Italy
| | - Diego Serraino
- Division of Medical Oncology, Unit of Epidemiology and Biostatistics, Division of Pathology, Scientific Directorate, Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientifico, Aviano, Italy
| | - Antonino Carbone
- Division of Medical Oncology, Unit of Epidemiology and Biostatistics, Division of Pathology, Scientific Directorate, Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientifico, Aviano, Italy
| | - Paolo De Paoli
- Division of Medical Oncology, Unit of Epidemiology and Biostatistics, Division of Pathology, Scientific Directorate, Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientifico, Aviano, Italy
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10
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Downregulation of interleukin-18-mediated cell signaling and interferon gamma expression by the hepatitis B virus e antigen. J Virol 2014; 88:10412-20. [PMID: 24872585 DOI: 10.1128/jvi.00111-14] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
UNLABELLED The mechanisms by which hepatitis B virus (HBV) establishes and maintains chronic hepatitis B infection (CHB) are poorly defined. Innate immune responses play an important role in reducing HBV replication and pathogenesis. HBV has developed numerous mechanisms to escape these responses, including the production of the secreted hepatitis B e antigen (HBeAg), which has been shown to regulate antiviral toll-like receptor (TLR) and interleukin-1 (IL-1) signaling. IL-18 is a related cytokine that inhibits HBV replication in hepatoma cell lines and in the liver through the induction of gamma interferon (IFN-γ) by NK cells and T cells. We hypothesized that HBV or HBV proteins inhibit IFN-γ expression by NK cells as an accessory immunomodulatory function. We show that HBeAg protein inhibits the NF-κB pathway and thereby downregulates NK cell IFN-γ expression. Additionally, IFN-γ expression was significantly inhibited by exposure to serum from individuals with HBeAg-positive but not HBeAg-negative chronic HBV infection. Further, we show that the HBeAg protein suppresses IL-18-mediated NF-κB signaling in NK and hepatoma cells via modulation of the NF-κB pathway. Together, these findings show that the HBeAg inhibits IL-18 signaling and IFN-γ expression, which may play an important role in the establishment and/or maintenance of persistent HBV infection. IMPORTANCE It is becoming increasingly apparent that NK cells play a role in the establishment and/or maintenance of chronic hepatitis B infection. The secreted HBeAg is an important regulator of innate and adaptive immune responses. We now show that the HBeAg downregulates NK cell-mediated IFN-γ production and IL-18 signaling, which may contribute to the establishment of infection and/or viral persistence. Our findings build on previous studies showing that the HBeAg also suppresses the TLR and IL-1 signaling pathways, suggesting that this viral protein is a key regulator of antiviral innate immune responses.
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Saha D, Pal A, Biswas A, Panigrahi R, Sarkar N, Das D, Sarkar J, Guha SK, Saha B, Chakrabarti S, Chakravarty R. Molecular characterization of HBV strains circulating among the treatment-naive HIV/HBV co-infected patients of eastern India. PLoS One 2014; 9:e90432. [PMID: 24587360 PMCID: PMC3938687 DOI: 10.1371/journal.pone.0090432] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 01/29/2014] [Indexed: 02/07/2023] Open
Abstract
Previously we reported that the exposure to hepatitis B virus (HBV) infection serves as a major threat among the treatment naive HIV infected population of eastern India. Hence, molecular characterization of these strains is of utmost importance in order to identify clinically significant HBV mutations. A total of 85 treatment naive HIV/HBV co-infected participants were included of whom the complete basal core promoter/precore region, the core and the whole envelope gene could be successfully sequenced for 59, 57 and 39 isolates respectively. Following phylogenetic analysis, it was found that HBV/D was the predominant genotype with HBV/D2 (38.5%) being the most prevalent subgenotype followed by HBV/A1. The major mutations affecting HBeAg expression includes the A1762T/G1764A (13.6%), G1896A (22%) and G1862T mutation (33.9%) which was predominantly associated with HBV/A1. Moreover, the prevalence of G1896A was considerably high among the HBeAg negative HIV/HBV co-infected subjects compared to HBV mono-infection. The main amino acid substitutions within the MHC class II restricted T-cell epitope of HBcAg includes the T12S (15.8%) and T67N (12.3%) mutation and the V27I (10.5%) mutation in the MHC class I restricted T-cell epitope. PreS1/S2 deletion was detected in 3 isolates with all harboring the BCP double mutation. Furthermore, the frequently occurring mutations in the major hydrophilic loop of the S gene include the T125M, A128V and M133I/L. Therefore, this study is the first from India to report useful information on the molecular heterogeneity of the HBV strains circulating among the treatment naive HIV/HBV co-infected population and is thus clinically relevant.
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Affiliation(s)
- Debraj Saha
- ICMR Virus Unit, Kolkata, ID & BG Hospital Campus, Kolkata, West Bengal, India
| | - Ananya Pal
- ICMR Virus Unit, Kolkata, ID & BG Hospital Campus, Kolkata, West Bengal, India
| | - Avik Biswas
- ICMR Virus Unit, Kolkata, ID & BG Hospital Campus, Kolkata, West Bengal, India
| | - Rajesh Panigrahi
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Neelakshi Sarkar
- ICMR Virus Unit, Kolkata, ID & BG Hospital Campus, Kolkata, West Bengal, India
| | - Dipanwita Das
- ICMR Virus Unit, Kolkata, ID & BG Hospital Campus, Kolkata, West Bengal, India
| | - Jayeeta Sarkar
- Calcutta School of Tropical Medicine, Kolkata, West Bengal, India
| | | | - Bibhuti Saha
- Calcutta School of Tropical Medicine, Kolkata, West Bengal, India
| | - Sekhar Chakrabarti
- National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
| | - Runu Chakravarty
- ICMR Virus Unit, Kolkata, ID & BG Hospital Campus, Kolkata, West Bengal, India
- * E-mail:
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