1
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Duncan JKS, Xu D, Licursi M, Joyce MA, Saffran HA, Liu K, Gohda J, Tyrrell DL, Kawaguchi Y, Hirasawa K. Interferon regulatory factor 3 mediates effective antiviral responses to human coronavirus 229E and OC43 infection. Front Immunol 2023; 14:930086. [PMID: 37197656 PMCID: PMC10183588 DOI: 10.3389/fimmu.2023.930086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 03/27/2023] [Indexed: 05/19/2023] Open
Abstract
Interferon regulatory factors (IRFs) are key elements of antiviral innate responses that regulate the transcription of interferons (IFNs) and IFN-stimulated genes (ISGs). While the sensitivity of human coronaviruses to IFNs has been characterized, antiviral roles of IRFs during human coronavirus infection are not fully understood. Type I or II IFN treatment protected MRC5 cells from human coronavirus 229E infection, but not OC43. Cells infected with 229E or OC43 upregulated ISGs, indicating that antiviral transcription is not suppressed. Antiviral IRFs, IRF1, IRF3 and IRF7, were activated in cells infected with 229E, OC43 or severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2). RNAi knockdown and overexpression of IRFs demonstrated that IRF1 and IRF3 have antiviral properties against OC43, while IRF3 and IRF7 are effective in restricting 229E infection. IRF3 activation effectively promotes transcription of antiviral genes during OC43 or 229E infection. Our study suggests that IRFs may be effective antiviral regulators against human coronavirus infection.
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Affiliation(s)
- Joseph K. Sampson Duncan
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Danyang Xu
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Maria Licursi
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Michael A. Joyce
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Holly A. Saffran
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Kaiwen Liu
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Jin Gohda
- Research Center for Asian Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - D. Lorne Tyrrell
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Yasushi Kawaguchi
- Research Center for Asian Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Kensuke Hirasawa
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL, Canada
- *Correspondence: Kensuke Hirasawa,
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2
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Babuadze GG, Fausther-Bovendo H, deLaVega MA, Lillie B, Naghibosadat M, Shahhosseini N, Joyce MA, Saffran HA, Lorne Tyrrell D, Falzarano D, Senthilkumaran C, Christie-Holmes N, Ahn S, Gray-Owen SD, Banerjee A, Mubareka S, Mossman K, Dupont C, Pedersen J, Lafrance MA, Kobinger GP, Kozak R. Two DNA vaccines protect against severe disease and pathology due to SARS-CoV-2 in Syrian hamsters. NPJ Vaccines 2022; 7:49. [PMID: 35474311 PMCID: PMC9042934 DOI: 10.1038/s41541-022-00461-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 02/18/2022] [Indexed: 12/30/2022] Open
Abstract
The SARS-CoV-2 pandemic is an ongoing threat to global health, and wide-scale vaccination is an efficient method to reduce morbidity and mortality. We designed and evaluated two DNA plasmid vaccines, based on the pIDV-II system, expressing the SARS-CoV-2 spike gene, with or without an immunogenic peptide, in mice, and in a Syrian hamster model of infection. Both vaccines demonstrated robust immunogenicity in BALB/c and C57BL/6 mice. Additionally, the shedding of infectious virus and the viral burden in the lungs was reduced in immunized hamsters. Moreover, high-titers of neutralizing antibodies with activity against multiple SARS-CoV-2 variants were generated in immunized animals. Vaccination also protected animals from weight loss during infection. Additionally, both vaccines were effective at reducing both pulmonary and extrapulmonary pathology in vaccinated animals. These data show the potential of a DNA vaccine for SARS-CoV-2 and suggest further investigation in large animal and human studies could be pursued.
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Affiliation(s)
- George Giorgi Babuadze
- grid.17063.330000 0001 2157 2938Biological Sciences Platform, University Toronto, Sunnybrook Research Institute at Sunnybrook Health Sciences Centre, Ontario, ON Canada
| | - Hugues Fausther-Bovendo
- grid.23856.3a0000 0004 1936 8390Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Quebec City, QC Canada
| | - Marc-Antoine deLaVega
- grid.23856.3a0000 0004 1936 8390Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Quebec City, QC Canada
| | - Brandon Lillie
- grid.34429.380000 0004 1936 8198Ontario Veterinary College, University of Guelph, Guelph, ON Canada
| | - Maedeh Naghibosadat
- grid.17063.330000 0001 2157 2938Biological Sciences Platform, University Toronto, Sunnybrook Research Institute at Sunnybrook Health Sciences Centre, Ontario, ON Canada
| | - Nariman Shahhosseini
- grid.23856.3a0000 0004 1936 8390Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Quebec City, QC Canada
| | - Michael A. Joyce
- grid.17089.370000 0001 2190 316XDepartment of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB Canada ,grid.17089.370000 0001 2190 316XLi Ka Shing Institute of Virology, University of Alberta, Edmonton, AB Canada
| | - Holly A. Saffran
- grid.17089.370000 0001 2190 316XDepartment of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB Canada ,grid.17089.370000 0001 2190 316XLi Ka Shing Institute of Virology, University of Alberta, Edmonton, AB Canada
| | - D. Lorne Tyrrell
- grid.17089.370000 0001 2190 316XDepartment of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB Canada ,grid.17089.370000 0001 2190 316XLi Ka Shing Institute of Virology, University of Alberta, Edmonton, AB Canada
| | - Darryl Falzarano
- grid.25152.310000 0001 2154 235XVaccine and Infectious Disease Organization, Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK Canada
| | - Chandrika Senthilkumaran
- grid.17063.330000 0001 2157 2938Biological Sciences Platform, University Toronto, Sunnybrook Research Institute at Sunnybrook Health Sciences Centre, Ontario, ON Canada
| | - Natasha Christie-Holmes
- grid.17063.330000 0001 2157 2938Combined Containment Level 3 Unit, Temerty Faculty of Medicine, University of Toronto, Toronto, ON Canada
| | - Steven Ahn
- grid.17063.330000 0001 2157 2938Department of Molecular Genetics, University of Toronto, Toronto, ON Canada
| | - Scott D. Gray-Owen
- grid.17063.330000 0001 2157 2938Department of Molecular Genetics, University of Toronto, Toronto, ON Canada
| | - Arinjay Banerjee
- grid.25152.310000 0001 2154 235XVaccine and Infectious Disease Organization, Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK Canada
| | - Samira Mubareka
- grid.17063.330000 0001 2157 2938Biological Sciences Platform, University Toronto, Sunnybrook Research Institute at Sunnybrook Health Sciences Centre, Ontario, ON Canada ,grid.413104.30000 0000 9743 1587Department of Laboratory Medicine and Molecular Diagnostics, Division of Microbiology, Sunnybrook Health Sciences Centre, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada
| | - Karen Mossman
- grid.25073.330000 0004 1936 8227Department of Medicine, McMaster University, Hamilton, ON Canada
| | - Chanel Dupont
- grid.17063.330000 0001 2157 2938Biological Sciences Platform, University Toronto, Sunnybrook Research Institute at Sunnybrook Health Sciences Centre, Ontario, ON Canada
| | - Jannie Pedersen
- grid.23856.3a0000 0004 1936 8390Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Quebec City, QC Canada
| | - Mark-Alexandre Lafrance
- grid.23856.3a0000 0004 1936 8390Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Quebec City, QC Canada
| | - Gary P. Kobinger
- grid.23856.3a0000 0004 1936 8390Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Quebec City, QC Canada ,grid.21613.370000 0004 1936 9609Department of Medical Microbiology, University of Manitoba, Winnipeg, MB Canada ,grid.25879.310000 0004 1936 8972Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA USA
| | - Robert Kozak
- grid.17063.330000 0001 2157 2938Biological Sciences Platform, University Toronto, Sunnybrook Research Institute at Sunnybrook Health Sciences Centre, Ontario, ON Canada ,grid.413104.30000 0000 9743 1587Department of Laboratory Medicine and Molecular Diagnostics, Division of Microbiology, Sunnybrook Health Sciences Centre, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada
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3
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Bai B, Belovodskiy A, Hena M, Kandadai AS, Joyce MA, Saffran HA, Shields JA, Khan MB, Arutyunova E, Lu J, Bajwa SK, Hockman D, Fischer C, Lamer T, Vuong W, van Belkum MJ, Gu Z, Lin F, Du Y, Xu J, Rahim M, Young HS, Vederas JC, Tyrrell DL, Lemieux MJ, Nieman JA. Peptidomimetic α-Acyloxymethylketone Warheads with Six-Membered Lactam P1 Glutamine Mimic: SARS-CoV-2 3CL Protease Inhibition, Coronavirus Antiviral Activity, and in Vitro Biological Stability. J Med Chem 2022; 65:2905-2925. [PMID: 34242027 PMCID: PMC8291138 DOI: 10.1021/acs.jmedchem.1c00616] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Indexed: 12/11/2022]
Abstract
Recurring coronavirus outbreaks, such as the current COVID-19 pandemic, establish a necessity to develop direct-acting antivirals that can be readily administered and are active against a broad spectrum of coronaviruses. Described in this Article are novel α-acyloxymethylketone warhead peptidomimetic compounds with a six-membered lactam glutamine mimic in P1. Compounds with potent SARS-CoV-2 3CL protease and in vitro viral replication inhibition were identified with low cytotoxicity and good plasma and glutathione stability. Compounds 15e, 15h, and 15l displayed selectivity for SARS-CoV-2 3CL protease over CatB and CatS and superior in vitro SARS-CoV-2 antiviral replication inhibition compared with the reported peptidomimetic inhibitors with other warheads. The cocrystallization of 15l with SARS-CoV-2 3CL protease confirmed the formation of a covalent adduct. α-Acyloxymethylketone compounds also exhibited antiviral activity against an alphacoronavirus and non-SARS betacoronavirus strains with similar potency and a better selectivity index than remdesivir. These findings demonstrate the potential of the substituted heteroaromatic and aliphatic α-acyloxymethylketone warheads as coronavirus inhibitors, and the described results provide a basis for further optimization.
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Affiliation(s)
- Bing Bai
- Li Ka Shing Applied Virology Institute,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - Alexandr Belovodskiy
- Li Ka Shing Applied Virology Institute,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - Mostofa Hena
- Li Ka Shing Applied Virology Institute,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - Appan Srinivas Kandadai
- Li Ka Shing Applied Virology Institute,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - Michael A. Joyce
- Li Ka Shing Institute of Virology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - Holly A. Saffran
- Li Ka Shing Institute of Virology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - Justin A. Shields
- Li Ka Shing Institute of Virology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - Muhammad Bashir Khan
- Department of Biochemistry, University of
Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Elena Arutyunova
- Li Ka Shing Institute of Virology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Biochemistry, University of
Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Jimmy Lu
- Li Ka Shing Institute of Virology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Biochemistry, University of
Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Sardeev K. Bajwa
- Department of Biochemistry, University of
Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Darren Hockman
- Li Ka Shing Applied Virology Institute,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - Conrad Fischer
- Department of Chemistry, University of
Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Tess Lamer
- Department of Chemistry, University of
Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Wayne Vuong
- Department of Chemistry, University of
Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Marco J. van Belkum
- Department of Chemistry, University of
Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Zhengxian Gu
- WuXi AppTec (Shanghai) Co., Ltd.,
G Warehouse #101, No. 10 Building, #227 Meisheng Road, WaiGaoQiao Free Trade Zone,
Shanghai 200131, China
| | - Fusen Lin
- WuXi AppTec (Shanghai) Co., Ltd.,
G Warehouse #101, No. 10 Building, #227 Meisheng Road, WaiGaoQiao Free Trade Zone,
Shanghai 200131, China
| | - Yanhua Du
- WuXi AppTec (Shanghai) Co., Ltd.,
G Warehouse #101, No. 10 Building, #227 Meisheng Road, WaiGaoQiao Free Trade Zone,
Shanghai 200131, China
| | - Jia Xu
- WuXi AppTec (Shanghai) Co., Ltd.,
G Warehouse #101, No. 10 Building, #227 Meisheng Road, WaiGaoQiao Free Trade Zone,
Shanghai 200131, China
| | - Mohammad Rahim
- Rane Pharmaceuticals, Inc.
4290 91a Street NW, Edmonton, Alberta T6E 5V2, Canada
| | - Howard S. Young
- Department of Biochemistry, University of
Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - John C. Vederas
- Department of Chemistry, University of
Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - D. Lorne Tyrrell
- Li Ka Shing Applied Virology Institute,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Li Ka Shing Institute of Virology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
| | - M. Joanne Lemieux
- Li Ka Shing Institute of Virology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Biochemistry, University of
Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - James A. Nieman
- Li Ka Shing Applied Virology Institute,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
- Department of Medical Microbiology and Immunology,
University of Alberta, Edmonton, Alberta T6G 2E1,
Canada
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4
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Bai B, Arutyunova E, Khan MB, Lu J, Joyce MA, Saffran HA, Shields JA, Kandadai AS, Belovodskiy A, Hena M, Vuong W, Lamer T, Young HS, Vederas JC, Tyrrell DL, Lemieux MJ, Nieman JA. Peptidomimetic nitrile warheads as SARS-CoV-2 3CL protease inhibitors. RSC Med Chem 2021; 12:1722-1730. [PMID: 34778773 PMCID: PMC8529539 DOI: 10.1039/d1md00247c] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 08/20/2021] [Indexed: 12/12/2022] Open
Abstract
Tragically, the death toll from the COVID-19 pandemic continues to rise, and with variants being observed around the globe new therapeutics, particularly direct-acting antivirals that are easily administered, are desperately needed. Studies targeting the SARS-CoV-2 3CL protease, which is critical for viral replication, with different peptidomimetics and warheads is an active area of research for development of potential drugs. To date, however, only a few publications have evaluated the nitrile warhead as a viral 3CL protease inhibitor, with only modest activity reported. This article describes our investigation of P3 4-methoxyindole peptidomimetic analogs with select P1 and P2 groups with a nitrile warhead that are potent inhibitors of SARS-CoV-2 3CL protease and demonstrate in vitro SARS-CoV-2 antiviral activity. A selectivity for SARS-CoV-2 3CL protease over human cathepsins B, S and L was also observed with the nitrile warhead, which was superior to that with the aldehyde warhead. A co-crystal structure with SARS-CoV-2 3CL protease and a reversibility study indicate that a reversible, thioimidate adduct is formed when the catalytic sulfur forms a covalent bond with the carbon of the nitrile. This effort also identified efflux as a property limiting antiviral activity of these compounds, and together with the positive attributes described these results provide insight for further drug development of novel nitrile peptidomimetics targeting SARS-CoV-2 3CL protease.
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Affiliation(s)
- Bing Bai
- Li Ka Shing Applied Virology Institute, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Elena Arutyunova
- Department of Biochemistry, University of Alberta Edmonton Alberta T6G 2H7 Canada
- Li Ka Shing Institute of Virology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Muhammad Bashir Khan
- Department of Biochemistry, University of Alberta Edmonton Alberta T6G 2H7 Canada
| | - Jimmy Lu
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Li Ka Shing Institute of Virology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Michael A Joyce
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Li Ka Shing Institute of Virology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Holly A Saffran
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Li Ka Shing Institute of Virology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Justin A Shields
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Li Ka Shing Institute of Virology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Appan Srinivas Kandadai
- Li Ka Shing Applied Virology Institute, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Alexandr Belovodskiy
- Li Ka Shing Applied Virology Institute, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Mostofa Hena
- Li Ka Shing Applied Virology Institute, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - Wayne Vuong
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Tess Lamer
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Howard S Young
- Li Ka Shing Institute of Virology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - John C Vederas
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - D Lorne Tyrrell
- Li Ka Shing Applied Virology Institute, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Li Ka Shing Institute of Virology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta Edmonton Alberta T6G 2H7 Canada
- Li Ka Shing Institute of Virology, University of Alberta Edmonton Alberta T6G 2E1 Canada
| | - James A Nieman
- Li Ka Shing Applied Virology Institute, University of Alberta Edmonton Alberta T6G 2E1 Canada
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton Alberta T6G 2E1 Canada
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5
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Law JLM, Logan M, Joyce MA, Landi A, Hockman D, Crawford K, Johnson J, LaChance G, Saffran HA, Shields J, Hobart E, Brassard R, Arutyunova E, Pabbaraju K, Croxen M, Tipples G, Lemieux MJ, Tyrrell DL, Houghton M. SARS-COV-2 recombinant Receptor-Binding-Domain (RBD) induces neutralizing antibodies against variant strains of SARS-CoV-2 and SARS-CoV-1. Vaccine 2021; 39:5769-5779. [PMID: 34481699 PMCID: PMC8387217 DOI: 10.1016/j.vaccine.2021.08.081] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 12/11/2022]
Abstract
SARS-CoV-2 is the etiological agent of COVID19. There are currently several licensed vaccines approved for human use and most of them target the spike protein in the virion envelope to induce protective immunity. Recently, variants that spread more quickly have emerged. There is evidence that some of these variants are less sensitive to neutralization in vitro, but it is not clear whether they can evade vaccine induced protection. In this study, we tested SARS-CoV-2 spike RBD as a vaccine antigen and explored the effect of formulation with Alum/MPLA or AddaS03 adjuvants. Our results show that RBD induces high titers of neutralizing antibodies and activates strong cellular immune responses. There is also significant cross-neutralization of variants B.1.1.7 and B.1.351 and to a lesser extent, SARS-CoV-1. These results indicate that recombinant RBD can be a viable candidate as a stand-alone vaccine or as a booster shot to diversify our strategy for COVID19 protection.
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Affiliation(s)
- John Lok Man Law
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada.
| | - Michael Logan
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Michael A Joyce
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Abdolamir Landi
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Darren Hockman
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Kevin Crawford
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Janelle Johnson
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Gerald LaChance
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Holly A Saffran
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Justin Shields
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Eve Hobart
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Raelynn Brassard
- Department of Biochemistry, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Elena Arutyunova
- Department of Biochemistry, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | | | | | - Graham Tipples
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada; Alberta Precision Laboratories, Edmonton, Canada
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - D Lorne Tyrrell
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| | - Michael Houghton
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada.
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6
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Feng W, Peng H, Xu J, Liu Y, Pabbaraju K, Tipples G, Joyce MA, Saffran HA, Tyrrell DL, Babiuk S, Zhang H, Le XC. Integrating Reverse Transcription Recombinase Polymerase Amplification with CRISPR Technology for the One-Tube Assay of RNA. Anal Chem 2021; 93:12808-12816. [PMID: 34506127 DOI: 10.1021/acs.analchem.1c03456] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CRISPR-Cas systems integrated with nucleic acid amplification techniques improve both analytical specificity and sensitivity. We describe here issues and solutions for the successful integration of reverse transcription (RT), recombinase polymerase amplification (RPA), and CRISPR-Cas12a nuclease reactions into a single tube under an isothermal condition (40 °C). Specific detection of a few copies of a viral DNA sequence was achieved in less than 20 min. However, the sensitivity was orders of magnitude lower for the detection of viral RNA due to the slow initiation of RPA when the complementary DNA (cDNA) template remained hybridized to RNA. During the delay of RPA, the crRNA-Cas12a ribonucleoprotein (RNP) gradually lost its activity in the RPA solution, and nonspecific amplification reactions consumed the RPA reagents. We overcame these problems by taking advantage of the endoribonuclease function of RNase H to remove RNA from the RNA-cDNA hybrids and free the cDNA as template for the RPA reaction. As a consequence, we significantly enhanced the overall reaction rate of an integrated assay using RT-RPA and CRISPR-Cas12a for the detection of RNA. We showed successful detection of 200 or more copies of the S gene sequence of SARS-CoV-2 RNA within 5-30 min. We applied our one-tube assay to 46 upper respiratory swab samples for COVID-19 diagnosis, and the results from both fluorescence intensity measurements and end-point visualization were consistent with those of RT-qPCR analysis. The strategy and technique improve the sensitivity and speed of RT-RPA and CRISPR-Cas12a assays, potentially useful for both semi-quantitative and point-of-care analyses of RNA molecules.
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Affiliation(s)
- Wei Feng
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - Hanyong Peng
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada.,State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jingyang Xu
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - Yanming Liu
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - Kanti Pabbaraju
- Provincial Laboratory for Public Health (ProvLab), Alberta Precision Laboratories, 3030 Hospital Drive, Calgary, Alberta T2N 4W4, Canada
| | - Graham Tipples
- Provincial Laboratory for Public Health, Alberta Precision Laboratories, University of Alberta Hospitals, 8440-112 St, Edmonton, Alberta T6G 2J2, Canada.,Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Michael A Joyce
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Holly A Saffran
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - D Lorne Tyrrell
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Shawn Babiuk
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, 1015 Arlington Street, Winnipeg, Manitoba R3E 3M4, Canada
| | - Hongquan Zhang
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - X Chris Le
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
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7
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Vuong W, Fischer C, Khan MB, van Belkum MJ, Lamer T, Willoughby KD, Lu J, Arutyunova E, Joyce MA, Saffran HA, Shields JA, Young HS, Nieman JA, Tyrrell DL, Lemieux MJ, Vederas JC. Improved SARS-CoV-2 M pro inhibitors based on feline antiviral drug GC376: Structural enhancements, increased solubility, and micellar studies. Eur J Med Chem 2021; 222:113584. [PMID: 34118724 PMCID: PMC8164773 DOI: 10.1016/j.ejmech.2021.113584] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/03/2021] [Accepted: 05/22/2021] [Indexed: 12/31/2022]
Abstract
Replication of SARS-CoV-2, the coronavirus causing COVID-19, requires a main protease (Mpro) to cleave viral proteins. Consequently, Mpro is a target for antiviral agents. We and others previously demonstrated that GC376, a bisulfite prodrug with efficacy as an anti-coronaviral agent in animals, is an effective inhibitor of Mpro in SARS-CoV-2. Here, we report structure-activity studies of improved GC376 derivatives with nanomolar affinities and therapeutic indices >200. Crystallographic structures of inhibitor-Mpro complexes reveal that an alternative binding pocket in Mpro, S4, accommodates the P3 position. Alternative binding is induced by polar P3 groups or a nearby methyl. NMR and solubility studies with GC376 show that it exists as a mixture of stereoisomers and forms colloids in aqueous media at higher concentrations, a property not previously reported. Replacement of its Na+ counter ion with choline greatly increases solubility. The physical, biochemical, crystallographic, and cellular data reveal new avenues for Mpro inhibitor design.
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Affiliation(s)
- Wayne Vuong
- Department of Chemistry, University of Alberta, Edmonton AB, T6G 2G2, Canada
| | - Conrad Fischer
- Department of Chemistry, University of Alberta, Edmonton AB, T6G 2G2, Canada
| | - Muhammad Bashir Khan
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton AB, T6G 2R3, Canada
| | - Marco J van Belkum
- Department of Chemistry, University of Alberta, Edmonton AB, T6G 2G2, Canada
| | - Tess Lamer
- Department of Chemistry, University of Alberta, Edmonton AB, T6G 2G2, Canada
| | - Kurtis D Willoughby
- Department of Chemistry, University of Alberta, Edmonton AB, T6G 2G2, Canada
| | - Jimmy Lu
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton AB, T6G 2R3, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton AB, T6G 2E1, Canada
| | - Elena Arutyunova
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton AB, T6G 2R3, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton AB, T6G 2E1, Canada
| | - Michael A Joyce
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton AB, T6G 2R3, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton AB, T6G 2E1, Canada
| | - Holly A Saffran
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton AB, T6G 2R3, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton AB, T6G 2E1, Canada
| | - Justin A Shields
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton AB, T6G 2R3, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton AB, T6G 2E1, Canada
| | - Howard S Young
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton AB, T6G 2R3, Canada
| | - James A Nieman
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton AB, T6G 2R3, Canada; Li Ka Shing Applied Virology Institute, University of Alberta, Edmonton AB, T6G 2E1, Canada
| | - D Lorne Tyrrell
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton AB, T6G 2R3, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton AB, T6G 2E1, Canada
| | - M Joanne Lemieux
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton AB, T6G 2R3, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton AB, T6G 2E1, Canada
| | - John C Vederas
- Department of Chemistry, University of Alberta, Edmonton AB, T6G 2G2, Canada.
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8
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Pandey M, Ozberk V, Eskandari S, Shalash AO, Joyce MA, Saffran HA, Day CJ, Lepletier A, Spillings BL, Mills JL, Calcutt A, Fan F, Williams JT, Stanisic DI, Hattingh L, Gerrard J, Skwarczynski M, Mak J, Jennings MP, Toth I, Tyrrell DL, Good MF. Antibodies to neutralising epitopes synergistically block the interaction of the receptor-binding domain of SARS-CoV-2 to ACE 2. Clin Transl Immunology 2021; 10:e1260. [PMID: 33732459 PMCID: PMC7937407 DOI: 10.1002/cti2.1260] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/02/2021] [Accepted: 02/06/2021] [Indexed: 12/12/2022] Open
Abstract
Objectives A major COVID‐19 vaccine strategy is to induce antibodies that prevent interaction between the Spike protein's receptor‐binding domain (RBD) and angiotensin‐converting enzyme 2 (ACE2). These vaccines will also induce T‐cell responses. However, concerns were raised that aberrant vaccine‐induced immune responses may exacerbate disease. We aimed to identify minimal epitopes on the RBD that would induce antibody responses that block the interaction of the RBD and ACE2 as a strategy leading to an effective vaccine with reduced risk of inducing immunopathology. Methods We procured a series of overlapping 20‐amino acid peptides spanning the RBD and asked which were recognised by plasma from COVID‐19 convalescent patients. Identified epitopes were conjugated to diphtheria‐toxoid and used to vaccinate mice. Immune sera were tested for binding to the RBD and for their ability to block the interaction of the RBD and ACE2. Results Seven putative vaccine epitopes were identified. Memory B‐cells (MBCs) specific for one of the epitopes were identified in the blood of convalescent patients. When used to vaccinate mice, six induced antibodies that bound recRBD and three induced antibodies that could partially block the interaction of the RBD and ACE2. However, when the sera were combined in pairs, we observed significantly enhanced inhibition of binding of RBD to ACE2. Two of the peptides were located in the main regions of the RBD known to contact ACE2. Of significant importance to vaccine development, two of the peptides were in regions that are invariant in the UK and South African strains. Conclusion COVID‐19 convalescent patients have SARS‐CoV‐2‐specific antibodies and MBCs, the specificities of which can be defined with short peptides. Epitope‐specific antibodies synergistically block RBD–ACE2 interaction.
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Affiliation(s)
- Manisha Pandey
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | - Victoria Ozberk
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | | | | | | | | | - Christopher J Day
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | - Ailin Lepletier
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | | | - Jamie-Lee Mills
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | - Ainslie Calcutt
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | - Fan Fan
- Olymvax Biopharmaceuticals Chengdu China
| | | | | | | | - John Gerrard
- Gold Coast Hospital and Health Service Gold Coast QLD Australia
| | | | - Johnson Mak
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | | | - Istvan Toth
- University of Queensland Brisbane QLD Australia
| | | | - Michael F Good
- Institute for Glycomics Griffith University Gold Coast QLD Australia
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9
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Pang B, Xu J, Liu Y, Peng H, Feng W, Cao Y, Wu J, Xiao H, Pabbaraju K, Tipples G, Joyce MA, Saffran HA, Tyrrell DL, Zhang H, Le XC. Isothermal Amplification and Ambient Visualization in a Single Tube for the Detection of SARS-CoV-2 Using Loop-Mediated Amplification and CRISPR Technology. Anal Chem 2020; 92:16204-16212. [PMID: 33238709 PMCID: PMC7724759 DOI: 10.1021/acs.analchem.0c04047] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/12/2020] [Indexed: 12/18/2022]
Abstract
We have developed a single-tube assay for SARS-CoV-2 in patient samples. This assay combined advantages of reverse transcription (RT) loop-mediated isothermal amplification (LAMP) with clustered regularly interspaced short palindromic repeats (CRISPRs) and the CRISPR-associated (Cas) enzyme Cas12a. Our assay is able to detect SARS-CoV-2 in a single tube within 40 min, requiring only a single temperature control (62 °C). The RT-LAMP reagents were added to the sample vial, while CRISPR Cas12a reagents were deposited onto the lid of the vial. After a half-hour RT-LAMP amplification, the tube was inverted and flicked to mix the detection reagents with the amplicon. The sequence-specific recognition of the amplicon by the CRISPR guide RNA and Cas12a enzyme improved specificity. Visible green fluorescence generated by the CRISPR Cas12a system was recorded using a smartphone camera. Analysis of 100 human respiratory swab samples for the N and/or E gene of SARS-CoV-2 produced 100% clinical specificity and no false positive. Analysis of 50 samples that were detected positive using reverse transcription quantitative polymerase chain reaction (RT-qPCR) resulted in an overall clinical sensitivity of 94%. Importantly, this included 20 samples that required 30-39 threshold cycles of RT-qPCR to achieve a positive detection. Integration of the exponential amplification ability of RT-LAMP and the sequence-specific processing by the CRISPR-Cas system into a molecular assay resulted in improvements in both analytical sensitivity and specificity. The single-tube assay is beneficial for future point-of-care applications.
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Affiliation(s)
- Bo Pang
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Jingyang Xu
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Yanming Liu
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Hanyong Peng
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Wei Feng
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Yiren Cao
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Jinjun Wu
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Huyan Xiao
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Kanti Pabbaraju
- Provincial
Laboratory for Public Health (ProvLab), Alberta Precision Laboratories, 3030 Hospital Drive, Calgary, Alberta, Canada T2N 4W4
| | - Graham Tipples
- Provincial
Laboratory for Public Health, Alberta Precision
Laboratories, University of Alberta Hospitals, 8440-112 Street, Edmonton, Alberta, Canada T6G 2J2
- Li
Ka Shing Institute of Virology, Department of Medical Microbiology
and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2E1
| | - Michael A. Joyce
- Li
Ka Shing Institute of Virology, Department of Medical Microbiology
and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2E1
| | - Holly A. Saffran
- Li
Ka Shing Institute of Virology, Department of Medical Microbiology
and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2E1
| | - D. Lorne Tyrrell
- Li
Ka Shing Institute of Virology, Department of Medical Microbiology
and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2E1
| | - Hongquan Zhang
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - X. Chris Le
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine
and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
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10
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Vuong W, Khan MB, Fischer C, Arutyunova E, Lamer T, Shields J, Saffran HA, McKay RT, van Belkum MJ, Joyce MA, Young HS, Tyrrell DL, Vederas JC, Lemieux MJ. Author Correction: Feline coronavirus drug inhibits the main protease of SARS-CoV-2 and blocks virus replication. Nat Commun 2020; 11:5409. [PMID: 33082353 PMCID: PMC7574666 DOI: 10.1038/s41467-020-19339-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Wayne Vuong
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, AB, Canada
| | - Muhammad Bashir Khan
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, T6G 2R3, AB, Canada
| | - Conrad Fischer
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, AB, Canada
| | - Elena Arutyunova
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, T6G 2R3, AB, Canada
| | - Tess Lamer
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, AB, Canada
| | - Justin Shields
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, T6G 2R3, AB, Canada.,Li Ka Shing Institute of Virology, University of Alberta, Edmonton, T6G 2E1, AB, Canada
| | - Holly A Saffran
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, T6G 2R3, AB, Canada.,Li Ka Shing Institute of Virology, University of Alberta, Edmonton, T6G 2E1, AB, Canada
| | - Ryan T McKay
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, AB, Canada
| | - Marco J van Belkum
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, AB, Canada
| | - Michael A Joyce
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, T6G 2R3, AB, Canada.,Li Ka Shing Institute of Virology, University of Alberta, Edmonton, T6G 2E1, AB, Canada
| | - Howard S Young
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, T6G 2R3, AB, Canada
| | - D Lorne Tyrrell
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, T6G 2R3, AB, Canada. .,Li Ka Shing Institute of Virology, University of Alberta, Edmonton, T6G 2E1, AB, Canada.
| | - John C Vederas
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, AB, Canada.
| | - M Joanne Lemieux
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, T6G 2R3, AB, Canada.
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11
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Lemieux J, Vuong W, Khan MB, Fischer C, Arutyunova E, Lamer T, Shields J, Saffran HA, McKay RT, van Belkum MJ, Joyce M, Young HS, Tyrrell DL, Vederas JC. Structural insights into the feline coronavirus drug GC376, which inhibits the main protease of SARS-CoV-2 and blocks virus replication. Acta Crystallogr A Found Adv 2020. [DOI: 10.1107/s0108767320097974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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12
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Dauber B, Saffran HA, Smiley JR. The herpes simplex virus host shutoff (vhs) RNase limits accumulation of double stranded RNA in infected cells: Evidence for accelerated decay of duplex RNA. PLoS Pathog 2019; 15:e1008111. [PMID: 31626661 PMCID: PMC6821131 DOI: 10.1371/journal.ppat.1008111] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/30/2019] [Accepted: 09/25/2019] [Indexed: 12/12/2022] Open
Abstract
The herpes simplex virus virion host shutoff (vhs) RNase destabilizes cellular and viral mRNAs and blunts host innate antiviral responses. Previous work demonstrated that cells infected with vhs mutants display enhanced activation of the host double-stranded RNA (dsRNA)-activated protein kinase R (PKR), implying that vhs limits dsRNA accumulation in infected cells. Confirming this hypothesis, we show that partially complementary transcripts of the UL23/UL24 and UL30/31 regions of the viral genome increase in abundance when vhs is inactivated, giving rise to greatly increased levels of intracellular dsRNA formed by annealing of the overlapping portions of these RNAs. Thus, vhs limits accumulation of dsRNA at least in part by reducing the levels of complementary viral transcripts. We then asked if vhs also destabilizes dsRNA after its initial formation. Here, we used a reporter system employing two mCherry expression plasmids bearing complementary 3’ UTRs to produce defined dsRNA species in uninfected cells. The dsRNAs are unstable, but are markedly stabilized by co-expressing the HSV dsRNA-binding protein US11. Strikingly, vhs delivered by super-infecting HSV virions accelerates the decay of these pre-formed dsRNAs in both the presence and absence of US11, a novel and unanticipated activity of vhs. Vhs binds the host RNA helicase eIF4A, and we find that vhs-induced dsRNA decay is attenuated by the eIF4A inhibitor hippuristanol, providing evidence that eIF4A participates in the process. Our results show that a herpesvirus host shutoff RNase destabilizes dsRNA in addition to targeting partially complementary viral mRNAs, raising the possibility that the mRNA destabilizing proteins of other viral pathogens dampen the host response to dsRNA through similar mechanisms. Essentially all viruses produce double-stranded RNA (dsRNA) during infection. Host organisms therefore deploy a variety of dsRNA receptors to trigger innate antiviral defenses. Not surprisingly, viruses in turn produce an array of antagonists to block this host response. The best characterized of the viral antagonists function by binding to and masking dsRNA and/or blocking downstream signaling events. Other less studied viral antagonists appear to function by reducing the levels of dsRNA in infected cells, but exactly how they do so remains unknown. Here we show that one such viral antagonist, the herpes simplex virus vhs ribonuclease, reduces dsRNA levels in two distinct ways. First, as previously suggested, it dampens the accumulation of partially complementary viral mRNAs, reducing the potential for generating dsRNA. Second, it helps remove dsRNA after its formation, a novel and surprising activity of a protein best known for its activity on single-stranded mRNA. Many other viral pathogens produce proteins that target mRNAs for rapid destruction, and it will be important to determine if these also limit host dsRNA responses in similar ways.
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Affiliation(s)
- Bianca Dauber
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Holly A. Saffran
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - James R. Smiley
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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13
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Strunk U, Ramos DG, Saffran HA, Smiley JR. Role of Herpes simplex virus 1 VP11/12 tyrosine-based binding motifs for Src family kinases, p85, Grb2 and Shc in activation of the phosphoinositide 3-kinase-Akt pathway. Virology 2016; 498:31-35. [DOI: 10.1016/j.virol.2016.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 12/25/2022]
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14
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Saffran HA, Smiley JR. The XIAP IRES activates 3' cistron expression by inducing production of monocistronic mRNA in the betagal/CAT bicistronic reporter system. RNA 2009; 15:1980-5. [PMID: 19713328 PMCID: PMC2764481 DOI: 10.1261/rna.1557809] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
X-chromosome linked inhibitor of apoptosis (XIAP) mRNA has been proposed to bear a stress-activated internal ribosome entry site (IRES) that stimulates translation under conditions that inhibit cap-dependent initiation. However, several reports have indicated that the strong activity of the XIAP IRES in certain bicistronic reporter assay systems stems from production of unintended monocistronic transcripts through splicing or cryptic promoter activity. Here we extend these findings by providing evidence that the XIAP IRES similarly provokes the production of monocistronic mRNA encompassing the 3' cistron in the betagal/CAT bicistronic reporter plasmid that was originally used to identify and characterize this putative IRES, through cryptic promoter activity.
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15
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Saffran HA, Pare JM, Corcoran JA, Weller SK, Smiley JR. Herpes simplex virus eliminates host mitochondrial DNA. EMBO Rep 2006; 8:188-93. [PMID: 17186027 PMCID: PMC1796774 DOI: 10.1038/sj.embor.7400878] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 11/08/2006] [Accepted: 11/13/2006] [Indexed: 11/08/2022] Open
Abstract
Mitochondria have crucial roles in the life and death of mammalian cells, and help to orchestrate host antiviral defences. Here, we show that the ubiquitous human pathogen herpes simplex virus (HSV) induces rapid and complete degradation of host mitochondrial DNA during productive infection of cultured mammalian cells. The depletion of mitochondrial DNA requires the viral UL12 gene, which encodes a conserved nuclease with orthologues in all herpesviruses. We show that an amino-terminally truncated UL12 isoform-UL12.5-localizes to mitochondria and triggers mitochondrial DNA depletion in the absence of other HSV gene products. By contrast, full-length UL12, a nuclear protein, has little or no effect on mitochondrial DNA levels. Our data document that HSV inflicts massive genetic damage to a crucial host organelle and show a novel mechanism of virus-induced shutoff of host functions, which is likely to contribute to the cell death and tissue damage caused by this widespread human pathogen.
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Affiliation(s)
| | - Justin M Pare
- Department of Medical Microbiology and Immunology
- Department of Cell Biology, University of Alberta, 632 Heritage Medical Research Center, Edmonton, Alberta T6G 2S2, Canada
| | | | - Sandra K Weller
- Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - James R Smiley
- Department of Medical Microbiology and Immunology
- Tel: +1 780 492 4070; Fax: +1 780 492 9828; E-mail:
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16
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Abstract
Herpes simplex virus (HSV) virion host shutoff protein (vhs) destabilizes cellular and viral mRNAs. Previous work from several laboratories has indicated that vhs accelerates the turnover of most host mRNAs and provided evidence that at least some of these are degraded via endonucleolytic cleavage near regions of translational initiation followed by 5'-->3' decay. In contrast, several recent reports have argued that vhs is selective, preferentially targeting a subset of mRNAs including some that bear AU-rich instability elements (such as the stress-inducible IEX-1 mRNA). These reports concluded that vhs triggers deadenylation, 3' cleavage, and 3'-->5' decay of IEX-1 mRNA. However, we report here that HSV infection does not increase the rate of degradation of IEX-1 mRNA; rather, actinomycin D chase assays indicate that the transcript is stabilized relative to that in uninfected cells in both the presence and absence of functional vhs. Moreover, deadenylated but otherwise intact IEX-1 mRNA was readily detected in uninfected cells cultured under our experimental conditions, and its relative abundance did not increase following HSV type 1 (HSV-1) infection. We confirm that HSV infection increases the relative abundance of a discrete 0.75-kb 3'-truncated IEX-1 RNA species in a vhs-dependent manner. This truncated transcript was also detected (albeit at lower levels) in cells infected with vhs mutants and in uninfected cells, where it increased in abundance in response to tumor necrosis factor alpha, cycloheximide, and puromycin. We conclude that IEX-1 mRNA is not preferentially degraded during HSV-1 infection and that HSV-1 instead inhibits the normal turnover of this mRNA.
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Affiliation(s)
- Wei-Li Hsu
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Alberta, Canada
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17
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Abstract
The herpes simplex virus virion host shutoff protein (vhs) is an mRNA-specific RNase that contributes to shutoff of host protein synthesis. We show here that vhs-induced mRNA decay proceeds 5' to 3' in an in vitro assay system derived from rabbit reticulocyte lysate.
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Affiliation(s)
- Jorge Perez-Parada
- Department of Medical Microbiology & Immunology, 632 Heritage Medical Research Centre, University of Alberta, Edmonton, Alberta, Canada
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18
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Doepker RC, Hsu WL, Saffran HA, Smiley JR. Herpes simplex virus virion host shutoff protein is stimulated by translation initiation factors eIF4B and eIF4H. J Virol 2004; 78:4684-99. [PMID: 15078951 PMCID: PMC387725 DOI: 10.1128/jvi.78.9.4684-4699.2004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The virion host shutoff protein (vhs) of herpes simplex virus triggers accelerated degradation of cellular and viral mRNAs while sparing other cytoplasmic RNA species. Previous work has shown that vhs forms a complex with translation initiation factor eIF4H, which displays detectable RNase activity in the absence of other viral or host proteins. However, the contributions of eIF4H and other host factors to the activity and mRNA targeting properties of vhs have not yet been directly examined. An earlier report from our laboratory demonstrated that rabbit reticulocyte lysate (RRL) contains one or more factors that strongly stimulate the RNase activity of vhs produced in Saccharomyces cerevisiae. We report here that such yeast extracts display significant vhs-dependent RNase activity in the absence of mammalian factors. This activity differs from that displayed by vhs generated in RRL in that it is not targeted to the encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES). Activity was strongly enhanced by the addition of RRL, eIF4H, or the related translation factor eIF4B. RRL also reconstituted strong targeting to the EMCV IRES, resulting in a major change in the RNA cleavage pattern. In contrast, eIF4H and eIF4B did not reconstitute IRES-directed targeting. These data indicate that eIF4B and 4H stimulate the nuclease activity of vhs, and they provide evidence that additional mammalian factors are required for targeting to the EMCV IRES.
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Affiliation(s)
- Rosalyn C Doepker
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2S2
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19
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Affiliation(s)
- J R Smiley
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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20
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Kumar R, Sharma N, Nath M, Saffran HA, Tyrrell DL. Synthesis and antiviral activity of novel acyclic nucleoside analogues of 5-(1-azido-2-haloethyl)uracils. J Med Chem 2001; 44:4225-9. [PMID: 11708924 DOI: 10.1021/jm010227k] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present the discovery of a novel category of 5-substituted acyclic pyrimidine nucleosides as potent antiviral agents. A series of 1-[(2-hydroxyethoxy)methyl] (5-7), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl] (8-10), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl] (11-13) derivatives of 5-(1-azido-2-haloethyl)uracil were synthesized and evaluated for their biological activity in cell culture. 1-[4-Hydroxy-3-(hydroxymethyl)-1-butyl]-5-(1-azido-2-chloroethyl)uracil (12) was the most effective antiviral agent in the in vitro assays against DHBV (EC(50) = 0.31-1.55 microM) and HCMV (EC(50) = 3.1 microM). None of the compounds investigated showed any detectable toxicity to several stationary and proliferating host cells.
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Affiliation(s)
- R Kumar
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton T6G 2H7, Canada.
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21
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Kumar R, Rai D, Sharma SK, Saffran HA, Blush R, Tyrrell DL. Synthesis and antiviral activity of novel 5-(1-cyanamido-2-haloethyl) and 5-(1-hydroxy(or methoxy)-2-azidoethyl) analogues of uracil nucleosides. J Med Chem 2001; 44:3531-8. [PMID: 11585457 DOI: 10.1021/jm010226s] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new class of 5-(1-cyanamido-2-haloethyl)-2'-deoxyuridines (4-6) and arabinouridines (7, 8) were synthesized by the regiospecific addition of halogenocyanamides (X-NHCN) to the 5-vinyl substituent of the respective 5-vinyl-2'-deoxyuridine (2) and 2'-arabinouridine (3). Reaction of 2 with sodium azide, ceric ammonium nitrate, and acetonitrile-methanol or water afforded the 5-(1-hydroxy-2-azidoethyl)-(10) and 5-(1-methoxy-2-azidoethyl)-2'-deoxyuridines (11). In vitro antiviral activities against HSV-1-TK(+) (KOS and E-377), HSV-1-TK(-), HSV-2, VZV, HCMV, and DHBV were determined. Of the newly synthesized compounds, 5-(1-cyanamido-2-iodoethyl)-2'-deoxyuridine (6) exhibited the most potent anti-HSV-1 activity, which was equipotent to acyclovir and superior to 5-ethyl-2'-deoxyuridine (EDU). In addition, it was significantly inhibitory for thymidine kinase deficient strain of HSV-1 (EC(50) = 2.3-15.3 microM). The 5-(1-cyanamido-2-haloethyl)-2'-deoxyuridines (4-6) all were approximately equipotent against HSV-2 and were approximately 1.5- and 15-fold less inhibitory for HSV-2 than EDU and acyclovir, respectively. Compounds 4-6 were all inactive against HCMV but exhibited appreciable antiviral activity against VZV. Their anti-VZV activity was similar or higher to that of EDU and approximately 5-12-fold lower than that of acyclovir. The 5-(1-cyanamido-2-haloethyl)-(7,8) analogues of arabinouridine were moderately inhibitory for VZV and HSV-1 (strain KOS), whereas compounds 10 and 11 were inactive against herpes viruses. Compounds 5 and 6 also demonstrated modest anti-hepatitis B virus activity against DHBV (EC(50) = 19.9-23.6 microM). Interestingly, the related 5-(1-azido-2-bromoethyl)-2'-deoxyuridine (1n) analogue proved to be markedly inhibitory to DHBV replication (EC(50) = 2.6-6.6 microM). All compounds investigated exhibited low host cell toxicity to several stationary and proliferating host cell lines as well as mitogen-stimulated proliferating human T lymphocytes.
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Affiliation(s)
- R Kumar
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton, AB, Canada T6G 2H7.
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22
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Lu P, Jones FE, Saffran HA, Smiley JR. Herpes simplex virus virion host shutoff protein requires a mammalian factor for efficient in vitro endoribonuclease activity. J Virol 2001; 75:1172-85. [PMID: 11152490 PMCID: PMC114023 DOI: 10.1128/jvi.75.3.1172-1185.2001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The virion host shutoff protein (vhs) of herpes simplex virus (HSV) triggers global shutoff of host protein synthesis and accelerated mRNA turnover during virus infection and induces endoribonucleolytic cleavage of exogenous RNA substrates when it is produced in a rabbit reticulocyte (RRL) in vitro translation system. Although vhs induces RNA turnover in the absence of other HSV gene products, it is not yet known whether cellular factors are required for its activity. As one approach to addressing this question, we expressed vhs in the budding yeast Saccharomyces cerevisiae. Expression of vhs inhibited colony formation, and the severity of this effect varied with the carbon source. The biological relevance of this effect was assessed by examining the activity of five mutant forms of vhs bearing previously characterized in-frame linker insertions. The results indicated a complete concordance between the growth inhibition phenotype in yeast and mammalian host cell shutoff. Despite these results, expression of vhs did not trigger global mRNA turnover in vivo, and cell extracts of yeast expressing vhs displayed little if any vhs-dependent endoribonuclease activity. However, activity was readily detected when such extracts were mixed with RRL. These data suggest that the vhs-dependent endoribonuclease requires one or more mammalian macromolecular factors for efficient activity.
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Affiliation(s)
- P Lu
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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23
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Lu P, Saffran HA, Smiley JR. The vhs1 mutant form of herpes simplex virus virion host shutoff protein retains significant internal ribosome entry site-directed RNA cleavage activity. J Virol 2001; 75:1072-6. [PMID: 11134323 PMCID: PMC114006 DOI: 10.1128/jvi.75.2.1072-1076.2001] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The virion host shutoff (vhs) protein of herpes simplex virus (HSV) triggers global shutoff of host protein synthesis and accelerated turnover of host and viral mRNAs during HSV infection. As well, it induces endoribonucleolytic cleavage of RNA substrates when produced in a rabbit reticulocyte lysate (RRL) in vitro translation system. The vhs1 point mutation (Thr 214-->Ile) eliminates vhs function during virus infection and in transiently transfected mammalian cells and was therefore previously considered to abolish vhs activity. Here we demonstrate that the vhs1 mutant protein induces readily detectable endoribonuclease activity on RNA substrates bearing the internal ribosome entry site of encephalomyocarditis virus in the RRL assay system. These data document that the vhs1 mutation does not eliminate catalytic activity and raise the possibility that the vhs-dependent endoribonuclease employs more than one mode of substrate recognition.
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Affiliation(s)
- P Lu
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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24
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Abstract
Interferon (IFN) is an important immune system molecule capable of inducing an antiviral state within cells. Herpes simplex virus type 1 (HSV-1) replication is somewhat reduced in tissue culture in the presence of IFN, presumably due to decreased viral transcription. Here, we show mutations that inactivate immediate-early (IE) gene product ICP0 render HSV-1 exquisitely sensitive to IFN inhibition, resulting in greatly decreased levels of viral mRNA transcripts and the resulting polypeptides and a severe reduction in plaque formation ability. Mutations in other HSV-1 genes, including the genes coding for virion transactivator VP16 and the virion host shutoff protein vhs, IE gene ICP22, and the protein kinase UL13 gene, do not increase the IFN sensitivity of HSV-1. Interestingly, ICP0 mutants demonstrate the same level of sensitivity to IFN as wild-type virus on U2OS cells, an osteosarcoma cell line that is known to complement mutations in ICP0 and VP16. Thus, in some cell types, functional ICP0 is required for HSV-1 to efficiently bypass the inhibitory effects of IFN in order to ensure its replication. The significance of this link between ICP0 and IFN resistance is discussed.
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Affiliation(s)
- K L Mossman
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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