1
|
Mavri M, Kubale V, Depledge DP, Zuo J, Huang CA, Breuer J, Vrecl M, Jarvis MA, Jovičić EJ, Petan T, Ehlers B, Rosenkilde MM, Spiess K. Epstein-Barr Virus-Encoded BILF1 Orthologues From Porcine Lymphotropic Herpesviruses Display Common Molecular Functionality. Front Endocrinol (Lausanne) 2022; 13:862940. [PMID: 35721730 PMCID: PMC9204316 DOI: 10.3389/fendo.2022.862940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
Infection of immunosuppressed transplant patients with the human γ-herpesvirus Epstein-Barr virus (EBV) is associated with post-transplant lymphoproliferative disease (PTLD), an often fatal complication. Immunosuppressed miniature pigs infected with γ-herpesvirus porcine lymphotropic herpesvirus 1 (PLHV1) develop a similar disease, identifying pigs as a potential preclinical model for PTLD in humans. BILF1 is a G protein-coupled receptor (GPCR) encoded by EBV with constitutive activity linked to tumorigenesis and immunoevasive function downregulating MHC-I. In the present study, we compared BILF1-orthologues encoded by the three known PLHVs (PLHV1-3) with EBV-BILF1 to determine pharmacological suitability of BILF1 orthologues as model system to study EBV-BILF1 druggability. Cell surface localization, constitutive internalization, and MHC-I downregulation as well as membrane proximal constitutive Gαi signaling patterns were conserved across all BILFs. Only subtle differences between the individual BILFs were observed in downstream transcription factor activation. Using Illumina sequencing, PLHV1 was observed in lymphatic tissue from PTLD-diseased, but not non-diseased pigs. Importantly, these tissues showed enhanced expression of PLHV1-BILF1 supporting its involvement in PTLD infection.
Collapse
Affiliation(s)
- Maša Mavri
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Valentina Kubale
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Daniel P. Depledge
- Department of Medicine, New York University School of Medicine, New York, NY, United States
| | - Jianmin Zuo
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Christene A. Huang
- Department of Surgery, Division of Plastic & Reconstructive Surgery, Division of Transplant Surgery, Anschutz Medical Campus, University of Colorado, Denver, CO, United States
| | - Judith Breuer
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Milka Vrecl
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Michael A. Jarvis
- The Vaccine Group Ltd, Plymouth; and the University of Plymouth, Plymouth, United Kingdom
| | - Eva Jarc Jovičić
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Bernhard Ehlers
- Division 12, Measles, Mumps, Rubella, and Viruses Affecting Immunocompromised Patients, Robert Koch Institute, Berlin, Germany
| | - Mette M. Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Katja Spiess, ; ; Mette M. Rosenkilde,
| | - Katja Spiess
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Katja Spiess, ; ; Mette M. Rosenkilde,
| |
Collapse
|
2
|
Trompet E, Temblador A, Gillemot S, Topalis D, Snoeck R, Andrei G. An MHV-68 Mutator Phenotype Mutant Virus, Confirmed by CRISPR/Cas9-Mediated Gene Editing of the Viral DNA Polymerase Gene, Shows Reduced Viral Fitness. Viruses 2021; 13:v13060985. [PMID: 34073189 PMCID: PMC8227558 DOI: 10.3390/v13060985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/11/2021] [Accepted: 05/24/2021] [Indexed: 12/04/2022] Open
Abstract
Drug resistance studies on human γ-herpesviruses are hampered by the absence of an in vitro system that allows efficient lytic viral replication. Therefore, we employed murine γ-herpesvirus-68 (MHV-68) that efficiently replicates in vitro as a model to study the antiviral resistance of γ-herpesviruses. In this study, we investigated the mechanism of resistance to nucleoside (ganciclovir (GCV)), nucleotide (cidofovir (CDV), HPMP-5azaC, HPMPO-DAPy) and pyrophosphate (foscarnet (PFA)) analogues and the impact of these drug resistance mutations on viral fitness. Viral fitness was determined by dual infection competition assays, where MHV-68 drug-resistant viral clones competed with the wild-type virus in the absence and presence of antivirals. Using next-generation sequencing, the composition of the viral populations was determined at the time of infection and after 5 days of growth. Antiviral drug resistance selection resulted in clones harboring mutations in the viral DNA polymerase (DP), denoted Y383SGCV, Q827RHPMP-5azaC, G302WPFA, K442TPFA, G302W+K442TPFA, C297WHPMPO-DAPy and C981YCDV. Without antiviral pressure, viral clones Q827RHPMP-5azaC, G302WPFA, K442TPFA and G302W+K442TPFA grew equal to the wild-type virus. However, in the presence of antivirals, these mutants had a growth advantage over the wild-type virus that was moderately to very strongly correlated with antiviral resistance. The Y383SGCV mutant was more fit than the wild-type virus with and without antivirals, except in the presence of brivudin. The C297W and C981Y changes were associated with a mutator phenotype and had a severely impaired viral fitness in the absence and presence of antivirals. The mutator phenotype caused by C297W in MHV-68 DP was validated by using a CRISPR/Cas9 genome editing approach.
Collapse
|
3
|
Trompet E, Topalis D, Gillemot S, Snoeck R, Andrei G. Viral fitness of MHV-68 viruses harboring drug resistance mutations in the protein kinase or thymidine kinase. Antiviral Res 2020; 182:104901. [PMID: 32763314 DOI: 10.1016/j.antiviral.2020.104901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 12/21/2022]
Abstract
Murine γ-herpesvirus-68 (MHV-68), genetically and biologically related to human γ-herpesviruses Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, can be easily propagated in vitro allowing drug resistance studies. Previously, we described specific changes in MHV-68 protein kinase (PK) or thymidine kinase (TK) associated with resistance to various purine or pyrimidine nucleoside analogues, respectively. To investigate how specific TK and PK mutations affect viral replication capacity, we performed dual infection competition assays in which wild-type and drug-resistant virus compete in absence or presence of antivirals in Vero cells. The composition of the mixed viral population was analyzed using next-generation sequencing and relative fitness of seven MHV-68 PK or TK mutants was calculated based on the frequency of viral variants at the time of infection and after 5-days growth. A MHV-68 mutant losing the PK function due to a 2-nucleotide deletion was less fit than the wild-type virus in absence of antivirals, consistent with the essential role of viral PKs during lytic replication, but overgrew the wild-type virus under pressure of purine nucleosides. TK mutant viruses, with frameshift or missense mutations, grew equal to wild-type virus in absence of antivirals, in accordance with the viral TK function only being essential in non-replicating or in TK-deficient cells, but were more fit when treated with pyrimidine nucleosides. Moreover, TK missense mutant viruses also increased fitness under pressure of antivirals other than pyrimidine nucleosides, indicating that MHV-68 TK mutations might influence viral fitness by acting on cellular and/or viral functions that are unrelated to nucleoside activation.
Collapse
Affiliation(s)
- Erika Trompet
- Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | - Sarah Gillemot
- Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Robert Snoeck
- Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Graciela Andrei
- Rega Institute for Medical Research, KU Leuven, Leuven, Belgium.
| |
Collapse
|
4
|
Zeippen C, Javaux J, Snoeck R, Neyts J, Gillet L. Antiviral effect of the nucleoside analogue cidofovir in the context of sexual transmission of a gammaherpesvirus in mice. J Antimicrob Chemother 2019; 73:2095-2103. [PMID: 29788354 DOI: 10.1093/jac/dky161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/07/2018] [Indexed: 12/31/2022] Open
Abstract
Objectives To investigate the efficacy of cidofovir to block gammaherpesvirus replication in the context of sexual transmission. Methods A luciferase-expressing strain of murid herpesvirus 4 (MuHV-4) was used to monitor genital virus excretion from infected female BALB/c mice and sexual transmission to naive males. The efficiency of cidofovir to block genital excretion from infected females or replication and host colonization of naive males after sexual contact was tested by treating infected females (either once daily or at a single timepoint), naive males before exposure (either once daily or at a single timepoint) or males 24 h post-exposure. Results We showed that daily treatment of infected females can reduce MuHV-4 genital shedding by 75%. Similarly, daily preventive treatment of naive males was sufficient to block viral replication and latency establishment in males. In contrast, a single administration of cidofovir to infected females at day 14 post-infection or to naive males 2 to 6 days before contact with MuHV-4-excreting females was not sufficient to significantly reduce viral shedding from females or infection of males, respectively. Interestingly, a single administration of cidofovir to males 24 h after contact with MuHV-4-infected females excreting the virus in the genital tract significantly reduced virus replication in males and seroconversion. Conclusions Altogether, our results show that cidofovir can significantly reduce gammaherpesvirus replication, excretion and colonization of the naive partner in the context of sexual transmission. Such treatments could therefore be recommended in some specific conditions where gammaherpesvirus infections could be deleterious.
Collapse
Affiliation(s)
| | - Justine Javaux
- Immunology-Vaccinology, FARAH, University of Liège, Belgium
| | - Robert Snoeck
- Laboratory of Virology and Chemotherapy (Rega Institute), Department of Microbiology and Immunology, University of Leuven, Belgium
| | - Johan Neyts
- Laboratory of Virology and Chemotherapy (Rega Institute), Department of Microbiology and Immunology, University of Leuven, Belgium
| | - Laurent Gillet
- Immunology-Vaccinology, FARAH, University of Liège, Belgium
| |
Collapse
|
5
|
Heidel KM, Dowd CS. Phosphonate prodrugs: an overview and recent advances. Future Med Chem 2019; 11:1625-1643. [PMID: 31469328 PMCID: PMC6722485 DOI: 10.4155/fmc-2018-0591] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/29/2019] [Indexed: 01/04/2023] Open
Abstract
Phosphonates, often used as isosteric replacements for phosphates, can provide important interactions with an enzyme. Due to their high charge at physiological pH, however, permeation into cells can be a challenge. Protecting phosphonates as prodrugs has shown promise in drug delivery. Thus, a variety of structures and cleavage/activation mechanisms exist, enabling release of the active compound. This review describes the structural diversity of these pro-moieties, relevant cleavage mechanisms and recent advances in the design of phosphonate prodrugs.
Collapse
Affiliation(s)
- Kenneth M Heidel
- Department of Chemistry, George Washington University, Washington, DC 20052, USA
| | - Cynthia S Dowd
- Department of Chemistry, George Washington University, Washington, DC 20052, USA
| |
Collapse
|
6
|
Novel Therapeutics for Epstein⁻Barr Virus. Molecules 2019; 24:molecules24050997. [PMID: 30871092 PMCID: PMC6429425 DOI: 10.3390/molecules24050997] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 12/11/2022] Open
Abstract
Epstein–Barr virus (EBV) is a human γ-herpesvirus that infects up to 95% of the adult population. Primary EBV infection usually occurs during childhood and is generally asymptomatic, though the virus can cause infectious mononucleosis in 35–50% of the cases when infection occurs later in life. EBV infects mainly B-cells and epithelial cells, establishing latency in resting memory B-cells and possibly also in epithelial cells. EBV is recognized as an oncogenic virus but in immunocompetent hosts, EBV reactivation is controlled by the immune response preventing transformation in vivo. Under immunosuppression, regardless of the cause, the immune system can lose control of EBV replication, which may result in the appearance of neoplasms. The primary malignancies related to EBV are B-cell lymphomas and nasopharyngeal carcinoma, which reflects the primary cell targets of viral infection in vivo. Although a number of antivirals were proven to inhibit EBV replication in vitro, they had limited success in the clinic and to date no antiviral drug has been approved for the treatment of EBV infections. We review here the antiviral drugs that have been evaluated in the clinic to treat EBV infections and discuss novel molecules with anti-EBV activity under investigation as well as new strategies to treat EBV-related diseases.
Collapse
|
7
|
Gregson A, Thompson K, Tsirka SE, Selwood DL. Emerging small-molecule treatments for multiple sclerosis: focus on B cells. F1000Res 2019; 8:F1000 Faculty Rev-245. [PMID: 30863536 PMCID: PMC6402079 DOI: 10.12688/f1000research.16495.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/20/2019] [Indexed: 12/27/2022] Open
Abstract
Multiple sclerosis (MS) is a major cause of disability in young adults. Following an unknown trigger (or triggers), the immune system attacks the myelin sheath surrounding axons, leading to progressive nerve cell death. Antibodies and small-molecule drugs directed against B cells have demonstrated good efficacy in slowing progression of the disease. This review focusses on small-molecule drugs that can affect B-cell biology and may have utility in disease management. The risk genes for MS are examined from the drug target perspective. Existing small-molecule therapies for MS with B-cell actions together with new drugs in development are described. The potential for experimental molecules with B-cell effects is also considered. Small molecules can have diverse actions on B cells and be cytotoxic, anti-inflammatory and anti-viral. The current B cell-directed therapies often kill B-cell subsets, which can be effective but lead to side effects and toxicity. A deeper understanding of B-cell biology and the effect on MS disease should lead to new drugs with better selectivity, efficacy, and an improved safety profile. Small-molecule drugs, once the patent term has expired, provide a uniquely sustainable form of healthcare.
Collapse
Affiliation(s)
- Aaron Gregson
- The Wolfson Institute for Biomedical Research, University College London, Gower Street, London, WC1E 6BT, UK
| | - Kaitlyn Thompson
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, 11794, USA
| | - Stella E Tsirka
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, 11794, USA
| | - David L Selwood
- The Wolfson Institute for Biomedical Research, University College London, Gower Street, London, WC1E 6BT, UK
| |
Collapse
|
8
|
A standardized approach to the evaluation of antivirals against DNA viruses: Polyomaviruses and lymphotropic herpesviruses. Antiviral Res 2018; 159:122-129. [PMID: 30287227 DOI: 10.1016/j.antiviral.2018.09.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/25/2018] [Accepted: 09/28/2018] [Indexed: 01/07/2023]
Abstract
The search for new compounds with a broad spectrum of antiviral activity is important and requires the evaluation of many compounds against several distinct viruses. Researchers attempting to develop new antiviral therapies for DNA virus infections currently use a variety of cell lines, assay conditions and measurement methods to determine in vitro drug efficacy, making it difficult to compare results from within the same laboratory as well as between laboratories. In this paper, we describe the assessment of antiviral activity of a set of nucleoside analogs against BK polyomavirus, JC polyomavirus, Epstein-Barr virus, human herpesvirus 6B, and human herpesvirus 8 in an automated 384-well format and utilize qPCR assays to measure the accumulation of viral DNA. In an accompanying paper, we present a standardized approach to evaluating antivirals against additional herpesviruses, orthopoxviruses, and adenovirus. Together, they reveal new activities for reference compounds and help to define the spectrum of antiviral activity for a set of nucleoside analogs against a set of 12 DNA viruses that infect humans including representative human herpesviruses, orthopoxviruses, adenoviruses, and polyomaviruses. This analysis helps provide perspective on combinations of agents that would help provide broad coverage of significant pathogens in immunocompromised patients as well as against emerging infections.
Collapse
|
9
|
Manners O, Murphy JC, Coleman A, Hughes DJ, Whitehouse A. Contribution of the KSHV and EBV lytic cycles to tumourigenesis. Curr Opin Virol 2018; 32:60-70. [PMID: 30268927 PMCID: PMC6259586 DOI: 10.1016/j.coviro.2018.08.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 08/24/2018] [Indexed: 12/21/2022]
Abstract
Kaposi's Sarcoma-associated herpesvirus (KSHV) and Epstein Barr virus (EBV) are the causative agents of several malignancies. Like all herpesviruses, KSHV and EBV undergo distinct latent and lytic replication programmes. The transition between these states allows the establishment of a lifelong persistent infection, dissemination to sites of disease and the spread to new hosts. Latency-associated viral proteins have been well characterised in transformation and tumourigenesis pathways; however, a number of studies have shown that abrogation of KSHV and EBV lytic gene expression impairs the oncogenesis of several cancers. Furthermore, several lytically expressed proteins have been functionally tethered to the angioproliferative and anti-apoptotic phenotypes of virus-infected cells. As a result, the investigation and therapeutic targeting of KSHV and EBV lytic cycles may be essential for the treatment of their associated malignancies.
Collapse
Affiliation(s)
- Oliver Manners
- School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - James C Murphy
- School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Alex Coleman
- School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - David J Hughes
- School of Biology, Biomolecular Sciences Building, University of St Andrews, Fife, KY16 9AJ, United Kingdom
| | - Adrian Whitehouse
- School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom; Department of Biochemistry & Microbiology, Rhodes University, Grahamstown, 6140, South Africa.
| |
Collapse
|
10
|
Topalis D, Gillemot S, Snoeck R, Andrei G. Thymidine kinase and protein kinase in drug-resistant herpesviruses: Heads of a Lernaean Hydra. Drug Resist Updat 2018; 37:1-16. [PMID: 29548479 DOI: 10.1016/j.drup.2018.01.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Herpesviruses thymidine kinase (TK) and protein kinase (PK) allow the activation of nucleoside analogues used in anti-herpesvirus treatments. Mutations emerging in these two genes often lead to emergence of drug-resistant strains responsible for life-threatening diseases in immunocompromised populations. In this review, we analyze the binding of different nucleoside analogues to the TK active site of the three α-herpesviruses [Herpes Simplex Virus 1 and 2 (HSV-1 and HSV-2) and Varicella-Zoster Virus (VZV)] and present the impact of known mutations on the structure of the viral TKs. Furthermore, models of β-herpesviruses [Human cytomegalovirus (HCMV) and human herpesvirus-6 (HHV-6)] PKs allow to link amino acid changes with resistance to ganciclovir and/or maribavir, an investigational chemotherapeutic used in patients with multidrug-resistant HCMV. Finally, we set the basis for the understanding of drug-resistance in γ-herpesviruses [Epstein-Barr virus (EBV) and Kaposi's sarcoma associated herpesvirus (KSHV)] TK and PK through the use of animal surrogate models.
Collapse
Affiliation(s)
- Dimitri Topalis
- Rega Institute for Medical Research, KU Leuven, Herestraat 49-box 1043, 3000 Leuven, Belgium.
| | - Sarah Gillemot
- Rega Institute for Medical Research, KU Leuven, Herestraat 49-box 1043, 3000 Leuven, Belgium.
| | - Robert Snoeck
- Rega Institute for Medical Research, KU Leuven, Herestraat 49-box 1043, 3000 Leuven, Belgium.
| | - Graciela Andrei
- Rega Institute for Medical Research, KU Leuven, Herestraat 49-box 1043, 3000 Leuven, Belgium.
| |
Collapse
|
11
|
Perlíková P, Hocek M. Pyrrolo[2,3-d]pyrimidine (7-deazapurine) as a privileged scaffold in design of antitumor and antiviral nucleosides. Med Res Rev 2017; 37:1429-1460. [PMID: 28834581 PMCID: PMC5656927 DOI: 10.1002/med.21465] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/26/2017] [Accepted: 07/26/2017] [Indexed: 12/17/2022]
Abstract
7-Deazapurine (pyrrolo[2,3-d]pyrimidine) nucleosides are important analogues of biogenic purine nucleosides with diverse biological activities. Replacement of the N7 atom with a carbon atom makes the five-membered ring more electron rich and brings a possibility of attaching additional substituents at the C7 position. This often leads to derivatives with increased base-pairing in DNA or RNA or better binding to enzymes. Several types of 7-deazapurine nucleosides with potent cytostatic or cytotoxic effects have been identified. The most promising are 7-hetaryl-7-deazaadenosines, which are activated in cancer cells by phosphorylation and get incorporated both to RNA (causing inhibition of proteosynthesis) and to DNA (causing DNA damage). Mechanism of action of other types of cytostatic nucleosides, 6-hetaryl-7-deazapurine and thieno-fused deazapurine ribonucleosides, is not yet known. Many 7-deazaadenosine derivatives are potent inhibitors of adenosine kinases. Many types of sugar-modified derivatives of 7-deazapurine nucleosides are also strong antivirals. Most important are 2'-C-methylribo- or 2'-C-methyl-2'-fluororibonucleosides with anti-HCV activities (several compounds underwent clinical trials). Some underexplored areas of potential interest are also outlined.
Collapse
Affiliation(s)
- Pavla Perlíková
- Institute of Organic Chemistry and BiochemistryCzech Academy of SciencesCZ‐16610Prague 6Czech Republic
| | - Michal Hocek
- Institute of Organic Chemistry and BiochemistryCzech Academy of SciencesCZ‐16610Prague 6Czech Republic
- Department of Organic ChemistryFaculty of ScienceCharles University in PragueCZ‐12843Prague 2Czech Republic
| |
Collapse
|
12
|
Kaposi's sarcoma-associated herpesvirus: the role of lytic replication in targeted therapy. Curr Opin Infect Dis 2016; 28:611-24. [PMID: 26524334 DOI: 10.1097/qco.0000000000000213] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE OF REVIEW To discuss the role of Kaposi's sarcoma-associated herpesvirus (KSHV) lytic replication in viral-associated diseases and assess the progress on targeting KSHV lytic replication as a strategy to prevent KSHV-related malignancies. RECENT FINDINGS New inhibitors of viral lytic replication are being developed as well as novel modalities are being investigated to target cellular processes that the virus hijacks during its life cycle. Research has also focused on reactivating viral lytic replication in latently infected tumour cells (lytic induction therapy) to promote death of tumour cells. SUMMARY KSHV is linked to three malignancies: Kaposi sarcoma, primary effusion lymphoma, and multicentric Castleman disease. Despite significant progress in understanding KSHV pathobiology, no therapeutic guidelines for the management of KSHV-related diseases exist, and current treatments are suboptimal and associated with toxicity. Antiherpesvirus drugs have shown inconsistent results in KSHV-associated malignancies that harbour the virus in a latent state. However, lytic replication plays a crucial role in the process of tumorigenesis. Therefore, not only antiviral agents directed against the virus replicative cycle but also agents that target cellular processes that are activated by the virus are being investigated. Antivirals may also be used in combination with inducers of the viral lytic stage.
Collapse
|
13
|
Coen N, Duraffour S, Snoeck R, Andrei G. KSHV targeted therapy: an update on inhibitors of viral lytic replication. Viruses 2014; 6:4731-59. [PMID: 25421895 PMCID: PMC4246246 DOI: 10.3390/v6114731] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 11/07/2014] [Accepted: 11/17/2014] [Indexed: 01/01/2023] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi’s sarcoma, primary effusion lymphoma and multicentric Castleman’s disease. Since the discovery of KSHV 20 years ago, there is still no standard treatment and the management of virus-associated malignancies remains toxic and incompletely efficacious. As the majority of tumor cells are latently infected with KSHV, currently marketed antivirals that target the virus lytic cycle have shown inconsistent results in clinic. Nevertheless, lytic replication plays a major role in disease progression and virus dissemination. Case reports and retrospective studies have pointed out the benefit of antiviral therapy in the treatment and prevention of KSHV-associated diseases. As a consequence, potent and selective antivirals are needed. This review focuses on the anti-KSHV activity, mode of action and current status of antiviral drugs targeting KSHV lytic cycle. Among these drugs, different subclasses of viral DNA polymerase inhibitors and compounds that do not target the viral DNA polymerase are being discussed. We also cover molecules that target cellular kinases, as well as the potential of new drug targets and animal models for antiviral testing.
Collapse
Affiliation(s)
- Natacha Coen
- Rega Institute for Medical Research, KU Leuven, B-3000 Leuven, Belgium.
| | - Sophie Duraffour
- Rega Institute for Medical Research, KU Leuven, B-3000 Leuven, Belgium.
| | - Robert Snoeck
- Rega Institute for Medical Research, KU Leuven, B-3000 Leuven, Belgium.
| | - Graciela Andrei
- Rega Institute for Medical Research, KU Leuven, B-3000 Leuven, Belgium.
| |
Collapse
|
14
|
Hornig J, McGregor A. Design and development of antivirals and intervention strategies against human herpesviruses using high-throughput approach. Expert Opin Drug Discov 2014; 9:891-915. [DOI: 10.1517/17460441.2014.922538] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
15
|
Antiherpesvirus activities of two novel 4'-thiothymidine derivatives, KAY-2-41 and KAH-39-149, are dependent on viral and cellular thymidine kinases. Antimicrob Agents Chemother 2014; 58:4328-40. [PMID: 24820089 DOI: 10.1128/aac.02825-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The emergence of drug-resistant herpesviruses represents a significant problem in clinical practice, primarily in immunocompromised patients. Furthermore, effective antiviral therapies against gammaherpesvirus-associated diseases are lacking. Here, we present two thiothymidine derivatives, KAY-2-41 and KAH-39-149, with different spectra of antiviral activity from those of the reference antiherpetic drugs, showing inhibitory activities against herpes simplex virus, varicella-zoster virus (VZV), and particularly against Epstein-Barr virus, with high selectivity in vitro. While KAY-2-41- and KAH-39-149-resistant herpesviruses were found to harbor mutations in the viral thymidine kinase (TK), these mutations conferred only low levels of resistance to these drugs but high levels to other TK-dependent drugs. Also, antiviral assays in HeLa TK-deficient cells showed a lack of KAY-2-41 and KAH-39-149 activities against herpes simplex virus 1 (HSV-1) and HSV-2 TK-deficient mutants. Furthermore, enzymatic TK assays showed the ability of HSV-1 TK, VZV TK, and cellular TK1 and TK2 to recognize and phosphorylate KAY-2-41 and KAH-39-149. These results demonstrate that the compounds depend on both viral and host TKs to exert antiviral activity. Additionally, the antiviral efficacy of KAH-39-149 proved to be superior to that of KAY-2-41 in a mouse model of gammaherpesvirus infection, highlighting the potential of this class of antiviral agents for further development as selective therapeutics against Epstein-Barr virus.
Collapse
|