1
|
Ciupe SM, Conway JM. Incorporating Intracellular Processes in Virus Dynamics Models. Microorganisms 2024; 12:900. [PMID: 38792730 PMCID: PMC11124127 DOI: 10.3390/microorganisms12050900] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/26/2024] Open
Abstract
In-host models have been essential for understanding the dynamics of virus infection inside an infected individual. When used together with biological data, they provide insight into viral life cycle, intracellular and cellular virus-host interactions, and the role, efficacy, and mode of action of therapeutics. In this review, we present the standard model of virus dynamics and highlight situations where added model complexity accounting for intracellular processes is needed. We present several examples from acute and chronic viral infections where such inclusion in explicit and implicit manner has led to improvement in parameter estimates, unification of conclusions, guidance for targeted therapeutics, and crossover among model systems. We also discuss trade-offs between model realism and predictive power and highlight the need of increased data collection at finer scale of resolution to better validate complex models.
Collapse
Affiliation(s)
- Stanca M. Ciupe
- Department of Mathematics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA
| | - Jessica M. Conway
- Department of Mathematics and Center for Infectious Disease Dynamics, Penn State University, State College, PA 16802, USA
| |
Collapse
|
2
|
Ciupe SM, Dahari H, Ploss A. Mathematical Models of Early Hepatitis B Virus Dynamics in Humanized Mice. Bull Math Biol 2024; 86:53. [PMID: 38594319 PMCID: PMC11003933 DOI: 10.1007/s11538-024-01284-2] [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: 10/25/2023] [Accepted: 03/15/2024] [Indexed: 04/11/2024]
Abstract
Analyzing the impact of the adaptive immune response during acute hepatitis B virus (HBV) infection is essential for understanding disease progression and control. Here we developed mathematical models of HBV infection which either lack terms for adaptive immune responses, or assume adaptive immune responses in the form of cytolytic immune killing, non-cytolytic immune cure, or non-cytolytic-mediated block of viral production. We validated the model that does not include immune responses against temporal serum hepatitis B DNA (sHBV) and temporal serum hepatitis B surface-antigen (HBsAg) experimental data from mice engrafted with human hepatocytes (HEP). Moreover, we validated the immune models against sHBV and HBsAg experimental data from mice engrafted with HEP and human immune system (HEP/HIS). As expected, the model that does not include adaptive immune responses matches the observed high sHBV and HBsAg concentrations in all HEP mice. By contrast, while all immune response models predict reduction in sHBV and HBsAg concentrations in HEP/HIS mice, the Akaike Information Criterion cannot discriminate between non-cytolytic cure (resulting in a class of cells refractory to reinfection) and antiviral block functions (of up to 99 % viral production 1-3 weeks following peak viral load). We can, however, reject cytolytic killing, as it can only match the sHBV and HBsAg data when we predict unrealistic levels of hepatocyte loss.
Collapse
Affiliation(s)
- Stanca M Ciupe
- Department of Mathematics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
| | - Harel Dahari
- Division of Hepatology, Department of Medicine, Loyola University, Chicago, IL, USA
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| |
Collapse
|
3
|
Gopalakrishna H, Mironova M, Dahari H, Koh C, Heller T. Advances and Challenges in Managing Hepatitis D Virus: Evolving Strategies. CURRENT HEPATOLOGY REPORTS 2024; 23:32-44. [PMID: 38533303 PMCID: PMC10965034 DOI: 10.1007/s11901-024-00643-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/14/2024] [Indexed: 03/28/2024]
Abstract
Purpose of Review Hepatitis D Virus (HDV), although a small defective virus, poses a substantial public health challenge due to lack of awareness, underrecognized prevalence, and limited treatment options. Universal HDV screening within hepatitis B virus (HBV) cohorts is essential to address this issue. Despite its aggressive nature, effective HDV therapies have remained elusive for over four decades. Recent Findings Advances in understanding HDV's biology and clinical behavior offer potential therapeutic breakthroughs, fostering optimism. As insights grow, effective and targeted therapies are being developed to improve HDV management. Summary This review delves into HDV's intricate structure and biology, highlighting formidable hurdles in antiviral development. It emphasizes the importance of widespread screening, exploring noninvasive diagnostics, and examining current and emerging innovative therapeutic strategies. Moreover, the review explores models for monitoring treatment response. In essence, this review simplifies the complexities of effectively combating HDV.
Collapse
Affiliation(s)
- Harish Gopalakrishna
- Liver Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Maria Mironova
- Liver Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Harel Dahari
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Christopher Koh
- Liver Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Theo Heller
- Liver Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
- Translational Hepatology Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 10 Center Drive, Building 10, Room 4-5722, Bethesda, MD 20892-1800, USA
| |
Collapse
|
4
|
Shekhtman L, Cotler SJ, Degasperi E, Anolli MP, Uceda Renteria SC, Sambarino D, Borghi M, Perbellini R, Facchetti F, Ceriotti F, Lampertico P, Dahari H. Modelling HDV kinetics under the entry inhibitor bulevirtide suggests the existence of two HDV-infected cell populations. JHEP Rep 2024; 6:100966. [PMID: 38274491 PMCID: PMC10808955 DOI: 10.1016/j.jhepr.2023.100966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 10/15/2023] [Accepted: 10/31/2023] [Indexed: 01/27/2024] Open
Abstract
Background & Aims Bulevirtide (BLV) was approved for the treatment of compensated chronic hepatitis D virus (HDV) infection in Europe in 2020. However, research into the effects of the entry inhibitor BLV on HDV-host dynamics is in its infancy. Methods Eighteen patients with HDV under nucleos(t)ide analogue treatment for hepatitis B, with compensated cirrhosis and clinically significant portal hypertension, received BLV 2 mg/day. HDV RNA, alanine aminotransferase (ALT), and hepatitis B surface antigen (HBsAg) were measured at baseline, weeks 4, 8 and every 8 weeks thereafter. A mathematical model was developed to account for HDV, HBsAg and ALT dynamics during BLV treatment. Results Median baseline HDV RNA, HBsAg, and ALT were 4.9 log IU/ml [IQR: 4.4-5.8], 3.7 log IU/ml [IQR: 3.4-3.9] and 106 U/L [IQR: 81-142], respectively. During therapy, patients fit into four main HDV kinetic patterns: monophasic (n = 2), biphasic (n = 10), flat-partial response (n = 4), and non-responder (n = 2). ALT normalization was achieved in 14 (78%) patients at a median of 8 weeks (range: 4-16). HBsAg remained at pre-treatment levels. Assuming that BLV completely (∼100%) blocks HDV entry, modeling indicated that two HDV-infected cell populations exist: fast HDV clearing (median t1/2 = 13 days) and slow HDV clearing (median t1/2 = 44 days), where the slow HDV-clearing population consisted of ∼1% of total HDV-infected cells, which could explain why most patients exhibited a non-monophasic pattern of HDV decline. Moreover, modeling explained ALT normalization without a change in HBsAg based on a non-cytolytic loss of HDV from infected cells, resulting in HDV-free HBsAg-producing cells that release ALT upon death at a substantially lower rate compared to HDV-infected cells. Conclusion The entry inhibitor BLV provides a unique opportunity to understand HDV, HBsAg, ALT, and host dynamics. Impact and implications Mathematical modeling of hepatitis D virus (HDV) treatment with the entry inhibitor bulevirtide (BLV) provides a novel window into the dynamics of HDV RNA and alanine aminotransferase. Kinetic data from patients treated with BLV monotherapy can be explained by hepatocyte populations with different basal HDV clearance rates and non-cytolytic clearance of infected cells. While further studies are needed to test and refine the kinetic characterization described here, this study provides a new perspective on viral dynamics, which could inform evolving treatment strategies for HDV.
Collapse
Affiliation(s)
- Louis Shekhtman
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
- Department of Information Science, Bar-Ilan University, Ramat Gan, Israel
| | - Scott J. Cotler
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Elisabetta Degasperi
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Maria Paola Anolli
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Dana Sambarino
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Marta Borghi
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Riccardo Perbellini
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Floriana Facchetti
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Ferruccio Ceriotti
- Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Virology Unit, Milan, Italy
| | - Pietro Lampertico
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- CRC “A. M. and A. Migliavacca” Center for Liver Disease, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Harel Dahari
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| |
Collapse
|
5
|
Shekhtman L, Duehren S, Etzion O, Cotler SJ, Dahari H. Hepatitis D Virus and HBsAg Dynamics in the era of new Antiviral Treatments. Curr Gastroenterol Rep 2023; 25:401-412. [PMID: 37819559 PMCID: PMC10842234 DOI: 10.1007/s11894-023-00901-9] [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] [Accepted: 09/19/2023] [Indexed: 10/13/2023]
Abstract
PURPOSE OF REVIEW Hepatitis D virus (HDV) infection is the most severe form of chronic viral hepatitis, with no FDA-approved therapy. Progress in the development of effective HDV treatments is accelerating. This review highlights how mathematical modeling is improving understanding of HDV-HBsAg-host dynamics during antiviral therapy and generating insights into the efficacy and modes of action (MOA) of new antiviral agents. RECENT FINDINGS Clinical trials with pegylated-interferon-λ, bulevertide, nucleic acid polymers, and/or lonafarnib against various steps of the HDV-life cycle have revealed new viral-kinetic patterns that were not observed under standard treatment with pegylated-interferon-α. Modeling indicated that the half-lives of circulating HDV and HBsAg are ~ 1.7 d and ~ 1.3 d, respectively, estimated the relative response of HDV and HBsAg during different antiviral therapies, and provided insights into the efficacy and MOA of drugs in development for treating HDV, which can inform response-guided therapy to individualize treatment duration. Mathematical modeling of HDV and HBsAg kinetics provides a window into the HDV virus lifecycle, HDV-HBsAg-host dynamics during antiviral therapy, and the MOA of new drugs for HDV.
Collapse
Affiliation(s)
- Louis Shekhtman
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Medical Center, Maywood, IL, USA
- Department of Information Science, Bar-Ilan University, Ramat Gan, Israel
| | - Sarah Duehren
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Medical Center, Maywood, IL, USA
| | - Ohad Etzion
- Department of Gastroenterology and Liver Diseases, Soroka University Medical Center, Beer-Sheva, Israel
| | - Scott J Cotler
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Medical Center, Maywood, IL, USA
| | - Harel Dahari
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Medical Center, Maywood, IL, USA.
| |
Collapse
|
6
|
Hershkovich L, Shekhtman L, Bazinet M, Pântea V, Placinta G, Cotler SJ, Vaillant A, Dahari H. Rapid monophasic HBsAg decline during nucleic-acid polymer-based therapy predicts functional cure. Hepatol Commun 2023; 7:e0205. [PMID: 37458583 PMCID: PMC10351942 DOI: 10.1097/hc9.0000000000000205] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 04/13/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND AND AIMS Analyzing the interplay among serum HBV DNA, HBsAg, anti-HBs, and alanine aminotransferase (ALT) during nucleic-acid polymer (NAP)-based therapy for chronic hepatitis B provides a unique opportunity to identify kinetic patterns associated with functional cure. METHODS All participants with HBeAg-negative chronic HBV infection in the REP 401 study (NCT02565719) first received 24 weeks of tenofovir-disoproxil-fumarate (TDF) monotherapy. The early triple therapy group (n = 20) next received 48 weeks of TDF+pegylated interferon-α2a (pegIFN)+NAPs. In contrast, the delayed triple therapy group (n = 20) next received 24 weeks of TDF+pegIFN before 48 weeks of triple therapy. Three participants discontinued treatment and were excluded. Functional cure (HBsAg and HBV DNA not detectable with normal ALT) was assessed at 48 weeks post-treatment. Different kinetic phases were defined by at least a 2-fold change in slope. A single-phase decline was categorized as monophasic, and 2-phase declines were categorized as biphasic. RESULTS Fourteen (35%) participants achieved a functional cure. HBV DNA remained below or near undetectable for all participants by the end of TDF monotherapy and during subsequent combination therapies. Three HBsAg kinetic patterns were found in both the early and delayed groups, nonresponders (n = 4 and n = 4), monophasic (n = 11 and n = 11), and biphasic (n = 4 and n = 3), respectively. All participants who achieved a functional cure had a monophasic HBsAg kinetic pattern during triple therapy. Among participants with a monophasic HBsAg decline, those who had a functional cure had a shorter median time to HBsAg loss of 21 (interquartile range=11) weeks compared with those who did not achieve functional cure [median: 27 (7) weeks] (p = 0.012). CONCLUSIONS Functional cure was associated with a rapid monophasic HBsAg decline during NAP-based therapy. A nonmonophasic HBsAg kinetic pattern had a 100% negative predictive value (NPV) for a functional cure.
Collapse
Affiliation(s)
- Leeor Hershkovich
- Program for Experimental & Theoretical Modeling, Department of Medicine, Division of Hepatology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA
| | - Louis Shekhtman
- Program for Experimental & Theoretical Modeling, Department of Medicine, Division of Hepatology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA
- Network Science Institute, Northeastern University, Boston, Massachusetts, USA
| | | | - Victor Pântea
- Department of Infectious Diseases, Nicolae Testemiţanu, State University of Medicine and Pharmacy, Chişinău, Republic of Moldova
| | - Gheorge Placinta
- Department of Infectious Diseases, Nicolae Testemiţanu, State University of Medicine and Pharmacy, Chişinău, Republic of Moldova
| | - Scott J. Cotler
- Program for Experimental & Theoretical Modeling, Department of Medicine, Division of Hepatology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA
| | | | - Harel Dahari
- Program for Experimental & Theoretical Modeling, Department of Medicine, Division of Hepatology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA
| |
Collapse
|
7
|
Soriano V, Moreno-Torres V, Treviño A, Corral O, de Mendoza C. Bulevirtide in the Treatment of Hepatitis Delta: Drug Discovery, Clinical Development and Place in Therapy. Drug Des Devel Ther 2023; 17:155-166. [PMID: 36712949 PMCID: PMC9875571 DOI: 10.2147/dddt.s379964] [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: 12/25/2022] [Accepted: 01/14/2023] [Indexed: 01/22/2023] Open
Abstract
It has been ten years since the identification of NTCP as the cell surface receptor for HBV and HDV entry into hepatocytes. The search for molecules interfering with the binding of NTCP and HBV/HDV led to design bulevirtide (BLV). This large polypeptide mimics a region of the pre-S1 HBsAg and blocks viral entry by inhibitory competition. BLV was initially tested in cell cultures, animal models and more recently in Phase I-III human trials (called 'MYRS'). As monotherapy or in combination with peginterferon, BLV is well tolerated and exhibits potent antiviral activity. Plasma viremia significantly declines and/or becomes undetectable in more than 75% of patients treated for >24 weeks. However, serum HBsAg concentrations remain unchanged. No selection of BLV resistance in HBV/HDV has been reported in vivo to date. BLV is administered subcutaneously once daily at doses between 2 and 10 mg. BLV received conditional approval in Europe in 2020 to treat chronic hepatitis delta. The advent of peginterferon lambda or new specific anti-HDV antivirals (lonafarnib, etc.) will open the door for combination therapies with BLV. Since there is no stable reservoir for HDV-RNA within infected hepatocytes, viral clearance might be achieved using antivirals for a minimum timeframe. This is what happens in hepatitis C combining several antivirals, curing nearly all patients treated for 3 months. Clearance of HDV-RNA genomes may occur despite HBV persistence as cccDNA or chromosome integrated HBV-DNA within hepatocytes. This is supported by cases of HDV elimination using BLV despite persistence of serum HBsAg. Another path for HDV cure will derive from achieving HBsAg clearance, the goal of new promising anti-HBV gene therapies (bepirovirsen, etc.). In summary, the advent of BLV has triggered a renovated interest for antiviral therapy in hepatitis delta. We envision combination therapies that will lead to HDV cure in the near future.
Collapse
Affiliation(s)
- Vicente Soriano
- Health Sciences School & Medical Center, Universidad Internacional La Rioja (UNIR), Madrid, Spain,Correspondence: Vicente Soriano, UNIR Health Sciences School & Medical Center, Calle García Martín 21, Pozuelo de Alarcón 28224, Madrid, Spain, Tel +34 659687981, Email
| | - Victor Moreno-Torres
- Health Sciences School & Medical Center, Universidad Internacional La Rioja (UNIR), Madrid, Spain,Puerta de Hierro University Hospital & Research Institute, Madrid, Spain
| | - Ana Treviño
- Health Sciences School & Medical Center, Universidad Internacional La Rioja (UNIR), Madrid, Spain
| | - Octavio Corral
- Health Sciences School & Medical Center, Universidad Internacional La Rioja (UNIR), Madrid, Spain
| | - Carmen de Mendoza
- Puerta de Hierro University Hospital & Research Institute, Madrid, Spain
| |
Collapse
|
8
|
Hepatitis B and Hepatitis D Viruses: A Comprehensive Update with an Immunological Focus. Int J Mol Sci 2022; 23:ijms232415973. [PMID: 36555623 PMCID: PMC9781095 DOI: 10.3390/ijms232415973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Hepatitis B virus (HBV) and hepatitis delta virus (HDV) are highly prevalent viruses estimated to infect approximately 300 million people and 12-72 million people worldwide, respectively. HDV requires the HBV envelope to establish a successful infection. Concurrent infection with HBV and HDV can result in more severe disease outcomes than infection with HBV alone. These viruses can cause significant hepatic disease, including cirrhosis, fulminant hepatitis, and hepatocellular carcinoma, and represent a significant cause of global mortality. Therefore, a thorough understanding of these viruses and the immune response they generate is essential to enhance disease management. This review includes an overview of the HBV and HDV viruses, including life cycle, structure, natural course of infection, and histopathology. A discussion of the interplay between HDV RNA and HBV DNA during chronic infection is also included. It then discusses characteristics of the immune response with a focus on reactions to the antigenic hepatitis B surface antigen, including small, middle, and large surface antigens. This paper also reviews characteristics of the immune response to the hepatitis D antigen (including small and large antigens), the only protein expressed by hepatitis D. Lastly, we conclude with a discussion of recent therapeutic advances pertaining to these viruses.
Collapse
|
9
|
Mhlanga A, Zakh R, Churkin A, Reinharz V, Glenn JS, Etzion O, Cotler SJ, Yurdaydin C, Barash D, Dahari H. Modeling the Interplay between HDV and HBV in Chronic HDV/HBV Patients. MATHEMATICS (BASEL, SWITZERLAND) 2022; 10:3917. [PMID: 36540372 PMCID: PMC9762680 DOI: 10.3390/math10203917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Hepatitis D virus is an infectious subviral agent that can only propagate in people infected with hepatitis B virus. In this study, we modified and further developed a recent model for early hepatitis D virus and hepatitis B virus kinetics to better reproduce hepatitis D virus and hepatitis B virus kinetics measured in infected patients during anti-hepatitis D virus treatment. The analytical solutions were provided to highlight the new features of the modified model. The improved model offered significantly better prospects for modeling hepatitis D virus and hepatitis B virus interactions.
Collapse
Affiliation(s)
- Adequate Mhlanga
- The Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 84101, USA
| | - Rami Zakh
- Department of Computer Science, Ben-Gurion University, Beer-Sheva 84105, Israel
- Department of Software Engineering, Sami Shamoon College of Engineering, Beer-Sheva 84108, Israel
| | - Alexander Churkin
- Department of Software Engineering, Sami Shamoon College of Engineering, Beer-Sheva 84108, Israel
| | - Vladimir Reinharz
- Department of Computer Science, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
| | - Jeffrey S. Glenn
- Division of Gastroenterology and Hepatology, Departments of Medicine, Microbiology & Immunology, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Ohad Etzion
- Department of Gastroenterology and Liver Diseases, Soroka University Medical Center, Beer-Sheva 84101, Israel
| | - Scott J. Cotler
- The Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 84101, USA
| | - Cihan Yurdaydin
- Department of Gastroenterology and Hepatology, Koç University Medical School, Istanbul 34450, Turkey
| | - Danny Barash
- Department of Computer Science, Ben-Gurion University, Beer-Sheva 84105, Israel
| | - Harel Dahari
- The Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 84101, USA
| |
Collapse
|
10
|
Advances in Parameter Estimation and Learning from Data for Mathematical Models of Hepatitis C Viral Kinetics. MATHEMATICS 2022; 10. [DOI: 10.3390/math10122136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mathematical models, some of which incorporate both intracellular and extracellular hepatitis C viral kinetics, have been advanced in recent years for studying HCV–host dynamics, antivirals mode of action, and their efficacy. The standard ordinary differential equation (ODE) hepatitis C virus (HCV) kinetic model keeps track of uninfected cells, infected cells, and free virus. In multiscale models, a fourth partial differential equation (PDE) accounts for the intracellular viral RNA (vRNA) kinetics in an infected cell. The PDE multiscale model is substantially more difficult to solve compared to the standard ODE model, with governing differential equations that are stiff. In previous contributions, we developed and implemented stable and efficient numerical methods for the multiscale model for both the solution of the model equations and parameter estimation. In this contribution, we perform sensitivity analysis on model parameters to gain insight into important properties and to ensure our numerical methods can be safely used for HCV viral dynamic simulations. Furthermore, we generate in-silico patients using the multiscale models to perform machine learning from the data, which enables us to remove HCV measurements on certain days and still be able to estimate meaningful observations with a sufficiently small error.
Collapse
|
11
|
Targeting Subviral Particles: A Critical Step in Achieving HBV Functional Cure but Where Are We with Current Agents in Clinical Development? Viruses 2022; 14:v14061193. [PMID: 35746664 PMCID: PMC9227515 DOI: 10.3390/v14061193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 02/04/2023] Open
|
12
|
Shekhtman L, Cotler SJ, Ploss A, Dahari H. Mathematical modeling suggests that entry-inhibitor bulevirtide may interfere with hepatitis D virus clearance from circulation. J Hepatol 2022; 76:1229-1231. [PMID: 34995688 PMCID: PMC9018506 DOI: 10.1016/j.jhep.2021.12.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/08/2021] [Accepted: 12/28/2021] [Indexed: 12/15/2022]
Affiliation(s)
- Louis Shekhtman
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA; Network Science Institute, Northeastern University, Boston, MA, USA
| | - Scott J Cotler
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Harel Dahari
- The Program for Experimental & Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.
| |
Collapse
|
13
|
Wat C, Gane E, Yuen MF, Pavlovic V, Mueller H, Krippendorff BF, Grippo JF, Ottosen S. Reply. Hepatology 2022; 75:1050-1051. [PMID: 34396570 DOI: 10.1002/hep.32113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 07/31/2021] [Indexed: 12/08/2022]
Affiliation(s)
| | - Edward Gane
- Auckland Clinical StudiesAucklandNew Zealand
| | - Man-Fung Yuen
- Queen Mary Hospital, The University of Hong KongHong Kong
| | | | | | | | | | - Soren Ottosen
- Roche Innovation Center Copenhagen A/SHørsholmDenmark
| |
Collapse
|
14
|
Vaillant A. Letter to the Editor: Is the HBsAg response to RO7062931 an antisense effect? Hepatology 2022; 75:230-231. [PMID: 34387887 DOI: 10.1002/hep.32103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 06/25/2021] [Indexed: 12/08/2022]
|
15
|
Zakh R, Churkin A, Bietsch W, Lachiany M, Cotler SJ, Ploss A, Dahari H, Barash D. A Mathematical Model for early HBV and -HDV Kinetics during Anti-HDV Treatment. MATHEMATICS (BASEL, SWITZERLAND) 2021; 9:3323. [PMID: 35282153 PMCID: PMC8916717 DOI: 10.3390/math9243323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Hepatitis delta virus (HDV) is an infectious subviral agent that can only propagate in people infected with hepatitis B virus (HBV). HDV/HBV infection is considered to be the most severe form of chronic viral hepatitis. In this contribution, a mathematical model for the interplay between HDV and HBV under anti-HDV treatment is presented. Previous models were not designed to account for the observation that HBV rises when HDV declines with HDV-specific therapy. In the simple model presented here, HDV and HBV kinetics are coupled, giving rise to an improved viral kinetic model that simulates the early interplay of HDV and HBV during anti-HDV therapy.
Collapse
Affiliation(s)
- Rami Zakh
- Department of Computer Science, Ben-Gurion University, Beer-Sheva 8410501, Israel
| | - Alexander Churkin
- Department of Software Engineering, Sami Shamoon College of Engineering, Beer-Sheva 8410501, Israel
| | - William Bietsch
- Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | | | - Scott J. Cotler
- Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Harel Dahari
- Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Danny Barash
- Department of Computer Science, Ben-Gurion University, Beer-Sheva 8410501, Israel
| |
Collapse
|
16
|
Lok AS, Negro F, Asselah T, Farci P, Rizzetto M. Endpoints and New Options for Treatment of Chronic Hepatitis D. Hepatology 2021; 74:3479-3485. [PMID: 34331781 PMCID: PMC9293075 DOI: 10.1002/hep.32082] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/24/2021] [Accepted: 07/24/2021] [Indexed: 12/18/2022]
Affiliation(s)
- Anna S. Lok
- Division of Gastroenterology and HepatologyUniversity of MichiganAnn ArborMI
| | - Francesco Negro
- Division of Gastroenterology and HepatologyGeneva University HospitalsGenevaSwitzerland,Division of Clinical PathologyGeneva University HospitalsGenevaSwitzerland
| | - Tarik Asselah
- Department of HepatologyINSERM U1149Université de ParisCRIHôpital BeaujonAP‐HPClichyFrance
| | - Patrizia Farci
- Hepatic Pathogenesis SectionLaboratory of Infectious DiseasesNational Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMD
| | - Mario Rizzetto
- Department of Medical SciencesUniversity of TorinoTorinoItaly
| |
Collapse
|
17
|
Bazinet M, Anderson M, Pântea V, Placinta G, Moscalu I, Cebotarescu V, Cojuhari L, Jimbei P, Iarovoi L, Smesnoi V, Musteata T, Jucov A, Dittmer U, Gersch J, Holzmayer V, Kuhns M, Cloherty G, Vaillant A. Analysis of HBsAg Immunocomplexes and cccDNA Activity During and Persisting After NAP-Based Therapy. Hepatol Commun 2021; 5:1873-1887. [PMID: 34558823 PMCID: PMC8557319 DOI: 10.1002/hep4.1767] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 02/06/2023] Open
Abstract
Therapy with nucleic acid polymers (NAPs), tenofovir disoproxil fumarate (TDF), and pegylated interferon (pegIFN) achieve high rates of HBsAg loss/seroconversion and functional cure in chronic hepatitis B virus (HBV) infection. The role of hepatitis B surface antigen (HBsAg) seroconversion and inactivation of covalently closed circular DNA (cccDNA) in establishing functional cure were examined. Archived serum from the REP 401 study was analyzed using the Abbott ARCHITECT HBsAg NEXT assay (Chicago, IL), Abbott research use-only assays for HBsAg immune complexes (HBsAg ICs), circulating HBV RNA, and the Fujirebio assay for hepatitis B core-related antigen (HBcrAg; Malvern, PA). HBsAg became < 0.005 IU/mL in 23 participants during NAP exposure, which persisted in all participants with functional cure. HBsAg IC declined during lead-in TDF monotherapy and correlated with minor declines in HBsAg. Following the addition of NAPs and pegIFN, minor HBsAg IC increases (n = 13) or flares (n = 2) during therapy were not correlated with HBsAg decline, hepatitis B surface antibody (anti-HBs) titers, or alanine aminotransferase. HBsAg IC universally declined during follow-up in participants with virologic control or functional cure. Universal declines in HBV RNA and HBcrAg during TDF monotherapy continued with NAP + pegIFN regardless of therapeutic outcome. At the end of therapy, HBV RNA was undetectable in only 5 of 14 participants with functional cure but became undetectable after removal of therapy in all participants with functional cure. Undetectable HBV RNA at the end of therapy in 5 participants was followed by relapse to virologic control or viral rebound. Conclusion: Anti-HBs-independent mechanisms contribute to HBsAg clearance during NAP therapy. Inactivation of cccDNA does not predict functional cure following NAP-based therapy; however, functional cure is accompanied by persistent inactivation of cccDNA. Persistent HBsAg loss with functional cure may also reflect reduction/clearance of integrated HBV DNA. Clinicaltrials.org number NCT02565719.
Collapse
Affiliation(s)
| | | | - Victor Pântea
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova
| | - Gheorghe Placinta
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova
| | - Iurie Moscalu
- ARENSIA Exploratory MedicineRepublican Clinical HospitalChișinăuRepublic of Moldova
| | - Valentin Cebotarescu
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova
| | - Lilia Cojuhari
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova
| | - Pavlina Jimbei
- Toma Ciorbǎ Infectious Clinical HospitalChișinăuRepublic of Moldova
| | - Liviu Iarovoi
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova
| | | | - Tatina Musteata
- Toma Ciorbǎ Infectious Clinical HospitalChișinăuRepublic of Moldova
| | - Alina Jucov
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova.,ARENSIA Exploratory MedicineRepublican Clinical HospitalChișinăuRepublic of Moldova
| | - Ulf Dittmer
- Institute for VirologyUniversity of Duisburg-EssenEssenGermany
| | | | | | | | | | | |
Collapse
|
18
|
Zakh R, Churkin A, Totzeck F, Parr M, Tuller T, Etzion O, Dahari H, Roggendorf M, Frishman D, Barash D. A Mathematical Analysis of HDV Genotypes: From Molecules to Cells. MATHEMATICS (BASEL, SWITZERLAND) 2021; 9:2063. [PMID: 34540628 PMCID: PMC8445514 DOI: 10.3390/math9172063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hepatitis D virus (HDV) is classified according to eight genotypes. The various genotypes are included in the HDVdb database, where each HDV sequence is specified by its genotype. In this contribution, a mathematical analysis is performed on RNA sequences in HDVdb. The RNA folding predicted structures of the Genbank HDV genome sequences in HDVdb are classified according to their coarse-grain tree-graph representation. The analysis allows discarding in a simple and efficient way the vast majority of the sequences that exhibit a rod-like structure, which is important for the virus replication, to attempt to discover other biological functions by structure consideration. After the filtering, there remain only a small number of sequences that can be checked for their additional stem-loops besides the main one that is known to be responsible for virus replication. It is found that a few sequences contain an additional stem-loop that is responsible for RNA editing or other possible functions. These few sequences are grouped into two main classes, one that is well-known experimentally belonging to genotype 3 for patients from South America associated with RNA editing, and the other that is not known at present belonging to genotype 7 for patients from Cameroon. The possibility that another function besides virus replication reminiscent of the editing mechanism in HDV genotype 3 exists in HDV genotype 7 has not been explored before and is predicted by eigenvalue analysis. Finally, when comparing native and shuffled sequences, it is shown that HDV sequences belonging to all genotypes are accentuated in their mutational robustness and thermodynamic stability as compared to other viruses that were subjected to such an analysis.
Collapse
Affiliation(s)
- Rami Zakh
- Department of Computer Science, Ben-Gurion University, Beer-Sheva 8410501, Israel
| | - Alexander Churkin
- Department of Software Engineering, Sami Shamoon College of Engineering, Beer-Sheva 8410501, Israel
| | - Franziska Totzeck
- Department of Bioinformatics, Wissenschaftszentrum Weihenstephan, Technische Universität München, Maximus-von-Imhof-Forum 3, 85354 Freising, Germany
| | - Marina Parr
- Department of Bioinformatics, Wissenschaftszentrum Weihenstephan, Technische Universität München, Maximus-von-Imhof-Forum 3, 85354 Freising, Germany
| | - Tamir Tuller
- Department of Biomedical Engineering, Tel-Aviv University, Tel-Aviv 6997801, Israel
| | - Ohad Etzion
- Soroka University Medical Center, Ben-Gurion University, Beer-Sheva 8410501, Israel
| | - Harel Dahari
- Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Michael Roggendorf
- Institute of Virology, Technische Universität München, 81675 Munich, Germany
| | - Dmitrij Frishman
- Department of Bioinformatics, Wissenschaftszentrum Weihenstephan, Technische Universität München, Maximus-von-Imhof-Forum 3, 85354 Freising, Germany
| | - Danny Barash
- Department of Computer Science, Ben-Gurion University, Beer-Sheva 8410501, Israel
| |
Collapse
|
19
|
Palom A, Sopena S, Riveiro-Barciela M, Carvalho-Gomes A, Madejón A, Rodriguez-Tajes S, Roade L, García-Eliz M, García-Samaniego J, Lens S, Berenguer-Hayme M, Rodríguez-Frías F, Hernandez-Évole H, Isabel Gil-García A, Barreira A, Esteban R, Buti M. One-quarter of chronic hepatitis D patients reach HDV-RNA decline or undetectability during the natural course of the disease. Aliment Pharmacol Ther 2021; 54:462-469. [PMID: 34181772 DOI: 10.1111/apt.16485] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/15/2021] [Accepted: 06/02/2021] [Indexed: 02/05/2023]
Abstract
BACKGROUND Spontaneous HDV-RNA fluctuations, assessed by nonstandardised in-house assays, have been reported during the course of chronic hepatitis delta (CHD). AIMS To evaluate changes in serum HDV-RNA concentrations in untreated CHD patients and correlate these changes with other HBV markers. METHODS A total of 323 consecutive serum samples from 56 CHD patients (detectable HDV-RNA) followed for >3 years were retested for HDV-RNA levels by a sensitive technique using the first WHO international HDV-RNA standard. Quantitative HBsAg, HBV-DNA, and HBV-RNA were also determined. RESULTS Most participants were male, middle-aged, white European, and HBeAg-negative (82%). Almost half had liver cirrhosis and 64% were receiving nucleos(t)ide analogues. At inclusion, median-HDV-RNA was 5.3 (4.2-6.5) log10 IU/mL, HBsAg 4.0 (3.5-4.3) log10 IU/mL, and HBV-DNA 1.6 (1.0-2.6) log10 IU/mL; ALT values were normal in 13 (23%). During a mean follow-up of 5.6 (3-16) years, 14 (25%) showed ≥2log10 HDV-RNA decline, including 11 (20%) who spontaneously achieved undetectable HDV-RNA. Four patients (7%) lost HBsAg, with undetectable HDV-RNA. The remaining 42 (75%) had persistently detectable HDV-RNA. During follow-up, patients with a ≥2log10 HDV-RNA decline showed a greater HBsAg drop (-0.7 ± 1.1 vs -0.09 ± 0.9 log IU/mL; P = 0.039) than those with a <2 log10 HDV-RNA decline. Overall, ALT and HBV-DNA levels decreased over time. There were no differences in clinical outcomes between groups. CONCLUSIONS One-quarter of untreated CHD patients showed a ≥2log10 decline in HDV-RNA and 20% reached HDV-RNA undetectability during a mean follow-up of 5.6 years. The decline was associated with ALT decrease. These findings have implications for designing new therapies for CHD.
Collapse
Affiliation(s)
- Adriana Palom
- Liver Unit, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Sara Sopena
- Biochemistry and Microbiology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Mar Riveiro-Barciela
- Liver Unit, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Instituto de Salud Carlos III, Madrid, Spain
| | - Angela Carvalho-Gomes
- Instituto de Salud Carlos III, Madrid, Spain
- Liver Transplantation and Hepatology Unit, Hospital U. y P. La Fe, Universitat de València, Valencia, Spain
| | - Antonio Madejón
- Instituto de Salud Carlos III, Madrid, Spain
- Liver Unit, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| | - Sergio Rodriguez-Tajes
- Instituto de Salud Carlos III, Madrid, Spain
- Liver Unit, Hospital Clinic Barcelona, IDIBAPS, Universitat de Barcelona, Barcelona, Spain
| | - Luisa Roade
- Liver Unit, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Instituto de Salud Carlos III, Madrid, Spain
| | - María García-Eliz
- Liver Transplantation and Hepatology Unit, Hospital U. y P. La Fe, Universitat de València, Valencia, Spain
| | - Javier García-Samaniego
- Instituto de Salud Carlos III, Madrid, Spain
- Liver Unit, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| | - Sabela Lens
- Instituto de Salud Carlos III, Madrid, Spain
- Liver Unit, Hospital Clinic Barcelona, IDIBAPS, Universitat de Barcelona, Barcelona, Spain
| | - Marina Berenguer-Hayme
- Instituto de Salud Carlos III, Madrid, Spain
- Liver Transplantation and Hepatology Unit, Hospital U. y P. La Fe, Universitat de València, Valencia, Spain
| | - Francisco Rodríguez-Frías
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Biochemistry and Microbiology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Instituto de Salud Carlos III, Madrid, Spain
| | - Helena Hernandez-Évole
- Liver Transplantation and Hepatology Unit, Hospital U. y P. La Fe, Universitat de València, Valencia, Spain
| | - Ana Isabel Gil-García
- Instituto de Salud Carlos III, Madrid, Spain
- Liver Unit, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| | - Ana Barreira
- Liver Unit, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Instituto de Salud Carlos III, Madrid, Spain
| | - Rafael Esteban
- Liver Unit, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Instituto de Salud Carlos III, Madrid, Spain
| | - Maria Buti
- Liver Unit, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
20
|
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
|
21
|
A putative amphipathic alpha helix in hepatitis B virus small envelope protein plays a critical role in the morphogenesis of subviral particles. J Virol 2021; 95:JVI.02399-20. [PMID: 33536177 PMCID: PMC8103704 DOI: 10.1128/jvi.02399-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hepatitis B virus (HBV) small (S) envelope protein has the intrinsic ability to direct the formation of small spherical subviral particles (SVPs) in eukaryotic cells. However, the molecular mechanism underlying the morphogenesis of SVPs from the monomeric S protein initially synthesized at the endoplasmic reticulum (ER) membrane remains largely elusive. Structure prediction and extensive mutagenesis analysis suggested that the amino acid residues spanning W156 to R169 of S protein form an amphipathic alpha helix and play essential roles in SVP production and S protein metabolic stability. Further biochemical analyses showed that the putative amphipathic alpha helix was not required for the disulfide-linked S protein oligomerization, but was essential for SVP morphogenesis. Pharmacological disruption of vesicle trafficking between the ER and Golgi complex in SVP producing cells supported the hypothesis that S protein-directed SVP morphogenesis takes place at the ER-Golgi intermediate compartment (ERGIC). Moreover, it was demonstrated that S protein is degraded in hepatocytes via a 20S proteasome-dependent, but ubiquitination-independent non-classic ER-associated degradation (ERAD) pathway. Taken together, the results reported herein favor a model in which the amphipathic alpha helix at the antigenic loop of S protein attaches to the lumen leaflet to facilitate SVP budding from the ERGIC compartment, whereas the failure of budding process may result in S protein degradation by 20S proteasome in an ubiquitination-independent manner.Importance Subviral particles are the predominant viral product produced by HBV-infected hepatocytes. Their levels exceed the virion particles by 10,000 to 100,000-fold in the blood of HBV infected individuals. The high levels of SVPs, or HBV surface antigen (HBsAg), in the circulation induces immune tolerance and contributes to the establishment of persistent HBV infection. The loss of HBsAg, often accompanied by appearance of anti-HBs antibodies, is the hallmark of durable immune control of HBV infection. Therapeutic induction of HBsAg loss is, therefore, considered to be essential for the restoration of host antiviral immune response and functional cure of chronic hepatitis B. Our findings on the mechanism of SVP morphogenesis and S protein metabolism will facilitate the rational discovery and development of antiviral drugs to achieve this therapeutic goal.
Collapse
|
22
|
Sagnelli C, Sagnelli E, Russo A, Pisaturo M, Occhiello L, Coppola N. HBV/HDV Co-Infection: Epidemiological and Clinical Changes, Recent Knowledge and Future Challenges. Life (Basel) 2021; 11:life11020169. [PMID: 33671730 PMCID: PMC7926847 DOI: 10.3390/life11020169] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Several investigations have been published on Hepatitis Delta Virus (HDV) infection in recent years, from which we have drawn the salient data to provide readers with useful information to improve their knowledge on the subject. HDV genotypes 5–8 have been recently imported to Western countries from central Africa, whose clinical relevance deserves further investigation. Ongoing HDV replication has been identified as an independent predictor of progression to cirrhosis and HCC for patients with HDV chronic hepatitis (HDV-CH). Long-term treatments of HDV-CH with standard or pegylated interferon alfa (peg-IFN-α) have all been unsatisfactory, leading to a sustained virological response (SVR) only in 20–30% of patients treated, faced with a poor tolerability and frequent serious adverse reactions; the addition of HBV nucleo(s)tide analogues to peg-IFN- α did not improve the rate of SVR. The improved knowledge of the HDV life cycle has allowed the development of direct acting agents towards key-points of the HDV life cycle, namely bulevirtide, lonafarnib and nucleic acid polymers. Preliminary data have shown that these drugs are more effective than interferon-based therapies, but adverse reactions are also common, which however seem toned down in combination therapy with other antivirals.
Collapse
|
23
|
Kadelka S, Dahari H, Ciupe SM. Understanding the antiviral effects of RNAi-based therapy in HBeAg-positive chronic hepatitis B infection. Sci Rep 2021; 11:200. [PMID: 33420293 PMCID: PMC7794570 DOI: 10.1038/s41598-020-80594-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 12/21/2020] [Indexed: 01/29/2023] Open
Abstract
The RNA interference (RNAi) drug ARC-520 was shown to be effective in reducing serum hepatitis B virus (HBV) DNA, hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) in HBeAg-positive patients treated with a single dose of ARC-520 and daily nucleosidic analogue (entecavir). To provide insights into HBV dynamics under ARC-520 treatment and its efficacy in blocking HBV DNA, HBsAg, and HBeAg production we developed a multi-compartmental pharmacokinetic-pharamacodynamic model and calibrated it with frequent measured HBV kinetic data. We showed that the time-dependent single dose ARC-520 efficacies in blocking HBsAg and HBeAg are more than 96% effective around day 1, and slowly wane to 50% in 1-4 months. The combined single dose ARC-520 and entecavir effect on HBV DNA was constant over time, with efficacy of more than 99.8%. The observed continuous HBV DNA decline is entecavir mediated, the strong but transient HBsAg and HBeAg decays are ARC-520 mediated. The modeling framework may help assess ongoing RNAi drug development for hepatitis B virus infection.
Collapse
Affiliation(s)
- Sarah Kadelka
- Department of Mathematics, Virginia Tech, Blacksburg, VA, 24060, USA
| | - Harel Dahari
- Program for Experimental and Theoretical Modeling, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Stanca M Ciupe
- Department of Mathematics, Virginia Tech, Blacksburg, VA, 24060, USA.
| |
Collapse
|
24
|
Churkin A, Lewkiewicz S, Reinharz V, Dahari H, Barash D. Efficient Methods for Parameter Estimation of Ordinary and Partial Differential Equation Models of Viral Hepatitis Kinetics. MATHEMATICS 2020; 8. [PMID: 33224865 PMCID: PMC7676746 DOI: 10.3390/math8091483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Parameter estimation in mathematical models that are based on differential equations is known to be of fundamental importance. For sophisticated models such as age-structured models that simulate biological agents, parameter estimation that addresses all cases of data points available presents a formidable challenge and efficiency considerations need to be employed in order for the method to become practical. In the case of age-structured models of viral hepatitis dynamics under antiviral treatment that deal with partial differential equations, a fully numerical parameter estimation method was developed that does not require an analytical approximation of the solution to the multiscale model equations, avoiding the necessity to derive the long-term approximation for each model. However, the method is considerably slow because of precision problems in estimating derivatives with respect to the parameters near their boundary values, making it almost impractical for general use. In order to overcome this limitation, two steps have been taken that significantly reduce the running time by orders of magnitude and thereby lead to a practical method. First, constrained optimization is used, letting the user add constraints relating to the boundary values of each parameter before the method is executed. Second, optimization is performed by derivative-free methods, eliminating the need to evaluate expensive numerical derivative approximations. The newly efficient methods that were developed as a result of the above approach are described for hepatitis C virus kinetic models during antiviral therapy. Illustrations are provided using a user-friendly simulator that incorporates the efficient methods for both the ordinary and partial differential equation models.
Collapse
Affiliation(s)
- Alexander Churkin
- Department of Software Engineering, Sami Shamoon College of Engineering, Beer-Sheva 8410501, Israel
- Correspondence: (A.C.); (D.B.); Tel.: +972-8-647-5281 (A.C.); +972-8-647-2714 (D.B.)
| | - Stephanie Lewkiewicz
- Department of Mathematics, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Vladimir Reinharz
- Department of Computer Science, Université du Québec à Montréal, Montreal, QC H3C 3P8, Canada
| | - Harel Dahari
- Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Stritch School of Medicine, Loyola University Medical Center, Maywoood, IL 60153, USA
| | - Danny Barash
- Department of Computer Science, Ben-Gurion University, Beer-Sheva 8410501, Israel
- Correspondence: (A.C.); (D.B.); Tel.: +972-8-647-5281 (A.C.); +972-8-647-2714 (D.B.)
| |
Collapse
|