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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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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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4
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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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5
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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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6
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Tabata K, Itakura Y, Ariizumi T, Igarashi M, Kobayashi H, Intaruck K, Kishimoto M, Kobayashi S, Hall WW, Sasaki M, Sawa H, Orba Y. Development of flavivirus subviral particles with low cross-reactivity by mutations of a distinct antigenic domain. Appl Microbiol Biotechnol 2023; 107:7515-7529. [PMID: 37831184 PMCID: PMC10656323 DOI: 10.1007/s00253-023-12817-5] [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: 05/23/2023] [Revised: 09/04/2023] [Accepted: 09/25/2023] [Indexed: 10/14/2023]
Abstract
The most conserved fusion loop (FL) domain present in the flavivirus envelope protein has been reported as a dominant epitope for cross-reactive antibodies to mosquito-borne flaviviruses (MBFVs). As a result, establishing accurate serodiagnosis for MBFV infections has been difficult as anti-FL antibodies are induced by both natural infection and following vaccination. In this study, we modified the most conserved FL domain to overcome this cross-reactivity. We showed that the FL domain of lineage I insect-specific flavivirus (ISFV) has differences in antigenicity from those of MBFVs and lineage II ISFV and determined the key amino acid residues (G106, L107, or F108), which contribute to the antigenic difference. These mutations were subsequently introduced into subviral particles (SVPs) of dengue virus type 2 (DENV2), Zika virus (ZIKV), Japanese encephalitis virus (JEV), and West Nile virus (WNV). In indirect enzyme-linked immunosorbent assays (ELISAs), these SVP mutants when used as antigens reduced the binding of cross-reactive IgG and total Ig induced by infection of ZIKV, JEV, and WNV in mice and enabled the sensitive detection of virus-specific antibodies. Furthermore, immunization of ZIKV or JEV SVP mutants provoked the production of antibodies with lower cross-reactivity to heterologous MBFV antigens compared to immunization with the wild-type SVPs in mice. This study highlights the effectiveness of introducing mutations in the FL domain in MBFV SVPs with lineage I ISFV-derived amino acids to produce SVP antigens with low cross-reactivity and demonstrates an improvement in the accuracy of indirect ELISA-based serodiagnosis for MBFV infections. KEY POINTS: • The FL domain of Lineage I ISFV has a different antigenicity from that of MBFVs. • Mutated SVPs reduce the binding of cross-reactive antibodies in indirect ELISAs. • Inoculation of mutated SVPs induces antibodies with low cross-reactivity.
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Affiliation(s)
- Koshiro Tabata
- Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
- Institute for Vaccine Research and Development, Hokkaido University, Sapporo, 001-0021, Japan
| | - Yukari Itakura
- Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
- Institute for Vaccine Research and Development, Hokkaido University, Sapporo, 001-0021, Japan
| | - Takuma Ariizumi
- Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
| | - Manabu Igarashi
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, N20, W10001-0020, Japan
| | - Hiroko Kobayashi
- Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
| | - Kittiya Intaruck
- Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
| | - Mai Kishimoto
- Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
- Laboratory of Veterinary Microbiology, Osaka Metropolitan University, Izumisano, 598-8531, Japan
| | - Shintaro Kobayashi
- Laboratory of Public Health, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, 060‑0818, Japan
| | - William W Hall
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, N20, W10001-0020, Japan
- Global Virus Network, Baltimore, MD, 21201, USA
- National Virus Reference Laboratory, University College Dublin, Belfield, Dublin, 4, Ireland
| | - Michihito Sasaki
- Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
- Institute for Vaccine Research and Development, Hokkaido University, Sapporo, 001-0021, Japan
| | - Hirofumi Sawa
- Institute for Vaccine Research and Development, Hokkaido University, Sapporo, 001-0021, Japan
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, N20, W10001-0020, Japan
- Global Virus Network, Baltimore, MD, 21201, USA
- One Health Research Center, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan
| | - Yasuko Orba
- Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, 001-0020, Japan.
- Institute for Vaccine Research and Development, Hokkaido University, Sapporo, 001-0021, Japan.
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, N20, W10001-0020, Japan.
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Crampon E, Covernton E, Vaney MC, Dellarole M, Sommer S, Sharma A, Haouz A, England P, Lepault J, Duquerroy S, Rey FA, Barba-Spaeth G. New insight into flavivirus maturation from structure/function studies of the yellow fever virus envelope protein complex. mBio 2023; 14:e0070623. [PMID: 37607061 PMCID: PMC10653854 DOI: 10.1128/mbio.00706-23] [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: 03/19/2023] [Accepted: 06/16/2023] [Indexed: 08/24/2023] Open
Abstract
IMPORTANCE All enveloped viruses enter cells by fusing their envelope with a target cell membrane while avoiding premature fusion with membranes of the producer cell-the latter being particularly important for viruses that bud at internal membranes. Flaviviruses bud in the endoplasmic reticulum, are transported through the TGN to reach the external milieu, and enter other cells via receptor-mediated endocytosis. The trigger for membrane fusion is the acidic environment of early endosomes, which has a similar pH to the TGN of the producer cell. The viral particles therefore become activated to react to mildly acidic pH only after their release into the neutral pH extracellular environment. Our study shows that for yellow fever virus (YFV), the mechanism of activation involves actively knocking out the fusion brake (protein pr) through a localized conformational change of the envelope protein upon exposure to the neutral pH external environment. Our study has important implications for understanding the molecular mechanism of flavivirus fusion activation in general and points to an alternative way of interfering with this process as an antiviral treatment.
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Affiliation(s)
- E. Crampon
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - E. Covernton
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - M. C. Vaney
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - M. Dellarole
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - S. Sommer
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - A. Sharma
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - A. Haouz
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Plateforme de Cristallographie-C2RT, Paris, France
| | - P. England
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Plateforme de Biophysique Moléculaire-C2RT, Paris, France
| | - J. Lepault
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - S. Duquerroy
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
- Université Paris-Saclay, Faculté des Sciences, Orsay, France
| | - F. A. Rey
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - G. Barba-Spaeth
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
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8
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Stiasny K, Medits I, Roßbacher L, Heinz FX. Impact of structural dynamics on biological functions of flaviviruses. FEBS J 2023; 290:1973-1985. [PMID: 35246954 PMCID: PMC10952610 DOI: 10.1111/febs.16419] [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: 01/11/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 11/30/2022]
Abstract
Flaviviruses comprise a number of mosquito- or tick-transmitted human pathogens of global public health importance. Advances in structural biology techniques have contributed substantially to our current understanding of the life cycle of these small enveloped RNA viruses and led to deep insights into details of virus assembly, maturation and cell entry. In addition to large-scale conformational changes and oligomeric rearrangements of envelope proteins during these processes, there is increasing evidence that smaller-scale protein dynamics (referred to as virus "breathing") can confer extra flexibility to these viruses for the fine-tuning of their interactions with the immune system and possibly with cellular factors they encounter in their complex ecological cycles in arthropod and vertebrate hosts. In this review, we discuss how work with tick-borne encephalitis virus has extended our view on flavivirus breathing, leading to the identification of a novel mechanism of antibody-mediated infection enhancement and demonstrating breathing intermediates of the envelope protein in the process of membrane fusion. These data are discussed in the context of other flaviviruses and the perspective of a potential role of virus breathing to cope with the requirements of adaptation and replication in evolutionarily very different hosts.
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Affiliation(s)
- Karin Stiasny
- Center for VirologyMedical University of ViennaAustria
| | - Iris Medits
- Center for VirologyMedical University of ViennaAustria
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9
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Zerfu B, Kassa T, Legesse M. Epidemiology, biology, pathogenesis, clinical manifestations, and diagnosis of dengue virus infection, and its trend in Ethiopia: a comprehensive literature review. Trop Med Health 2023; 51:11. [PMID: 36829222 PMCID: PMC9950709 DOI: 10.1186/s41182-023-00504-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/15/2023] [Indexed: 02/26/2023] Open
Abstract
Dengue fever is a dengue virus infection, emerging rapidly and posing public health threat worldwide, primarily in tropical and subtropical countries. Nearly half of the world's population is now at risk of contracting the dengue virus, including new countries with no previous history-like Ethiopia. However, little is known about the epidemiology and impact of the disease in different countries. This is especially true in countries, where cases have recently begun to be reported. This review aims to summarize epidemiology, biology, pathogenesis, clinical manifestations, and diagnosis of dengue virus infection and its trend in Ethiopia. It may help countries, where dengue fever is not yet on the public health list-like Ethiopia to alert healthcare workers to consider the disease for diagnosis and treatment. The review retrieved and incorporated 139 published and organizational reports showing approximately 390 million new infections. About 100 million of these infections develop the clinical features of dengue, and thousands of people die annually from severe dengue fever in 129 countries. It is caused by being bitten by a dengue virus-infected female mosquito, primarily Aedes aegypti and, lesser, Ae. albopictus. Dengue virus is a member of the Flavivirus genus of the Flaviviridae family and has four independent but antigen-related single-stranded positive-sense RNA virus serotypes. The infection is usually asymptomatic but causes illnesses ranging from mild febrile illness to fatal dengue hemorrhagic fever or shock syndrome. Diagnosis can be by detecting the virus genome using nucleic acids amplification tests or testing NS1 antigen and/or anti-dengue antibodies from serum, plasma, circulating blood cells, or other tissues. Dengue cases and outbreaks have increased in recent decades, with a significant public health impact. Ethiopia has had nearly annual outbreaks since 2013, devastating an already fragmented health system and economy. Standardization of medication, population-level screening for early diagnosis and prompt treatment, and minimization of mosquito bites reduce overall infection and mortality rates.
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Affiliation(s)
- Biruk Zerfu
- Department of Medical Laboratory Science, College of Health Science, Addis Ababa University, Addis Ababa, Ethiopia. .,Aklilu Lema Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
| | - Tesfu Kassa
- grid.7123.70000 0001 1250 5688Aklilu Lema Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Mengistu Legesse
- grid.7123.70000 0001 1250 5688Aklilu Lema Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
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10
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Bignon E, Dumont E, Monari A. Molecular Basis of the pH-Controlled Maturation of the Tick-Borne Encephalitis Flavivirus. J Phys Chem Lett 2023; 14:1977-1982. [PMID: 36790164 DOI: 10.1021/acs.jpclett.2c03551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Flaviviruses are enveloped viruses causing high public concerns. Their maturation spans several cellular compartments having different pH. Thus, complex control mechanisms are in place to avoid premature maturation. Here we report the dynamical behavior at neutral and acidic pH of the precursor of the membrane fusion protein E of tick-borne encephalitis, showing the different stabilizations of the E dimer and the role played by the small fusion-assisting protomer (pr). The comprehension, at atomic resolution, of the fine regulation of viral maturation will be fundamental to the development of efficient strategies against emerging viral threats.
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Affiliation(s)
- Emmanuelle Bignon
- Université de Lorraine and CNRS, UMR 7019 LPCT, F-5400, Nancy, France
| | - Elise Dumont
- Université Côte d'Azur, Institut de Chimie de Nice, UMR 7272, Parc Valrose, 28 avenue Valrose, F-06108, Nice, France
- Institut Universitaire de France, 5 rue Descartes, F-75005, Paris, France
| | - Antonio Monari
- Université Paris Cité and CNRS, ITODYS, F-75006, Paris, France
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11
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Saivish MV, Pacca CC, da Costa VG, de Lima Menezes G, da Silva RA, Nebo L, da Silva GCD, de Aguiar Milhim BHG, da Silva Teixeira I, Henrique T, Mistrão NFB, Hernandes VM, Zini N, de Carvalho AC, Fontoura MA, Rahal P, Sacchetto L, Marques RE, Nogueira ML. Caffeic Acid Has Antiviral Activity against Ilhéus Virus In Vitro. Viruses 2023; 15:494. [PMID: 36851709 PMCID: PMC9961518 DOI: 10.3390/v15020494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 01/28/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
Ilhéus virus (ILHV) is a neglected mosquito-borne flavivirus. ILHV infection may lead to Ilhéus fever, an emerging febrile disease like dengue fever with the potential to evolve into a severe neurological disease characterized by meningoencephalitis; no specific treatments are available for this disease. This study assessed the antiviral properties of caffeic acid, an abundant component of plant-based food products that is also compatible with the socioeconomic limitations associated with this neglected infectious disease. The in vitro activity of caffeic acid on ILHV replication was investigated in Vero and A549 cell lines using plaque assays, quantitative RT-PCR, and immunofluorescence assays. We observed that 500 µM caffeic acid was virucidal against ILHV. Molecular docking indicated that caffeic acid might interact with an allosteric binding site on the envelope protein.
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Affiliation(s)
- Marielena Vogel Saivish
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
- Brazilian Biosciences National Laboratory, Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas 13083-100, SP, Brazil
| | - Carolina Colombelli Pacca
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
- Laboratório de Estudos Genômicos, Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, São José do Rio Preto 15054-000, SP, Brazil
- Faceres Medical School, São José do Rio Preto 15090-000, SP, Brazil
| | - Vivaldo Gomes da Costa
- Laboratório de Estudos Genômicos, Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, São José do Rio Preto 15054-000, SP, Brazil
| | - Gabriela de Lima Menezes
- Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, Natal 59072-970, RN, Brazil
- Unidade Especial de Ciências Exatas, Universidade Federal de Jataí, Jataí 75801-615, GO, Brazil
| | | | - Liliane Nebo
- Unidade Especial de Ciências Exatas, Universidade Federal de Jataí, Jataí 75801-615, GO, Brazil
| | - Gislaine Celestino Dutra da Silva
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
| | - Bruno Henrique Gonçalves de Aguiar Milhim
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
| | - Igor da Silva Teixeira
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
| | - Tiago Henrique
- Laboratório de Marcadores Moleculares e Bioinformática, Departamento de Biologia Molecular, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
| | - Natalia Franco Bueno Mistrão
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
| | - Victor Miranda Hernandes
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
| | - Nathalia Zini
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
| | - Ana Carolina de Carvalho
- Brazilian Biosciences National Laboratory, Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas 13083-100, SP, Brazil
| | - Marina Alves Fontoura
- Brazilian Biosciences National Laboratory, Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas 13083-100, SP, Brazil
| | - Paula Rahal
- Laboratório de Estudos Genômicos, Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, São José do Rio Preto 15054-000, SP, Brazil
| | - Lívia Sacchetto
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
| | - Rafael Elias Marques
- Brazilian Biosciences National Laboratory, Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas 13083-100, SP, Brazil
| | - Maurício Lacerda Nogueira
- Laboratório de Pesquisas em Virologia, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto 15090-000, SP, Brazil
- Brazilian Biosciences National Laboratory, Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas 13083-100, SP, Brazil
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555, USA
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12
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Keelapang P, Supasa P, Sriburi R, Puttikhunt C, Cardosa J, Kasinrerk W, Malasit P, Sittisombut N. A group of infection-enhancing and focus size-reducing monoclonal antibodies recognized an 'a and c' strands epitope in the pr domain of Dengue Virus prM. Virus Res 2023; 323:199015. [PMID: 36455752 PMCID: PMC9742851 DOI: 10.1016/j.virusres.2022.199015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/31/2022] [Accepted: 11/28/2022] [Indexed: 11/30/2022]
Abstract
Partial cleavage of a dengue virus envelope protein, prM, by furin results in a mixture of extracellular particles with variable levels of maturation and infectivity. Partially mature particles can infect leukocytes via interaction between the prM-anti-prM antibody complex with Fcγ receptors. Known prM epitopes involved in antibody-mediated infection are localized to the pr domain. In this study, a group of murine anti-prM monoclonal antibodies with strong infection-enhancing activity was found to reduce the focus size of subsets of multiple dengue serotypes that they could enhance. By employing sets of overlapping peptides, four antibodies recognizing 2-mercaptoethanol-insensitive epitopes were mapped to a common tetrapeptide located distantly in the b-c loop and furin binding site. Substitution mutations of each, or both, of the tetrapeptides in virus-like particles, however, failed to reduce binding. Further mapping experiments were performed using immature virus-like particles with abolished furin binding site to minimize the differential influence of various pr substitutions on pr-M cleavage. Reduction of antibody binding was detected when single alanine substitutions were introduced into the 'a' strand and 'c' strand of pr domain. These findings suggest that the pr 'a and c' strands region is the major binding site of these unusual focus size-reducing anti-prM antibodies.
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Affiliation(s)
- Poonsook Keelapang
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Medical Biotechnology Research Unit. National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, Thailand
| | - Piyada Supasa
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Rungtawan Sriburi
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Chunya Puttikhunt
- Medical Biotechnology Research Unit. National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, Thailand; Molecular Biology of Dengue and Flaviviruses Research Team, Medical Molecular Biotechnology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand; Division of Dengue Hemorrhagic Fever Research and Siriraj Center of Research Excellence in Dengue and Emerging Pathogens, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Jane Cardosa
- Institute of Health and Community Medicine, Universiti Malaysia Sarawak, Kuching, Sarawak, Malaysia
| | - Watchara Kasinrerk
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand; Biomedical Technology Research Center, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at the Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Prida Malasit
- Medical Biotechnology Research Unit. National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, Thailand; Division of Dengue Hemorrhagic Fever Research and Siriraj Center of Research Excellence in Dengue and Emerging Pathogens, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nopporn Sittisombut
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Medical Biotechnology Research Unit. National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, Thailand
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13
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Winter SL, Chlanda P. The Art of Viral Membrane Fusion and Penetration. Subcell Biochem 2023; 106:113-152. [PMID: 38159225 DOI: 10.1007/978-3-031-40086-5_4] [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: 01/03/2024]
Abstract
As obligate pathogens, viruses have developed diverse mechanisms to deliver their genome across host cell membranes to sites of virus replication. While enveloped viruses utilize viral fusion proteins to accomplish fusion of their envelope with the cellular membrane, non-enveloped viruses rely on machinery that causes local membrane ruptures and creates an opening through which the capsid or viral genome is released. Both membrane fusion and membrane penetration take place at the plasma membrane or in intracellular compartments, often involving the engagement of the cellular machinery and antagonism of host restriction factors. Enveloped and non-enveloped viruses have evolved intricate mechanisms to enable virus uncoating and modulation of membrane fusion in a spatiotemporally controlled manner. This chapter summarizes and discusses the current state of understanding of the mechanisms of viral membrane fusion and penetration. The focus is on the role of lipids, viral scaffold uncoating, viral membrane fusion inhibitors, and host restriction factors as physicochemical modulators. In addition, recent advances in visualizing and detecting viral membrane fusion and penetration using cryo-electron microscopy methods are presented.
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Affiliation(s)
- Sophie L Winter
- Schaller Research Group, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Petr Chlanda
- Schaller Research Group, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.
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14
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Konevtsova OV, Golushko IY, Podgornik R, Rochal SB. Hidden symmetry of the flavivirus protein shell and pH-controlled reconstruction of the viral surface. Biomater Sci 2022; 11:225-234. [PMID: 36426630 DOI: 10.1039/d2bm01562e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Using recent Zika virus structural data we reveal a hidden symmetry of protein order in immature and mature flavivirus shells, violating the Caspar-Klug paradigmatic model of capsid structures. We show that proteins of the outer immature shell layer exhibit trihexagonal tiling, while proteins from inner and outer layers conjointly form a double-shelled close-packed structure, based on a common triangular spherical lattice. Within the proposed structural model, we furthermore rationalize the structural organization of misassembled non-infectious subviral particles that have no inner capsid. We consider a pH-controlled structural reconstruction of the outer shell from the trimeric to the dimeric state, and demonstrate that this transition, occurring during the virus maturation, can be induced by changes in protein charges at lower pH, leading to a decrease in the electrostatic interaction free energy. This transition could also be assisted by electrostatic attraction of shell proteins to the interposed lipid membrane substrate separating the shells.
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Affiliation(s)
- Olga V Konevtsova
- Physics Faculty, Southern Federal University, Rostov-on-Don, Russia.
| | - Ivan Yu Golushko
- Physics Faculty, Southern Federal University, Rostov-on-Don, Russia.
| | - Rudolf Podgornik
- School of Physical Sciences and Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.,CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China. .,Wenzhou Institute of the University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325000, China
| | - Sergei B Rochal
- Physics Faculty, Southern Federal University, Rostov-on-Don, Russia.
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15
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Structural characterization of protective non-neutralizing antibodies targeting Crimean-Congo hemorrhagic fever virus. Nat Commun 2022; 13:7298. [PMID: 36435827 PMCID: PMC9701186 DOI: 10.1038/s41467-022-34923-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 11/10/2022] [Indexed: 11/28/2022] Open
Abstract
Crimean-Congo Hemorrhagic Fever Virus (CCHFV) causes a life-threatening disease with up to a 40% mortality rate. With no approved medical countermeasures, CCHFV is considered a public health priority agent. The non-neutralizing mouse monoclonal antibody (mAb) 13G8 targets CCHFV glycoprotein GP38 and protects mice from lethal CCHFV challenge when administered prophylactically or therapeutically. Here, we reveal the structures of GP38 bound with a human chimeric 13G8 mAb and a newly isolated CC5-17 mAb from a human survivor. These mAbs bind overlapping epitopes with a shifted angle. The broad-spectrum potential of c13G8 and CC5-17 and the practicality of using them against Aigai virus, a closely related nairovirus were examined. Binding studies demonstrate that the presence of non-conserved amino acids in Aigai virus corresponding region prevent CCHFV mAbs from binding Aigai virus GP38. This information, coupled with in vivo efficacy, paves the way for future mAb therapeutics effective against a wide swath of CCHFV strains.
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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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Jose J, Hafenstein SL. Asymmetry in icosahedral viruses. Curr Opin Virol 2022; 54:101230. [DOI: 10.1016/j.coviro.2022.101230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 04/07/2022] [Accepted: 04/13/2022] [Indexed: 01/24/2023]
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18
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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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19
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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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20
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Replication is the key barrier during the dual-host adaptation of mosquito-borne flaviviruses. Proc Natl Acad Sci U S A 2022; 119:e2110491119. [PMID: 35294288 PMCID: PMC8944775 DOI: 10.1073/pnas.2110491119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Most viruses have a relatively narrow host range. In contrast, vector-borne flaviviruses, such as dengue virus and Zika virus, maintain their transmission cycle between arthropods and vertebrates, belonging to different phyla. How do these viruses adapt to the distinct cellular environments of two phyla? By comparing the single-host insect--specific flavivirus and dual-host Zika virus, we identified three key molecular factors that determine MBF host tropism. This study will greatly increase the understanding of entry, replication, and cross-species evolution of mosquito-borne flaviviruses. Mosquito-borne flaviviruses (MBFs) adapt to a dual-host transmission circle between mosquitoes and vertebrates. Dual-host affiliated insect-specific flaviviruses (dISFs), discovered from mosquitoes, are phylogenetically similar to MBFs but do not infect vertebrates. Thus, dISF–MBF chimeras could be an ideal model to study the dual-host adaptation of MBFs. Using the pseudoinfectious reporter virus particle and reverse genetics systems, we found dISFs entered vertebrate cells as efficiently as the MBFs but failed to initiate replication. Exchange of the untranslational regions (UTRs) of Donggang virus (DONV), a dISF, with those from Zika virus (ZIKV) rescued DONV replication in vertebrate cells, and critical secondary RNA structures were further mapped. Essential UTR-binding host factors were screened for ZIKV replication in vertebrate cells, displaying different binding patterns. Therefore, our data demonstrate a post-entry cross-species transmission mechanism of MBFs, while UTR-host interaction is critical for dual-host adaptation.
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21
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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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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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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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24
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Dengue and the Lectin Pathway of the Complement System. Viruses 2021; 13:v13071219. [PMID: 34202570 PMCID: PMC8310334 DOI: 10.3390/v13071219] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/17/2021] [Accepted: 06/19/2021] [Indexed: 12/15/2022] Open
Abstract
Dengue is a mosquito-borne viral disease causing significant health and economic burdens globally. The dengue virus (DENV) comprises four serotypes (DENV1-4). Usually, the primary infection is asymptomatic or causes mild dengue fever (DF), while secondary infections with a different serotype increase the risk of severe dengue disease (dengue hemorrhagic fever, DHF). Complement system activation induces inflammation and tissue injury, contributing to disease pathogenesis. However, in asymptomatic or primary infections, protective immunity largely results from the complement system’s lectin pathway (LP), which is activated through foreign glycan recognition. Differences in N-glycans displayed on the DENV envelope membrane influence the lectin pattern recognition receptor (PRR) binding efficiency. The important PRR, mannan binding lectin (MBL), mediates DENV neutralization through (1) a complement activation-independent mechanism via direct MBL glycan recognition, thereby inhibiting DENV attachment to host target cells, or (2) a complement activation-dependent mechanism following the attachment of complement opsonins C3b and C4b to virion surfaces. The serum concentrations of lectin PRRs and their polymorphisms influence these LP activities. Conversely, to escape the LP attack and enhance the infectivity, DENV utilizes the secreted form of nonstructural protein 1 (sNS1) to counteract the MBL effects, thereby increasing viral survival and dissemination.
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