1
|
Debing Y, Vanrusselt H, Degrauwe L, Silva de Oliveira DA, Kariuki CK, Ebwanga EJ, Bashir S, Merckx W, Thatikonda SK, Rajwanshi V, Gohil V, Hong J, Kum DB, Acosta Sanchez A, Chanda S, Blatt LM, Jekle A, Symons JA, Smith DB, Raboisson P, Lin TI, Beigelman L, Paeshuyse J. An in vivo duck hepatitis B virus model recapitulates key aspects of nucleic acid polymer treatment outcomes in chronic hepatitis B patients. Antiviral Res 2024; 224:105835. [PMID: 38401714 DOI: 10.1016/j.antiviral.2024.105835] [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: 12/11/2023] [Revised: 01/30/2024] [Accepted: 02/13/2024] [Indexed: 02/26/2024]
Abstract
Nucleic acid polymers (NAPs) are an attractive treatment modality for chronic hepatitis B (CHB), with REP2139 and REP2165 having shown efficacy in CHB patients. A subset of patients achieve functional cure, whereas the others exhibit a moderate response or are non-responders. NAP efficacy has been difficult to recapitulate in animal models, with the duck hepatitis B virus (DHBV) model showing some promise but remaining underexplored for NAP efficacy testing. Here we report on an optimized in vivo DHBV duck model and explore several characteristics of NAP treatment. REP2139 was efficacious in reducing DHBV DNA and DHBsAg levels in approximately half of the treated ducks, whether administered intraperitoneally or subcutaneously. Intrahepatic or serum NAP concentrations did not correlate with efficacy, nor did the appearance of anti-DHBsAg antibodies. Furthermore, NAP efficacy was only observed in experimentally infected ducks, not in endogenously infected ducks (vertical transmission). REP2139 add-on to entecavir treatment induced a deeper and more sustained virological response compared to entecavir monotherapy. Destabilized REP2165 showed a different activity profile with a more homogenous antiviral response followed by a faster rebound. In conclusion, subcutaneous administration of NAPs in the DHBV duck model provides a useful tool for in vivo evaluation of NAPs. It recapitulates many aspects of this class of compound's efficacy in CHB patients, most notably the clear division between responders and non-responders.
Collapse
Affiliation(s)
| | | | - Lars Degrauwe
- Laboratory of Host Pathogen Interactions, Department of Biosystems, KU Leuven, Leuven, Belgium
| | | | | | - Ebanja Joseph Ebwanga
- Laboratory of Host Pathogen Interactions, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Shahbaz Bashir
- Laboratory of Host Pathogen Interactions, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Wouter Merckx
- TRANSfarm, Science, Engineering & Technology Group, KU Leuven, Leuven, Belgium
| | | | | | - Vikrant Gohil
- Aligos Therapeutics, Inc., South San Francisco, CA, USA
| | - Jin Hong
- Aligos Therapeutics, Inc., South San Francisco, CA, USA
| | | | | | | | | | - Andreas Jekle
- Aligos Therapeutics, Inc., South San Francisco, CA, USA
| | | | - David B Smith
- Aligos Therapeutics, Inc., South San Francisco, CA, USA
| | | | | | | | - Jan Paeshuyse
- Laboratory of Host Pathogen Interactions, Department of Biosystems, KU Leuven, Leuven, Belgium.
| |
Collapse
|
2
|
Hu JL, Huang AL. Classifying hepatitis B therapies with insights from covalently closed circular DNA dynamics. Virol Sin 2024; 39:9-23. [PMID: 38110037 PMCID: PMC10877440 DOI: 10.1016/j.virs.2023.12.005] [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: 01/29/2023] [Accepted: 12/13/2023] [Indexed: 12/20/2023] Open
Abstract
The achievement of a functional cure for chronic hepatitis B (CHB) remains limited to a minority of patients treated with currently approved drugs. The primary objective in developing new anti-HBV drugs is to enhance the functional cure rates for CHB. A critical prerequisite for the functional cure of CHB is a substantial reduction, or even eradication of covalently closed circular DNA (cccDNA). Within this context, the changes in cccDNA levels during treatment become as a pivotal concern. We have previously analyzed the factors influencing cccDNA dynamics and introduced a preliminary classification of hepatitis B treatment strategies based on these dynamics. In this review, we employ a systems thinking perspective to elucidate the fundamental aspects of the HBV replication cycle and to rationalize the classification of treatment strategies according to their impact on the dynamic equilibrium of cccDNA. Building upon this foundation, we categorize current anti-HBV strategies into two distinct groups and advocate for their combined use to significantly reduce cccDNA levels within a well-defined timeframe.
Collapse
Affiliation(s)
- Jie-Li Hu
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China.
| | - Ai-Long Huang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China.
| |
Collapse
|
3
|
Pan C, Gish R, Jacobson IM, Hu KQ, Wedemeyer H, Martin P. Diagnosis and Management of Hepatitis Delta Virus Infection. Dig Dis Sci 2023; 68:3237-3248. [PMID: 37338616 PMCID: PMC10374831 DOI: 10.1007/s10620-023-07960-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 04/24/2023] [Indexed: 06/21/2023]
Abstract
Hepatitis D virus (HDV) depends on hepatitis B virus (HBV) to enter and exit hepatocytes and to replicate. Despite this dependency, HDV can cause severe liver disease. HDV accelerates liver fibrosis, increases the risk of hepatocellular carcinoma, and hastens hepatic decompensation compared to chronic HBV monoinfection. The Chronic Liver Disease Foundation (CLDF) formed an expert panel to publish updated guidelines on the testing, diagnosis, and management of hepatitis delta virus. The panel group performed network data review on the transmission, epidemiology, natural history, and disease sequelae of acute and chronic HDV infection. Based on current available evidence, we provide recommendations for screening, testing, diagnosis, and treatment of hepatitis D infection and review upcoming novel agents that may expand treatment options. The CLDF recommends universal HDV screening for all patients who are Hepatitis B surface antigen-positive. Initial screening should be with an assay to detect antibodies generated against HDV (anti-HDV). Patients who are positive for anti-HDV IgG antibodies should then undergo quantitative HDV RNA testing. We also provide an algorithm that describes CLDF recommendations on the screening, diagnosis, testing, and initial management of Hepatitis D infection.
Collapse
Affiliation(s)
- Calvin Pan
- Guangzhou Eighth People’s Hospital, Guangzhou Medical University, Guangzhou, China
- Gastroenterology and Hepatology, NYU Langone Health, NYU Grossman School of Medicine, New York, USA
| | - Robert Gish
- Robert G. Gish Consultants, LLC, 6022 La Jolla Mesa Dr, La Jolla, CA 92037-7814 USA
- Medical Director Hepatitis B Foundation, Doylestown, PA USA
| | - Ira M. Jacobson
- NYU Langone Gastroenterology Associates, 240 East 38Th Street, 23Rd Floor, New York, NY 10016 USA
| | - Ke-Qin Hu
- University of California, Irvine, 101 The City Dr S, Building 22C, Room 1503, Orange, CA 92868 USA
| | - Heiner Wedemeyer
- Clinic for Gastroenterology, Hepatology and Endocrinology Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Paul Martin
- University of Miami Miller School of Medicine, 1500 NW 12 AVE., E Tower #1101, Miami, FL 33136 USA
| |
Collapse
|
4
|
Blaney H, Khalid M, Heller T, Koh C. Epidemiology, presentation, and therapeutic approaches for hepatitis D infections. Expert Rev Anti Infect Ther 2023; 21:127-142. [PMID: 36519386 PMCID: PMC9905306 DOI: 10.1080/14787210.2023.2159379] [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: 10/27/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Chronic Hepatitis D virus (HDV) infection remains an important global public health problem, with a changing epidemiological landscape over the past decade along with widespread implementation of hepatitis B vaccination and human migration. The landscape of HDV treatments has been changing, with therapies that have been under development for the last decade now in late stage clinical trials. The anticipated availability of these new therapies will hopefully replace the current therapies which are minimally effective. AREAS COVERED This narrative review discusses the clinical course, screening and diagnosis, transmission risk factors, epidemiology, current and investigational therapies, and liver transplantation in HDV. Literature review was performed using PubMed and ClinicalTrials.gov and includes relevant articles from 1977 to 2022. EXPERT OPINION HDV infection is an important global public health issue with a true prevalence that is still unknown. The distribution of HDV infection has changed globally with the availability of HBV vaccination and patterns of human migration. As HDV infection is associated with accelerated disease courses and poor outcomes, the global community needs to agree upon a uniform HDV screening strategy to understand the truth of global prevalence such that new therapies can target appropriate individuals as they become available in the future.
Collapse
Affiliation(s)
- Hanna Blaney
- Digestive Diseases Branch, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Mian Khalid
- Digestive Diseases Branch, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Theo Heller
- Liver Diseases Branch, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Christopher Koh
- Liver Diseases Branch, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
5
|
Khalfi P, Kennedy PT, Majzoub K, Asselah T. Hepatitis D virus: Improving virological knowledge to develop new treatments. Antiviral Res 2023; 209:105461. [PMID: 36396025 DOI: 10.1016/j.antiviral.2022.105461] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/21/2022] [Accepted: 11/05/2022] [Indexed: 11/16/2022]
Abstract
Hepatitis delta virus (HDV), a satellite of hepatitis B virus (HBV), possesses the smallest viral genome known to infect animals. HDV needs HBV surface protein for secretion and entry into target liver cells. However, HBV is dispensable for HDV genome amplification, as it relies almost exclusively on cellular host factors for replication. HBV/HDV co-infections affect over 12 million people worldwide and constitute the most severe form of viral hepatitis. Co-infected individuals are at higher risk of developing liver cirrhosis and hepatocellular carcinoma compared to HBV mono-infected patients. Bulevirtide, an entry inhibitor, was conditionally approved in July 2020 in the European Union for adult patients with chronic hepatitis delta (CHD) and compensated liver disease. There are several drugs in development, including lonafarnib and interferon lambda, with different modes of action. In this review, we detail our current fundamental knowledge of HDV lifecycle and review antiviral treatments under development against this virus, outlining their respective mechanisms-of-action. Finally, we describe the antiviral effect these compounds are showing in ongoing clinical trials, discussing their promise and potential pitfalls for managing HDV infected patients.
Collapse
Affiliation(s)
- Pierre Khalfi
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, Montpellier 34293 cedex 5, France
| | - Patrick T Kennedy
- The Blizard Institute, Queen Mary University of London, The Royal London Hospital, Barts Health NHS Trust, London, UK
| | - Karim Majzoub
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, Montpellier 34293 cedex 5, France.
| | - Tarik Asselah
- Université de Paris, Cité CRI, INSERM UMR 1149, Department of Hepatology, AP-HP Hôpital Beaujon, Clichy, France.
| |
Collapse
|
6
|
Vaillant A. Oligonucleotide-Based Therapies for Chronic HBV Infection: A Primer on Biochemistry, Mechanisms and Antiviral Effects. Viruses 2022; 14:v14092052. [PMID: 36146858 PMCID: PMC9502277 DOI: 10.3390/v14092052] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/08/2022] [Accepted: 09/08/2022] [Indexed: 11/21/2022] Open
Abstract
Three types of oligonucleotide-based medicines are under clinical development for the treatment of chronic HBV infection. Antisense oligonucleotides (ASOs) and synthetic interfering RNA (siRNA) are designed to degrade HBV mRNA, and nucleic acid polymers (NAPs) stop the assembly and secretion of HBV subviral particles. Extensive clinical development of ASOs and siRNA for a variety of liver diseases has established a solid understanding of their pharmacodynamics, accumulation in different tissue types in the liver, pharmacological effects, off-target effects and how chemical modifications and delivery approaches affect these parameters. These effects are highly conserved for all ASO and siRNA used in human studies to date. The clinical assessment of several ASO and siRNA compounds in chronic HBV infection in recent years is complicated by the different delivery approaches used. Moreover, these assessments have not considered the large clinical database of ASO/siRNA function in other liver diseases and known off target effects in other viral infections. The goal of this review is to summarize the current understanding of ASO/siRNA/NAP pharmacology and integrate these concepts into current clinical results for these compounds in the treatment of chronic HBV infection.
Collapse
Affiliation(s)
- Andrew Vaillant
- Replicor Inc., 6100 Royalmount Avenue, Montreal, QC H4P 2R2, Canada
| |
Collapse
|
7
|
Editorial: In vitro mechanistic evaluation of nucleic acid polymers: A cautionary tale. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 28:168-174. [PMID: 35402067 PMCID: PMC8956958 DOI: 10.1016/j.omtn.2022.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
8
|
Novel Pegylated Interferon for the Treatment of Chronic Viral Hepatitis. Viruses 2022; 14:v14061128. [PMID: 35746606 PMCID: PMC9230558 DOI: 10.3390/v14061128] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/12/2022] [Accepted: 05/20/2022] [Indexed: 11/17/2022] Open
Abstract
Ropeginterferon alfa-2b is a novel mono-pegylated and extra-long-acting interferon, being developed for the treatment of myeloproliferative neoplasm (MPN) and chronic viral hepatitis. It has a favorable pharmacokinetic profile and less frequent dosing schedule, i.e., once every two to four weeks, compared to conventional pegylated interferon products, which have multiple isomers and are administered weekly. It was approved for the long-term treatment of polycythemia vera, an MPN, and has been included in the NCCN clinical practice guidelines for this indication. Ropeginterferon alfa-2b has demonstrated efficacy and showed a favorable safety profile for the treatment of chronic viral hepatitis in several clinical studies. In this article, we review its pharmacokinetics and available clinical data and suggest that ropeginterferon alfa-2b administered once every two weeks can serve as a new treatment option for patients with chronic viral hepatitis, including chronic hepatitis B, C, and D.
Collapse
|
9
|
Kao CC, Nie Y, Ren S, De Costa NTTS, Pandey RK, Hong J, Smith DB, Symons JA, Beigelman L, Blatt LM. Mechanism of action of hepatitis B virus S antigen transport-inhibiting oligonucleotide polymer, STOPS, molecules. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 27:335-348. [PMID: 35024245 PMCID: PMC8717253 DOI: 10.1016/j.omtn.2021.12.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 12/09/2021] [Indexed: 12/16/2022]
Abstract
A functional cure of chronic hepatitis B requires eliminating the hepatitis B virus (HBV)-encoded surface antigen (HBsAg), which can suppress immune responses. STOPS are phosphorothioated single-stranded oligonucleotides containing novel chemistries that significantly reduce HBsAgs produced by HBV-infected liver cells. The STOPS molecule ALG-10000 functions inside cells to reduce the levels of multiple HBV-encoded molecules. However, it does not bind HBV molecules. An affinity resin coupled with ALG-10000 was found to bind several proteins from liver cells harboring replicating HBV. Silencing RNAs targeting host factors SRSF1, HNRNPA2B1, GRP78 (HspA5), RPLP1, and RPLP2 reduced HBsAg levels and other HBV molecules that are concomitantly reduced by STOPS. Host proteins RPLP1/RPLP2 and GRP78 function in the translation of membrane proteins, protein folding, and degradation. ALG-10000 and the knockdowns of RPLP1/2 and GRP78 decreased the levels of HBsAg and increased their ubiquitination and proteasome degradation. GRP78, RPLP1, and RPLP2 affected HBsAg production only when HBsAg was expressed with HBV regulatory sequences, suggesting that HBV has evolved to engage with these STOPS-interacting molecules. The STOPS inhibition of HBsAg levels in HBV-infected cells occurs by sequestering cellular proteins needed for proper expression and folding of HBsAg.
Collapse
Affiliation(s)
- C Cheng Kao
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| | - Yuchun Nie
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| | - Suping Ren
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| | | | - Rajendra K Pandey
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| | - Jin Hong
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| | - David B Smith
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| | - Julian A Symons
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| | - Leonid Beigelman
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| | - Lawrence M Blatt
- Aligos Therapeutics, Inc., 1 Corporate Drive, South San Francisco, CA 94080, USA
| |
Collapse
|
10
|
Khan IW, Dad Ullah MU, Choudhry M, Ali MJ, Ali MA, Lam SLK, Shah PA, Kaur SP, Lau DTY. Novel Therapies of Hepatitis B and D. Microorganisms 2021; 9:2607. [PMID: 34946209 PMCID: PMC8707465 DOI: 10.3390/microorganisms9122607] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 02/05/2023] Open
Abstract
Hepatitis B virus (HBV) infection is a global public health issue and is a major cause of cirrhosis and hepatocellular carcinoma (HCC). Hepatitis D virus (HDV) requires the hepatitis B surface antigen (HBsAg) to replicate. The eradication of HBV, therefore, can also cure HDV. The current therapies for chronic hepatitis B and D are suboptimal and cannot definitely cure the viruses. In order to achieve functional or complete cure of these infections, novel therapeutic agents that target the various sites of the viral replicative cycle are necessary. Furthermore, novel immunomodulatory agents are also essential to achieve viral clearance. Many of these new promising compounds such as entry inhibitors, covalently closed circular DNA (cccDNA) inhibitors, small interfering RNAs (siRNAs), capsid assembly modulators and nucleic acid polymers are in various stages of clinical developments. In this review article, we provided a comprehensive overview of the structure and lifecycle of HBV, the limitations of the current therapies and a summary of the novel therapeutic agents for both HDV and HBV infection.
Collapse
Affiliation(s)
- Iman Waheed Khan
- Liver Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; (I.W.K.); (M.U.D.U.); (M.C.); (M.J.A.); (M.A.A.); (S.P.K.)
| | - Mati Ullah Dad Ullah
- Liver Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; (I.W.K.); (M.U.D.U.); (M.C.); (M.J.A.); (M.A.A.); (S.P.K.)
| | - Mina Choudhry
- Liver Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; (I.W.K.); (M.U.D.U.); (M.C.); (M.J.A.); (M.A.A.); (S.P.K.)
| | - Mukarram Jamat Ali
- Liver Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; (I.W.K.); (M.U.D.U.); (M.C.); (M.J.A.); (M.A.A.); (S.P.K.)
| | - Muhammad Ashar Ali
- Liver Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; (I.W.K.); (M.U.D.U.); (M.C.); (M.J.A.); (M.A.A.); (S.P.K.)
| | - Sam L. K. Lam
- Liver Center, Department of Medicine, Department of Pharmacy, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA;
| | - Pir Ahmad Shah
- Department of Internal Medicine, University of Texas, San Antonio, TX 78229, USA;
| | - Satinder Pal Kaur
- Liver Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; (I.W.K.); (M.U.D.U.); (M.C.); (M.J.A.); (M.A.A.); (S.P.K.)
| | - Daryl T. Y. Lau
- Liver Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; (I.W.K.); (M.U.D.U.); (M.C.); (M.J.A.); (M.A.A.); (S.P.K.)
| |
Collapse
|
11
|
Kuroki A, Tay J, Lee GH, Yang YY. Broad-Spectrum Antiviral Peptides and Polymers. Adv Healthc Mater 2021; 10:e2101113. [PMID: 34599850 DOI: 10.1002/adhm.202101113] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/13/2021] [Indexed: 12/18/2022]
Abstract
As the human cost of the pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still being witnessed worldwide, the development of broad-spectrum antiviral agents against emerging and re-emerging viruses is seen as a necessity to hamper the spread of infections. Various targets during the viral life-cycle can be considered to inhibit viral infection, from viral attachment to viral fusion or replication. Macromolecules represent a particularly attractive class of therapeutics due to their multivalency and versatility. Although several antiviral macromolecules hold great promise in clinical applications, the emergence of resistance after prolonged exposure urges the need for improved solutions. In the present article, the recent advancement in the discovery of antiviral peptides and polymers with diverse structural features and antiviral mechanisms is reviewed. Future perspectives, such as, the development of virucidal peptides/polymers and their coatings against SARS-CoV-2 infection, standardization of antiviral testing protocols, and use of artificial intelligence or machine learning as a tool to accelerate the discovery of antiviral macromolecules, are discussed.
Collapse
Affiliation(s)
- Agnès Kuroki
- Yong Loo Lin School of Medicine National University of Singapore Singapore 117597 Singapore
- Institute of Bioengineering and Bioimaging 31 Biopolis Ways, The Nanos Singapore 138669 Singapore
| | - Joyce Tay
- Institute of Bioengineering and Bioimaging 31 Biopolis Ways, The Nanos Singapore 138669 Singapore
| | - Guan Huei Lee
- Yong Loo Lin School of Medicine National University of Singapore Singapore 117597 Singapore
| | - Yi Yan Yang
- Institute of Bioengineering and Bioimaging 31 Biopolis Ways, The Nanos Singapore 138669 Singapore
| |
Collapse
|
12
|
The Inaugural Australian Centre for Hepatitis Virology Public Panel Discussion on Viral Hepatitis Research-Lessons in Scientific Community Outreach. Viruses 2021; 13:v13091838. [PMID: 34578419 PMCID: PMC8472947 DOI: 10.3390/v13091838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 09/10/2021] [Indexed: 11/17/2022] Open
Abstract
Viral hepatitis remains one of the most significant health issues globally, directly responsible for over 1 million deaths each year and affecting almost 300 million people around the world. Scientific research in recent decades has brought about improvements in the lives of people living with chronic viral hepatitis. On the 29 July 2021, the Australian Centre for Hepatitis Virology (ACHV) for the first time held a public educational forum for the general public. The main aim of this event was to inform the affected community about the importance of scientific research and give an overview of upcoming developments in the field. Here, we provide a detailed report of the panel discussion (including its organisation, execution, and lessons learned to incorporate into future events) and provide strategies that can be used by other scientific societies to hold similar events in their own communities.
Collapse
|
13
|
Vaillant A. HBsAg, Subviral Particles, and Their Clearance in Establishing a Functional Cure of Chronic Hepatitis B Virus Infection. ACS Infect Dis 2021; 7:1351-1368. [PMID: 33302622 DOI: 10.1021/acsinfecdis.0c00638] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In diverse viral infections, the production of excess viral particles containing only viral glycoproteins (subviral particles or SVP) is commonly observed and is a commonly evolved mechanism for immune evasion. In hepatitis B virus (HBV) infection, spherical particles contain the hepatitis B surface antigen, outnumber infectious virus 10 000-100 000 to 1, and have diverse inhibitory effects on the innate and adaptive immune response, playing a major role in the chronic nature of HBV infection. The current goal of therapies in development for HBV infection is a clinical outcome called functional cure, which signals a persistent and effective immune control of the infection. Although removal of spherical SVP (and the HBsAg they carry) is an important milestone in achieving functional cure, this outcome is rarely achieved with current therapies due to distinct mechanisms for assembly, secretion, and persistence of SVP, which are poorly targeted by direct acting antivirals or immunotherapies. In this Review, the current understanding of the distinct mechanisms involved in the production and persistence of spherical SVP in chronic HBV infection and their immunoinhibitory activity will be reviewed as well as current therapies in development with the goal of clearing spherical SVP and achieving functional cure.
Collapse
Affiliation(s)
- Andrew Vaillant
- Replicor Inc., 6100 Royalmount Avenue, Montreal, Quebec H8Y 3E6, Canada
| |
Collapse
|
14
|
Maepa MB, Bloom K, Ely A, Arbuthnot P. Hepatitis B virus: promising drug targets and therapeutic implications. Expert Opin Ther Targets 2021; 25:451-466. [PMID: 33843412 DOI: 10.1080/14728222.2021.1915990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: Current therapy for infection with hepatitis B virus (HBV) rarely clears the virus, and viremia commonly resurges following treatment withdrawal. To prevent serious complications of the infection, research has been aimed at identifying new viral and host targets that can be exploited to inactivate HBV replication.Areas covered: This paper reviews the use of these new molecular targets to advance anti-HBV therapy. Emphasis is on appraising data from pre-clinical and early clinical studies described in journal articles published during the past 10 years and available from PubMed.Expert opinion: The wide range of viral and host factors that can be targeted to disable HBV is impressive and improved insight into HBV molecular biology continues to provide the basis for new drug design. In addition to candidate therapies that have direct or indirect actions on HBV covalently closed circular DNA (cccDNA), compounds that inhibit HBsAg secretion, viral entry, destabilize viral RNA and effect enhanced immune responses to HBV show promise. Preclinical and clinical evaluation of drug candidates, as well as investigating use of treatment combinations, are encouraging. The field is poised at an interesting stage and indications are that reliably achieving functional cure from HBV infection is a tangible goal.
Collapse
Affiliation(s)
- Mohube Betty Maepa
- School of Pathology, Faculty of Health Sciences, Wits/SAMRC Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Kristie Bloom
- School of Pathology, Faculty of Health Sciences, Wits/SAMRC Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Abdullah Ely
- School of Pathology, Faculty of Health Sciences, Wits/SAMRC Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Patrick Arbuthnot
- School of Pathology, Faculty of Health Sciences, Wits/SAMRC Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| |
Collapse
|
15
|
Boulon R, Blanchet M, Lemasson M, Vaillant A, Labonté P. Characterization of the antiviral effects of REP 2139 on the HBV lifecycle in vitro. Antiviral Res 2020; 183:104853. [PMID: 32585322 DOI: 10.1016/j.antiviral.2020.104853] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/22/2020] [Accepted: 06/11/2020] [Indexed: 12/18/2022]
Abstract
During hepatitis B virus (HBV) infection, HBV subviral particles (SVP) are produced in large excess in comparison to infectious virions and account for the major source of HBV surface antigen (HBsAg) in the blood. This abundant circulating HBsAg has been postulated to promote HBV chronicity by inducing immune exhaustion against HBsAg. Nucleic acid polymers (NAPs) such as REP 2139 display promising antiviral activity against both HBV and hepatitis Delta virus (HDV) in clinical trials. REP 2139 is accompanied by clearance of HBsAg from blood with concomitant reappearance of anti-HBsAg antibodies. To decipher the mechanism-of-action of NAPs, a recently developed cell-based assay in human HepG2.2.15 cells was used (Blanchet et al., 2019). This assay recapitulates the HBsAg secretion inhibition observed in treated patients. In the present study, we analysed the antiviral effect of REP 2139 on the HBV lifecycle. Importantly, we confirm here the potent inhibitory activity of the compound on HBsAg secretion, and report minor or no effect on other viral markers such as intracellular DNA and RNA, and HBeAg or Dane particle secretion. Notably, intracellular HBsAg accumulation is prevented by proteasomal and lysosomal degradation.
Collapse
Affiliation(s)
| | - Matthieu Blanchet
- INRS-Institut Armand Frappier, Laval, H7V 1B7, Canada; Replicor Inc. Montréal, H4P 2R2, Canada
| | - Matthieu Lemasson
- Institut National de La Transfusion Sanguine, CNRS-INSERM U1134, Paris, 75739, France
| | | | | |
Collapse
|
16
|
Gilman C, Heller T, Koh C. Chronic hepatitis delta: A state-of-the-art review and new therapies. World J Gastroenterol 2019; 25:4580-4597. [PMID: 31528088 PMCID: PMC6718034 DOI: 10.3748/wjg.v25.i32.4580] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/03/2019] [Accepted: 07/19/2019] [Indexed: 02/06/2023] Open
Abstract
Chronic delta hepatitis is the most severe form of viral hepatitis affecting nearly 65 million people worldwide. Individuals with this devastating illness are at higher risk for developing cirrhosis and hepatocellular carcinoma. Delta virus is a defective RNA virus that requires hepatitis B surface antigen for propagation in humans. Infection can occur in the form of a co-infection with hepatitis B, which can be self-limiting, vs superinfection in a patient with established hepatitis B infection, which often leads to chronicity in majority of cases. Current noninvasive tools to assess for advanced liver disease have limited utility in delta hepatitis. Guidelines recommend treatment with pegylated interferon, but this is limited to patients with compensated disease and is efficacious in about 30% of those treated. Due to limited treatment options, novel agents are being investigated and include entry, assembly and export inhibitors of viral particles in addition to stimulators of the host immune response. Future clinical trials should take into consideration the interaction of hepatitis B and hepatitis D as suppression of one virus can lead to the activation of the other. Also, surrogate markers of treatment efficacy have been proposed.
Collapse
MESH Headings
- Antiviral Agents/pharmacology
- Antiviral Agents/therapeutic use
- Coinfection/drug therapy
- Coinfection/epidemiology
- Coinfection/virology
- Drug Therapy, Combination/methods
- Global Burden of Disease
- Hepatitis B Surface Antigens/immunology
- Hepatitis B Surface Antigens/metabolism
- Hepatitis B virus/immunology
- Hepatitis B virus/pathogenicity
- Hepatitis B, Chronic/drug therapy
- Hepatitis B, Chronic/epidemiology
- Hepatitis B, Chronic/virology
- Hepatitis D, Chronic/drug therapy
- Hepatitis D, Chronic/epidemiology
- Hepatitis D, Chronic/virology
- Hepatitis Delta Virus/immunology
- Hepatitis Delta Virus/pathogenicity
- Humans
- Interferon-alpha/pharmacology
- Interferon-alpha/therapeutic use
- Lipopeptides/pharmacology
- Lipopeptides/therapeutic use
- Organic Anion Transporters, Sodium-Dependent/antagonists & inhibitors
- Organic Anion Transporters, Sodium-Dependent/metabolism
- Piperidines/pharmacology
- Piperidines/therapeutic use
- Pyridines/pharmacology
- Pyridines/therapeutic use
- Randomized Controlled Trials as Topic
- Review Literature as Topic
- Superinfection/drug therapy
- Superinfection/epidemiology
- Superinfection/virology
- Symporters/antagonists & inhibitors
- Symporters/metabolism
- Therapies, Investigational/methods
- Treatment Outcome
- Virus Assembly/drug effects
- Virus Internalization/drug effects
Collapse
Affiliation(s)
- Christy Gilman
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, United States
| | - Theo Heller
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, United States
| | - Christopher Koh
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, United States
| |
Collapse
|
17
|
Yurdaydin C. New treatment options for delta virus: Is a cure in sight? J Viral Hepat 2019; 26:618-626. [PMID: 30771261 DOI: 10.1111/jvh.13081] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 01/25/2019] [Indexed: 12/12/2022]
Abstract
Current treatment of chronic hepatitis D viral infection with interferons is poorly tolerated and effective only in a minority of patients. Despite delta virus causing the most severe form of chronic viral hepatitis, no other treatments are available. After many years of inactivity, there is now hope for new treatment approaches for delta virus and some are likely to enter clinical practice in the near future. Four new treatment approaches are currently being evaluated in phase 2 studies. These involve the hepatocyte entry inhibitor myrcludex B, the farnesyl transferase inhibitor lonafarnib, the nucleic acid inhibitor REP 2139 Ca and pegylated interferon lambda. Results obtained so far are promising, and phase 3 studies are expected shortly. This review summarizes the available data on the efficacy and safety of these new drugs.
Collapse
Affiliation(s)
- Cihan Yurdaydin
- Department of Gastroenterology, Ankara University Medical School, Ankara, Turkey.,Department of Gastroenterology and Hepatology, Koc University, Istanbul, Turkey
| |
Collapse
|
18
|
Vaillant A. REP 2139: Antiviral Mechanisms and Applications in Achieving Functional Control of HBV and HDV Infection. ACS Infect Dis 2019; 5:675-687. [PMID: 30199230 DOI: 10.1021/acsinfecdis.8b00156] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nucleic acid polymers (NAPs) are broad spectrum antiviral agents whose antiviral activity in hepatitis B virus (HBV) infection is derived from their ability to block the release of the hepatitis B virus surface antigen (HBsAg). This pharmacological activity blocks replenishment of HBsAg in the circulation, allowing host mediated clearance. This effect has important clinical significance as the clearance of circulating HBsAg dramatically potentiates the ability of immunotherapies to restore functional control of HBV infection which persists after antiviral therapy is removed. These effects are reproducible in preclinical evaluations and in several clinical trials that have evaluated the activity of the lead NAP, REP 2139, in monotherapy and in combination with immunotherapy in hepatitis B e antigen (HBeAg) negative and HBeAg positive HBV infection and also in HBeAg negative HBV/hepatitis D virus (HDV) coinfection. These antiviral effects of REP 2139 are achieved in the absence of any direct immunostimulatory effect in the liver and also without any discernible direct interaction with viral components. The search for the host protein interaction with NAPs that drives their antiviral effects is ongoing, and the interaction targeted by REP 2139 within infected cells has not yet been elucidated. This article provides an updated review of available data on the effects of REP 2139 in HBV and HDV infection and the ability of REP 2139-based combination therapy to achieve functional control of HBV and HDV infection in patients.
Collapse
Affiliation(s)
- Andrew Vaillant
- Replicor Inc., 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada
| |
Collapse
|
19
|
Blanchet M, Sinnathamby V, Vaillant A, Labonté P. Inhibition of HBsAg secretion by nucleic acid polymers in HepG2.2.15 cells. Antiviral Res 2019; 164:97-105. [PMID: 30771404 DOI: 10.1016/j.antiviral.2019.02.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/08/2019] [Accepted: 02/12/2019] [Indexed: 02/07/2023]
Abstract
More than 290 million people have chronic HBV infection and are at risk of developing cirrhosis and hepatocellular carcinoma. HBV subviral particles are produced in large excess over virions in infected patients and are the primary source of HBsAg, which is postulated to be important in allowing HBV to chronically persist by interfering with immune function. Nucleic acid polymers (NAPs) have been shown to result in clearance of HBsAg from the blood in pre-clinical and clinical studies. In this study, we show for the first time the recapitulation of NAP- induced inhibition of secretion of HBsAg in vitro using the human HepG2.2.15 cell line. With the restoration of endosomal release of NAPs in vitro using the UNC7938 compound, NAPs were observed to selectively impair the secretion of HBsAg without any intracellular HBsAg accumulation. Additionally, the structure-activity relationship of NAPs for this antiviral activity is similar to that previously reported in other infectious diseases and identifies an exposed hydrophobic protein domain as the target interface for this antiviral effect. The presented in vitro model, the first one to be based on a human derived cell line that constitutively expresses HBV, is a very promising tool for the identification of the host proteins(s) targeted by NAPs.
Collapse
Affiliation(s)
- Matthieu Blanchet
- Replicor.inc, Montréal, Canada; INRS-Institut Armand-Frappier, Institut National de la Recherche Scientifique, Laval, Canada
| | - Vigigah Sinnathamby
- INRS-Institut Armand-Frappier, Institut National de la Recherche Scientifique, Laval, Canada
| | | | - Patrick Labonté
- INRS-Institut Armand-Frappier, Institut National de la Recherche Scientifique, Laval, Canada.
| |
Collapse
|
20
|
Abstract
An estimated 240 million people worldwide are chronically infected with the hepatitis B virus (HBV). Despite readily available vaccination, HBV infections remain highly prevalent. As established HBV infections constitute a strong risk factor for developing hepatocellular carcinoma their treatment is a major task for the health system. Unfortunately, HBV is not curable with today's medicine. Approximately 15 million HBV patients have developed a hepatitis delta (HDV) infection on top of their HBV infection. The patients superinfected with this satellite virus suffer from a more severe disease development. The knowledge of the viruses, their classifications, clinical implications, treatment options and efforts to increase the drug variety are compiled in this review. The current standard therapies include nucleosidic reverse transcriptase inhibitors and interferon. As the known treatments fail to cure HBV and HDV, targeted treatment is highly warranted. The focus of this review is set on the drugs currently under clinical investigation. Furthermore, strategies for the development of targeted treatment, and compounds with novel mode of action are described.
Collapse
|
21
|
Levrero M, Subic M, Villeret F, Zoulim F. Perspectives and limitations for nucleo(t)side analogs in future HBV therapies. Curr Opin Virol 2018; 30:80-89. [DOI: 10.1016/j.coviro.2018.04.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 12/12/2022]
|
22
|
Farci P, Anna Niro G. Current and Future Management of Chronic Hepatitis D. Gastroenterol Hepatol (N Y) 2018; 14:342-351. [PMID: 30166948 PMCID: PMC6111511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Hepatitis D virus (HDV) is a defective RNA virus that requires the hepatitis B surface antigen (HBsAg) of the hepatitis B virus (HBV) for its assembly, release, and transmission. HDV is highly pathogenic, causing the least common, but most severe, form of chronic viral hepatitis at all ages. Although significant advances have been made in the treatment of chronic viral hepatitis, targeting HDV remains a major challenge because of the unconventional nature of this virus and the severity of its disease. The virus contains a ribonucleoprotein complex formed by the RNA genome with a single structural protein, delta antigen (HDAg), which exists in 2 forms (small and large HDAg) and is coated by HBsAg. Farnesylation of the large HDAg is essential for anchoring the ribonucleoprotein to HBsAg for the assembly of virion particles. HDV enters into hepatocytes by using the HBV receptor, the sodium taurocholate cotransporting polypeptide (NTCP). Unlike other RNA viruses, HDV does not encode its own polymerase but exploits the host RNA polymerase II for replication. Thus, in contrast to HBV and hepatitis C virus, which possess virus-specific enzymes that can be targeted by specific inhibitors, the lack of a virus-specific polymerase makes HDV a particularly challenging therapeutic target. Treatment of hepatitis D remains unsatisfactory, and interferon-α has been the only approved drug over the past 30 years. This article examines the unconventional nature of HDV, the current management of chronic hepatitis D, and how new insights from the HDV life cycle have led to the development of 3 novel classes of drugs (NTCP receptor inhibitors, farnesyltransferase inhibitors, and nucleic acid polymers) that are currently under clinical evaluation.
Collapse
Affiliation(s)
- Patrizia Farci
- Dr Farci is chief of the Hepatic Pathogenesis Section of the Laboratory of Infectious Diseases at the National Institute of Allergy and Infectious Diseases in the National Institutes of Health in Bethesda, Maryland
- Dr Niro is a senior staff clinician in the Gastroenterology Unit at IRCCS Casa Sollievo Sofferenza Hospital in San Giovanni Rotondo, Foggia, Italy
| | - Grazia Anna Niro
- Dr Farci is chief of the Hepatic Pathogenesis Section of the Laboratory of Infectious Diseases at the National Institute of Allergy and Infectious Diseases in the National Institutes of Health in Bethesda, Maryland
- Dr Niro is a senior staff clinician in the Gastroenterology Unit at IRCCS Casa Sollievo Sofferenza Hospital in San Giovanni Rotondo, Foggia, Italy
| |
Collapse
|
23
|
Abstract
With high morbidity and mortality worldwide, there is great interest in effective therapies for chronic hepatitis B (CHB) virus. There are currently several dozen investigational agents being developed for treatment of CHB. They can be broadly divided into two categories: (1) direct-acting antivirals (DAAs) that interfere with a specific step in viral replication; and (2) host-targeting agents that inhibit viral replication by modifying host cell function, with the latter group further divided into the subcategories of immune modulators and agents that target other host functions. Included among the DAAs being developed are RNA interference therapies, covalently closed circular DNA (cccDNA) formation and transcription inhibitors, core/capsid inhibitors, reverse transcriptase inhibitors, hepatitis B surface antigen (HBsAg) release inhibitors, antisense oligonucleotides, and helioxanthin analogues. Included among the host-targeting agents are entry inhibitors, cyclophilin inhibitors, and multiple immunomodulatory agents, including Toll-like receptor agonists, immune checkpoint inhibitors, therapeutic vaccines, engineered T cells, and several cytokine agents, including recombinant human interleukin-7 (CYT107) and SB 9200, a novel therapy that is believed to both have direct antiviral properties and to induce endogenous interferon. In this review we discuss agents that are currently in the clinical stage of development for CHB treatment as well as strategies and agents currently at the evaluation and discovery phase and potential future targets. Effective approaches to CHB may require suppression of viral replication combined with one or more host-targeting agents. Some of the recent research advances have led to the hope that with such a combined approach we may have a functional cure for CHB in the not distant future.
Collapse
Affiliation(s)
- Altaf Dawood
- Department of Internal Medicine, Section of Gastroenterology, University of Nevada School of Medicine, Las Vegas, NV, USA
| | - Syed Abdul Basit
- Department of Internal Medicine, Section of Gastroenterology, University of Nevada School of Medicine, Las Vegas, NV, USA
| | - Mahendran Jayaraj
- Department of Internal Medicine, Section of Gastroenterology, University of Nevada School of Medicine, Las Vegas, NV, USA
| | - Robert G Gish
- Department of Internal Medicine, Section of Gastroenterology, University of Nevada School of Medicine, Las Vegas, NV, USA.
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University Medical Center, Stanford, CA, USA.
- Hepatitis B Foundation, Doylestown, PA, USA.
- Asian Pacific Health Foundation, San Diego, CA, USA.
- National Viral Hepatitis Roundtable, Washington, DC, USA.
| |
Collapse
|
24
|
Overcoming immune tolerance in chronic hepatitis B by therapeutic vaccination. Curr Opin Virol 2018; 30:58-67. [PMID: 29751272 DOI: 10.1016/j.coviro.2018.04.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/03/2018] [Accepted: 04/18/2018] [Indexed: 12/14/2022]
Abstract
The currently used nucleoside analogs (i.e. entecavir and tenofovir) with high barrier-to-resistance efficiently suppress viral replication, limit inflammation and reduce the sequelae of chronic hepatitis B, but cannot cure the disease and thus have to be applied long-term. Therapeutic vaccination as an approach to cure chronic hepatitis B has shown promising pre-clinical results, nevertheless the proof of its efficacy in clinical trials is still missing. This may be partially due to suboptimal vaccine design. A main obstacle in chronic hepatitis B, however, is the high load of viral antigens expressed and secreted, which has been proposed to cause antigen-specific immune tolerance. Reduction of the viral antigen load is therefore considered a key factor for success of immune-based therapies. Although nucleoside analogs do not reduce viral antigen expression, new antiviral strategies are becoming available. Targeting viral translation by siRNA or targeting release of HBsAg from infected hepatocytes by nucleic acid polymers both reduce the antigen load. They may be considered as pre-treatment for therapeutic vaccination to increase the potential to elicit an HBV-specific immune response able to control and cure chronic HBV infection.
Collapse
|
25
|
Dusheiko G. Current and future directions of management of hepatitis B: steps toward a cure. Future Virol 2018. [DOI: 10.2217/fvl-2017-0103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Universal hepatitis B virus vaccination has been effective in reducing incident chronic hepatitis B but will not have the requisite effect on the prevalence of end-stage liver disease in chronically infected persons. The natural history and immunological stages of hepatitis B virus infection are still being defined. Over three decades, current therapies have reduced morbidity from chronic hepatitis B. The majority require nucleoside analog maintenance therapy. The preferential preservation of covalently closed circular DNA (cccDNA), and capsid reverse transcriptase–cccDNA interactions currently precludes cure in most. A functional cure in the host may require several synergistic antiviral and immunological intercessions. The correct sequencing and combinations of treatment with either host or viral targeting agents have yet to be determined. Proven surrogates for cccDNA for clinical trials are required. Different strategies may become apparent for patients at different stages of the disease. Curative therapies will require affordability. This review focuses on steps toward a cure.
Collapse
Affiliation(s)
- Geoffrey Dusheiko
- Kings College Hospital & University College London Medical School, Denmark Hill, London SE5 9RS, UK
| |
Collapse
|
26
|
Nucleic Acid Polymers Are Active against Hepatitis Delta Virus Infection In Vitro. J Virol 2018; 92:JVI.01416-17. [PMID: 29212929 DOI: 10.1128/jvi.01416-17] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 11/22/2017] [Indexed: 12/14/2022] Open
Abstract
In this study, an in vitro infection model for the hepatitis delta virus (HDV) was used to evaluate the antiviral effects of phosphorothioate nucleic acid polymers (NAPs) and investigate their mechanism of action. The results show that NAPs inhibit HDV infection at concentrations less than 4 μM in cultures of differentiated human hepatoma cells. NAPs were shown to be active at viral entry but inactive postentry on HDV RNA replication. Inhibition was independent of the NAP nucleotide sequence but dependent on both size and amphipathicity of the polymer. NAP antiviral activity was effective against HDV virions bearing the main hepatitis B virus (HBV) immune escape substitutions (D144A and G145R) and was pangenomic with regard to HBV envelope proteins. Furthermore, similar to immobilized heparin, immobilized NAPs could bind HDV particles, suggesting that entry inhibition was due, at least in part, to preventing attachment of the virus to cell surface glycosaminoglycans. The results document NAPs as a novel class of antiviral compounds that can prevent HDV propagation.IMPORTANCE HDV infection causes the most severe form of viral hepatitis in humans and one of the most difficult to cure. Currently, treatments are limited to long-term administration of interferon at high doses, which provide only partial efficacy. There is thus an urgent need for innovative approaches to identify new antiviral against HDV. The significance of our study is in demonstrating that nucleic acid polymers (NAPs) are active against HDV by targeting the envelope of HDV virions. In an in vitro infection assay, NAP activity was recorded at concentrations less than 4 μM in the absence of cell toxicity. Furthermore, the fact that NAPs could block HDV at viral entry suggests their potential to control the spread of HDV in a chronically HBV-infected liver. In addition, NAP anti-HDV activity was pangenomic with regard to HBV envelope proteins and not circumvented by HBsAg substitutions associated with HBV immune escape.
Collapse
|
27
|
Schöneweis K, Motter N, Roppert PL, Lu M, Wang B, Roehl I, Glebe D, Yang D, Morrey JD, Roggendorf M, Vaillant A. Activity of nucleic acid polymers in rodent models of HBV infection. Antiviral Res 2017; 149:26-33. [PMID: 29126900 DOI: 10.1016/j.antiviral.2017.10.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 09/19/2017] [Accepted: 10/27/2017] [Indexed: 12/18/2022]
Abstract
Nucleic acid polymers (NAPs) block the release of HBsAg from infected hepatocytes. These compounds have been previously shown to have the unique ability to eliminate serum surface antigen in DHBV-infected Pekin ducks and achieve multilog reduction of HBsAg or HBsAg loss in patients with chronic HBV infection and HBV/HDV coinfection. In ducks and humans, the blockage of HBsAg release by NAPs occurs by the selective targeting of the assembly and/or secretion of subviral particles (SVPs). The clinically active NAP species REP 2055 and REP 2139 were investigated in other relevant animal models of HBV infection including woodchucks chronically infected with WHV, HBV transgenic mice and HBV infected SCID-Hu mice. The liver accumulation of REP 2139 in woodchucks following subcutaneous administration was examined and was found to be similar to that observed in mice and ducks. However, in woodchucks, NAP treatment was associated with only mild (36-79% relative to baseline) reductions in WHsAg (4/10 animals) after 3-5 weeks of treatment without changes in serum WHV DNA. In HBV infected SCID-Hu mice, REP 2055 treatment was not associated with any reduction of HBsAg, HBeAg or HBV DNA in the serum after 28 days of treatment. In HBV transgenic mice, no reductions in serum HBsAg were observed with REP 2139 with up to 12 weeks of treatment. In conclusion, the antiviral effects of NAPs in DHBV infected ducks and patients with chronic HBV infection were weak or absent in woodchuck and mouse models despite similar liver accumulation of NAPs in all these species, suggesting that the mechanisms of SVP assembly and or secretion present in rodent models differs from that in DHBV and chronic HBV infections.
Collapse
Affiliation(s)
- Katrin Schöneweis
- Department of Virology, University of Duisburg-Essen, Essen, Germany
| | - Neil Motter
- Institute for Antiviral Research, Utah State University, Logan, UT, USA
| | - Pia L Roppert
- Institute of Medical Virology, National Reference Centre for Hepatitis B and D Viruses, German Centre for Infection Research (DZIF), Justus Liebig University of Giessen, Giessen, Germany
| | - Mengji Lu
- Department of Virology, University of Duisburg-Essen, Essen, Germany
| | - Baoju Wang
- Department of Infectious Disease, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | | | - Dieter Glebe
- Institute of Medical Virology, National Reference Centre for Hepatitis B and D Viruses, German Centre for Infection Research (DZIF), Justus Liebig University of Giessen, Giessen, Germany
| | - Dongliang Yang
- Department of Infectious Disease, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - John D Morrey
- Institute for Antiviral Research, Utah State University, Logan, UT, USA
| | | | | |
Collapse
|
28
|
Abstract
Hepatitis D virus (HDV) infection leads to the most severe form of chronic viral hepatitis and requires the attention of a liver specialist. In this review, I will recapitulate recent advances in the management of HDV, present background information on HDV infection as well as current chronic hepatitis D treatment, briefly examine the HDV life cycle and discuss new management strategies.
Collapse
Affiliation(s)
- Cihan Yurdaydin
- Department of Gastroenterology, University of Ankara Medical School, Ankara, Turkey.,Hepatology Institute, University of Ankara, Ankara, Turkey
| |
Collapse
|
29
|
Pei Y, Wang C, Yan SF, Liu G. Correction to Past, Current, and Future Developments of Therapeutic Agents for Treatment of Chronic Hepatitis B Virus Infection. J Med Chem 2017; 60:6766-6767. [PMID: 28613860 DOI: 10.1021/acs.jmedchem.7b00781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
30
|
Lempp FA, Urban S. Hepatitis Delta Virus: Replication Strategy and Upcoming Therapeutic Options for a Neglected Human Pathogen. Viruses 2017; 9:E172. [PMID: 28677645 PMCID: PMC5537664 DOI: 10.3390/v9070172] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 12/15/2022] Open
Abstract
The human Hepatitis Delta Virus (HDV) is unique among all viral pathogens. Encoding only one protein (Hepatitis Delta Antigen; HDAg) within its viroid-like self-complementary RNA, HDV constitutes the smallest known virus in the animal kingdom. To disseminate in its host, HDV depends on a helper virus, the human Hepatitis B virus (HBV), which provides the envelope proteins required for HDV assembly. HDV affects an estimated 15-20 million out of the 240 million chronic HBV-carriers and disperses unequally in disparate geographical regions of the world. The disease it causes (chronic Hepatitis D) presents as the most severe form of viral hepatitis, leading to accelerated progression of liver dysfunction including cirrhosis and hepatocellular carcinoma and a high mortality rate. The lack of approved drugs interfering with specific steps of HDV replication poses a high burden for gaining insights into the molecular biology of the virus and, consequently, the development of specific novel medications that resiliently control HDV replication or, in the best case, functionally cure HDV infection or HBV/HDV co-infection. This review summarizes our current knowledge of HBV molecular biology, presents an update on novel cell culture and animal models to study the virus and provides updates on the clinical development of the three developmental drugs Lonafarnib, REP2139-Ca and Myrcludex B.
Collapse
Affiliation(s)
- Florian A Lempp
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany.
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, 69120 Heidelberg, Germany.
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany.
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, 69120 Heidelberg, Germany.
| |
Collapse
|
31
|
Guillot C, Martel N, Berby F, Bordes I, Hantz O, Blanchet M, Sureau C, Vaillant A, Chemin I. Inhibition of hepatitis B viral entry by nucleic acid polymers in HepaRG cells and primary human hepatocytes. PLoS One 2017. [PMID: 28636622 PMCID: PMC5479567 DOI: 10.1371/journal.pone.0179697] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatitis B virus (HBV) infection remains a major public health concern worldwide with 240 million individuals chronically infected and at risk of developing cirrhosis and hepatocellular carcinoma. Current treatments rarely cure chronic hepatitis B infection, highlighting the need for new anti-HBV drugs. Nucleic acid polymers (NAPs) are phosphorothioated oligonucleotides that have demonstrated a great potential to inhibit infection with several viruses. In chronically infected human patients, NAPs administration lead to a decline of blood HBsAg and HBV DNA and to HBsAg seroconversion, the expected signs of functional cure. NAPs have also been shown to prevent infection of duck hepatocytes with the Avihepadnavirus duck hepatitis B virus (DHBV) and to exert an antiviral activity against established DHBV infection in vitro and in vivo. In this study, we investigated the specific anti-HBV antiviral activity of NAPs in the HepaRG human hepatoma cell line and primary cultures of human hepatocytes. NAPs with different chemical features (phosphorothioation, 2’O-methyl ribose, 5-methylcytidine) were assessed for antiviral activity when provided at the time of HBV inoculation or post-inoculation. NAPs dose-dependently inhibited HBV entry in a phosphorothioation-dependent, sequence-independent and size-dependent manner. This inhibition of HBV entry by NAPs was impaired by 2’O-methyl ribose modification. NAP treatment after viral inoculation did not elicit any antiviral activity.
Collapse
Affiliation(s)
- Clément Guillot
- Centre de Recherche en Cancérologie de Lyon INSERM U1052, CNRS UMR5286, Université de Lyon, Lyon, France
| | - Nora Martel
- Centre de Recherche en Cancérologie de Lyon INSERM U1052, CNRS UMR5286, Université de Lyon, Lyon, France
| | - Françoise Berby
- Centre de Recherche en Cancérologie de Lyon INSERM U1052, CNRS UMR5286, Université de Lyon, Lyon, France
| | - Isabelle Bordes
- Centre de Recherche en Cancérologie de Lyon INSERM U1052, CNRS UMR5286, Université de Lyon, Lyon, France
| | - Olivier Hantz
- Centre de Recherche en Cancérologie de Lyon INSERM U1052, CNRS UMR5286, Université de Lyon, Lyon, France
| | | | - Camille Sureau
- Molecular Virology Laboratory, Institut National de la Transfusion Sanguine (INTS), CNRS INSERM U1134, Paris, France
| | | | - Isabelle Chemin
- Centre de Recherche en Cancérologie de Lyon INSERM U1052, CNRS UMR5286, Université de Lyon, Lyon, France
- * E-mail: (IC); (AV)
| |
Collapse
|
32
|
Li Y, Liu Z, Hui L, Liu X, Feng A, Wang W, Zhang L, Li N, Zhou G, Wang Q, Han Q, Lv Y, Wang Q, Yang G, Wang Y. Transbody against virus core protein potently inhibits hepadnavirus replication in vivo: evidence from a duck model of hepatitis B virus. Br J Pharmacol 2017; 174:2261-2272. [PMID: 28383135 DOI: 10.1111/bph.13811] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE The therapeutic management of hepatitis B virus (HBV) infections remains challenging, and novel antiviral strategies are urgently required. The HBV transbody, a monoclonal antibody (MAb) against human HBcAg coupled with the trans-activator of transcription protein transduction domain (TAT PTD), was previously shown to possess cell-penetrating ability and potent antiviral activity in vitro. The purpose of the present study was to evaluate the antiviral activity of the HBcMAb-TAT PTD conjugate in vivo in a duck model of HBV. EXPERIMENTAL APPROACH Female Peking ducks were injected i.p. with 0.03-0.3 mg·kg-1 ·day-1 of the DHBV transbody (DHBcMAb-TAT PTD conjugate) for 30 days. Serum DHBV DNA levels and liver DHBV DNA and covalently closed circular DNA (cccDNA) loads were determined at scheduled time points. Immunohistological examination of DHBcAg in the duck liver was also performed. KEY RESULTS The DHBV transbody significantly reduced the serum and liver DHBV DNA levels at doses of 0.1 and 0.3 mg·kg-1 ·day-1 and liver cccDNA levels at a dose of 0.3 mg·kg-1 ·day-1 after 30 days of treatment. The suppressive effects of the DHBV transbody at 0.3 mg·kg-1 ·day-1 on the serum and liver DHBV DNA and liver cccDNA levels remained significant, even at 15 days after treatment cessation. Similarly, immunohistochemistry of liver sections revealed decreased DHBcAg levels within hepatocytes 15 days after treatment termination. CONCLUSIONS AND IMPLICATIONS The DHBV transbody inhibits DHBV replication and possesses potent anti-DHBV activities in vivo. The cell-permeable antibody against the virus core antigen may be developed as a novel treatment for patients with hepadnavirus infections.
Collapse
Affiliation(s)
- Yiping Li
- School of Pharmacy, Xi'an Jiaotong University, Xi'an, China
| | - Zhengwen Liu
- Department of Infectious Diseases, First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China.,Institute of Advanced Surgical Technology and Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Lingyun Hui
- Department of Laboratory Medicine, First Affiliated Hospital, School of medicine, Xi'an Jiaotong University, Xi'an, China
| | - Xi Liu
- Department of Pathology, First Affiliated Hospital, School of medicine, Xi'an Jiaotong University, Xi'an, China
| | - Ai Feng
- Department of Laboratory Medicine, First Affiliated Hospital, School of medicine, Xi'an Jiaotong University, Xi'an, China
| | - Wei Wang
- Department of Laboratory Medicine, First Affiliated Hospital, School of medicine, Xi'an Jiaotong University, Xi'an, China
| | - Lin Zhang
- Department of Laboratory Medicine, First Affiliated Hospital, School of medicine, Xi'an Jiaotong University, Xi'an, China
| | - Na Li
- Department of Infectious Diseases, First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Guoqing Zhou
- School of Computer Science and Engineering, Northwestern Polytechnical University, Xi'an, China
| | - Quanli Wang
- Department of Epidemiology and Statistics, School of medicine, Xi'an Jiaotong University, Xi'an, China
| | - Qunying Han
- Department of Infectious Diseases, First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Yi Lv
- Institute of Advanced Surgical Technology and Engineering, Xi'an Jiaotong University, Xi'an, China.,Department of Hepatobiliary Surgery, First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Quanying Wang
- Xi'an Hua Guang Biological Engineering Company, Xi'an, China
| | - Guangxiao Yang
- Xi'an Hua Guang Biological Engineering Company, Xi'an, China
| | - Yawen Wang
- Department of Laboratory Medicine, First Affiliated Hospital, School of medicine, Xi'an Jiaotong University, Xi'an, China
| |
Collapse
|
33
|
Roehl I, Seiffert S, Brikh C, Quinet J, Jamard C, Dorfler N, Lockridge JA, Cova L, Vaillant A. Nucleic Acid Polymers with Accelerated Plasma and Tissue Clearance for Chronic Hepatitis B Therapy. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 8:1-12. [PMID: 28918011 PMCID: PMC5466589 DOI: 10.1016/j.omtn.2017.04.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 12/18/2022]
Abstract
REP 2139 is a nucleic acid polymer (NAP) currently under clinical development for chronic hepatitis B (HBV) therapy. This preclinical study investigated different REP 2139 analogs that would display reduced accumulation in the serum and tissues, while retaining an antiviral effect against HBV infection. REP 2139 analogs were evaluated in human plasma, CD-1 mice, cynomolgus monkeys, and Pekin ducks. Discrete ribose transformation to 2'OH in selected riboadenosines resulted in a slow degradation in acidified human plasma that plateaued after 48 hr. REP 2165, a REP 2139 analog containing three unmodified riboadenosines equally spaced throughout the polymer, showed similar plasma clearance and tissue distribution as REP 2139 in mice and cynomolgus monkeys after a single dose. Interestingly, after repeated administration, accumulation of REP 2165 in plasma and organs was reduced, indicating a dramatically faster rate of clearance from organs after therapy was ended in both species. Both REP 2139 and REP 2165 were well tolerated at clinically relevant doses, with no alterations in liver, kidney, or hematological function. In chronic duck HBV (DHBV) infection, REP 2165 displayed significantly reduced liver accumulation after repeated dosing but retained antiviral activity similar to REP 2139. These results indicate the therapeutic potential of REP 2165 against chronic HBV infection in patients is similar to REP 2139, but with significantly reduced drug accumulation and improved tissue clearance.
Collapse
|
34
|
Pei Y, Wang C, Yan SF, Liu G. Past, Current, and Future Developments of Therapeutic Agents for Treatment of Chronic Hepatitis B Virus Infection. J Med Chem 2017; 60:6461-6479. [PMID: 28383274 DOI: 10.1021/acs.jmedchem.6b01442] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
For decades, treatment of hepatitis B virus (HBV) infection has been relying on interferon (IFN)-based therapies and nucleoside/nucleotide analogues (NAs) that selectively target the viral polymerase reverse transcriptase (RT) domain and thereby disrupt HBV viral DNA synthesis. We have summarized here the key steps in the HBV viral life cycle, which could potentially be targeted by novel anti-HBV therapeutics. A wide range of next-generation direct antiviral agents (DAAs) with distinct mechanisms of actions are discussed, including entry inhibitors, transcription inhibitors, nucleoside/nucleotide analogues, inhibitors of viral ribonuclease H (RNase H), modulators of viral capsid assembly, inhibitors of HBV surface antigen (HBsAg) secretion, RNA interference (RNAi) gene silencers, antisense oligonucleotides (ASOs), and natural products. Compounds that exert their antiviral activities mainly through host factors and immunomodulation, such as host targeting agents (HTAs), programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors, and Toll-like receptor (TLR) agonists, are also discussed. In this Perspective, we hope to provide an overview, albeit by no means being comprehensive, for the recent development of novel therapeutic agents for the treatment of chronic HBV infection, which not only are able to sustainably suppress viral DNA but also aim to achieve functional cure warranted by HBsAg loss and ultimately lead to virus eradication and cure of hepatitis B.
Collapse
Affiliation(s)
- Yameng Pei
- School of Pharmaceutical Sciences, Tsinghua University , Beijing 100084, China
| | - Chunting Wang
- School of Pharmaceutical Sciences, Tsinghua University , Beijing 100084, China
| | - S Frank Yan
- Molecular Design and Chemical Biology, Roche Pharma Research and Early Development, Roche Innovation Center Shanghai , Shanghai 201203, China
| | - Gang Liu
- School of Pharmaceutical Sciences, Tsinghua University , Beijing 100084, China
| |
Collapse
|
35
|
Nucleic acid-based polymers effective against hepatitis B Virus infection in patients don't harbor immunostimulatory properties in primary isolated liver cells. Sci Rep 2017; 7:43838. [PMID: 28272460 PMCID: PMC5341074 DOI: 10.1038/srep43838] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 01/30/2017] [Indexed: 12/18/2022] Open
Abstract
Nucleic acid polymers (NAPs) block the release of subviral particles from hepatocytes, a mechanism consistent with their antiviral activity against hepatitis B virus (HBV) in patients. Analysis of immunostimulatory properties of NAPs were conducted with several NAP species: REP 2006, the prototypic degenerate NAP [dN]40, containing TLR9-stimulatory CpG; REP 2055 a clinically active NAP with a sequence [dAdC]20 devoid of CpG content; REP 2139 (also clinically active) and REP 2165 (REP 2055 analogues further rendered immunologically inactive by replacing cytidine with 5-methylcytidine and incorporating 2′-O methylation of riboses). These analyses revealed pro-inflammatory responses in human peripheral blood mononuclear cells with REP 2006 and with REP 2139 and REP 2165 only at high dose but displayed no significant antiviral activity. In primary isolated human hepatocytes and liver sinusoidal endothelial cells no significant inflammatory or antiviral responses were detected for any NAPs. In human Kupffer cells pro-inflammatory activity was observed with REP 2006 and REP 2055, whereas a weak but significant induction of interferon genes was only observed with REP 2006 at the highest concentration. We therefore hypothesize that the antiviral activity of NAPs optimized to treat HBV infection in patients cannot be explained by direct induction of innate antiviral responses.
Collapse
|
36
|
Ward H, Tang L, Poonia B, Kottilil S. Treatment of hepatitis B virus: an update. Future Microbiol 2016; 11:1581-1597. [PMID: 27855500 DOI: 10.2217/fmb-2016-0128] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chronic hepatitis B virus infection is a global health concern as it affects over 240 million people worldwide and an estimated 686,000 people die annually as a result of complications of the disease. With the development of newer antiviral drugs, viral suppression of HBV is achievable, however elimination of HBV from infected individuals (functional cure) remains an issue. Due to persistence of HBV DNA (cccDNA) in infected cells, chronically infected patients who discontinue therapy prior to HBsAg loss or seroconversion are likely to relapse. Several novel therapeutic strategies are being researched and studied in clinical trials. Here we review these novel strategies to achieve sustained cure or elimination of HBV. These strategies include the targeting of the host or viral factors required for viral persistence as well as therapeutic vaccines.
Collapse
Affiliation(s)
- Haley Ward
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lydia Tang
- Division of Clinical Care & Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Bhawna Poonia
- Division of Clinical Care & Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Shyam Kottilil
- Division of Clinical Care & Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| |
Collapse
|
37
|
Wranke A, Wedemeyer H. Antiviral therapy of hepatitis delta virus infection - progress and challenges towards cure. Curr Opin Virol 2016; 20:112-118. [PMID: 27792905 DOI: 10.1016/j.coviro.2016.10.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 10/03/2016] [Accepted: 10/10/2016] [Indexed: 12/14/2022]
Abstract
Hepatitis B-/D-virus co-infection causes the most severe form of viral hepatitis, frequently leading to liver cirrhosis, hepatic decompensation and consecutive liver-related mortality. Treatment options for hepatitis delta are limited. The only recommended therapy is pegylated interferon alpha which leads to virological responses in about 25-30% of patients. However, interferon therapy is associated with frequent side-effects and late HDV RNA relapses have been described during long-term follow even in patients who were HDV RNA negative 24 weeks after the end of therapy. Thus, alternative treatment options are urgently needed. Clinical studies have been performed exploring prenylation inhibitors, viral entry inhibitors and nucleic acid polymers to block particle release. We here summarize the progress and challenges towards cure of HDV infection.
Collapse
Affiliation(s)
- Anika Wranke
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Heiner Wedemeyer
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany; German Center for Infection Research (DZIF), Partner Side HepNet Study-House, Hannover, Germany; HepNet Study-House, Hannover, Germany; Integrated Research and Treatment Center Transplantation, Hannover Medical School, Germany.
| |
Collapse
|
38
|
Abstract
Chronic hepatitis B virus (HBV) infection continues to be a major health burden worldwide. Currently available antiviral treatment options for chronic hepatitis B include pegylated interferon alpha2a (PegIFN) or nucleos(t)ide analogues (NAs). The major advantages of NAs are good tolerance and potent antiviral activity associated with high rates of sustained on-treatment response to therapy. The advantages of PegIFN include a finite course of treatment, the absence of drug resistance, and an opportunity to obtain a durable post-treatment response to therapy. Furthermore, PegIFN is the only approved agent known to be active against hepatitis D virus (HDV). The use of these two antiviral agents with different mechanisms of action in combination against hepatitis B is theoretically an attractive approach for treatment. Although several studies have confirmed certain virological advantages of combination therapies, data supporting a long-term clinical benefit for patients are lacking and monotherapy with PegIFN or NAs remains the therapy of choice. Moreover, with the current treatment approaches, only a limited number of patients achieve hepatitis B surface antigen (HBsAg) loss. HBsAg loss is considered a "functional cure", but does not mean viral eradication. There is a need for novel therapeutic approaches that enable not only suppression of viral replication, but resolution of HBV infection. A key challenge is to target covalently closed circular DNA (cccDNA) in the nucleus of infected hepatocytes. The recent development and availability of innovative in vitro and in vivo systems and sensitive molecular techniques has opened new possibilities to study the complex network of interactions that HBV establishes with the host in the course of infection and to define new targets for antiviral strategies. Several new antiviral or immunomodulatory compounds have reached preclinical or clinical testing with the aim of silencing or eradicating cccDNA to achieve functional cure. Many of these strategies may also be effective for the treatment of HDV, which is dependent on HBsAg for its life cycle. This Clinical Trial Watch summarizes the most recent therapeutic strategies designed to directly target the viruses B and D or to improve immune responses during chronic HBV infection.
Collapse
|
39
|
Vaillant A. Nucleic acid polymers: Broad spectrum antiviral activity, antiviral mechanisms and optimization for the treatment of hepatitis B and hepatitis D infection. Antiviral Res 2016; 133:32-40. [PMID: 27400989 DOI: 10.1016/j.antiviral.2016.07.004] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/04/2016] [Accepted: 07/06/2016] [Indexed: 12/18/2022]
Abstract
Antiviral polymers are a well-studied class of broad spectrum viral attachment/entry inhibitors whose activity increases with polymer length and with increased amphipathic (hydrophobic) character. The newest members of this class of compounds are nucleic acid polymers whose activity is derived from the sequence independent properties of phosphorothioated oligonucleotides as amphipathic polymers. Although the antiviral mechanisms and broad spectrum antiviral activity of nucleic acid polymers mirror the functionality of other members of this class, they exert in addition a unique post entry activity in hepatitis B infection which inhibits the release of HBsAg from infected hepatocytes. This review provides a general overview of the antiviral polymer class with a focus on nucleic acid polymers and their development as therapeutic agents for the treatment of hepatitis B/hepatitis D. This article forms part of a symposium in Antiviral Research on ''An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B.''.
Collapse
Affiliation(s)
- Andrew Vaillant
- Replicor Inc., 6100 Royalmount Avenue, Montreal, Quebec, H4P 2R2, Canada.
| |
Collapse
|
40
|
Safety and Efficacy of Nucleic Acid Polymers in Monotherapy and Combined with Immunotherapy in Treatment-Naive Bangladeshi Patients with HBeAg+ Chronic Hepatitis B Infection. PLoS One 2016; 11:e0156667. [PMID: 27257978 PMCID: PMC4892580 DOI: 10.1371/journal.pone.0156667] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/16/2016] [Indexed: 02/07/2023] Open
Abstract
Previous in vivo studies have suggested that nucleic acid polymers (NAPs) may reduce circulating levels of HBsAg in the blood by blocking its release from infected hepatocytes and that this effect may have clinical benefit. NAP treatment, was evaluated in two clinical studies in patients with HBeAg positive chronic HBV infection. The REP 101 study examined REP 2055 monotherapy in 8 patients and the REP 102 study examined REP 2139-Ca, in monotherapy in 12 patients, 9 of which transitioned to short term combined treatment with pegylated interferon alpha 2a or thymosin alpha 1. In both studies NAP monotherapy was accompanied by 2–7 log reductions of serum HBsAg, 3–9 log reductions in serum HBV DNA and the appearance of serum anti-HBsAg antibodies (10–1712 mIU / ml). Eight of the 9 patients transitioning to combined treatment with immunotherapy (pegylated interferon or thymosin alpha 1) in the REP 102 study experienced HBsAg loss and all 9 patients experienced substantial increases in serum anti-HBsAg antibody titers before withdrawal of therapy. For 52 weeks after removal of REP 2055 therapy, rebound of serum viremia (HBV DNA > 1000 copies / ml, HBsAg > 1IU / ml) was not observed in 3 / 8 patients. Suppression of serum virema was further maintained for 290 and 231 weeks in 2 of these patients. After withdrawal of all therapy in the 9 patients that transitioned to combination therapy in the REP 102 study, 8 patients achieved HBV DNA < 116 copies / ml after treatment withdrawal. Viral rebound occurred over a period of 12 to 123 weeks in 7 patients but was still absent in two patients at 135 and 137 weeks of follow-up. Administration tolerability issues observed with REP 2055 were rare with REP 2139-Ca but REP 2139-Ca therapy was accompanied by hair loss, dysphagia and dysgeusia which were considered related to heavy metal exposure endemic at the trial site. These preliminary studies suggest that NAP can elicit important antiviral responses during treatment which may improve the effect of immunotherapy. NAPs may be a potentially useful component of future combination therapies for the treatment of chronic hepatitis B. Trial Registration: ClinicalTrials.gov NCT02646163 and NCT02646189
Collapse
|
41
|
Demma S, Dusheiko G. The current treatment situation and definitions of a cure for chronic HBV infection. Future Virol 2016. [DOI: 10.2217/fvl.15.93] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
HBV vaccination, while effective in reducing incident chronic disease in endemic regions, will not have the desired impact on the rates of end-stage liver disease in chronically infected persons. Over three decades, IFN-α and nucleoside analogs have reduced the morbidity from the disease. A large reservoir of chronic infection remains. The natural history of HBV infection is still being defined. Understanding the interactions between HBV and the host will be fundamental to achieving higher rates of cure. Curing hepatitis B will require several steps for either eradication, or a functional cure in the host. It is unclear whether covently closed circular DNA chromatin would need to be cleared to cure hepatitis B, or whether low threshold levels would slow the disease.
Collapse
Affiliation(s)
- Shirin Demma
- UCL institute of Liver & Digestive Health & Royal Free NHS Foundation Trust, London, UK
- Hepatology Unit, Department of Medical & Pediatric Sciences, University of Catania, Policlinic, Via S. Sofia No 78, 95123 Catania, Italy
| | - Geoffrey Dusheiko
- UCL institute of Liver & Digestive Health & Royal Free NHS Foundation Trust, London, UK
| |
Collapse
|
42
|
Noordeen F, Scougall CA, Grosse A, Qiao Q, Ajilian BB, Reaiche-Miller G, Finnie J, Werner M, Broering R, Schlaak JF, Vaillant A, Jilbert AR. Therapeutic Antiviral Effect of the Nucleic Acid Polymer REP 2055 against Persistent Duck Hepatitis B Virus Infection. PLoS One 2015; 10:e0140909. [PMID: 26560490 PMCID: PMC4641618 DOI: 10.1371/journal.pone.0140909] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/01/2015] [Indexed: 12/18/2022] Open
Abstract
Previous studies have demonstrated that nucleic acid polymers (NAPs) have both entry and post-entry inhibitory activity against duck hepatitis B virus (DHBV) infection. The inhibitory activity exhibited by NAPs prevented DHBV infection of primary duck hepatocytes in vitro and protected ducks from DHBV infection in vivo and did not result from direct activation of the immune response. In the current study treatment of primary human hepatocytes with NAP REP 2055 did not induce expression of the TNF, IL6, IL10, IFNA4 or IFNB1 genes, confirming the lack of direct immunostimulation by REP 2055. Ducks with persistent DHBV infection were treated with NAP 2055 to determine if the post-entry inhibitory activity exhibited by NAPs could provide a therapeutic effect against established DHBV infection in vivo. In all REP 2055-treated ducks, 28 days of treatment lead to initial rapid reductions in serum DHBsAg and DHBV DNA and increases in anti-DHBs antibodies. After treatment, 6/11 ducks experienced a sustained virologic response: DHBsAg and DHBV DNA remained at low or undetectable levels in the serum and no DHBsAg or DHBV core antigen positive hepatocytes and only trace amounts of DHBV total and covalently closed circular DNA (cccDNA) were detected in the liver at 9 or 16 weeks of follow-up. In the remaining 5/11 REP 2055-treated ducks, all markers of DHBV infection rapidly rebounded after treatment withdrawal: At 9 and 16 weeks of follow-up, levels of DHBsAg and DHBcAg and DHBV total and cccDNA in the liver had rebounded and matched levels observed in the control ducks treated with normal saline which remained persistently infected with DHBV. These data demonstrate that treatment with the NAP REP 2055 can lead to sustained control of persistent DHBV infection. These effects may be related to the unique ability of REP 2055 to block release of DHBsAg from infected hepatocytes.
Collapse
Affiliation(s)
- Faseeha Noordeen
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
- Department of Microbiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
| | - Catherine A. Scougall
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Arend Grosse
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Qiao Qiao
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Behzad B. Ajilian
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Georget Reaiche-Miller
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - John Finnie
- SA Pathology, Hanson Institute, Centre For Neurological Diseases, Adelaide, SA, Australia
| | - Melanie Werner
- Department of Gastroenterology and Hepatology, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Ruth Broering
- Department of Gastroenterology and Hepatology, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Joerg F. Schlaak
- Department of Gastroenterology and Hepatology, University Hospital, University of Duisburg-Essen, Essen, Germany
| | | | - Allison R. Jilbert
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
- * E-mail: (AJ); (AV)
| |
Collapse
|
43
|
Alfaiate D, Dény P, Durantel D. Hepatitis delta virus: From biological and medical aspects to current and investigational therapeutic options. Antiviral Res 2015; 122:112-29. [DOI: 10.1016/j.antiviral.2015.08.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 12/14/2022]
|
44
|
Guo Z, King T. Therapeutic Strategies and New Intervention Points in Chronic Hepatitis Delta Virus Infection. Int J Mol Sci 2015; 16:19537-52. [PMID: 26295228 PMCID: PMC4581312 DOI: 10.3390/ijms160819537] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/05/2015] [Accepted: 08/07/2015] [Indexed: 12/18/2022] Open
Abstract
Chronic hepatitis delta virus infection (CHD) is a condition arising from super-infection of hepatitis B virus (HBV)-infected patients, resulting in a more rapid advance in liver pathology and hepatocellular carcinoma than is observed for HBV mono-infection. Although hepatitis delta virus (HDV) is structurally simple, its life cycle involves the complex participation of host enzymes, HBV-derived surface antigen (HBsAg), and HDV-auto-ribozyme and hepatitis delta antigen (HDAg) activities. Unsatisfactory clinical trial results with interferon-based therapies are motivating researchers to adjust and redirect the approach to CHD drug development. This new effort will likely require additional structural and functional studies of the viral and cellular/host components involved in the HDV replication cycle. This review highlights recent work aimed at new drug interventions for CHD, with interpretation of key pre-clinical- and clinical trial outcomes and a discussion of promising new technological approaches to antiviral drug design.
Collapse
Affiliation(s)
- Zhimin Guo
- Huron Peak Ave., Superior, CO 80027, USA.
| | - Thomas King
- Allevagen, LLC, 4105 Perry St., Denver, CO 80212, USA.
| |
Collapse
|
45
|
Hepatitis B virus infection: An insight into infection outcomes and recent treatment options. Virusdisease 2015; 26:1-8. [PMID: 26436115 DOI: 10.1007/s13337-015-0247-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 03/04/2015] [Indexed: 12/18/2022] Open
Abstract
Hepatitis B virus (HBV) currently infects an estimated population of 2 billion individuals in the world, including 400 million people with chronic HBV infection. HBV virology, replication and the host's immune response to HBV infection contribute to different infection outcomes. Acute hepatitis HBV infection is self-limiting but it leaves a residual infection that can become active in an individual during immunosuppression. In chronic HBV infection, the virus persistently replicates in hepatocytes leading to immune mediated hepatocellular damage. Despite the inability to remove the virus in more than 70 % of patients, current treatments for chronic HBV infection, interferon alpha and antiviral nucleotide/nucleoside analogues, aim to reduce viral replication to prevent or at least delay the progression to cirrhosis and hepatocellular carcinoma. In both self resolved acute and persistent HBV infection, the long term existence of chromatinised covalently closed circular DNA (cccDNA) in the nuclei of infected hepatocytes cannot be targeted by current treatments to eliminate these templates to eradicate the viral persistence. Identifying the mechanisms involve in the removal of infected hepatocytes will be useful as treatment options. In this context, DNA based novel therapeutic and immunization strategies might help to remove stable cccDNA and thus viral persistence.
Collapse
|
46
|
Abstract
Australian antigen, the envelope protein of hepatitis B virus (HBV), was discovered in 1967 as a prevalent serum antigen in hepatitis B patients. Early electron microscopy (EM) studies showed that this antigen was present in 22-nm particles in patient sera, which were believed to be incomplete virus. Complete virus, much less abundant than the 22-nm particles, was finally visualized in 1970. HBV was soon found to infect chimpanzees, gorillas, orangutans, gibbon apes, and, more recently, tree shrews (Tupaia belangeri) and cynomolgus macaques (Macaca fascicularis). This restricted host range placed limits on the kinds of studies that might be performed to better understand the biology and molecular biology of HBV and to develop antiviral therapies to treat chronic infections. About 10 years after the discovery of HBV, this problem was bypassed with the discovery of viruses related to HBV in woodchucks, ground squirrels, and ducks. Although unlikely animal models, their use revealed the key steps in hepadnavirus replication and in the host response to infection, including the fact that the viral nuclear episome is the ultimate target for immune clearance of transient infections and antiviral therapy of chronic infections. Studies with these and other animal models have also suggested interesting clues into the link between chronic HBV infection and hepatocellular carcinoma.
Collapse
|
47
|
Sauter MM, Gauger JJL, Brandt CR. Oligonucleotides designed to inhibit TLR9 block Herpes simplex virus type 1 infection at multiple steps. Antiviral Res 2014; 109:83-96. [PMID: 24995383 DOI: 10.1016/j.antiviral.2014.06.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 06/10/2014] [Accepted: 06/23/2014] [Indexed: 01/09/2023]
Abstract
Herpes simplex virus type 1 (HSV-1) is an important human pathogen which requires activation of nuclear factor-kappa B (NFκB) during its replication cycle. The persistent nature of HSV-1 infection, and the emergence of drug-resistant strains, highlights the importance of research to develop new antiviral agents. Toll-like receptors (TLRs) play a prominent role during the early antiviral response by recognizing viral nucleic acid and gene products, activating NFκB, and stimulating the production of inflammatory cytokines. We demonstrate a significant effect on HSV-1 replication in ARPE-19 and Vero cells when oligonucleotides designed to inhibit TLR9 are added 2h prior to infection. A greater than 90% reduction in the yield of infectious virus was achieved at oligonucleotide concentrations of 10-20 μM. TLR9 inhibitory oligonucleotides prevented expression of essential immediate early herpes gene products as determined by immunofluorescence microscopy and Western blotting. TLR9 oligonucleotides also interfered with viral attachment and entry. A TLR9 inhibitory oligonucleotide containing five adjacent guanosine residues (G-ODN) exhibited virucidal activity and inhibited HSV-1 replication when added post-infection. The antiviral effect of the TLR9 inhibitory oligonucleotides did not depend on the presence of TLR9 protein, suggesting a mechanism of inhibition that is not TLR9 specific. TLR9 inhibitory oligonucleotides also reduced NFκB activity in nuclear extracts. Studies using these TLR inhibitors in the context of viral infection should be interpreted with caution.
Collapse
Affiliation(s)
- Monica M Sauter
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, United States.
| | - Joshua J L Gauger
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States.
| | - Curtis R Brandt
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53706, United States.
| |
Collapse
|
48
|
Nucleic acid polymers inhibit duck hepatitis B virus infection in vitro. Antimicrob Agents Chemother 2013; 57:5291-8. [PMID: 23939902 DOI: 10.1128/aac.01003-13] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nucleic acid polymers (NAPs) utilize the sequence-independent properties of phosphorothioate oligonucleotides (PS-ONs) to target protein interactions involved in viral replication. NAPs are broadly active against a diverse range of enveloped viruses that use type I entry mechanisms. The antiviral activity of NAPs against hepatitis B virus (HBV) infection was assessed in vitro in duck hepatitis B virus (DHBV)-infected primary duck hepatocytes (PDH). NAPs efficiently entered PDH in the absence of any transfection agent and displayed antiviral activity at concentrations of 0.01 to 10 μM, measured by their ability to prevent the intracellular accumulation of DHBV surface antigen, which was independent of their nucleotide sequence and was specifically dependent on phosphorothioation. Higher levels of antiviral activity were observed with NAPs 40 nucleotides in length or longer. The fully degenerate NAP (REP 2006) was active during DHBV infection or when added 12 h after infection. In contrast, an acidic-pH-sensitive NAP (REP 2031) that was broadly active against other viruses displayed antiviral activity when present during DHBV infection but no activity when added 12 h after infection, suggesting that NAPs exert their postentry effect in an acidic environment unique to DHBV infection. Both REP 2006 and REP 2031 displayed negligible cytotoxicity in PDH at concentrations of up to 10 μM, as assessed using an XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] cytotoxicity assay. The antiviral activity of NAPs against DHBV in vitro was strictly dependent on their amphipathic character, suggesting that NAPs interact with amphipathic target(s) that are important for DHBV entry and postentry mechanisms required for infection.
Collapse
|