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Giannakopoulou E, Pardali V, Edwards TC, Woodson M, Tajwar R, Tavis JE, Zoidis G. Identification and assessment of the 1,6-dihydroxy-pyridin-2-one moiety as privileged scaffold for HBV ribonuclease H inhibition. Antiviral Res 2024; 223:105833. [PMID: 38325606 DOI: 10.1016/j.antiviral.2024.105833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/20/2024] [Accepted: 02/02/2024] [Indexed: 02/09/2024]
Abstract
The Hepatitis B Virus (HBV) ribonuclease H (RNase H) although promising remains an unexploited therapeutic target. HBV RNase H inhibition causes premature termination of viral minus-polarity DNA strands, prevents the synthesis of the viral positive-polarity DNA strand, and causes accumulation of RNA:DNA heteroduplexes within viral capsids. As part of our ongoing research to develop more potent anti-HBV RNase H inhibitors, we designed, synthesized and analyzed a library of 18 novel compounds (17 N-hydroyxpyridinedione (HPD) imine derivatives and 1 barbituric acid analogue) as potential leads for HBV treatment development. In cell assays, fourteen HPDs showed significant anti-HBV activity with EC50s from 1.1 to 2.5 μM and selectivity indices (SI) of up to 58. Three of them exhibited more than 3-fold improvement in the SI over the best previous HPD imine (SI = 13). To gain insight to the interaction between the tested compounds and the active site of HBV RNase H, docking experiments were undertaken. In almost all binding poses, the novel HPDs coordinated both active site Mg2+ ions via their oxygen trident. Furthermore, the novel HPDs displayed high cell permeability and solubility as well as good drug-like properties. These results reveal that HPD imines can be significantly active and selective HBV inhibitors, and that the HPD scaffold merits further development towards anti-HBV agents.
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Affiliation(s)
- Erofili Giannakopoulou
- School of Health Sciences, Department of Pharmacy, Division of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771, Athens, Greece
| | - Vasiliki Pardali
- School of Health Sciences, Department of Pharmacy, Division of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771, Athens, Greece
| | - Tiffany C Edwards
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, United States
| | - Molly Woodson
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, United States
| | - Razia Tajwar
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, United States
| | - John E Tavis
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, United States
| | - Grigoris Zoidis
- School of Health Sciences, Department of Pharmacy, Division of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771, Athens, Greece.
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2
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Li Q, Tavis JE. In Vitro Enzymatic and Cell Culture-Based Assays for Measuring Activity of HBV Ribonuclease H Inhibitors. Methods Mol Biol 2024; 2837:257-270. [PMID: 39044091 DOI: 10.1007/978-1-0716-4027-2_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
HBV is a small, enveloped DNA virus that replicates by reverse transcription of an RNA intermediate. Current anti-HBV treatment regiments employ interferon α or nucleos(t)ide analogs, but they are not curative, are of long duration, and can be accompanied by systemic side-effects. The HBV ribonuclease H (RNaseH) is essential for viral replication; however, it is unexploited as a drug target. RNaseH inhibitors that actively block viral replication would represent an important addition to the potential new drugs for treating HBV infection. Here, we describe two methods to measure the activity of RNaseH inhibitors. The DNA oligonucleotide-directed RNA cleavage assay allows mechanistic analysis of compounds for anti-HBV RNaseH activity. Analysis of preferential inhibition of plus-polarity DNA strand synthesis by HBV RNaseH inhibitors in a cell culture model of HBV replication can be used to measure the ability of RNaseH inhibitors to block viral replication.
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Affiliation(s)
- Qilan Li
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine and Saint Louis University Liver Center, Saint Louis, MO, USA
| | - John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine and Saint Louis University Liver Center, Saint Louis, MO, USA.
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Durantel D. Therapies against chronic hepatitis B infections: The times they are a-changin', but the changing is slow! Antiviral Res 2023; 210:105515. [PMID: 36603773 DOI: 10.1016/j.antiviral.2022.105515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 01/04/2023]
Abstract
PREAMBULAR NOTA BENE As a tribute to Dr Mike Bray, the following review of literature willbe mainly based on published data andconcepts, but will also contain my personal views, and in this respect could be more considered as a bioassay. Even though a cost-effective and excellent prophylactic vaccine exists since many years to protect against hepatitis B virus (HBV) infection, academic-researcher/drug-developers/stakeholders are still busy with the R&D of novel therapies that could eventually have an impact on its worldwide incidence. The Taiwanese experience have univocally demonstrated the effectiveness of constrained national HBV prophylactic vaccination programs to prevent the most dramatic HBV-induced end-stage liver disease, which is hepatocellular carcinoma; but yet the number of individuals chronically infected with the virus, for whom the existing prophylactic vaccine is no longer useful, remains high, with around 300 million individuals around the globe. In this review/bioassay, recent findings and novel concepts on prospective therapies against HBV infections will be discussed; yet it does not have the pretention to be exhaustive, as "pure immunotherapeutic concepts" will be mainly let aside (or referred to other reviews) due to a lack of expertise of this writer, but also due to the lack of, or incremental, positive results in clinical trials as-off today with these approaches.
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Affiliation(s)
- David Durantel
- Centre International de Recherche en Infectiologie (CIRI), INSERM U1111, UMR_5308 CNRS-Université de Lyon (UCBL1), ENS de Lyon, Lyon, 69007, France.
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4
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Geerling E, Murphy V, Mai MC, Stone ET, Casals AG, Hassert M, O’Dea AT, Cao F, Donlin MJ, Elagawany M, Elgendy B, Pardali V, Giannakopoulou E, Zoidis G, Schiavone DV, Berkowitz AJ, Agyemang NB, Murelli RP, Tavis JE, Pinto AK, Brien JD. Metal coordinating inhibitors of Rift Valley fever virus replication. PLoS One 2022; 17:e0274266. [PMID: 36112605 PMCID: PMC9481026 DOI: 10.1371/journal.pone.0274266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/24/2022] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a veterinary and human pathogen and is an agent of bioterrorism concern. Currently, RVFV treatment is limited to supportive care, so new drugs to control RVFV infection are urgently needed. RVFV is a member of the order Bunyavirales, whose replication depends on the enzymatic activity of the viral L protein. Screening for RVFV inhibitors among compounds with divalent cation-coordinating motifs similar to known viral nuclease inhibitors identified 47 novel RVFV inhibitors with selective indexes from 1.1–103 and 50% effective concentrations of 1.2–56 μM in Vero cells, primarily α-Hydroxytropolones and N-Hydroxypyridinediones. Inhibitor activity and selective index was validated in the human cell line A549. To evaluate specificity, select compounds were tested against a second Bunyavirus, La Crosse Virus (LACV), and the flavivirus Zika (ZIKV). These data indicate that the α-Hydroxytropolone and N-Hydroxypyridinedione chemotypes should be investigated in the future to determine their mechanism(s) of action allowing further development as therapeutics for RVFV and LACV, and these chemotypes should be evaluated for activity against related pathogens, including Hantaan virus, severe fever with thrombocytopenia syndrome virus, Crimean-Congo hemorrhagic fever virus.
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Affiliation(s)
- Elizabeth Geerling
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Valerie Murphy
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Maria C. Mai
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - E. Taylor Stone
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Andreu Gazquez Casals
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Mariah Hassert
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Austin T. O’Dea
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Feng Cao
- John Cochran Division, Department of Veterans Affairs Medical Center, Saint Louis, Missouri, United States of America
| | - Maureen J. Donlin
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Mohamed Elagawany
- Center for Clinical Pharmacology, Washington University School of Medicine and University of Health Sciences and Pharmacy, Saint Louis, Missouri, United States of America
| | - Bahaa Elgendy
- Center for Clinical Pharmacology, Washington University School of Medicine and University of Health Sciences and Pharmacy, Saint Louis, Missouri, United States of America
- Department of Pharmaceutical and Administrative Sciences, University of Health Sciences and Pharmacy, Saint Louis, Missouri, United States of America
| | - Vasiliki Pardali
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Erofili Giannakopoulou
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Grigoris Zoidis
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Daniel V. Schiavone
- Department of Chemistry and The Graduate Center of The City University of New York, Brooklyn College, The City University of New York, Brooklyn, New York, United States of America
| | - Alex J. Berkowitz
- Department of Chemistry and The Graduate Center of The City University of New York, Brooklyn College, The City University of New York, Brooklyn, New York, United States of America
| | - Nana B. Agyemang
- Department of Chemistry and The Graduate Center of The City University of New York, Brooklyn College, The City University of New York, Brooklyn, New York, United States of America
| | - Ryan P. Murelli
- Department of Chemistry and The Graduate Center of The City University of New York, Brooklyn College, The City University of New York, Brooklyn, New York, United States of America
| | - John E. Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Amelia K. Pinto
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - James D. Brien
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
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Alpha-hydroxytropolones are noncompetitive inhibitors of human RNase H1 that bind to the active site and modulate substrate binding. J Biol Chem 2022; 298:101790. [PMID: 35247386 PMCID: PMC9034292 DOI: 10.1016/j.jbc.2022.101790] [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: 12/12/2021] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 11/23/2022] Open
Abstract
The ribonucleases H (RNases H) of HIV and hepatitis B virus are type 1 RNases H that are promising drug targets because inhibiting their activity blocks viral replication. Eukaryotic ribonuclease H1 (RNase H1) is an essential protein and a probable off-target enzyme for viral RNase H inhibitors. α-hydroxytropolones (αHTs) are a class of anti-RNase H inhibitors that can inhibit the HIV, hepatitis B virus, and human RNases H1; however, it is unclear how these inhibitors could be developed to distinguish between these enzymes. To accelerate the development of selective RNase H inhibitors, we performed biochemical and kinetic studies on the human enzyme, which was recombinantly expressed in Escherichia coli. Size-exclusion chromatography showed that free RNase H1 is monomeric and forms a 2:1 complex with a substrate of 12 bp. FRET heteroduplex cleavage assays were used to test inhibition of RNase H1 in steady-state kinetics by two structurally diverse αHTs, 110 and 404. We determined that turnover rate was reduced, but inhibition was not competitive with substrate, despite inhibitor binding to the active site. Given the compounds’ reversible binding to the active site, we concluded that traditional noncompetitive and mixed inhibition mechanisms are unlikely. Instead, we propose a model in which, by binding to the active site, αHTs stabilize an inactive enzyme–substrate–inhibitor complex. This new model clarifies the mechanism of action of αHTs against RNase H1 and will aid the development of RNase H inhibitors selective for the viral enzymes.
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Efficient Inhibition of Hepatitis B Virus (HBV) Replication and cccDNA Formation by HBV Ribonuclease H Inhibitors during Infection. Antimicrob Agents Chemother 2021; 65:e0146021. [PMID: 34516242 DOI: 10.1128/aac.01460-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The hepatitis B virus (HBV) ribonuclease H (RNase H) is an attractive but unexploited drug target. Here, we addressed three limitations to the current state of RNase H inhibitor development: (a) Efficacy has been assessed only in transfected cell lines. (b) Cytotoxicity data are from transformed cell lines rather than primary cells. (c) It is unknown how the compounds work against nucleos(t)ide analog resistant HBV strains. Three RNase H inhibitors from different chemotypes, 110 (α-hydroxytropolone), 1133 (N-hydroxypyridinedione), and 1073 (N-hydroxynapthyridinone), were tested in HBV-infected HepG2-NTCP cells for inhibition of cccDNA accumulation and HBV product formation. 50% effective concentrations (EC50s) were 0.049-0.078 μM in the infection studies compared to 0.29-1.6 μM in transfected cells. All compounds suppressed cccDNA formation by >98% at 5 μM when added shortly after infection. HBV RNA, intracellular and extracellular DNA, and HBsAg secretion were all robustly suppressed. The greater efficacy of the inhibitors when added shortly after infection is presumably due to blocking amplification of the HBV cccDNA, which suppresses events downstream of cccDNA formation. The compounds had 50% cytotoxic concentrations (CC50s) of 16-100 μM in HepG2-derived cell lines but were nontoxic in primary human hepatocytes, possibly due to the quiescent state of the hepatocytes. The compounds had similar EC50s against replication of wild-type, lamivudine-resistant, and adefovir/lamivudine-resistant HBV, as expected because the RNase H inhibitors do not target the viral reverse transcriptase active site. These studies expand confidence in inhibiting the HBV RNase H as a drug strategy and support inclusion of RNase H inhibitors in novel curative drug combinations for HBV.
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7
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Prifti GM, Moianos D, Giannakopoulou E, Pardali V, Tavis JE, Zoidis G. Recent Advances in Hepatitis B Treatment. Pharmaceuticals (Basel) 2021; 14:417. [PMID: 34062711 PMCID: PMC8147224 DOI: 10.3390/ph14050417] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 01/10/2023] Open
Abstract
Hepatitis B virus infection affects over 250 million chronic carriers, causing more than 800,000 deaths annually, although a safe and effective vaccine is available. Currently used antiviral agents, pegylated interferon and nucleos(t)ide analogues, have major drawbacks and fail to completely eradicate the virus from infected cells. Thus, achieving a "functional cure" of the infection remains a real challenge. Recent findings concerning the viral replication cycle have led to development of novel therapeutic approaches including viral entry inhibitors, epigenetic control of cccDNA, immune modulators, RNA interference techniques, ribonuclease H inhibitors, and capsid assembly modulators. Promising preclinical results have been obtained, and the leading molecules under development have entered clinical evaluation. This review summarizes the key steps of the HBV life cycle, examines the currently approved anti-HBV drugs, and analyzes novel HBV treatment regimens.
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Affiliation(s)
- Georgia-Myrto Prifti
- Department of Pharmacy, Division of Pharmaceutical Chemistry, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece; (G.-M.P.); (D.M.); (E.G.); (V.P.)
| | - Dimitrios Moianos
- Department of Pharmacy, Division of Pharmaceutical Chemistry, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece; (G.-M.P.); (D.M.); (E.G.); (V.P.)
| | - Erofili Giannakopoulou
- Department of Pharmacy, Division of Pharmaceutical Chemistry, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece; (G.-M.P.); (D.M.); (E.G.); (V.P.)
| | - Vasiliki Pardali
- Department of Pharmacy, Division of Pharmaceutical Chemistry, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece; (G.-M.P.); (D.M.); (E.G.); (V.P.)
| | - John E. Tavis
- Molecular Microbiology and Immunology, Saint Louis University, Saint Louis, MO 63104, USA;
| | - Grigoris Zoidis
- Department of Pharmacy, Division of Pharmaceutical Chemistry, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece; (G.-M.P.); (D.M.); (E.G.); (V.P.)
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Bassit L, Ono SK, Schinazi RF. Moving Fast Toward Hepatitis B Virus Elimination. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1322:115-138. [PMID: 34258739 DOI: 10.1007/978-981-16-0267-2_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Currently, there are two safe and effective therapeutic strategies for chronic hepatitis B treatment, namely, nucleoside analogs and interferon alpha (pegylated or non-pegylated). These treatments can control viral replication and improve survival; however, they do not eliminate the virus and therefore require long-term continued therapy. In addition, there are significant concerns about virus rebound on discontinuation of therapy and the development of fibrosis and hepatocellular carcinoma despite therapy. Therefore, the search for new, more effective, and safer antiviral agents that can cure hepatitis B virus (HBV) continues. Anti-HBV drug discovery and development is fundamentally impacted by our current understanding of HBV replication, disease physiopathology, and persistence of HBV covalently closed circular DNA (cccDNA). Several HBV replication targets are the basis for novel anti-HBV drug development strategies. Many of them are already in clinical trial phase 1 or 2, while others with promising results are still in preclinical stages. As research intensifies, potential HBV curative therapies and modalities in the pipeline are now on the horizon.
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Affiliation(s)
- Leda Bassit
- Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Suzane Kioko Ono
- Department of Gastroenterology, University of Sao Paulo School of Medicine, Sao Paulo, SP, Brazil
| | - Raymond F Schinazi
- Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, Atlanta, GA, USA.
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Bak E, Miller JT, Noronha A, Tavis J, Gallicchio E, Murelli RP, Le Grice SFJ. 3,7-Dihydroxytropolones Inhibit Initiation of Hepatitis B Virus Minus-Strand DNA Synthesis. Molecules 2020; 25:molecules25194434. [PMID: 32992516 PMCID: PMC7583054 DOI: 10.3390/molecules25194434] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/15/2020] [Accepted: 09/19/2020] [Indexed: 02/07/2023] Open
Abstract
Initiation of protein-primed (-) strand DNA synthesis in hepatitis B virus (HBV) requires interaction of the viral reverse transcriptase with epsilon (ε), a cis-acting regulatory signal located at the 5' terminus of pre-genomic RNA (pgRNA), and several host-encoded chaperone proteins. Binding of the viral polymerase (P protein) to ε is necessary for pgRNA encapsidation and synthesis of a short primer covalently attached to its terminal domain. Although we identified small molecules that recognize HBV ε RNA, these failed to inhibit protein-primed DNA synthesis. However, since initiation of HBV (-) strand DNA synthesis occurs within a complex of viral and host components (e.g., Hsp90, DDX3 and APOBEC3G), we considered an alternative therapeutic strategy of allosteric inhibition by disrupting the initiation complex or modifying its topology. To this end, we show here that 3,7-dihydroxytropolones (3,7-dHTs) can inhibit HBV protein-primed DNA synthesis. Since DNA polymerase activity of a ribonuclease (RNase H)-deficient HBV reverse transcriptase that otherwise retains DNA polymerase function is also abrogated, this eliminates direct involvement of RNase (ribonuclease) H activity of HBV reverse transcriptase and supports the notion that the HBV initiation complex might be therapeutically targeted. Modeling studies also provide a rationale for preferential activity of 3,7-dHTs over structurally related α-hydroxytropolones (α-HTs).
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Affiliation(s)
- Ellen Bak
- Basic Research Laboratory National Cancer Institute, Frederick, MD 21702, USA; (E.B.); (J.T.M.); (A.N.)
| | - Jennifer T. Miller
- Basic Research Laboratory National Cancer Institute, Frederick, MD 21702, USA; (E.B.); (J.T.M.); (A.N.)
| | - Andrea Noronha
- Basic Research Laboratory National Cancer Institute, Frederick, MD 21702, USA; (E.B.); (J.T.M.); (A.N.)
| | - John Tavis
- Department of Molecular Microbiology and Immunology, St. Louis University, St. Louis, MO 63104, USA;
| | - Emilio Gallicchio
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY 11210, USA; (E.G.); (R.P.M.)
- PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY 10016, USA
- PhD Program in Biochemistry, The Graduate Center of The City University of New York, New York, NY 10016, USA
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY 11210, USA; (E.G.); (R.P.M.)
- PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY 10016, USA
- PhD Program in Biochemistry, The Graduate Center of The City University of New York, New York, NY 10016, USA
| | - Stuart F. J. Le Grice
- Basic Research Laboratory National Cancer Institute, Frederick, MD 21702, USA; (E.B.); (J.T.M.); (A.N.)
- Correspondence:
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1,2,4-Triazolo[1,5- a]pyrimidines as a Novel Class of Inhibitors of the HIV-1 Reverse Transcriptase-Associated Ribonuclease H Activity. Molecules 2020; 25:molecules25051183. [PMID: 32151066 PMCID: PMC7179434 DOI: 10.3390/molecules25051183] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/25/2020] [Accepted: 03/03/2020] [Indexed: 12/27/2022] Open
Abstract
Despite great efforts have been made in the prevention and therapy of human immunodeficiency virus (HIV-1) infection, however the difficulty to eradicate latent viral reservoirs together with the emergence of multi-drug-resistant strains require the search for innovative agents, possibly exploiting novel mechanisms of action. In this context, the HIV-1 reverse transcriptase (RT)-associated ribonuclease H (RNase H), which is one of the few HIV-1 encoded enzymatic function still not targeted by any current drug, can be considered as an appealing target. In this work, we repurposed in-house anti-influenza derivatives based on the 1,2,4-triazolo[1,5-a]-pyrimidine (TZP) scaffold for their ability to inhibit HIV-1 RNase H function. Based on the results, a successive multi-step structural exploration around the TZP core was performed leading to identify catechol derivatives that inhibited RNase H in the low micromolar range without showing RT-associated polymerase inhibitory activity. The antiviral evaluation of the compounds in the MT4 cells showed any activity against HIV-1 (IIIB strain). Molecular modelling and mutagenesis analysis suggested key interactions with an unexplored allosteric site providing insights for the future optimization of this class of RNase H inhibitors.
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