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Maepa MB, Ely A, Kramvis A, Bloom K, Naidoo K, Simani OE, Maponga TG, Arbuthnot P. Hepatitis B Virus Research in South Africa. Viruses 2022; 14:v14091939. [PMID: 36146747 PMCID: PMC9503375 DOI: 10.3390/v14091939] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/11/2022] [Accepted: 08/26/2022] [Indexed: 11/18/2022] Open
Abstract
Despite being vaccine-preventable, hepatitis B virus (HBV) infection remains the seventh leading cause of mortality in the world. In South Africa (SA), over 1.9 million people are chronically infected with HBV, and 70% of all Black chronic carriers are infected with HBV subgenotype A1. The virus remains a significant burden on public health in SA despite the introduction of an infant immunization program implemented in 1995 and the availability of effective treatment for chronic HBV infection. In addition, the high prevalence of HIV infection amplifies HBV replication, predisposes patients to chronicity, and complicates management of the infection. HBV research has made significant progress leading to better understanding of HBV epidemiology and management challenges in the SA context. This has led to recent revision of the national HBV infection management guidelines. Research on developing new vaccines and therapies is underway and progress has been made with designing potentially curative gene therapies against HBV. This review summarizes research carried out in SA on HBV molecular biology, epidemiology, treatment, and vaccination strategies.
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Affiliation(s)
- Mohube B. Maepa
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, Infectious Diseases and Oncology Research Institute (IDORI), University of the Witwatersrand, Johannesburg 2000, South Africa
- Correspondence:
| | - Abdullah Ely
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, Infectious Diseases and Oncology Research Institute (IDORI), University of the Witwatersrand, Johannesburg 2000, South Africa
| | - Anna Kramvis
- Hepatitis Diversity Research Unit, Department of Internal Medicine, Faculty of Health Sciences, School of Clinical Medicine, University of the Witwatersrand, Johannesburg 2000, South Africa
| | - Kristie Bloom
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, Infectious Diseases and Oncology Research Institute (IDORI), University of the Witwatersrand, Johannesburg 2000, South Africa
| | - Kubendran Naidoo
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, Infectious Diseases and Oncology Research Institute (IDORI), University of the Witwatersrand, Johannesburg 2000, South Africa
- National Health Laboratory Service, Johannesburg 2000, South Africa
| | - Omphile E. Simani
- HIV and Hepatitis Research Unit, Department of Virology, Sefako Makgatho Health Sciences University, Pretoria 0204, South Africa
| | - Tongai G. Maponga
- Division of Medical Virology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town 7602, South Africa
| | - Patrick Arbuthnot
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, Infectious Diseases and Oncology Research Institute (IDORI), University of the Witwatersrand, Johannesburg 2000, South Africa
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Jacobs R, Singh P, Smith T, Arbuthnot P, Maepa MB. Prospects of viral vector-mediated delivery of sequences encoding anti-HBV designer endonucleases. Gene Ther 2022:10.1038/s41434-022-00342-5. [PMID: 35606493 DOI: 10.1038/s41434-022-00342-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 11/09/2022]
Abstract
Available treatment for chronic hepatitis B virus (HBV) infection offers modest functional curative efficacy. The viral replicative intermediate comprising covalently closed circular DNA (cccDNA) is responsible for persistent chronic HBV infection. Hence, current efforts have focused on developing therapies that disable cccDNA. Employing gene editing tools has emerged as an attractive strategy, with the end goal of establishing permanently inactivated cccDNA. Although anti-HBV designer nucleases are effective in vivo, none has yet progressed to clinical trial. Lack of safe and efficient delivery systems remains the limiting factor. Several vectors may be used to deliver anti-HBV gene editor-encoding sequences, with viral vectors being at the forefront. Despite the challenges associated with packaging large gene editor-encoding sequences into viral vectors, advancement in the field is overcoming such limitations. Translation of viral vector-mediated gene editing against HBV to clinical application is within reach. This review discusses the prospects of delivering HBV targeted designer nucleases using viral vectors.
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Affiliation(s)
- Ridhwaanah Jacobs
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Prashika Singh
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Tiffany Smith
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Patrick Arbuthnot
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Mohube Betty Maepa
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
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Muriungi NG, Ueda K. TIMM29 interacts with hepatitis B virus preS1 to modulate the HBV life cycle. Microbiol Immunol 2020; 64:792-809. [PMID: 32970362 DOI: 10.1111/1348-0421.12852] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 12/28/2022]
Abstract
Hepatitis B virus (HBV), a major global health problem, can cause chronic hepatitis, liver cirrhosis, and hepatocellular carcinomas in chronically infected patients. However, before HBV infection can be adequately controlled, many mysteries about the HBV life cycle must be solved. In this study, TIMM29, an inner mitochondrial membrane protein, was identified as an interaction partner of the preS1 region of the HBV large S protein. The interaction was verified by both an immunoprecipitation with preS1 peptides and a GST-pulldown assay. Immunofluorescence studies also showed colocalization of preS1 and TIMM29. Moreover, it was determined that the preS1 bound with amino acids 92-189 of the TIMM29 protein. Infection of HBV in TIMM29-overexpressing NTCP/G2 cells resulted in a significant decrease of HBeAg and both extracellular particle-associated and core particle-associated HBV DNA without affecting cccDNA formation. Comparable results were obtained with TIMM29-overexpressing HB611 cells, which constitutively produce HBV. In contrast, knockout of TIMM29 in NTCP/G2 cells led to a higher production of HBV including HBeAg expression, as did knockout of TIMM29 in HB611. Collectively, these results suggested that TIMM29 interacts with the preS1 region of the HBV large S protein and modulates HBV amplification.
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Affiliation(s)
- Nelly Gakii Muriungi
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Keiji Ueda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
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Sustained Inhibition of HBV Replication In Vivo after Systemic Injection of AAVs Encoding Artificial Antiviral Primary MicroRNAs. MOLECULAR THERAPY. NUCLEIC ACIDS 2017. [PMID: 28624194 PMCID: PMC5415967 DOI: 10.1016/j.omtn.2017.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic infection with hepatitis B virus (HBV) remains a problem of global significance and improving available treatment is important to prevent life-threatening complications arising in persistently infected individuals. HBV is susceptible to silencing by exogenous artificial intermediates of the RNA interference (RNAi) pathway. However, toxicity of Pol III cassettes and short duration of silencing by effectors of the RNAi pathway may limit anti-HBV therapeutic utility. To advance RNAi-based HBV gene silencing, mono- and trimeric artificial primary microRNAs (pri-miRs) derived from pri-miR-31 were placed under control of the liver-specific modified murine transthyretin promoter. The sequences, which target the X sequence of HBV, were incorporated into recombinant hepatotropic self-complementary adeno-associated viruses (scAAVs). Systemic intravenous injection of the vectors into HBV transgenic mice at a dose of 1 × 1011 per animal effected significant suppression of markers of HBV replication for at least 32 weeks. The pri-miRs were processed according to the intended design, and intrahepatic antiviral guide sequences were detectable for 40 weeks after the injection. There was no evidence of toxicity, and innate immunostimulation was not detectable following the injections. This efficacy is an improvement on previously reported RNAi-based inhibition of HBV replication and is important to clinical translation of the technology.
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Li B, Sun S, Li M, Cheng X, Li H, Kang F, Kang J, Dörnbrack K, Nassal M, Sun D. Suppression of hepatitis B virus antigen production and replication by wild-type HBV dependently replicating HBV shRNA vectors in vitro and in vivo. Antiviral Res 2016; 134:117-129. [PMID: 27591142 DOI: 10.1016/j.antiviral.2016.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 07/07/2016] [Accepted: 08/07/2016] [Indexed: 02/08/2023]
Abstract
Chronic infection with hepatitis B virus (HBV), a small DNA virus that replicates by reverse transcription of a pregenomic (pg) RNA precursor, greatly increases the risk for terminal liver disease. RNA interference (RNAi) based therapy approaches have shown potential to overcome the limited efficacy of current treatments. However, synthetic siRNAs as well as small hairpin (sh) RNAs expressed from non-integrating vectors require repeated applications; integrating vectors suffer from safety concerns. We pursue a new concept by which HBV itself is engineered into a conditionally replicating, wild-type HBV dependent anti-HBV shRNA vector. Beyond sharing HBV's hepatocyte tropism, such a vector would be self-renewing, but only as long as wild-type HBV is present. Here, we realized several important aspects of this concept. We identified two distinct regions in the 3.2 kb HBV genome which tolerate replacement by shRNA expression cassettes without compromising reverse transcription when complemented in vitro by HBV helper constructs or by wild-type HBV; a representative HBV shRNA vector was infectious in cell culture. The vector-encoded shRNAs were active, including on HBV as target. A dual anti-HBV shRNA vector delivered into HBV transgenic mice, which are not susceptible to HBV infection, by a chimeric adenovirus-HBV shuttle reduced serum hepatitis B surface antigen (HBsAg) up to ∼4-fold, and virus particles up to ∼20-fold. Importantly, a fraction of the circulating particles contained vector-derived DNA, indicating successful complementation in vivo. These data encourage further investigations to prove antiviral efficacy and the predicted self-limiting vector spread in a small animal HBV infection model.
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Affiliation(s)
- Baosheng Li
- Chinese PLA Medical School, Chinese PLA General Hospital, 100853, Beijing, PR China; The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China
| | - Shuo Sun
- The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China; Troop 66220 of PLA, Xingtai, Hebei Province, 054000, PR China
| | - Minran Li
- The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China; The Fourth Department of the Fifth Hospital, Shijiazhuang City, 050017, PR China
| | - Xin Cheng
- The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China
| | - Haijun Li
- The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China
| | - Fubiao Kang
- The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China
| | - Jiwen Kang
- The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China
| | - Katharina Dörnbrack
- Internal Medicine II/Molecular Biology, University Hospital Freiburg, D-79106, Freiburg, Germany
| | - Michael Nassal
- Internal Medicine II/Molecular Biology, University Hospital Freiburg, D-79106, Freiburg, Germany.
| | - Dianxing Sun
- The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China.
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Recent advances in use of gene therapy to treat hepatitis B virus infection. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 848:31-49. [PMID: 25757614 DOI: 10.1007/978-1-4939-2432-5_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chronic infection with hepatitis B virus (HBV) occurs in approximately 5 % of the world's human population and persistence of the virus is associated with serious complications of cirrhosis and liver cancer. Currently available treatments are modestly effective and advancing novel therapeutic strategies is a medical priority. Stability of the viral cccDNA replication intermediate is a major factor that has impeded the development of therapies that are capable of eliminating chronic infection. Recent advances that employ gene therapy strategies offer useful advantages over current therapeutics. Silencing of HBV gene expression by harnessing the RNA interference pathway has been shown to be highly effective in cell culture and in vivo. However, a potential limitation of this approach is that the post-transcriptional mechanism of gene silencing does not disable cccDNA. Early results using designer transcription activator-like effector nucleases (TALENs) and repressor TALEs (rTALEs) have shown potential as a mode of inactivating cccDNA. In this article, we review the recent advances that have been made in HBV gene therapy, with a particular emphasis on the potential anti-HBV therapeutic utility of designed sequence-specific DNA binding proteins and their derivatives.
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Marimani MD, Ely A, Buff MCR, Bernhardt S, Engels JW, Scherman D, Escriou V, Arbuthnot P. Inhibition of replication of hepatitis B virus in transgenic mice following administration of hepatotropic lipoplexes containing guanidinopropyl-modified siRNAs. J Control Release 2015; 209:198-206. [PMID: 25937322 DOI: 10.1016/j.jconrel.2015.04.042] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 04/24/2015] [Accepted: 04/27/2015] [Indexed: 12/11/2022]
Abstract
Chronic infection with hepatitis B virus (HBV) occurs commonly and complications that arise from persistence of the virus are associated with high mortality. Available licensed drugs have modest curative efficacy and advancing new therapeutic strategies to eliminate the virus is therefore a priority. HBV is susceptible to inactivation by exogenous gene silencers that harness RNA interference (RNAi) and the approach has therapeutic potential. To advance RNAi-based treatment for HBV infection, use in vivo of hepatotropic lipoplexes containing siRNAs with guanidinopropyl (GP) modifications is reported here. Lipoplexes contained polyglutamate, which has previously been shown to facilitate formulation and improve efficiency of the non-viral vectors. GP moieties were included in a previously described anti-HBV siRNA that effectively targeted the conserved viral X sequence. Particles had physical properties that were suitable for use in vivo: average diameter was approximately 50-200 nm and surface charge (zeta potential) was +65 mV. Efficient hepatotropic delivery of labeled siRNA was observed following systemic intravenous injection of the particles into HBV transgenic mice. Good inhibition of markers of viral replication was observed without evidence of toxicity. Efficacy of the GP-modified siRNAs was significantly more durable and formulations made up with chemically modified siRNAs were less immunostimulatory. An RNAi-mediated mechanism was confirmed by demonstrating that HBV mRNA cleavage occurred in vivo at the intended target site. Collectively these data indicate that GP-modified siRNAs formulated in anionic polymer-containing lipoplexes are effective silencers of HBV replication in vivo and have therapeutic potential.
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Affiliation(s)
- Musa D Marimani
- Wits/SA MRC Antiviral Gene Therapy Research Unit, School of Pathology, Health Sciences Faculty, University of the Witwatersrand, Johannesburg, Private Bag 3, Wits 2050, South Africa
| | - Abdullah Ely
- Wits/SA MRC Antiviral Gene Therapy Research Unit, School of Pathology, Health Sciences Faculty, University of the Witwatersrand, Johannesburg, Private Bag 3, Wits 2050, South Africa
| | - Maximilian C R Buff
- Goethe-University, Institute of Organic Chemistry & Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Stefan Bernhardt
- Goethe-University, Institute of Organic Chemistry & Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Joachim W Engels
- Goethe-University, Institute of Organic Chemistry & Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Daniel Scherman
- UTCBS, CNRS UMR8258, INSERM U1022, Université Paris Descartes, Chimie ParisTech, 75006 Paris, France
| | - Virginie Escriou
- UTCBS, CNRS UMR8258, INSERM U1022, Université Paris Descartes, Chimie ParisTech, 75006 Paris, France
| | - Patrick Arbuthnot
- Wits/SA MRC Antiviral Gene Therapy Research Unit, School of Pathology, Health Sciences Faculty, University of the Witwatersrand, Johannesburg, Private Bag 3, Wits 2050, South Africa.
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Gebbing M, Bergmann T, Schulz E, Ehrhardt A. Gene therapeutic approaches to inhibit hepatitis B virus replication. World J Hepatol 2015; 7:150-164. [PMID: 25729471 PMCID: PMC4342598 DOI: 10.4254/wjh.v7.i2.150] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 10/23/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
Acute and chronic hepatitis B virus (HBV) infections remain to present a major global health problem. The infection can be associated with acute symptomatic or asymptomatic hepatitis which can cause chronic inflammation of the liver and over years this can lead to cirrhosis and the development of hepatocellular carcinomas. Currently available therapeutics for chronically infected individuals aim at reducing viral replication and to slow down or stop the progression of the disease. Therefore, novel treatment options are needed to efficiently combat and eradicate this disease. Here we provide a state of the art overview of gene therapeutic approaches to inhibit HBV replication. We discuss non-viral and viral approaches which were explored to deliver therapeutic nucleic acids aiming at reducing HBV replication. Types of delivered therapeutic nucleic acids which were studied since many years include antisense oligodeoxynucleotides and antisense RNA, ribozymes and DNAzymes, RNA interference, and external guide sequences. More recently designer nucleases gained increased attention and were exploited to destroy the HBV genome. In addition we mention other strategies to reduce HBV replication based on delivery of DNA encoding dominant negative mutants and DNA vaccination. In combination with available cell culture and animal models for HBV infection, in vitro and in vivo studies can be performed to test efficacy of gene therapeutic approaches. Recent progress but also challenges will be specified and future perspectives will be discussed. This is an exciting time to explore such approaches because recent successes of gene therapeutic strategies in the clinic to treat genetic diseases raise hope to find alternative treatment options for patients chronically infected with HBV.
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da Silva AS, Raposo JV, Pereira TC, Pinto MA, de Paula VS. Effects of RNA interference therapy against herpes simplex virus type 1 encephalitis. Antivir Ther 2015; 21:225-35. [DOI: 10.3851/imp3016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2015] [Indexed: 10/22/2022]
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Inhibition of hepatitis B virus replication by helper dependent adenoviral vectors expressing artificial anti-HBV pri-miRs from a liver-specific promoter. BIOMED RESEARCH INTERNATIONAL 2014; 2014:718743. [PMID: 25003129 PMCID: PMC4066856 DOI: 10.1155/2014/718743] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Revised: 04/25/2014] [Accepted: 05/08/2014] [Indexed: 12/17/2022]
Abstract
Research on applying RNA interference (RNAi) to counter HBV replication has led to identification of potential therapeutic sequences. However, before clinical application liver-specific expression and efficient delivery of these sequences remain an important objective. We recently reported short-term inhibition of HBV replication in vivo by using helper dependent adenoviral vectors (HD Ads) expressing anti-HBV sequences from a constitutively active cytomegalovirus (CMV) promoter. To develop the use of liver-specific transcription regulatory elements we investigated the utility of the murine transthyretin (MTTR) promoter for expression of anti-HBV primary microRNAs (pri-miRs). HD Ads containing MTTR promoter effected superior expression of anti-HBV pri-miRs in mice compared to HD Ads containing the CMV promoter. MTTR-containing HD Ads resulted in HBV replication knockdown of up to 94% in mice. HD Ads expressing trimeric anti-HBV pri-miRs silenced HBV replication for 5 weeks. We previously showed that the product of the codelivered lacZ gene induces an immune response, and the duration of HBV silencing in vivo is likely to be attenuated by this effect. Nevertheless, expression of anti-HBV pri-miRs from MTTR promoter is well suited to countering HBV replication and development of HD Ads through attenuation of their immunostimulatory effects should advance their clinical utility.
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