1
|
Abstract
Bovine viral diarrhea virus (BVDV) belongs to the family Flaviviridae genus pestivirus. The viral genome is a single-stranded, positive-sense RNA that encodes four structural proteins (i.e., C, Erns, E1, and E2) and eight non-structural proteins (NSPs) (i.e., Npro, p7, NS2, NS3, NS4A, NS4B, NS5A, and NS5B). Cattle infected with BVDV exhibit a number of different clinical signs including diarrhea, abortion, and other reproductive disorders which have a serious impact on the cattle industry worldwide. Research on BVDV mainly focuses on its structural protein, however, progress in understanding the functions of the NSPs of BVDV has also been made in recent decades. The knowledge gained on the BVDV non-structural proteins is helpful to more fully understand the viral replication process and the molecular mechanism of viral persistent infection. This review focuses on the functions of BVDV NSPs and provides references for the identification of BVDV, the diagnosis and prevention of Bovine viral diarrhea mucosal disease (BVD-MD), and the development of vaccines.
Collapse
|
2
|
Deciphering the Role of Bovine Viral Diarrhea Virus Non-Structural NS4B Protein in Viral Pathogenesis. Vet Sci 2020; 7:vetsci7040169. [PMID: 33142856 PMCID: PMC7712251 DOI: 10.3390/vetsci7040169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/16/2020] [Accepted: 10/28/2020] [Indexed: 12/22/2022] Open
Abstract
Bovine viral diarrhea virus (BVDV) is a (+) ssRNA virus that belongs to the family Flaviviridae. BVDV is a significant animal pathogen causing substantial economic losses to the cattle industry worldwide through respiratory and gastrointestinal infections and abortion or birth of persistently infected calves. While the immunogenic profile of some of the BVDV proteins (i.e., Erns, E2 and NS3) is well established during viral pathogenesis, very little information is available about most of BVDV's non-structural proteins in this regard. In recent times, the NS4B protein has emerged as an interesting target of diagnostic, vaccination and therapeutic value in viral infections of other members of the family Flaviviridae due to its key scaffold-like contribution in the viral replication complex. Although, BVDV-NS4B has a membrane topology alongside its role in induction of autophagosomes in vitro. However, information on its immunogenicity during BVDV pathogenesis and vaccination is scarce. To characterize the immunogenic profile of the NS4B, five cows were vaccinated with the live attenuated BVDV vaccine Bovela® and blood samples were taken pre- and post-immunization for serum isolation. Virus neutralization assay (VNA) confirmed the presence of anti-BVDV antibodies in the sera of vaccinated cows. VNA also revealed pre-existing antibodies against BVDV in the pre-immunization sera of two cows. To identify BVDV-NS4B specific antibodies, the NS4B protein was expressed in mammalian cells by using the pCI-neo vector system. The sera from BVDV vaccinated cows were evaluated for the presence of BVDV-NS4B specific antibodies through western blot and indirect ELISA. Interestingly, t sera from cows with pre-existing immunity against BVDV were able to detect NS4B in western blot and ELISA, suggesting the presence of NS4B-specific antibodies. The obtained results provide the first indication of the immunogenic nature of BVDV-NS4B protein in sero-converted animals. These findings are consistent with the observation made for NS4B in other Flaviviridae members and confirm this protein as an interesting target with diagnostic, vaccination and therapeutic value.
Collapse
|
3
|
Preclinical evaluation of Amphihevir, a first-in-class clinical Hepatitis C virus NS4B inhibitor. Antimicrob Agents Chemother 2019:AAC.01237-19. [PMID: 31527036 DOI: 10.1128/aac.01237-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Amphihevir, a benzofuran derivative, is the first reported NS4B inhibitor that has advanced to clinical trials (currently in Phase Ib). Here, we report the results of a preclinical study of its potency, toxicity, selectivity, DMPK, and safety profiles. Amphihevir displayed good antiviral activities against genotype 1a (EC50=0.34 nM) and genotype 1b (EC50=1.97 nM) replicons and evident cytotoxicity in twelve strains of cell lines derived from animals and humans. Amphihevir was found to be inactive against other viruses, human kinases, and GPCRs, which implies its good selectivity. A 9-day long-term treatment of genotype 1b replicon with Amphihevir resulted in a 3.8 Log10 decline of the hepatitis C viral RNA at a concentration of 25×EC90 Drug resistance screening showed that mutations occurred at H94, F98, and V105 of NS4B, which mediated the resistance to Amphihevir. This result suggests that NS4B is the main target of Amphihevir. There was no cross-resistances between Amphihevir and NS5A, NS3/4A, and NS5B inhibitors, suggesting that Amphihevir on combination of other anti- hepatitis C virus drugs could treat hepatitis C, as proven by studies of Amphihevir and other hepatitis C virus inhibitors. Pharmacokinetic studies demonstrated that Amphihevir has good oral bioavailability and appropriate T1/2 in rats and dogs, thereby supporting its use once per day. Finally, Amphihevir showed good safety profiles in rats and dogs. The results shed light on the use of Amphihevir as a potential treatment option for chronic hepatitis C patients.
Collapse
|
4
|
Ashraf MU, Iman K, Khalid MF, Salman HM, Shafi T, Rafi M, Javaid N, Hussain R, Ahmad F, Shahzad-Ul-Hussan S, Mirza S, Shafiq M, Afzal S, Hamera S, Anwar S, Qazi R, Idrees M, Qureshi SA, Chaudhary SU. Evolution of efficacious pangenotypic hepatitis C virus therapies. Med Res Rev 2018; 39:1091-1136. [PMID: 30506705 DOI: 10.1002/med.21554] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 12/12/2022]
Abstract
Hepatitis C compromises the quality of life of more than 350 million individuals worldwide. Over the last decade, therapeutic regimens for treating hepatitis C virus (HCV) infections have undergone rapid advancements. Initially, structure-based drug design was used to develop molecules that inhibit viral enzymes. Subsequently, establishment of cell-based replicon systems enabled investigations into various stages of HCV life cycle including its entry, replication, translation, and assembly, as well as role of host proteins. Collectively, these approaches have facilitated identification of important molecules that are deemed essential for HCV life cycle. The expanded set of putative virus and host-encoded targets has brought us one step closer to developing robust strategies for efficacious, pangenotypic, and well-tolerated medicines against HCV. Herein, we provide an overview of the development of various classes of virus and host-directed therapies that are currently in use along with others that are undergoing clinical evaluation.
Collapse
Affiliation(s)
- Muhammad Usman Ashraf
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Kanzal Iman
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Muhammad Farhan Khalid
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Department of Biomedical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Hafiz Muhammad Salman
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Plant Biotechnology Laboratory, Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan
| | - Talha Shafi
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Momal Rafi
- Department of Statistics, University of Gujrat, Gujrat, Pakistan
| | - Nida Javaid
- Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Rashid Hussain
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Fayyaz Ahmad
- Department of Statistics, University of Gujrat, Gujrat, Pakistan
| | | | - Shaper Mirza
- Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Muhammad Shafiq
- Plant Biotechnology Laboratory, Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan
| | - Samia Afzal
- Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sadia Hamera
- Department of Plant Genetics, Institute of Life Sciences, University of Rostock, Germany
| | - Saima Anwar
- Department of Biomedical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Romena Qazi
- Department of Pathology, Shaukat Khanum Memorial Cancer Hospital & Research Centre, Lahore, Pakistan
| | - Muhammad Idrees
- Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.,Hazara University, Mansehra, Pakistan
| | - Sohail A Qureshi
- Institute of Integrative Biosciences, CECOS-University of Information Technology and Emerging Sciences, Peshawar, Pakistan
| | - Safee Ullah Chaudhary
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| |
Collapse
|
5
|
PTC725, an NS4B-Targeting Compound, Inhibits a Hepatitis C Virus Genotype 3 Replicon, as Predicted by Genome Sequence Analysis and Determined Experimentally. Antimicrob Agents Chemother 2016; 60:7060-7066. [PMID: 27620477 PMCID: PMC5118984 DOI: 10.1128/aac.01272-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/01/2016] [Indexed: 01/03/2023] Open
Abstract
PTC725 is a small molecule NS4B-targeting inhibitor of hepatitis C virus (HCV) genotype (gt) 1 RNA replication that lacks activity against HCV gt2. We analyzed the Los Alamos HCV sequence database to predict susceptible/resistant HCV gt's according to the prevalence of known resistance-conferring amino acids in the NS4B protein. Our analysis predicted that HCV gt3 would be highly susceptible to the activity of PTC725. Indeed, PTC725 was shown to be active against a gt3 subgenomic replicon with a 50% effective concentration of ∼5 nM. De novo resistance selection identified mutations encoding amino acid substitutions mapping to the first predicted transmembrane region of NS4B, a finding consistent with results for PTC725 and other NS4B-targeting compounds against HCV gt1. This is the first report of the activity of an NS4B targeting compound against HCV gt3. In addition, we have identified previously unreported amino acid substitutions selected by PTC725 treatment which further demonstrate that these compounds target the NS4B first transmembrane region.
Collapse
|
6
|
Mouse Systems to Model Hepatitis C Virus Treatment and Associated Resistance. Viruses 2016; 8:v8060176. [PMID: 27338446 PMCID: PMC4926196 DOI: 10.3390/v8060176] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 05/12/2016] [Accepted: 06/16/2016] [Indexed: 12/15/2022] Open
Abstract
While addition of the first-approved protease inhibitors (PIs), telaprevir and boceprevir, to pegylated interferon (PEG-IFN) and ribavirin (RBV) combination therapy significantly increased sustained virologic response (SVR) rates, PI-based triple therapy for the treatment of chronic hepatitis C virus (HCV) infection was prone to the emergence of resistant viral variants. Meanwhile, multiple direct acting antiviral agents (DAAs) targeting either the HCV NS3/4A protease, NS5A or NS5B polymerase have been approved and these have varying potencies and distinct propensities to provoke resistance. The pre-clinical in vivo assessment of drug efficacy and resistant variant emergence underwent a great evolution over the last decade. This field had long been hampered by the lack of suitable small animal models that robustly support the entire HCV life cycle. In particular, chimeric mice with humanized livers (humanized mice) and chimpanzees have been instrumental for studying HCV inhibitors and the evolution of drug resistance. In this review, we present the different in vivo HCV infection models and discuss their applicability to assess HCV therapy response and emergence of resistant variants.
Collapse
|
7
|
Zhang N, Turpoff A, Zhang X, Huang S, Liu Y, Almstead N, Njoroge FG, Gu Z, Graci J, Jung SP, Pichardo J, Colacino J, Lahser F, Ingravallo P, Weetall M, Nomeir A, Karp GM. Discovery of 2-(4-sulfonamidophenyl)-indole 3-carboxamides as potent and selective inhibitors with broad hepatitis C virus genotype activity targeting HCV NS4B. Bioorg Med Chem Lett 2015; 26:594-601. [PMID: 26652483 DOI: 10.1016/j.bmcl.2015.11.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Revised: 11/13/2015] [Accepted: 11/19/2015] [Indexed: 01/24/2023]
Abstract
A novel series of 2-(4-sulfonamidophenyl)-indole 3-carboxamides was identified and optimized for activity against the HCV genotype 1b replicon resulting in compounds with potent and selective activity. Further evaluation of this series demonstrated potent activity across HCV genotypes 1a, 2a and 3a. Compound 4z had reduced activity against HCV genotype 1b replicons containing single mutations in the NS4B coding sequence (F98C and V105M) indicating that NS4B is the target. This novel series of 2-(4-sulfonamidophenyl)-indole 3-carboxamides serves as a promising starting point for a pan-genotype HCV discovery program.
Collapse
Affiliation(s)
- Nanjing Zhang
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Anthony Turpoff
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Xiaoyan Zhang
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Song Huang
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Yalei Liu
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Neil Almstead
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - F George Njoroge
- Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Zhengxian Gu
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Jason Graci
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Stephen P Jung
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - John Pichardo
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Joseph Colacino
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Fred Lahser
- Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Paul Ingravallo
- Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Marla Weetall
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Amin Nomeir
- Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Gary M Karp
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| |
Collapse
|