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Kingston NJ, Snowden JS, Martyna A, Shegdar M, Grehan K, Tedcastle A, Pegg E, Fox H, Macadam AJ, Martin J, Hogle JM, Rowlands DJ, Stonehouse NJ. Production of antigenically stable enterovirus A71 virus-like particles in Pichia pastoris as a vaccine candidate. J Gen Virol 2023; 104:001867. [PMID: 37390009 PMCID: PMC10773253 DOI: 10.1099/jgv.0.001867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/12/2023] [Indexed: 07/02/2023] Open
Abstract
Enterovirus A71 (EVA71) causes widespread disease in young children with occasional fatal consequences. In common with other picornaviruses, both empty capsids (ECs) and infectious virions are produced during the viral lifecycle. While initially antigenically indistinguishable from virions, ECs readily convert to an expanded conformation at moderate temperatures. In the closely related poliovirus, these conformational changes result in loss of antigenic sites required to elicit protective immune responses. Whether this is true for EVA71 remains to be determined and is the subject of this investigation.We previously reported the selection of a thermally resistant EVA71 genogroup B2 population using successive rounds of heating and passage. The mutations found in the structural protein-coding region of the selected population conferred increased thermal stability to both virions and naturally produced ECs. Here, we introduced these mutations into a recombinant expression system to produce stabilized virus-like particles (VLPs) in Pichia pastoris.The stabilized VLPs retain the native virion-like antigenic conformation as determined by reactivity with a specific antibody. Structural studies suggest multiple potential mechanisms of antigenic stabilization, however, unlike poliovirus, both native and expanded EVA71 particles elicited antibodies able to directly neutralize virus in vitro. Therefore, anti-EVA71 neutralizing antibodies are elicited by sites which are not canonically associated with the native conformation, but whether antigenic sites specific to the native conformation provide additional protective responses in vivo remains unclear. VLPs are likely to provide cheaper and safer alternatives for vaccine production and these data show that VLP vaccines are comparable with inactivated virus vaccines at inducing neutralising antibodies.
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Affiliation(s)
- Natalie J. Kingston
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Joseph S. Snowden
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Agnieszka Martyna
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK
| | - Mona Shegdar
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Keith Grehan
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Alison Tedcastle
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK
| | - Elaine Pegg
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK
| | - Helen Fox
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK
| | - Andrew J. Macadam
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK
| | - Javier Martin
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK
| | - James M. Hogle
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - David J. Rowlands
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Nicola J. Stonehouse
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
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Kingston NJ, Snowden JS, Martyna A, Shegdar M, Grehan K, Tedcastle A, Pegg E, Fox H, Macadam AJ, Martin J, Hogle JM, Rowlands DJ, Stonehouse NJ. Production of antigenically stable enterovirus A71 virus-like particles in Pichia pastoris as a vaccine candidate. bioRxiv 2023:2023.01.30.526315. [PMID: 36778240 PMCID: PMC9915507 DOI: 10.1101/2023.01.30.526315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Enterovirus A71 (EVA71) causes widespread disease in young children with occasional fatal consequences. In common with other picornaviruses, both empty capsids (ECs) and infectious virions are produced during the viral lifecycle. While initially antigenically indistinguishable from virions, ECs readily convert to an expanded conformation at moderate temperatures. In the closely related poliovirus, these conformational changes result in loss of antigenic sites required to elicit protective immune responses. Whether this is true for EVA71 remains to be determined and is the subject of this investigation. We previously reported the selection of a thermally resistant EVA71 genogroup B2 population using successive rounds of heating and passage. The mutations found in the structural protein-coding region of the selected population conferred increased thermal stability to both virions and naturally produced ECs. Here, we introduced these mutations into a recombinant expression system to produce stabilised virus-like particles (VLPs) in Pichia pastoris . The stabilised VLPs retain the native virion-like antigenic conformation as determined by reactivity with a specific antibody. Structural studies suggest multiple potential mechanisms of antigenic stabilisation, however, unlike poliovirus, both native and expanded EVA71 particles elicited antibodies able to directly neutralise virus in vitro . Therefore, the anti-EVA71 neutralising antibodies are elicited by sites which are not canonically associated with the native conformation, but whether antigenic sites specific to the native conformation provide additional protective responses in vivo remains unclear. VLPs are likely to provide cheaper and safer alternatives for vaccine production and these data show that VLP vaccines are comparable with inactivated virus vaccines at inducing neutralising antibodies.
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Affiliation(s)
- Natalie J Kingston
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Joseph S Snowden
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Agnieszka Martyna
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Mona Shegdar
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Keith Grehan
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Alison Tedcastle
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Elaine Pegg
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Helen Fox
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Andrew J Macadam
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Javier Martin
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - James M Hogle
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - David J Rowlands
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Nicola J Stonehouse
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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Bahar MW, Nasta V, Fox H, Sherry L, Grehan K, Porta C, Macadam AJ, Stonehouse NJ, Rowlands DJ, Fry EE, Stuart DI. Publisher Correction: A conserved glutathione binding site in poliovirus is a target for antivirals and vaccine stabilisation. Commun Biol 2022; 5:1413. [PMID: 36564504 PMCID: PMC9789091 DOI: 10.1038/s42003-022-04378-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Mohammad W Bahar
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK.
| | - Veronica Nasta
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
- Magnetic Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
- Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy
| | - Helen Fox
- The National Institute for Biological Standards and Control, Potters Bar, EN6 3QG, UK
| | - Lee Sherry
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Keith Grehan
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Claudine Porta
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK
| | - Andrew J Macadam
- The National Institute for Biological Standards and Control, Potters Bar, EN6 3QG, UK
| | - Nicola J Stonehouse
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - David J Rowlands
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Elizabeth E Fry
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
| | - David I Stuart
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK.
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
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Bahar MW, Nasta V, Fox H, Sherry L, Grehan K, Porta C, Macadam AJ, Stonehouse NJ, Rowlands DJ, Fry EE, Stuart DI. A conserved glutathione binding site in poliovirus is a target for antivirals and vaccine stabilisation. Commun Biol 2022; 5:1293. [PMID: 36434067 PMCID: PMC9700776 DOI: 10.1038/s42003-022-04252-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/11/2022] [Indexed: 11/27/2022] Open
Abstract
Strategies to prevent the recurrence of poliovirus (PV) after eradication may utilise non-infectious, recombinant virus-like particle (VLP) vaccines. Despite clear advantages over inactivated or attenuated virus vaccines, instability of VLPs can compromise their immunogenicity. Glutathione (GSH), an important cellular reducing agent, is a crucial co-factor for the morphogenesis of enteroviruses, including PV. We report cryo-EM structures of GSH bound to PV serotype 3 VLPs showing that it can enhance particle stability. GSH binds the positively charged pocket at the interprotomer interface shown recently to bind GSH in enterovirus F3 and putative antiviral benzene sulphonamide compounds in other enteroviruses. We show, using high-resolution cryo-EM, the binding of a benzene sulphonamide compound with a PV serotype 2 VLP, consistent with antiviral activity through over-stabilizing the interprotomer pocket, preventing the capsid rearrangements necessary for viral infection. Collectively, these results suggest GSH or an analogous tight-binding antiviral offers the potential for stabilizing VLP vaccines.
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Affiliation(s)
- Mohammad W Bahar
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK.
| | - Veronica Nasta
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
- Magnetic Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
- Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy
| | - Helen Fox
- The National Institute for Biological Standards and Control, Potters Bar, EN6 3QG, UK
| | - Lee Sherry
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Keith Grehan
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Claudine Porta
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK
| | - Andrew J Macadam
- The National Institute for Biological Standards and Control, Potters Bar, EN6 3QG, UK
| | - Nicola J Stonehouse
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - David J Rowlands
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Elizabeth E Fry
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
| | - David I Stuart
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK.
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
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Bahar MW, Porta C, Fox H, Macadam AJ, Fry EE, Stuart DI. Mammalian expression of virus-like particles as a proof of principle for next generation polio vaccines. NPJ Vaccines 2021; 6:5. [PMID: 33420068 PMCID: PMC7794334 DOI: 10.1038/s41541-020-00267-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 12/02/2020] [Indexed: 02/07/2023] Open
Abstract
Global vaccination programs using live-attenuated oral and inactivated polio vaccine (OPV and IPV) have almost eradicated poliovirus (PV) but these vaccines or their production pose significant risk in a polio-free world. Recombinant PV virus-like particles (VLPs), lacking the viral genome, represent safe next-generation vaccines, however their production requires optimisation. Here we present an efficient mammalian expression strategy producing good yields of wild-type PV VLPs for all three serotypes and a thermostabilised variant for PV3. Whilst the wild-type VLPs were predominantly in the non-native C-antigenic form, the thermostabilised PV3 VLPs adopted the native D-antigenic conformation eliciting neutralising antibody titres equivalent to the current IPV and were indistinguishable from natural empty particles by cryo-electron microscopy with a similar stabilising lipidic pocket-factor in the VP1 β-barrel. This factor may not be available in alternative expression systems, which may require synthetic pocket-binding factors. VLPs equivalent to these mammalian expressed thermostabilized particles, represent safer non-infectious vaccine candidates for the post-eradication era.
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Affiliation(s)
- Mohammad W Bahar
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK.
| | - Claudine Porta
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK
| | - Helen Fox
- The National Institute for Biological Standards and Control, Potters Bar, EN6 3QG, UK
| | - Andrew J Macadam
- The National Institute for Biological Standards and Control, Potters Bar, EN6 3QG, UK
| | - Elizabeth E Fry
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
| | - David I Stuart
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK.
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
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Van Damme P, De Coster I, Bandyopadhyay AS, Revets H, Withanage K, De Smedt P, Suykens L, Oberste MS, Weldon WC, Costa-Clemens SA, Clemens R, Modlin J, Weiner AJ, Macadam AJ, Andino R, Kew OM, Konopka-Anstadt JL, Burns CC, Konz J, Wahid R, Gast C. The safety and immunogenicity of two novel live attenuated monovalent (serotype 2) oral poliovirus vaccines in healthy adults: a double-blind, single-centre phase 1 study. Lancet 2019; 394:148-158. [PMID: 31174831 PMCID: PMC6626986 DOI: 10.1016/s0140-6736(19)31279-6] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND Use of oral live-attenuated polio vaccines (OPV), and injected inactivated polio vaccines (IPV) has almost achieved global eradication of wild polio viruses. To address the goals of achieving and maintaining global eradication and minimising the risk of outbreaks of vaccine-derived polioviruses, we tested novel monovalent oral type-2 poliovirus (OPV2) vaccine candidates that are genetically more stable than existing OPVs, with a lower risk of reversion to neurovirulence. Our study represents the first in-human testing of these two novel OPV2 candidates. We aimed to evaluate the safety and immunogenicity of these vaccines, the presence and extent of faecal shedding, and the neurovirulence of shed virus. METHODS In this double-blind, single-centre phase 1 trial, we isolated participants in a purpose-built containment facility at the University of Antwerp Hospital (Antwerp, Belgium), to minimise the risk of environmental release of the novel OPV2 candidates. Participants, who were recruited by local advertising, were adults (aged 18-50 years) in good health who had previously been vaccinated with IPV, and who would not have any contact with immunosuppressed or unvaccinated people for the duration of faecal shedding at the end of the study. The first participant randomly chose an envelope containing the name of a vaccine candidate, and this determined their allocation; the next 14 participants to be enrolled in the study were sequentially allocated to this group and received the same vaccine. The subsequent 15 participants enrolled after this group were allocated to receive the other vaccine. Participants and the study staff were masked to vaccine groups until the end of the study period. Participants each received a single dose of one vaccine candidate (candidate 1, S2/cre5/S15domV/rec1/hifi3; or candidate 2, S2/S15domV/CpG40), and they were monitored for adverse events, immune responses, and faecal shedding of the vaccine virus for 28 days. Shed virus isolates were tested for the genetic stability of attenuation. The primary outcomes were the incidence and type of serious and severe adverse events, the proportion of participants showing viral shedding in their stools, the time to cessation of viral shedding, the cell culture infective dose of shed virus in virus-positive stools, and a combined index of the prevalence, duration, and quantity of viral shedding in all participants. This study is registered with EudraCT, number 2017-000908-21 and ClinicalTrials.gov, number NCT03430349. FINDINGS Between May 22 and Aug 22, 2017, 48 volunteers were screened, of whom 15 (31%) volunteers were excluded for reasons relating to the inclusion or exclusion criteria, three (6%) volunteers were not treated because of restrictions to the number of participants in each group, and 30 (63%) volunteers were sequentially allocated to groups (15 participants per group). Both novel OPV2 candidates were immunogenic and increased the median blood titre of serum neutralising antibodies; all participants were seroprotected after vaccination. Both candidates had acceptable tolerability, and no serious adverse events occurred during the study. However, severe events were reported in six (40%) participants receiving candidate 1 (eight events) and nine (60%) participants receiving candidate 2 (12 events); most of these events were increased blood creatinine phosphokinase but were not accompanied by clinical signs or symptoms. Vaccine virus was detected in the stools of 15 (100%) participants receiving vaccine candidate 1 and 13 (87%) participants receiving vaccine candidate 2. Vaccine poliovirus shedding stopped at a median of 23 days (IQR 15-36) after candidate 1 administration and 12 days (1-23) after candidate 2 administration. Total shedding, described by the estimated median shedding index (50% cell culture infective dose/g), was observed to be greater with candidate 1 than candidate 2 across all participants (2·8 [95% CI 1·8-3·5] vs 1·0 [0·7-1·6]). Reversion to neurovirulence, assessed as paralysis of transgenic mice, was low in isolates from those vaccinated with both candidates, and sequencing of shed virus indicated that there was no loss of attenuation in domain V of the 5'-untranslated region, the primary site of reversion in Sabin OPV. INTERPRETATION We found that the novel OPV2 candidates were safe and immunogenic in IPV-immunised adults, and our data support the further development of these vaccines to potentially be used for maintaining global eradication of neurovirulent type-2 polioviruses. FUNDING Bill & Melinda Gates Foundation.
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Affiliation(s)
- Pierre Van Damme
- Centre for the Evaluation of Vaccination, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium.
| | - Ilse De Coster
- Centre for the Evaluation of Vaccination, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | | | - Hilde Revets
- Centre for the Evaluation of Vaccination, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | - Kanchanamala Withanage
- Centre for the Evaluation of Vaccination, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | - Philippe De Smedt
- Centre for the Evaluation of Vaccination, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | - Leen Suykens
- Centre for the Evaluation of Vaccination, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | | | | | | | - Ralf Clemens
- Global Research in Infectious Diseases, Rio de Janeiro, Brazil
| | - John Modlin
- Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Amy J Weiner
- Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Andrew J Macadam
- National Institute for Biological Standards and Control, Ridge, UK
| | - Raul Andino
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA, USA
| | - Olen M Kew
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Cara C Burns
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - John Konz
- Center for Vaccine Innovation and Access, PATH, Seattle, WA, USA
| | - Rahnuma Wahid
- Center for Vaccine Innovation and Access, PATH, Seattle, WA, USA
| | - Christopher Gast
- Center for Vaccine Innovation and Access, PATH, Seattle, WA, USA
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Farcet MR, Modrof J, Rabel PO, Schirmer A, Macadam AJ, Fox H, Minor PD, Kreil TR. Continued use of poliovirus after eradication: hyper‐attenuated strains as a safe alternative for release testing of human immunoglobulins. Transfusion 2018; 58 Suppl 3:3084-3089. [DOI: 10.1111/trf.15048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 10/26/2018] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - Andrew J. Macadam
- Division of Virology National Institute for Biological Standards and Control Hertfordshire UK
| | - Helen Fox
- Division of Virology National Institute for Biological Standards and Control Hertfordshire UK
| | - Philip D. Minor
- Division of Virology National Institute for Biological Standards and Control Hertfordshire UK
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8
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Marsian J, Fox H, Bahar MW, Kotecha A, Fry EE, Stuart DI, Macadam AJ, Rowlands DJ, Lomonossoff GP. Plant-made polio type 3 stabilized VLPs-a candidate synthetic polio vaccine. Nat Commun 2017; 8:245. [PMID: 28811473 PMCID: PMC5557999 DOI: 10.1038/s41467-017-00090-w] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [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: 11/24/2016] [Accepted: 05/31/2017] [Indexed: 11/24/2022] Open
Abstract
Poliovirus (PV) is the causative agent of poliomyelitis, a crippling human disease known since antiquity. PV occurs in two distinct antigenic forms, D and C, of which only the D form elicits a robust neutralizing response. Developing a synthetically produced stabilized virus-like particle (sVLP)-based vaccine with D antigenicity, without the drawbacks of current vaccines, will be a major step towards the final eradication of poliovirus. Such a sVLP would retain the native antigenic conformation and the repetitive structure of the original virus particle, but lack infectious genomic material. In this study, we report the production of synthetically stabilized PV VLPs in plants. Mice carrying the gene for the human PV receptor are protected from wild-type PV when immunized with the plant-made PV sVLPs. Structural analysis of the stabilized mutant at 3.6 Å resolution by cryo-electron microscopy and single-particle reconstruction reveals a structure almost indistinguishable from wild-type PV3.Despite the success of current vaccination against poliomyelitis, safe, cheap and effective vaccines remain sought for continuing eradication effort. Here the authors use plants to express stabilized virus-like particles of type 3 poliovirus that can induce a protective immune response in mice transgenic for the human poliovirus receptor.
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Affiliation(s)
- Johanna Marsian
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Helen Fox
- The National Institute for Biological Standards and Control, Potters Bar, EN6 3QG, UK
| | - Mohammad W Bahar
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
| | - Abhay Kotecha
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
| | - Elizabeth E Fry
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
| | - David I Stuart
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, OX3 7BN, UK
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Andrew J Macadam
- The National Institute for Biological Standards and Control, Potters Bar, EN6 3QG, UK
| | - David J Rowlands
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
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9
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Fox H, Knowlson S, Minor PD, Macadam AJ. Genetically Thermo-Stabilised, Immunogenic Poliovirus Empty Capsids; a Strategy for Non-replicating Vaccines. PLoS Pathog 2017; 13:e1006117. [PMID: 28103317 PMCID: PMC5245777 DOI: 10.1371/journal.ppat.1006117] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [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: 08/05/2016] [Accepted: 12/10/2016] [Indexed: 01/13/2023] Open
Abstract
While wild type polio has been nearly eradicated there will be a need to continue immunisation programmes for some time because of the possibility of re-emergence and the existence of long term excreters of poliovirus. All vaccines in current use depend on growth of virus and most of the non-replicating (inactivated) vaccines involve wild type viruses known to cause poliomyelitis. The attenuated vaccine strains involved in the eradication programme have been used to develop new inactivated vaccines as production is thought safer. However it is known that the Sabin vaccine strains are genetically unstable and can revert to a virulent transmissible form. A possible solution to the need for virus growth would be to generate empty viral capsids by recombinant technology, but hitherto such particles are so unstable as to be unusable. We report here the genetic manipulation of the virus to generate stable empty capsids for all three serotypes. The particles are shown to be extremely stable and to generate high levels of protective antibodies in animal models. There is a need for safe production of polio vaccines as eradication is approached. Empty capsids in a native conformation are produced by poliovirus and other picornaviruses seemingly as a necessary part of the assembly process, possibly to provide a reservoir of subunits in a form that is resistant to cellular pathways that target unfolded or hydrophobic motifs for proteolytic degradation. Normally they are not very stable prior to genome encapsidation but more stable forms, if they existed, could potentially be useful as vaccines. Genetic variants that increase empty capsid stability have been identified and by artificially combining several in one sequence the evolutionary constraints have been bypassed, with the resulting stable empty capsids representing essentially dead-end products. They induce antibody efficiently and are stable on storage. Empty capsids can be produced by recombinant expression which, if it were efficient enough, could provide a source of immunogenic particles suitable for use as vaccines without the need for live virus at any stage of production. This would be ideal for a post-eradication world.
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Affiliation(s)
- Helen Fox
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Sarah Knowlson
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Philip D. Minor
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Andrew J. Macadam
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
- * E-mail:
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10
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Knowlson S, Burlison J, Giles E, Fox H, Macadam AJ, Minor PD. New Strains Intended for the Production of Inactivated Polio Vaccine at Low-Containment After Eradication. PLoS Pathog 2015; 11:e1005316. [PMID: 26720150 PMCID: PMC4699825 DOI: 10.1371/journal.ppat.1005316] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [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: 08/28/2015] [Accepted: 11/09/2015] [Indexed: 11/29/2022] Open
Abstract
Poliomyelitis has nearly been eradicated through the efforts of the World Health Organization's Global Eradication Initiative raising questions on containment of the virus after it has been eliminated in the wild. Most manufacture of inactivated polio vaccines currently requires the growth of large amounts of highly virulent poliovirus, and release from a production facility after eradication could be disastrous; WHO have therefore recommended the use of the attenuated Sabin strains for production as a safer option although it is recognised that they can revert to a transmissible paralytic form. We have exploited the understanding of the molecular virology of the Sabin vaccine strains to design viruses that are extremely genetically stable and hyperattenuated. The viruses are based on the type 3 Sabin vaccine strain and have been genetically modified in domain V of the 5' non-coding region by changing base pairs to produce a cassette into which capsid regions of other serotypes have been introduced. The viruses give satisfactory yields of antigenically and immunogenically correct viruses in culture, are without measurable neurovirulence and fail to infect non-human primates under conditions where the Sabin strains will do so.
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Affiliation(s)
- Sarah Knowlson
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - John Burlison
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Elaine Giles
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Helen Fox
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Andrew J. Macadam
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
| | - Philip D. Minor
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
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11
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Macadam AJ, Ferguson G, Stone DM, Meredith J, Knowlson S, Auda G, Almond JW, Minor PD. Rational design of genetically stable, live-attenuated poliovirus vaccines of all three serotypes: relevance to poliomyelitis eradication. J Virol 2006; 80:8653-63. [PMID: 16912313 PMCID: PMC1563845 DOI: 10.1128/jvi.00370-06] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [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: 11/20/2022] Open
Abstract
The global eradication of poliomyelitis caused by wild-type virus is likely to be completed within the next few years, despite immense logistic and political difficulties, and may ultimately be followed by the cessation of vaccination. However, the existing live-attenuated vaccines have the potential to revert to virulence, causing occasional disease, and viruses can be shed by immunocompromised individuals for prolonged periods of time. Moreover, several outbreaks of poliomyelitis have been shown to be caused by viruses derived from the Sabin vaccine strains. The appearance of such strains depends on the prevailing circumstances but poses a severe obstacle to strategies for stopping vaccination. Vaccine strains that are incapable of reversion at a measurable rate would provide a possible solution. Here, we describe the constructions of strains of type 3 poliovirus that are stabilized by the introduction of four mutations in the 5' noncoding region compared to the present vaccine. The strains are genetically and phenotypically stable under conditions where the present vaccine loses the attenuating mutation in the 5' noncoding region completely. Type 1 and type 2 strains in which the entire 5' noncoding regions of Sabin 1 and Sabin 2 were replaced exactly with that of one of the type 3 strains were also constructed. The genetic stability of 5' noncoding regions of these viruses matched that of the type 3 strains, but significant phenotypic reversion occurred, illustrating the potential limitations of a rational approach to the genetic stabilization of live RNA virus vaccines.
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12
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Macadam AJ, Ferguson G, Stone DM, Meredith J, Almond JW, Minor PD. Live-attenuated strains of improved genetic stability. Dev Biol (Basel) 2002; 105:179-87. [PMID: 11763326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The current live-attenuated vaccine strains of poliovirus are genetically unstable and capable of rapid evolution in human hosts, resulting in reversion to neurovirulence and, occasionally, disease. They can also be shed by recipients for a considerable time after vaccination. This raises questions about how and when to stop vaccination after wild-type viruses have been eliminated. Persistence of vaccine revertant viruses in the population would present a risk to new cohorts of unvaccinated children and threaten the success of the eradication programme. A number of Sabin vaccine strain derivatives have been described that are, in theory, genetically more stable than the present vaccines and therefore less likely to revert to virulence. The approaches used in their derivation are outlined here and data presented for two strains showing a significant improvement in genetic stability. These strains were designed according to our understanding of the molecular basis of attenuation and incorporate changes in the sequence of an RNA structural domain that plays a key role in attenuation. They may also be less transmissible than the current type 3 vaccine strain and are potentially useful in the strategically difficult final stages of poliomyelitis eradication.
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Affiliation(s)
- A J Macadam
- National Institute for Biological Standards and Control, Potters Bar, UK
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13
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Abstract
Previously we have shown that polioviruses with mutations that disrupt the predicted secondary structure of the 5' noncoding region of domain V are temperature sensitive for growth. Non-temperature-sensitive revertant viruses had mutations that re-formed secondary structure by a direct back mutation of changes in the opposite strand. We mutated unpaired regions and selected revertants of viruses with single base deletions, where no obvious back mutation was available in order to gain information on secondary structure. Results indicated that conservation of length of a three base loop between two double-stranded stems was essential for a functional domain V to form. The requirement for the unpaired "hinge" base at 484 which is implicated in the attenuation of Sabin 2 was also confirmed. Results also underline the necessity for functional folding over local secondary structure stability.
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Affiliation(s)
- A Rowe
- Division of Virology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts, EN6 3QG, United Kingdom.
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14
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Rowe A, Ferguson GL, Minor PD, Macadam AJ. Coding changes in the poliovirus protease 2A compensate for 5'NCR domain V disruptions in a cell-specific manner. Virology 2000; 269:284-93. [PMID: 10753707 DOI: 10.1006/viro.2000.0244] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [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: 01/09/2023]
Abstract
Polioviruses are single-stranded RNA viruses with an unusually long noncoding region (NCR) at the 5' end predicted to have an elaborate secondary structure made up of six domains. Mutations in domain V of the poliovirus 5'NCR that disrupt secondary structure are responsible for attenuation of the virus and a temperature-sensitive (ts) phenotype in vitro. In addition to direct back mutation or compensatory second site mutation in the 5'NCR as previously documented, the ts phenotype was found to be compensated for in monkey kidney cells in vitro by a coding change in the protease 2A. These coding changes were found throughout the protease with no obvious pattern or trend. They were not all found to be equivalent and limited in ability to compensate for the severest domain V disruption. The compensatory effect of the 2A changes was found to be cell specific, having no effect on monkey neurovirulence and in a mouse cell line but a significant effect in two monkey cell lines and a human epithelial line.
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Affiliation(s)
- A Rowe
- Department of Virology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, EN6 3QG, United Kingdom
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15
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Abstract
A new generation of tests to control live attenuated poliovirus vaccines are under development based on major advances in our understanding of the molecular basis of attenuation and reversion to virulence of polioviruses. These include an alternative in vivo neurovirulence test in transgenic mice that express the human poliovirus receptor and a new in vitro test, the MAPREC (mutant analysis by polymerose chain reaction and restriction enzyme cleavage assay, that assesses consistency of production at a molecular level. Excellent progress is being made with both methods but neither is sufficiently developed yet for regulatory use. Critical review of existing control tests shows that the WHO neurovirulence test is well standardized and contributes significantly to the assessment of each batch. On the other hand, the current rct40 test is neither standardized nor particularly informative, though improvements could be made in both areas. The continued relevance of other marker tests such as the d or antigenic marker is doubtful. Potency, identity and thermal stability tests are crucial for control of the final trivalent vaccine.
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Affiliation(s)
- D J Wood
- NIBSC, South Mimms, Potters Bar, UK
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16
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McGoldrick A, Macadam AJ, Dunn G, Rowe A, Burlison J, Minor PD, Meredith J, Evans DJ, Almond JW. Role of mutations G-480 and C-6203 in the attenuation phenotype of Sabin type 1 poliovirus. J Virol 1995; 69:7601-5. [PMID: 7494267 PMCID: PMC189699 DOI: 10.1128/jvi.69.12.7601-7605.1995] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [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: 02/06/2023] Open
Abstract
Of the 55 point mutations which distinguish the type 1 poliovirus vaccine strain (Sabin 1) from its neurovirulent progenitor (P1/Mahoney), two have been strongly implicated by previous studies as determinants of the attenuation phenotype. A change of an A to a G at position 480, located within the 5' noncoding region, has been suggested to be the major attenuating mutation, analogous to the mutations at positions 481 and 472 in poliovirus types 2 and 3, respectively. In addition, the change of a U to a C at position 6203, resulting in an amino acid change in the polymerase protein 3D, has also been implicated as a determinant of attenuation, albeit to a lesser extent. To assess the contributions of these mutations to attenuation and temperature sensitivity, reciprocal changes were generated at these positions in infectious cDNA clones of Sabin 1 and P1/Mahoney. Assays in tissue culture and primates indicated that the two mutations make some contribution to the temperature sensitivity of the Sabin 1 strain but that neither is a strong determinant of attenuation.
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Affiliation(s)
- A McGoldrick
- School of Animal and Microbial Sciences, University of Reading, Whiteknigts, Reading, United Kingdom
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17
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Mahon BP, Katrak K, Nomoto A, Macadam AJ, Minor PD, Mills KH. Poliovirus-specific CD4+ Th1 clones with both cytotoxic and helper activity mediate protective humoral immunity against a lethal poliovirus infection in transgenic mice expressing the human poliovirus receptor. J Exp Med 1995; 181:1285-92. [PMID: 7699320 PMCID: PMC2191967 DOI: 10.1084/jem.181.4.1285] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The current understanding of the function of CD4+ T helper (Th) cells in immunity to infectious diseases is that Th1 cells, which secrete interleukin (IL)-2 and interferon-gamma, induce cellular immune responses, whereas Th2 cells, which secrete IL-4, IL-5, IL-6, and IL-10, provide helper function for humoral immunity. We have used a panel of poliovirus-specific murine CD4+ T cell clones and mice transgenic for the human poliovirus receptor to evaluate the role of Th cell subpopulations in protective immunity to poliovirus. The majority of T cell clones, as well as polyclonal T cells generated from mice infected or immunized with poliovirus, secreted IL-2 and interferon-gamma, but not IL-4, IL-5, or IL-10, a profile typical of Th1 cells. The Th1 clones displayed major histocompatibility complex class II-restricted cytotoxic T lymphocyte activity against specific poliovirus peptide-pulsed target cells, but also provided help for antipoliovirus neutralizing antibody production. To examine the mechanism of immunity in vivo, we have used poliovirus receptor-transgenic mice on a BALB/c (H-2d) background. These animals developed a poliomyelitis-like disease when challenged intravenously with a virulent wild-type strain of poliovirus, but not with an attenuated vaccine strain. Furthermore, mice immunized with the vaccine strain were protected against a subsequent challenge with wild-type virus. Using an adoptive transfer technique, we demonstrated that it was possible to confer protection with primed B cells in the presence of polyclonal poliovirus-specific T cells, but not when transgenic mice received either B cells or T cells alone. Furthermore, protection was observed when mice received primed B cells in the presence of a VP4-specific Th1 clone. The findings demonstrate that Th1 cells can mediate a protective immune response against poliovirus infection in vivo through helper activity for humoral immunity and that CD4+ T cells, specific for the internal poliovirus capsid protein, VP4, can provide effective help for a protective antibody response directed against surface capsid proteins.
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MESH Headings
- Animals
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/immunology
- Antibody Formation
- B-Lymphocytes/transplantation
- CD4 Antigens/analysis
- Capsid/immunology
- Capsid Proteins
- H-2 Antigens/immunology
- Histocompatibility Antigens Class II/immunology
- Immunotherapy, Adoptive
- Interferon-gamma/metabolism
- Interleukin-2/metabolism
- Membrane Proteins
- Mice
- Mice, Inbred BALB C
- Mice, Inbred CBA
- Mice, Inbred ICR
- Mice, Transgenic
- Poliomyelitis/prevention & control
- Poliovirus/immunology
- Poliovirus/pathogenicity
- Receptors, Virus/biosynthesis
- Receptors, Virus/genetics
- Receptors, Virus/physiology
- Recombinant Proteins/biosynthesis
- Spleen/cytology
- Spleen/immunology
- T-Lymphocyte Subsets/transplantation
- T-Lymphocytes, Cytotoxic/immunology
- Th1 Cells/immunology
- Virulence
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Affiliation(s)
- B P Mahon
- Department of Biology, St. Patrick's College, Maynooth, County Kildare, Ireland
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18
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Abstract
All three live, attenuated vaccine strains of poliovirus contain important attenuation determinants in a short conserved sequence in the 5' noncoding region. Evidence suggests these act by weakening a secondary-structural element critical for the unusual mechanism of translational initiation of picornaviruses, in which ribosomes bind directly to a site far downstream of the 5' end. Understanding the molecular basis of attenuation may allow novel vaccine strains to be designed.
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Affiliation(s)
- A J Macadam
- Divn of Virology, National Institute for Biological Standards and Control, South Mimms, Herts., UK
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19
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Abstract
Viral protein synthesis in poliovirus infected cells was found to be influenced by mutations in part of the viral 5'-non-coding region (NCR) in a temperature dependent manner. At elevated temperatures these mutations resulted in virus titre reductions that allowed selection of revertant viruses. Some revertants were found to have retained the 5'-NCR mutations but had compensating mutations in the 2A protease gene that were responsible for the suppression of the temperature sensitive phenotypes. The mutations in 2A enhanced viral protein synthesis at a stage when cap dependent translation was already abolished, suggesting that the virally encoded protein 2A is directly involved in the process of cap independent translation in addition to its role in abolishing cap dependent translation.
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Affiliation(s)
- A J Macadam
- National Institute for Biological Standards and Control, Herts, UK
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20
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Affiliation(s)
- P D Minor
- National Institute for Biological Standards and Control, Division of Virology, Potters Bar, Herts, U.K
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21
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Macadam AJ, Pollard SR, Ferguson G, Skuce R, Wood D, Almond JW, Minor PD. Genetic basis of attenuation of the Sabin type 2 vaccine strain of poliovirus in primates. Virology 1993; 192:18-26. [PMID: 8390752 DOI: 10.1006/viro.1993.1003] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.5] [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: 01/30/2023]
Abstract
The type 2 live-attenuated vaccine strain of poliovirus (P2/Sabin) is associated with rare cases of poliomyelitis in vaccinees or their contacts. Recombinants were generated between infectious clones of a neurovirulent isolate from one such case (P2/117) and P2/Sabin and neurovirulence assays suggested that a maximum of six nucleotide differences between the two strains were responsible for their phenotypic difference. Site-directed mutagenesis of P2/Sabin showed that mutations at just two positions, at 481 in the 5' non-coding region and at VP1-143 in the capsid proteins, resulted in a highly neurovirulent virus. Other nucleotide changes may have weaker phenotypic effects. These results are consistent with those reported in the mouse model by Ren et al. [J. Virol. 65, 1377, (1991)] indicating that, for P2/Sabin at least, the same determinants of attenuation are important in both primates and transgenic mice expressing the poliovirus receptor. Sequence analysis of isolates from other vaccine-associated cases of poliomyelitis and from healthy vaccinees showed that both major determinants of attenuation are unstable on human passage, although selection pressures against an A at 481 are stronger than those against an Ile at 1143.
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Affiliation(s)
- A J Macadam
- National Institute for Biological Standards and Control, Potters Bar, Herts, United Kingdom
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22
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Macadam AJ, Ferguson G, Burlison J, Stone D, Skuce R, Almond JW, Minor PD. Correlation of RNA secondary structure and attenuation of Sabin vaccine strains of poliovirus in tissue culture. Virology 1992; 189:415-22. [PMID: 1641974 DOI: 10.1016/0042-6822(92)90565-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [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: 12/28/2022]
Abstract
Part of the 5' noncoding regions of all three Sabin vaccine strains of poliovirus contains determinants of attenuation that are shown here to influence the ability of these strains to grow at elevated temperatures in BGM cells. The predicted RNA secondary structure of this region (nt 464-542 in P3/Sabin) suggests that both phenotypes are due to perturbation of base-paired stems. Ts phenotypes of site-directed mutants with defined changes in this region correlated well with predicted secondary structure stabilities. Reversal of base-pair orientation had little effect whereas stem disruption led to marked increases in temperature sensitivity. Phenotypic revertants of such viruses displayed mutations on either side of the stem. Mutations destabilizing stems led to intermediate phenotypes. These results provided evidence for the biological significance of the predicted RNA secondary structure.
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Affiliation(s)
- A J Macadam
- National Institute for Biological Standards and Control, South Mimms, Potters Bar, Herts, United Kingdom
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23
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Macadam AJ, Ferguson G, Arnold C, Minor PD. An assembly defect as a result of an attenuating mutation in the capsid proteins of the poliovirus type 3 vaccine strain. J Virol 1991; 65:5225-31. [PMID: 1654440 PMCID: PMC249000 DOI: 10.1128/jvi.65.10.5225-5231.1991] [Citation(s) in RCA: 36] [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: 12/28/2022] Open
Abstract
The molecular basis of the temperature-sensitive (ts) phenotype of P3/Sabin, the type 3 vaccine strain of poliovirus, was investigated in light of the known correlation between ts and attenuation phenotypes. A phenylalanine at residue 91 of the capsid protein VP3 was a major determinant of both phenotypes, and attenuation and ts could be reverted by the same second-site mutations. The ts phenotype was due to a defect early in the assembly process that inhibited the formation of 14S pentamers, empty capsids, and virions. It was further shown that capsid proteins that were not incorporated into higher-order structures had short half-lives at the nonpermissive temperature.
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Affiliation(s)
- A J Macadam
- National Institute for Biological Standards and Control, Hertfordshire, United Kingdom
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24
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Macadam AJ, Pollard SR, Ferguson G, Dunn G, Skuce R, Almond JW, Minor PD. The 5' noncoding region of the type 2 poliovirus vaccine strain contains determinants of attenuation and temperature sensitivity. Virology 1991; 181:451-8. [PMID: 1707566 DOI: 10.1016/0042-6822(91)90877-e] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.5] [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: 12/28/2022]
Abstract
Intratypic recombinants of P2/Sabin and P2/117, a neurovirulent vaccine revertant, have been generated in vitro using infectious cDNA clones and used to demonstrate that strong determinants of the attenuation and temperature-sensitive phenotypes of P2/Sabin reside in the 5' 492 nucleotides. In this region of the genome the viruses differ only at nucleotides 437 and 481. The ts phenotype associated with the 5' noncoding region is expressed at different temperatures in different cell lines, suggesting an involvement of cellular factors which may be species specific. Suppression of both the ts and attenuation phenotypes correlates with an A-G mutation at nucleotide 481, although other changes are also involved.
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Affiliation(s)
- A J Macadam
- National Institute for Biological Standards and Control, Potters Bar, Herts, United Kingdom
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25
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Macadam AJ, Arnold C, Howlett J, John A, Marsden S, Taffs F, Reeve P, Hamada N, Wareham K, Almond J. Reversion of the attenuated and temperature-sensitive phenotypes of the Sabin type 3 strain of poliovirus in vaccinees. Virology 1989; 172:408-14. [PMID: 2552655 DOI: 10.1016/0042-6822(89)90183-9] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.6] [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: 01/01/2023]
Abstract
Isolates of type 3 poliovirus from vaccine-recipients were characterized in terms of virulence, sensitivity of growth to high temperatures, and differences in genome structure from the Sabin type 3 vaccine strain. These included point mutations in the region of the genome coding for the structural proteins and in the 5' noncoding region, and the presence of type 1 or type 2 poliovirus genomic sequences resulting from intertypic recombination. Isolates from healthy vaccinees resembled those from vaccine-associated cases of poliomyelitis in all of these properties. Suppression of the temperature-sensitive phenotype was strictly correlated with reversion to virulence in nonrecombinant type 3 strains. Recombinant isolates were more attenuated than expected, even when they had lost all mutations known to attenuate the type 3 vaccine strain.
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Affiliation(s)
- A J Macadam
- National Institute for Biological Standards and Control, Potters Bar, Herts, United Kingdom
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26
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Filman DJ, Syed R, Chow M, Macadam AJ, Minor PD, Hogle JM. Structural factors that control conformational transitions and serotype specificity in type 3 poliovirus. EMBO J 1989; 8:1567-79. [PMID: 2548847 PMCID: PMC400988 DOI: 10.1002/j.1460-2075.1989.tb03541.x] [Citation(s) in RCA: 243] [Impact Index Per Article: 6.9] [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] [Indexed: 11/07/2022] Open
Abstract
The three-dimensional structure of the Sabin strain of type 3 poliovirus has been determined at 2.4 A resolution. Significant structural differences with the Mahoney strain of type 1 poliovirus are confined to loops and terminal extensions of the capsid proteins, occur in all of the major antigenic sites of the virion and typically involve insertions, deletions or the replacement of prolines. Several newly identified components of the structure participate in assembly-dependent interactions which are relevant to the biologically important processes of viral assembly and uncoating. These include two sites of lipid substitution, two putative nucleotides and a beta sheet formed by the N-termini of capsid proteins VP4 and VP1. The structure provides an explanation for the temperature sensitive phenotype of the P3/Sabin strain. Amino acids that regulate temperature sensitivity in type 3 poliovirus are located in the interfaces between promoters, in the binding site for a lipid substituent and in an assembly-dependent extended beta sheet that stabilizes the association of pentamers. Several lines of evidence indicate that these structural components also control conformational transitions at various stages of the viral life cycle.
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Affiliation(s)
- D J Filman
- Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, CA 92037
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