1
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Pichkur EB, Vorovitch MF, Ivanova AL, Protopopova EV, Loktev VB, Osolodkin DI, Ishmukhametov AA, Samygina VR. The structure of inactivated mature tick-borne encephalitis virus at 3.0 Å resolution. Emerg Microbes Infect 2024; 13:2313849. [PMID: 38465849 DOI: 10.1080/22221751.2024.2313849] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 01/30/2024] [Indexed: 03/12/2024]
Abstract
Tick-borne encephalitis virus (TBEV) causes a severe disease, tick-borne encephalitis (TBE), that has a substantial epidemiological importance for Northern Eurasia. Between 10,000 and 15,000 TBE cases are registered annually despite the availability of effective formaldehyde-inactivated full-virion vaccines due to insufficient vaccination coverage, as well as sporadic cases of vaccine breakthrough. The development of improved vaccines would benefit from the atomic resolution structure of the antigen. Here we report the refined single-particle cryo-electron microscopy (cryo-EM) structure of the inactivated mature TBEV vaccine strain Sofjin-Chumakov (Far-Eastern subtype) at a resolution of 3.0 Å. The increase of the resolution with respect to the previously published structures of TBEV strains Hypr and Kuutsalo-14 (European subtype) was reached due to improvement of the virus sample quality achieved by the optimized preparation methods. All the surface epitopes of TBEV were structurally conserved in the inactivated virions. ELISA studies with monoclonal antibodies supported the hypothesis of TBEV protein shell cross-linking upon inactivation with formaldehyde.
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Affiliation(s)
| | - Mikhail F Vorovitch
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russian Federation
- Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow, Russian Federation
| | - Alla L Ivanova
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russian Federation
| | - Elena V Protopopova
- State Research Center of Virology and Biotechnology "Vector", Novosibirsk, Russian Federation
| | - Valery B Loktev
- State Research Center of Virology and Biotechnology "Vector", Novosibirsk, Russian Federation
| | - Dmitry I Osolodkin
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russian Federation
- Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow, Russian Federation
| | - Aydar A Ishmukhametov
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russian Federation
- Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow, Russian Federation
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2
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Moiseenko A, Zhang Y, Vorovitch MF, Ivanova AL, Liu Z, Osolodkin DI, Egorov AM, Ishmukhametov AA, Sokolova OS. Structural diversity of tick-borne encephalitis virus particles in the inactivated vaccine based on strain Sofjin. Emerg Microbes Infect 2024; 13:2290833. [PMID: 38073510 DOI: 10.1080/22221751.2023.2290833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 11/29/2023] [Indexed: 03/12/2024]
Abstract
The main approach to preventing tick-borne encephalitis (TBE) is vaccination. Formaldehyde-inactivated TBE vaccines have a proven record of safety and efficiency but have never been characterized structurally with atomic resolution. We report a cryoelectron microscopy (cryo-EM) structure of the formaldehyde-inactivated TBE virus (TBEV) of Sofjin-Chumakov strain representing the Far-Eastern subtype. A 3.8 Å resolution reconstruction reveals the structural integrity of the envelope E proteins, specifically the E protein ectodomains. The comparative study shows a high structural similarity to the previously published structures of the TBEV European subtype strains Hypr and Kuutsalo-14. A fraction of inactivated virions exhibits asymmetric features including the deformations of the membrane profile. We propose that the heterogeneity is caused by inactivation and perform a local variability analysis on the small parts of the envelope protein shell to reveal membrane curvature features possibly induced by the inactivation. The results of this study will have implications for the design of novel vaccines against diseases caused by flaviviruses.
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Affiliation(s)
- Andrey Moiseenko
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Yichen Zhang
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen, People's Republic of China
| | - Mikhail F Vorovitch
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russia
- Sechenov First Moscow State Medical University, Moscow, Russia
| | - Alla L Ivanova
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russia
| | - Zheng Liu
- Kobilka Institute of Innovative Drug Discovery, School of Medicine, Chinese University of Hong Kong, Shenzhen, People's Republic of China
| | - Dmitry I Osolodkin
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russia
- Sechenov First Moscow State Medical University, Moscow, Russia
| | - Alexey M Egorov
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russia
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
| | - Aydar A Ishmukhametov
- FSASI "Chumakov FSC R&D IBP RAS" (Institute of Poliomyelitis), Moscow, Russia
- Sechenov First Moscow State Medical University, Moscow, Russia
| | - Olga S Sokolova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen, People's Republic of China
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3
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Harrison JJ, Nguyen W, Morgan MS, Tang B, Habarugira G, de Malmanche H, Freney ME, Modhiran N, Watterson D, Cox AL, Yan K, Yuen NKY, Bowman DH, Kirkland PD, Bielefeldt-Ohmann H, Suhrbier A, Hall RA, Rawle DJ, Hobson-Peters J. A chimeric vaccine derived from Australian genotype IV Japanese encephalitis virus protects mice from lethal challenge. NPJ Vaccines 2024; 9:134. [PMID: 39085247 PMCID: PMC11291493 DOI: 10.1038/s41541-024-00903-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 05/23/2024] [Indexed: 08/02/2024] Open
Abstract
In 2022, a genotype IV (GIV) strain of Japanese encephalitis virus (JEV) caused an unprecedented and widespread outbreak of disease in pigs and humans in Australia. As no veterinary vaccines against JEV are approved in Australia and all current approved human and veterinary vaccines are derived from genotype (G) III JEV strains, we used the recently described insect-specific Binjari virus (BinJV) chimeric flavivirus vaccine technology to produce a JEV GIV vaccine candidate. Herein we describe the production of a chimeric virus displaying the structural prM and E proteins of a JEV GIV isolate obtained from a stillborn piglet (JEVNSW/22) in the genomic backbone of BinJV (BinJ/JEVNSW/22-prME). BinJ/JEVNSW/22-prME was shown to be antigenically indistinguishable from the JEVNSW/22 parental virus by KD analysis and a panel of JEV-reactive monoclonal antibodies in ELISA. BinJ/JEVNSW/22-prME replicated efficiently in C6/36 cells, reaching titres of >107 infectious units/mL - an important attribute for vaccine manufacture. As expected, BinJ/JEVNSW/22-prME failed to replicate in a variety of vertebrate cells lines. When used to immunise mice, the vaccine induced a potent virus neutralising response against JEVNSW/22 and to GII and GIII JEV strains. The BinJ/JEVNSW/22-prME vaccine provided complete protection against lethal challenge with JEVNSW/22, whilst also providing partial protection against viraemia and disease for the related Murray Valley encephalitis virus. Our results demonstrate that BinJ/JEVNSW/22-prME is a promising vaccine candidate against JEV.
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Affiliation(s)
- Jessica J Harrison
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Wilson Nguyen
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
| | - Mahali S Morgan
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Bing Tang
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
| | - Gervais Habarugira
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Henry de Malmanche
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Morgan E Freney
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Naphak Modhiran
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Daniel Watterson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia
| | - Abigail L Cox
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
| | - Kexin Yan
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
| | - Nicholas K Y Yuen
- School of Veterinary Science, The University of Queensland, Gatton, QLD, 4343, Australia
| | - Dylan H Bowman
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Peter D Kirkland
- Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, NSW, 2568, Australia
| | - Helle Bielefeldt-Ohmann
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia
| | - Andreas Suhrbier
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia
| | - Roy A Hall
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia
| | - Daniel J Rawle
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia.
| | - Jody Hobson-Peters
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia.
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia.
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Stevens A, Kashyap S, Crofut EH, Wang SE, Muratore KA, Johnson PJ, Zhou ZH. Structures of Native Doublet Microtubules from Trichomonas vaginalis Reveal Parasite-Specific Proteins as Potential Drug Targets. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598142. [PMID: 38915691 PMCID: PMC11195118 DOI: 10.1101/2024.06.11.598142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Doublet microtubules (DMTs) are flagellar components required for the protist Trichomonas vaginalis ( Tv ) to swim through the human genitourinary tract to cause trichomoniasis, the most common non-viral sexually transmitted disease. Lack of DMT structures has prevented structure-guided drug design to manage Tv infection. Here, we determined the cryo-EM structure of native Tv- DMTs, identifying 29 unique proteins, including 18 microtubule inner proteins and 9 microtubule outer proteins. While the A-tubule is simplistic compared to DMTs of other organisms, the B-tubule features specialized, parasite-specific proteins, like Tv FAP40 and Tv FAP35 that form filaments near the inner and outer junctions, respectively, to stabilize DMTs and enable Tv locomotion. Notably, a small molecule, assigned as IP6, is coordinated within a pocket of Tv FAP40 and has characteristics of a drug molecule. This first atomic model of the Tv -DMT highlights the diversity of eukaryotic motility machinery and provides a structural framework to inform the rational design of therapeutics.
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Wang LL, Cheng Q, Newton ND, Wolfinger MT, Morgan MS, Slonchak A, Khromykh AA, Cheng TY, Parry RH. Xinyang flavivirus, from Haemaphysalis flava ticks in Henan Province, China, defines a basal, likely tick-only Orthoflavivirus clade. J Gen Virol 2024; 105:001991. [PMID: 38809251 PMCID: PMC11165663 DOI: 10.1099/jgv.0.001991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Accepted: 05/08/2024] [Indexed: 05/30/2024] Open
Abstract
Tick-borne orthoflaviviruses (TBFs) are classified into three conventional groups based on genetics and ecology: mammalian, seabird and probable-TBF group. Recently, a fourth basal group has been identified in Rhipicephalus ticks from Africa: Mpulungu flavivirus (MPFV) in Zambia and Ngoye virus (NGOV) in Senegal. Despite attempts, isolating these viruses in vertebrate and invertebrate cell lines or intracerebral injection of newborn mice with virus-containing homogenates has remained unsuccessful. In this study, we report the discovery of Xinyang flavivirus (XiFV) in Haemaphysalis flava ticks from Xìnyáng, Henan Province, China. Phylogenetic analysis shows that XiFV was most closely related to MPFV and NGOV, marking the first identification of this tick orthoflavivirus group in Asia. We developed a reverse transcriptase quantitative PCR assay to screen wild-collected ticks and egg clutches, with absolute infection rates of 20.75 % in adult females and 15.19 % in egg clutches, suggesting that XiFV could be potentially spread through transovarial transmission. To examine potential host range, dinucleotide composition analyses revealed that XiFV, MPFV and NGOV share a closer composition to classical insect-specific orthoflaviviruses than to vertebrate-infecting TBFs, suggesting that XiFV could be a tick-only orthoflavivirus. Additionally, both XiFV and MPFV lack a furin cleavage site in the prM protein, unlike other TBFs, suggesting these viruses might exist towards a biased immature particle state. To examine this, chimeric Binjari virus with XIFV-prME (bXiFV) was generated, purified and analysed by SDS-PAGE and negative-stain transmission electron microscopy, suggesting prototypical orthoflavivirus size (~50 nm) and bias towards uncleaved prM. In silico structural analyses of the 3'-untranslated regions show that XiFV forms up to five pseudo-knot-containing stem-loops and a prototypical orthoflavivirus dumbbell element, suggesting the potential for multiple exoribonuclease-resistant RNA structures.
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Affiliation(s)
- Lan-Lan Wang
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province, PR China
| | - Qia Cheng
- Children’s Medical Center, Hunan Provincial People’s Hospital, Changsha, PR China
| | - Natalee D. Newton
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Michael T. Wolfinger
- Department of Theoretical Chemistry, University of Vienna, Vienna, Austria
- Research Group Bioinformatics and Computational Biology, Faculty of Computer Science, University of Vienna, Vienna, Austria
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
- RNA Forecast e.U., Vienna, Austria
| | - Mahali S. Morgan
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Andrii Slonchak
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Alexander A. Khromykh
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
- GVN Center of Excellence, Australian Infectious Diseases Research Centre, Brisbane, QLD, Australia
| | - Tian-Yin Cheng
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province, PR China
| | - Rhys H. Parry
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
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6
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Jablunovsky A, Jose J. The Dynamic Landscape of Capsid Proteins and Viral RNA Interactions in Flavivirus Genome Packaging and Virus Assembly. Pathogens 2024; 13:120. [PMID: 38392858 PMCID: PMC10893219 DOI: 10.3390/pathogens13020120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
The Flavivirus genus of the Flaviviridae family of enveloped single-stranded RNA viruses encompasses more than 70 members, many of which cause significant disease in humans and livestock. Packaging and assembly of the flavivirus RNA genome is essential for the formation of virions, which requires intricate coordination of genomic RNA, viral structural, and nonstructural proteins in association with virus-induced, modified endoplasmic reticulum (ER) membrane structures. The capsid (C) protein, a small but versatile RNA-binding protein, and the positive single-stranded RNA genome are at the heart of the elusive flavivirus assembly process. The nucleocapsid core, consisting of the genomic RNA encapsidated by C proteins, buds through the ER membrane, which contains viral glycoproteins prM and E organized as trimeric spikes into the lumen, forming an immature virus. During the maturation process, which involves the low pH-mediated structural rearrangement of prM and E and furin cleavage of prM in the secretory pathway, the spiky immature virus with a partially ordered nucleocapsid core becomes a smooth, mature virus with no discernible nucleocapsid. This review focuses on the mechanisms of genome packaging and assembly by examining the structural and functional aspects of C protein and viral RNA. We review the current lexicon of critical C protein features and evaluate interactions between C and genomic RNA in the context of assembly and throughout the life cycle.
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Affiliation(s)
- Anastazia Jablunovsky
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA;
| | - Joyce Jose
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA;
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
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7
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Jablunovsky A, Narayanan A, Jose J. Identification of a critical role for ZIKV capsid α3 in virus assembly and its genetic interaction with M protein. PLoS Negl Trop Dis 2024; 18:e0011873. [PMID: 38166143 PMCID: PMC10786401 DOI: 10.1371/journal.pntd.0011873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 01/12/2024] [Accepted: 12/19/2023] [Indexed: 01/04/2024] Open
Abstract
Flaviviruses such as Zika and dengue viruses are persistent health concerns in endemic regions worldwide. Efforts to combat the spread of flaviviruses have been challenging, as no antivirals or optimal vaccines are available. Prevention and treatment of flavivirus-induced diseases require a comprehensive understanding of their life cycle. However, several aspects of flavivirus biogenesis, including genome packaging and virion assembly, are not well characterized. In this study, we focused on flavivirus capsid protein (C) using Zika virus (ZIKV) as a model to investigate the role of the externally oriented α3 helix (C α3) without a known or predicted function. Alanine scanning mutagenesis of surface-exposed amino acids on C α3 revealed a critical CN67 residue essential for ZIKV virion production. The CN67A mutation did not affect dimerization or RNA binding of purified C protein in vitro. The virus assembly is severely affected in cells transfected with an infectious cDNA clone of ZIKV with CN67A mutation, resulting in a highly attenuated phenotype. We isolated a revertant virus with a partially restored phenotype by continuous passage of the CN67A mutant virus in Vero E6 cells. Sequence analysis of the revertant revealed a second site mutation in the viral membrane (M) protein MF37L, indicating a genetic interaction between the C and M proteins of ZIKV. Introducing the MF37L mutation on the mutant ZIKV CN67A generated a double-mutant virus phenotypically consistent with the isolated genetic revertant. Similar results were obtained with analogous mutations on C and M proteins of dengue virus, suggesting the critical nature of C α3 and possible C and M residues contributing to virus assembly in other Aedes-transmitted flaviviruses. This study provides the first experimental evidence of a genetic interaction between the C protein and the viral envelope protein M, providing a mechanistic understanding of the molecular interactions involved in the assembly and budding of Aedes-transmitted flaviviruses.
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Affiliation(s)
- Anastazia Jablunovsky
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Anoop Narayanan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Joyce Jose
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
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8
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Vorovitch MF, Samygina VR, Pichkur E, Konarev PV, Peters G, Khvatov EV, Ivanova AL, Tuchynskaya KK, Konyushko OI, Fedotov AY, Armeev G, Shaytan KV, Kovalchuk MV, Osolodkin DI, Egorov AM, Ishmukhametov AA. Preparation and characterization of inactivated tick-borne encephalitis virus samples for single-particle imaging at the European XFEL. Acta Crystallogr D Struct Biol 2024; 80:44-59. [PMID: 38164954 DOI: 10.1107/s2059798323010562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 12/10/2023] [Indexed: 01/03/2024] Open
Abstract
X-ray imaging of virus particles at the European XFEL could eventually allow their complete structures to be solved, potentially approaching the resolution of other structural virology methods. To achieve this ambitious goal with today's technologies, about 1 ml of purified virus suspension containing at least 1012 particles per millilitre is required. Such large amounts of concentrated suspension have never before been obtained for enveloped viruses. Tick-borne encephalitis virus (TBEV) represents an attractive model system for the development of enveloped virus purification and concentration protocols, given the availability of large amounts of inactivated virus material provided by vaccine-manufacturing facilities. Here, the development of a TBEV vaccine purification and concentration scheme is presented combined with a quality-control protocol that allows substantial amounts of highly concentrated non-aggregated suspension to be obtained. Preliminary single-particle imaging experiments were performed for this sample at the European XFEL, showing distinct diffraction patterns.
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Affiliation(s)
- Mikhail F Vorovitch
- Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow 119991, Russian Federation
| | | | - Evgeny Pichkur
- NRC `Kurchatov Insitute', Moscow 123182, Russian Federation
| | | | - Georgy Peters
- NRC `Kurchatov Insitute', Moscow 123182, Russian Federation
| | - Evgeny V Khvatov
- FSASI `Chumakov FSC R&D IBP RAS' (Institute of Poliomyelitis), Moscow 108819, Russian Federation
| | - Alla L Ivanova
- FSASI `Chumakov FSC R&D IBP RAS' (Institute of Poliomyelitis), Moscow 108819, Russian Federation
| | - Ksenia K Tuchynskaya
- FSASI `Chumakov FSC R&D IBP RAS' (Institute of Poliomyelitis), Moscow 108819, Russian Federation
| | - Olga I Konyushko
- FSASI `Chumakov FSC R&D IBP RAS' (Institute of Poliomyelitis), Moscow 108819, Russian Federation
| | - Anton Y Fedotov
- FSASI `Chumakov FSC R&D IBP RAS' (Institute of Poliomyelitis), Moscow 108819, Russian Federation
| | - Grigory Armeev
- Department of Biology, Lomonosov Moscow State University, Moscow 119991, Russian Federation
| | - Konstantin V Shaytan
- Department of Biology, Lomonosov Moscow State University, Moscow 119991, Russian Federation
| | | | - Dmitry I Osolodkin
- FSASI `Chumakov FSC R&D IBP RAS' (Institute of Poliomyelitis), Moscow 108819, Russian Federation
| | - Alexey M Egorov
- FSASI `Chumakov FSC R&D IBP RAS' (Institute of Poliomyelitis), Moscow 108819, Russian Federation
| | - Aydar A Ishmukhametov
- FSASI `Chumakov FSC R&D IBP RAS' (Institute of Poliomyelitis), Moscow 108819, Russian Federation
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9
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Lata K, Charles S, Mangala Prasad V. Advances in computational approaches to structure determination of alphaviruses and flaviviruses using cryo-electron microscopy. J Struct Biol 2023; 215:107993. [PMID: 37414374 DOI: 10.1016/j.jsb.2023.107993] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/15/2023] [Accepted: 07/03/2023] [Indexed: 07/08/2023]
Abstract
Advancements in the field of cryo-electron microscopy (cryo-EM) have greatly contributed to our current understanding of virus structures and life cycles. In this review, we discuss the application of single particle cryo-electron microscopy (EM) for the structure elucidation of small enveloped icosahedral viruses, namely, alpha- and flaviviruses. We focus on technical advances in cryo-EM data collection, image processing, three-dimensional reconstruction, and refinement strategies for obtaining high-resolution structures of these viruses. Each of these developments enabled new insights into the alpha- and flavivirus architecture, leading to a better understanding of their biology, pathogenesis, immune response, immunogen design, and therapeutic development.
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Affiliation(s)
- Kiran Lata
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Sylvia Charles
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Vidya Mangala Prasad
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka 560012, India; Center for Infectious Disease Research, Indian Institute of Science, Bengaluru, Karnataka 560012, India
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10
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Hsieh YC, Delarue M, Orland H, Koehl P. Analyzing the Geometry and Dynamics of Viral Structures: A Review of Computational Approaches Based on Alpha Shape Theory, Normal Mode Analysis, and Poisson-Boltzmann Theories. Viruses 2023; 15:1366. [PMID: 37376665 DOI: 10.3390/v15061366] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
The current SARS-CoV-2 pandemic highlights our fragility when we are exposed to emergent viruses either directly or through zoonotic diseases. Fortunately, our knowledge of the biology of those viruses is improving. In particular, we have more and more structural information on virions, i.e., the infective form of a virus that includes its genomic material and surrounding protective capsid, and on their gene products. It is important to have methods that enable the analyses of structural information on such large macromolecular systems. We review some of those methods in this paper. We focus on understanding the geometry of virions and viral structural proteins, their dynamics, and their energetics, with the ambition that this understanding can help design antiviral agents. We discuss those methods in light of the specificities of those structures, mainly that they are huge. We focus on three of our own methods based on the alpha shape theory for computing geometry, normal mode analyses to study dynamics, and modified Poisson-Boltzmann theories to study the organization of ions and co-solvent and solvent molecules around biomacromolecules. The corresponding software has computing times that are compatible with the use of regular desktop computers. We show examples of their applications on some outer shells and structural proteins of the West Nile Virus.
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Affiliation(s)
- Yin-Chen Hsieh
- Institute for Arctic and Marine Biology, Department of Biosciences, Fisheries, and Economics, UiT The Arctic University of Norway, 9037 Tromso, Norway
| | - Marc Delarue
- Institut Pasteur, Université Paris-Cité and CNRS, UMR 3528, Unité Architecture et Dynamique des Macromolécules Biologiques, 75015 Paris, France
| | - Henri Orland
- Institut de Physique Théorique, CEA, CNRS, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
| | - Patrice Koehl
- Department of Computer Science, University of California, Davis, CA 95616, USA
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11
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Colombarolli SG, Batista ICA, Tavares NC, de Oliveira ES, Nascimento CS, Felgner PL, de Assis RR, Calzavara-Silva CE. Peptide Microarrays for Flavivirus Diagnosis. Methods Mol Biol 2023; 2578:199-208. [PMID: 36152289 DOI: 10.1007/978-1-0716-2732-7_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Flavivirus are the most alarming prevalent viruses worldwide due to its vast impact on public health. Most early symptoms of diseases caused by Flavivirus are similar among each other and to other febrile illnesses making the clinical differential diagnosis challenging. In addition, due to cross-reactivity and a relatively limited persistence of viral RNA in infected individuals, the current available diagnosis strategies fail to efficiently provide a differential viral identification. In this context, virus-specific tests are essential to improve patient care, as well as to facilitate disease surveillance and the effective control of transmission. Here, we describe the use of protein microarrays as an effective tool for screening peptides differentially recognized by anti-Yellow Fever virus antibodies induced by vaccination or by natural viral infection.
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Affiliation(s)
- Stella Garcia Colombarolli
- National Research Council of Italy, Istituto di Scienze e Tecnologie Chimiche (SCITEC-CNR), Rome, Italy
- Laboratório de Imunologia Celular e Molecular, Instituto Rene Rachou, Fiocruz, MG, Brazil
| | | | | | - Eneida Santos de Oliveira
- Laboratório de Imunologia Celular e Molecular, Instituto Rene Rachou, Fiocruz, MG, Brazil
- Gerência da Rede Ambulatorial Especializada, Secretaria Municipal de Saúde de Belo Horizonte, Prefeitura de Belo Horizonte, MG, Brazil
| | | | - Philip Louis Felgner
- Vaccine Research and Development Center, Department of Physiology, University of California, Irvine, CA, USA
| | - Rafael Ramiro de Assis
- Vaccine Research and Development Center, Department of Physiology, University of California, Irvine, CA, USA
| | - Carlos Eduardo Calzavara-Silva
- Laboratório de Imunologia Celular e Molecular, Instituto Rene Rachou, Fiocruz, MG, Brazil.
- Vaccine Research and Development Center, Department of Physiology, University of California, Irvine, CA, USA.
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12
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Colmant AMG, Charrel RN, Coutard B. Jingmenviruses: Ubiquitous, understudied, segmented flavi-like viruses. Front Microbiol 2022; 13:997058. [PMID: 36299728 PMCID: PMC9589506 DOI: 10.3389/fmicb.2022.997058] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/22/2022] [Indexed: 11/21/2022] Open
Abstract
Jingmenviruses are a group of viruses identified recently, in 2014, and currently classified by the International Committee on Taxonomy of Viruses as unclassified Flaviviridae. These viruses closely related to flaviviruses are unique due to the segmented nature of their genome. The prototype jingmenvirus, Jingmen tick virus (JMTV), was discovered in Rhipicephalus microplus ticks collected from China in 2010. Jingmenviruses genomes are composed of four to five segments, encoding for up to seven structural proteins and two non-structural proteins, both of which display strong similarities with flaviviral non-structural proteins (NS2B/NS3 and NS5). Jingmenviruses are currently separated into two phylogenetic clades. One clade includes tick- and vertebrate-associated jingmenviruses, which have been detected in ticks and mosquitoes, as well as in humans, cattle, monkeys, bats, rodents, sheep, and tortoises. In addition to these molecular and serological detections, over a hundred human patients tested positive for jingmenviruses after developing febrile illness and flu-like symptoms in China and Serbia. The second phylogenetic clade includes insect-associated jingmenvirus sequences, which have been detected in a wide range of insect species, as well as in crustaceans, plants, and fungi. In addition to being found in various types of hosts, jingmenviruses are endemic, as they have been detected in a wide range of environments, all over the world. Taken together, all of these elements show that jingmenviruses correspond exactly to the definition of emerging viruses at risk of causing a pandemic, since they are already endemic, have a close association with arthropods, are found in animals in close contact with humans, and have caused sporadic cases of febrile illness in multiple patients. Despite these arguments, the vast majority of published data is from metagenomics studies and many aspects of jingmenvirus replication remain to be elucidated, such as their tropism, cycle of transmission, structure, and mechanisms of replication and restriction or epidemiology. It is therefore crucial to prioritize jingmenvirus research in the years to come, to be prepared for their emergence as human or veterinary pathogens.
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13
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Khare B, Kuhn RJ. The Japanese Encephalitis Antigenic Complex Viruses: From Structure to Immunity. Viruses 2022; 14:2213. [PMID: 36298768 PMCID: PMC9607441 DOI: 10.3390/v14102213] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 11/09/2022] Open
Abstract
In the last three decades, several flaviviruses of concern that belong to different antigenic groups have expanded geographically. This has resulted in the presence of often more than one virus from a single antigenic group in some areas, while in Europe, Africa and Australia, additionally, multiple viruses belonging to the Japanese encephalitis (JE) serogroup co-circulate. Morphological heterogeneity of flaviviruses dictates antibody recognition and affects virus neutralization, which influences infection control. The latter is further impacted by sequential infections involving diverse flaviviruses co-circulating within a region and their cross-reactivity. The ensuing complex molecular virus-host interplay leads to either cross-protection or disease enhancement; however, the molecular determinants and mechanisms driving these outcomes are unclear. In this review, we provide an overview of the epidemiology of four JE serocomplex viruses, parameters affecting flaviviral heterogeneity and antibody recognition, host immune responses and the current knowledge of the cross-reactivity involving JE serocomplex flaviviruses that leads to differential clinical outcomes, which may inform future preventative and therapeutic interventions.
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Affiliation(s)
- Baldeep Khare
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Richard J. Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
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14
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Hour MJ, Chen Y, Lin CS, Baltina LA, Kan JY, Tsai YT, Kiu YT, Lai HC, Baltina LA, Petrova SF, Lin CW. Glycyrrhizic Acid Derivatives Bearing Amino Acid Residues in the Carbohydrate Part as Dengue Virus E Protein Inhibitors: Synthesis and Antiviral Activity. Int J Mol Sci 2022; 23:10309. [PMID: 36142222 PMCID: PMC9499324 DOI: 10.3390/ijms231810309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/23/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Dengue virus (DENV) is one of the most geographically distributed mosquito-borne flaviviruses, like Japanese encephalitis virus (JEV), and Zika virus (ZIKV). In this study, a library of the known and novel Glycyrrhizic acid (GL) derivatives bearing amino acid residues or their methyl/ethyl esters in the carbohydrate part were synthesized and studied as DENV inhibitors in vitro using the cytopathic effect (CPE), viral infectivity and virus yield assays with DENV1 and DENV-2 in Vero E6 and A549 cells. Among the GL conjugates tested, compound hits GL-D-ValOMe 3, GL-TyrOMe 6, GL-PheOEt 11, and GL-LysOMe 21 were discovered to have better antiviral activity than GL, with IC50 values ranging from <0.1 to 5.98 μM on the in vitro infectivity of DENV1 and DENV2 in Vero E6 and A549 cells. Compound hits 3, 6, 11, and 21 had a concentration-dependent inhibition on the virus yield in Vero E6, in which GL-D-ValOMe 3 and GL-PheOEt 11 were the most active inhibitors of DENV2 yield. Meanwhile, the time-of-addition assay indicated that conjugates GL-D-ValOMe 3 and GL-PheOEt 11 exhibited a substantial decrease in the DENV2 attachment stage. Subsequently, chimeric single-round infectious particles (SRIPs) of DENV2 C-prM-E protein/JEV replicon and DENV2 prM-E/ZIKV replicon were utilized for the DENV envelope I protein-mediated attachment assay. GL conjugates 3 and 11 significantly reduced the attachment of chimeric DENV2 C-prM-E/JEV and DENV2 prM-E/ZIKV SRIPs onto Vero E6 cells in a concentration-dependent manner but did not impede the attachment of wild-type JEV CprME/JEV and ZIKV prM-E/ZIKV SRIPs, indicating the inhibition of Compounds 3 and 11 on DENV2 E-mediated attachment. Molecular docking data revealed that Compounds 3 and 11 have hydrophobic interactions within a hydrophobic pocket among the interfaces of Domains I, II, and the stem region of the DENV2 envelope (E) protein. These results displayed that Compounds 3 and 11 were the lead compounds targeting the DENV E protein. Altogether, our findings provide new insights into the structure−activity relationship of GL derivatives conjugated with amino acid residues and can be the new fundamental basis for the search and development of novel flavivirus inhibitors based on natural compounds.
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Affiliation(s)
- Mann-Jen Hour
- School of Pharmacy, China Medical University, Taichung 40402, Taiwan
| | - Yeh Chen
- Institute of New Drug Development, China Medical University, Taichung 40402, Taiwan
| | - Chen-Sheng Lin
- Division of Gastroenterology, Kuang Tien General Hospital, No. 117 Shatian Road, Shalu District, Taichung 43303, Taiwan
| | - Lidia A. Baltina
- Ufa Institute of Chemistry, Ufa Federal Research Centre of RAS, 71 Prospect Oktyabrya, 450054 Ufa, Russia
| | - Ju-Ying Kan
- Graduate Institute of Biomedical Sciences, China Medical University, 91, Hsueh-Shin Road, Taichung 40402, Taiwan
| | - Yan-Ting Tsai
- Department of Medical Laboratory Science and Biotechnology, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan
- Department of Medical Laboratory Science and Biotechnology, Asia University, 500 Lioufeng Road, Wufeng, Taichung 41354, Taiwan
| | - Yan-Tung Kiu
- Department of Medical Laboratory Science and Biotechnology, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan
| | - Hsueh-Chou Lai
- School of Chinese Medicine, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan
| | - Lia A. Baltina
- Ufa Institute of Chemistry, Ufa Federal Research Centre of RAS, 71 Prospect Oktyabrya, 450054 Ufa, Russia
| | - Svetlana F. Petrova
- Ufa Institute of Chemistry, Ufa Federal Research Centre of RAS, 71 Prospect Oktyabrya, 450054 Ufa, Russia
| | - Cheng-Wen Lin
- Graduate Institute of Biomedical Sciences, China Medical University, 91, Hsueh-Shin Road, Taichung 40402, Taiwan
- Department of Medical Laboratory Science and Biotechnology, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan
- Department of Medical Laboratory Science and Biotechnology, Asia University, 500 Lioufeng Road, Wufeng, Taichung 41354, Taiwan
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15
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Liu H, Hong X, Xi J, Menne S, Hu J, Wang JCY. Cryo-EM structures of human hepatitis B and woodchuck hepatitis virus small spherical subviral particles. SCIENCE ADVANCES 2022; 8:eabo4184. [PMID: 35930632 PMCID: PMC9355357 DOI: 10.1126/sciadv.abo4184] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
The loss of detectable hepatitis B surface antigen (HBsAg) is considered a functional cure in chronic hepatitis B. Naturally, HBsAg can be incorporated into the virion envelope or assembled into subviral particles (SVPs) with lipid from host cells. Until now, there has been no detailed structure of HBsAg, and the published SVP structures are controversial. Here, we report the first subnanometer-resolution structures of spherical SVP from hepatitis B virus (HBV) and the related woodchuck hepatitis virus (WHV) determined by cryo-electron microscopy in combination with AlphaFold2 prediction. Both structures showed unique rhombicuboctahedral symmetry with 24 protruding spikes comprising dimer of small HBsAg with four helical domains. The lipid moiety in the SVP is organized in a noncanonical lipid patch instead of a lipid bilayer, which can accommodate the exposed hydrophobic surface and modulate particle stability. Together, these findings advance our knowledge of viral membrane organization and the structures of HBV and WHV spherical SVPs.
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Affiliation(s)
- Haitao Liu
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Xupeng Hong
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Ji Xi
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Stephan Menne
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington DC 20007, USA
| | - Jianming Hu
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Joseph Che-Yen Wang
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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16
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Vaney MC, Dellarole M, Duquerroy S, Medits I, Tsouchnikas G, Rouvinski A, England P, Stiasny K, Heinz FX, Rey FA. Evolution and activation mechanism of the flavivirus class II membrane-fusion machinery. Nat Commun 2022; 13:3718. [PMID: 35764616 PMCID: PMC9239988 DOI: 10.1038/s41467-022-31111-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 06/03/2022] [Indexed: 11/08/2022] Open
Abstract
The flavivirus envelope glycoproteins prM and E drive the assembly of icosahedral, spiky immature particles that bud across the membrane of the endoplasmic reticulum. Maturation into infectious virions in the trans-Golgi network involves an acid-pH-driven rearrangement into smooth particles made of (prM/E)2 dimers exposing a furin site for prM cleavage into "pr" and "M". Here we show that the prM "pr" moiety derives from an HSP40 cellular chaperonin. Furthermore, the X-ray structure of the tick-borne encephalitis virus (pr/E)2 dimer at acidic pH reveals the E 150-loop as a hinged-lid that opens at low pH to expose a positively-charged pr-binding pocket at the E dimer interface, inducing (prM/E)2 dimer formation to generate smooth particles in the Golgi. Furin cleavage is followed by lid-closure upon deprotonation in the neutral-pH extracellular environment, expelling pr while the 150-loop takes the relay in fusion loop protection, thus revealing the elusive flavivirus mechanism of fusion activation.
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Affiliation(s)
- Marie-Christine Vaney
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - Mariano Dellarole
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
- CIBION, CONICET, Buenos Aires, Argentina
| | - Stéphane Duquerroy
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
- Université Paris Saclay, Faculté des Sciences, Orsay, France
| | - Iris Medits
- Center for Virology, Medical University of Vienna, Vienna, Austria
| | - Georgios Tsouchnikas
- Center for Virology, Medical University of Vienna, Vienna, Austria
- HOOKIPA Pharma 19 Inc, Vienna, Austria
| | - Alexander Rouvinski
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Kuvin Center for the Study of Infectious and Tropical Diseases, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Patrick England
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Plateforme de Biophysique Moléculaire, Paris, France
| | - Karin Stiasny
- Center for Virology, Medical University of Vienna, Vienna, Austria.
| | - Franz X Heinz
- Center for Virology, Medical University of Vienna, Vienna, Austria.
| | - Félix A Rey
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France.
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17
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Abstract
Maturation of dengue viruses (DENVs) alters the structure, immunity, and infectivity of the virion and highly mature particles represent the dominant form in vivo. The production of highly mature virions principally relies on the structure and function of the viral premature membrane protein (prM) and its cleavage by the host protease furin. We redeveloped a reliable clonal cell line (VF1) which produces single-round mature DENVs without the need for DENV reverse genetics. More importantly, using protein engineering and directed evolution of the prM cleavage site, we engineered genetically stable mature DENVs in all serotypes independent of cell or host, usually with minimal impact on viral yield. Using these complementary strategies to regulate maturation, we demonstrate that the resulting mature DENVs are antigenically distinct from their isogenic partially mature forms. Given the clinical importance of mature DENVs in immunity, our study provides reliable strategies and reagents for the production of stable, high-titer mature DENVs for DENV antibody neutralization and vaccination immunity studies. Biologically, our data from directed evolution across host species reveals distinct maturation-dependent selective pressures between mammalian and insect cells, verifying the substrate preference between mammalian and insect furin, while hinting at an evolutionary equilibrium of DENV prM cleavage site between its host and vector in nature.
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18
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Molecular Organisation of Tick-Borne Encephalitis Virus. Viruses 2022; 14:v14040792. [PMID: 35458522 PMCID: PMC9027435 DOI: 10.3390/v14040792] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 01/19/2023] Open
Abstract
Tick-borne encephalitis virus (TBEV) is a pathogenic, enveloped, positive-stranded RNA virus in the family Flaviviridae. Structural studies of flavivirus virions have primarily focused on mosquito-borne species, with only one cryo-electron microscopy (cryo-EM) structure of a tick-borne species published. Here, we present a 3.3 Å cryo-EM structure of the TBEV virion of the Kuutsalo-14 isolate, confirming the overall organisation of the virus. We observe conformational switching of the peripheral and transmembrane helices of M protein, which can explain the quasi-equivalent packing of the viral proteins and highlights their importance in stabilising membrane protein arrangement in the virion. The residues responsible for M protein interactions are highly conserved in TBEV but not in the structurally studied Hypr strain, nor in mosquito-borne flaviviruses. These interactions may compensate for the lower number of hydrogen bonds between E proteins in TBEV compared to the mosquito-borne flaviviruses. The structure reveals two lipids bound in the E protein which are important for virus assembly. The lipid pockets are comparable to those recently described in mosquito-borne Zika, Spondweni, Dengue, and Usutu viruses. Our results thus advance the understanding of tick-borne flavivirus architecture and virion-stabilising interactions.
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19
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Soñora M, Barrera EE, Pantano S. The stressed life of a lipid in the Zika virus membrane. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183804. [PMID: 34656553 DOI: 10.1016/j.bbamem.2021.183804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 09/30/2021] [Accepted: 10/08/2021] [Indexed: 06/13/2023]
Abstract
Protein-lipid interactions modulate a plethora of physiopathologic processes and have been the subject of countless studies. However, these kinds of interactions in the context of viral envelopes have remained relatively unexplored, partially because the intrinsically small dimensions of the molecular systems escape to the current resolution of experimental techniques. However, coarse-grained and multiscale simulations may fill that niche, providing nearly atomistic resolution at an affordable computational price. Here we use multiscale simulations to characterize the lipid-protein interactions in the envelope of the Zika Virus, a prominent member of the Flavivirus genus. Comparisons between the viral envelope and simpler molecular systems indicate that the viral membrane is under extreme pressures and asymmetric forces. Furthermore, the dense net of protein-protein contacts established by the envelope proteins creates poorly solvated regions that destabilize the external leaflet leading to a decoupled dynamics between both membrane layers. These findings lead to the idea that the Flaviviral membrane may store a significant amount of elastic energy, playing an active role in the membrane fusion process.
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Affiliation(s)
- Martín Soñora
- Biomolecular Simulations Group, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - Exequiel E Barrera
- Biomolecular Simulations Group, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay; Instituto de Histología y Embriología (IHEM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CC56, Universidad Nacional de Cuyo (UNCuyo), Mendoza, Argentina
| | - Sergio Pantano
- Biomolecular Simulations Group, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay.
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20
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Hazlewood JE, Tang B, Yan K, Rawle DJ, Harrison JJ, Hall RA, Hobson-Peters J, Suhrbier A. The Chimeric Binjari-Zika Vaccine Provides Long-Term Protection against ZIKA Virus Challenge. Vaccines (Basel) 2022; 10:85. [PMID: 35062746 PMCID: PMC8781009 DOI: 10.3390/vaccines10010085] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 01/27/2023] Open
Abstract
We recently developed a chimeric flavivirus vaccine technology based on the novel insect-specific Binjari virus (BinJV) and used this to generate a chimeric ZIKV vaccine (BinJ/ZIKA-prME) that protected IFNAR-/- dams and fetuses from infection. Herein, we show that a single vaccination of IFNAR-/- mice with unadjuvanted BinJ/ZIKA-prME generated neutralizing antibody responses that were retained for 14 months. At 15 months post vaccination, mice were also completely protected against detectable viremia and substantial body weight loss after challenge with ZIKVPRVABC59. BinJ/ZIKA-prME vaccination thus provided long-term protective immunity without the need for adjuvant or replication of the vaccine in the vaccine recipient, both attractive features for a ZIKV vaccine.
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Affiliation(s)
- Jessamine E. Hazlewood
- Inflammation Biology Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia; (J.E.H.); (B.T.); (K.Y.); (D.J.R.)
| | - Bing Tang
- Inflammation Biology Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia; (J.E.H.); (B.T.); (K.Y.); (D.J.R.)
| | - Kexin Yan
- Inflammation Biology Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia; (J.E.H.); (B.T.); (K.Y.); (D.J.R.)
| | - Daniel J. Rawle
- Inflammation Biology Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia; (J.E.H.); (B.T.); (K.Y.); (D.J.R.)
| | - Jessica J. Harrison
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD 4072, Australia; (J.J.H.); (R.A.H.)
| | - Roy A. Hall
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD 4072, Australia; (J.J.H.); (R.A.H.)
- Australian Infectious Disease Research Centre, GVN Center of Excellence, The University of Queensland and QIMR Berghofer Medical Research Institute, St Lucia, QLD 4067, Australia
| | - Jody Hobson-Peters
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD 4072, Australia; (J.J.H.); (R.A.H.)
- Australian Infectious Disease Research Centre, GVN Center of Excellence, The University of Queensland and QIMR Berghofer Medical Research Institute, St Lucia, QLD 4067, Australia
| | - Andreas Suhrbier
- Inflammation Biology Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia; (J.E.H.); (B.T.); (K.Y.); (D.J.R.)
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21
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Sharma A, Zhang X, Dejnirattisai W, Dai X, Gong D, Wongwiwat W, Duquerroy S, Rouvinski A, Vaney MC, Guardado-Calvo P, Haouz A, England P, Sun R, Zhou ZH, Mongkolsapaya J, Screaton GR, Rey FA. The epitope arrangement on flavivirus particles contributes to Mab C10's extraordinary neutralization breadth across Zika and dengue viruses. Cell 2021; 184:6052-6066.e18. [PMID: 34852239 PMCID: PMC8724787 DOI: 10.1016/j.cell.2021.11.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 09/06/2021] [Accepted: 11/08/2021] [Indexed: 10/26/2022]
Abstract
The human monoclonal antibody C10 exhibits extraordinary cross-reactivity, potently neutralizing Zika virus (ZIKV) and the four serotypes of dengue virus (DENV1-DENV4). Here we describe a comparative structure-function analysis of C10 bound to the envelope (E) protein dimers of the five viruses it neutralizes. We demonstrate that the C10 Fab has high affinity for ZIKV and DENV1 but not for DENV2, DENV3, and DENV4. We further show that the C10 interaction with the latter viruses requires an E protein conformational landscape that limits binding to only one of the three independent epitopes per virion. This limited affinity is nevertheless counterbalanced by the particle's icosahedral organization, which allows two different dimers to be reached by both Fab arms of a C10 immunoglobulin. The epitopes' geometric distribution thus confers C10 its exceptional neutralization breadth. Our results highlight the importance not only of paratope/epitope complementarity but also the topological distribution for epitope-focused vaccine design.
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Affiliation(s)
- Arvind Sharma
- Institut Pasteur, Université de Paris, CNRS UMR3569, Unité de Virologie Structurale, 75015 Paris, France
| | - Xiaokang Zhang
- Institut Pasteur, Université de Paris, CNRS UMR3569, Unité de Virologie Structurale, 75015 Paris, France; Interdisciplinary Center for Brain Information, the Brain Cognition and Brain Disease Institute, Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, Guangdong 518055, China
| | - Wanwisa Dejnirattisai
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Xinghong Dai
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Danyang Gong
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Wiyada Wongwiwat
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Stéphane Duquerroy
- Institut Pasteur, Université de Paris, CNRS UMR3569, Unité de Virologie Structurale, 75015 Paris, France; Université Paris-Saclay, Faculté des Sciences, F-91405 Orsay, France
| | - Alexander Rouvinski
- Institut Pasteur, Université de Paris, CNRS UMR3569, Unité de Virologie Structurale, 75015 Paris, France
| | - Marie-Christine Vaney
- Institut Pasteur, Université de Paris, CNRS UMR3569, Unité de Virologie Structurale, 75015 Paris, France
| | - Pablo Guardado-Calvo
- Institut Pasteur, Université de Paris, CNRS UMR3569, Unité de Virologie Structurale, 75015 Paris, France
| | - Ahmed Haouz
- Institut Pasteur, Université de Paris, CNRS UMR 3528, Center for Technological Resources and Research, 75015 Paris, France
| | - Patrick England
- Institut Pasteur, Université de Paris, CNRS UMR 3528, Center for Technological Resources and Research, 75015 Paris, France
| | - Ren Sun
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Z Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Juthathip Mongkolsapaya
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Dengue Hemorrhagic Fever Research Unit, Office for Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | - Felix A Rey
- Institut Pasteur, Université de Paris, CNRS UMR3569, Unité de Virologie Structurale, 75015 Paris, France.
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22
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Harrison JJ, Hobson-Peters J, Bielefeldt-Ohmann H, Hall RA. Chimeric Vaccines Based on Novel Insect-Specific Flaviviruses. Vaccines (Basel) 2021; 9:1230. [PMID: 34835160 PMCID: PMC8623431 DOI: 10.3390/vaccines9111230] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/18/2021] [Accepted: 10/19/2021] [Indexed: 12/30/2022] Open
Abstract
Vector-borne flaviviruses are responsible for nearly half a billion human infections worldwide each year, resulting in millions of cases of debilitating and severe diseases and approximately 115,000 deaths. While approved vaccines are available for some of these viruses, the ongoing efficacy, safety and supply of these vaccines are still a significant problem. New technologies that address these issues and ideally allow for the safe and economical manufacture of vaccines in resource-poor countries where flavivirus vaccines are in most demand are urgently required. Preferably a new vaccine platform would be broadly applicable to all flavivirus diseases and provide new candidate vaccines for those diseases not yet covered, as well as the flexibility to rapidly pivot to respond to newly emerged flavivirus diseases. Here, we review studies conducted on novel chimeric vaccines derived from insect-specific flaviviruses that provide a potentially safe and simple system to produce highly effective vaccines against a broad spectrum of flavivirus diseases.
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Affiliation(s)
- Jessica J. Harrison
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; (J.H.-P.); (H.B.-O.); (R.A.H.)
| | - Jody Hobson-Peters
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; (J.H.-P.); (H.B.-O.); (R.A.H.)
| | - Helle Bielefeldt-Ohmann
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; (J.H.-P.); (H.B.-O.); (R.A.H.)
- School of Veterinary Science, University of Queensland, Gatton, QLD 4343, Australia
| | - Roy A. Hall
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; (J.H.-P.); (H.B.-O.); (R.A.H.)
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23
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Blahove MR, Carter JR. Flavivirus Persistence in Wildlife Populations. Viruses 2021; 13:v13102099. [PMID: 34696529 PMCID: PMC8541186 DOI: 10.3390/v13102099] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 10/01/2021] [Accepted: 10/08/2021] [Indexed: 12/14/2022] Open
Abstract
A substantial number of humans are at risk for infection by vector-borne flaviviruses, resulting in considerable morbidity and mortality worldwide. These viruses also infect wildlife at a considerable rate, persistently cycling between ticks/mosquitoes and small mammals and reptiles and non-human primates and humans. Substantially increasing evidence of viral persistence in wildlife continues to be reported. In addition to in humans, viral persistence has been shown to establish in mammalian, reptile, arachnid, and mosquito systems, as well as insect cell lines. Although a considerable amount of research has centered on the potential roles of defective virus particles, autophagy and/or apoptosis-induced evasion of the immune response, and the precise mechanism of these features in flavivirus persistence have yet to be elucidated. In this review, we present findings that aid in understanding how vector-borne flavivirus persistence is established in wildlife. Research studies to be discussed include determining the critical roles universal flavivirus non-structural proteins played in flaviviral persistence, the advancement of animal models of viral persistence, and studying host factors that allow vector-borne flavivirus replication without destructive effects on infected cells. These findings underscore the viral–host relationships in wildlife animals and could be used to elucidate the underlying mechanisms responsible for the establishment of viral persistence in these animals.
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24
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Scott CAP, Amarilla AA, Bibby S, Newton ND, Hall RA, Hobson-Peters J, Muller DA, Chappell KJ, Young PR, Modhiran N, Watterson D. Implications of Dengue Virus Maturation on Vaccine Induced Humoral Immunity in Mice. Viruses 2021; 13:v13091843. [PMID: 34578424 PMCID: PMC8473161 DOI: 10.3390/v13091843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 11/16/2022] Open
Abstract
The use of dengue virus (DENV) vaccines has been hindered by the complexities of antibody dependent enhancement (ADE). Current late-stage vaccine candidates utilize attenuated and chimeric DENVs that produce particles of varying maturities. Antibodies that are elicited by preferentially exposed epitopes on immature virions have been linked to increased ADE. We aimed to further understand the humoral immunity promoted by DENV particles of varying maturities in an AG129 mouse model using a chimeric insect specific vaccine candidate, bDENV-2. We immunized mice with mature, partially mature, and immature bDENV-2 and found that immunization with partially mature bDENV-2 produced more robust and cross-neutralizing immune responses than immunization with immature or mature bDENV-2. Upon challenge with mouse adapted DENV-2 (D220), we observed 80% protection for mature bDENV-2 vaccinated mice and 100% for immature and partially mature vaccinated mice, suggesting that protection to homotypic challenge is not dependent on maturation. Finally, we found reduced in vitro ADE at subneutralising serum concentrations for mice immunized with mature bDENV-2. These results suggest that both immature and mature DENV particles play a role in homotypic protection; however, the increased risk of in vitro ADE from immature particles indicates potential safety benefits from mature DENV-based vaccines.
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Affiliation(s)
- Connor A. P. Scott
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
| | - Alberto A. Amarilla
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
| | - Summa Bibby
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
| | - Natalee D. Newton
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
| | - Roy A. Hall
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
- Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Jody Hobson-Peters
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
- Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - David A. Muller
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
| | - Keith J. Chappell
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
- Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Paul R. Young
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
- Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Naphak Modhiran
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
- Correspondence: (N.M.); (D.W.)
| | - Daniel Watterson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.A.P.S.); (A.A.A.); (S.B.); (N.D.N.); (R.A.H.); (J.H.-P.); (D.A.M.); (K.J.C.); (P.R.Y.)
- Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, QLD 4072, Australia
- Correspondence: (N.M.); (D.W.)
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25
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An Absolutely Conserved Tryptophan in the Stem of the Envelope Protein E of Flaviviruses Is Essential for the Formation of Stable Particles. Viruses 2021; 13:v13091727. [PMID: 34578308 PMCID: PMC8473212 DOI: 10.3390/v13091727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/27/2021] [Indexed: 11/17/2022] Open
Abstract
The major envelope protein E of flaviviruses contains an ectodomain that is connected to the transmembrane domain by the so-called “stem” region. In mature flavivirus particles, the stem is composed of two or three mostly amphipathic α-helices and a conserved sequence element (CS) with an undefined role in the viral life cycle. A tryptophan is the only residue within this region which is not only conserved in all vector-borne flaviviruses, but also in the group with no known vector. We investigated the importance of this residue in different stages of the viral life cycle by a mutagenesis-based approach using tick-borne encephalitis virus (TBEV). Replacing W421 by alanine or histidine strongly reduced the release of infectious virions and their thermostability, whereas fusion-related entry functions and virus maturation were still intact. Serial passaging of the mutants led to the emergence of a same-site compensatory mutation to leucine that largely restored these properties of the wildtype. The conserved tryptophan in CS (or another big hydrophobic amino acid at the same position) is thus essential for the assembly and infectivity of flaviviruses by being part of a network required for conferring stability to infectious particles.
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Abstract
Usutu virus (USUV) is an emerging arbovirus in Europe that has been increasingly identified in asymptomatic humans and donated blood samples and is a cause of increased incidents of neuroinvasive human disease. Treatment or prevention options for USUV disease are currently nonexistent, the result of a lack of understanding of the fundamental elements of USUV pathogenesis. Here, we report two structures of the mature USUV virus, determined at a resolution of 2.4 Å, using single-particle cryogenic electron microscopy. Mature USUV is an icosahedral shell of 180 copies of envelope (E) and membrane (M) proteins arranged in the classic herringbone pattern. However, unlike previous reports of flavivirus structures, we observe virus subpopulations and differences in the fusion loop disulfide bond. Presence of a second, unique E glycosylation site could elucidate host interactions, contributing to the broad USUV tissue tropism. The structures provide a basis for exploring USUV interactions with glycosaminoglycans and lectins, the role of the RGD motif as a receptor, and the inability of West Nile virus therapeutic antibody E16 to neutralize the mature USUV strain SAAR-1776. Finally, we identify three lipid binding sites and predict key residues that likely participate in virus stability and flexibility during membrane fusion. Our findings provide a framework for the development of USUV therapeutics and expand the current knowledge base of flavivirus biology.
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27
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Fibriansah G, Lim XN, Lok SM. Morphological Diversity and Dynamics of Dengue Virus Affecting Antigenicity. Viruses 2021; 13:v13081446. [PMID: 34452312 PMCID: PMC8402850 DOI: 10.3390/v13081446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/15/2021] [Accepted: 07/21/2021] [Indexed: 01/30/2023] Open
Abstract
The four serotypes of the mature dengue virus can display different morphologies, including the compact spherical, the bumpy spherical and the non-spherical clubshape morphologies. In addition, the maturation process of dengue virus is inefficient and therefore some partially immature dengue virus particles have been observed and they are infectious. All these viral particles have different antigenicity profiles and thus may affect the type of the elicited antibodies during an immune response. Understanding the molecular determinants and environmental conditions (e.g., temperature) in inducing morphological changes in the virus and how potent antibodies interact with these particles is important for designing effective therapeutics or vaccines. Several techniques, including cryoEM, site-directed mutagenesis, hydrogen-deuterium exchange mass spectrometry, time-resolve fluorescence resonance energy transfer, and molecular dynamic simulation, have been performed to investigate the structural changes. This review describes all known morphological variants of DENV discovered thus far, their surface protein dynamics and the key residues or interactions that play important roles in the structural changes.
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Affiliation(s)
- Guntur Fibriansah
- Programme in Emerging Infectious Diseases, Duke–National University of Singapore Medical School, Singapore 169857, Singapore; (G.F.); (X.-N.L.)
- Centre for BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore 117557, Singapore
| | - Xin-Ni Lim
- Programme in Emerging Infectious Diseases, Duke–National University of Singapore Medical School, Singapore 169857, Singapore; (G.F.); (X.-N.L.)
- Centre for BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore 117557, Singapore
| | - Shee-Mei Lok
- Programme in Emerging Infectious Diseases, Duke–National University of Singapore Medical School, Singapore 169857, Singapore; (G.F.); (X.-N.L.)
- Centre for BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore 117557, Singapore
- Correspondence:
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