1
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Uribe FR, González VPI, Kalergis AM, Soto JA, Bohmwald K. Understanding the Neurotrophic Virus Mechanisms and Their Potential Effect on Systemic Lupus Erythematosus Development. Brain Sci 2024; 14:59. [PMID: 38248274 PMCID: PMC10813552 DOI: 10.3390/brainsci14010059] [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: 11/07/2023] [Revised: 12/24/2023] [Accepted: 01/03/2024] [Indexed: 01/23/2024] Open
Abstract
Central nervous system (CNS) pathologies are a public health concern, with viral infections one of their principal causes. These viruses are known as neurotropic pathogens, characterized by their ability to infiltrate the CNS and thus interact with various cell populations, inducing several diseases. The immune response elicited by neurotropic viruses in the CNS is commanded mainly by microglia, which, together with other local cells, can secrete inflammatory cytokines to fight the infection. The most relevant neurotropic viruses are adenovirus (AdV), cytomegalovirus (CMV), enterovirus (EV), Epstein-Barr Virus (EBV), herpes simplex virus type 1 (HSV-1), and herpes simplex virus type 2 (HSV-2), lymphocytic choriomeningitis virus (LCMV), and the newly discovered SARS-CoV-2. Several studies have associated a viral infection with systemic lupus erythematosus (SLE) and neuropsychiatric lupus (NPSLE) manifestations. This article will review the knowledge about viral infections, CNS pathologies, and the immune response against them. Also, it allows us to understand the relevance of the different viral proteins in developing neuronal pathologies, SLE and NPSLE.
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Affiliation(s)
- Felipe R. Uribe
- Millennium Institute on Immunology and Immunotherapy, Laboratorio de Inmunología Traslacional, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile; (F.R.U.); (V.P.I.G.)
| | - Valentina P. I. González
- Millennium Institute on Immunology and Immunotherapy, Laboratorio de Inmunología Traslacional, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile; (F.R.U.); (V.P.I.G.)
| | - Alexis M. Kalergis
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8330025, Chile;
- Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Jorge A. Soto
- Millennium Institute on Immunology and Immunotherapy, Laboratorio de Inmunología Traslacional, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile; (F.R.U.); (V.P.I.G.)
| | - Karen Bohmwald
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma, Santiago 8910060, Chile
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2
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Huang C, Mantlo E, Paessler S. Lassa virus NP DEDDh 3'-5' exoribonuclease activity is required for optimal viral RNA replication and mutation control. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.12.536665. [PMID: 37090668 PMCID: PMC10120729 DOI: 10.1101/2023.04.12.536665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Lassa virus (LASV), a mammarenavirus from Arenaviridae, is the causative agent of Lassa fever (LF) endemic in West Africa. Currently, there are no vaccines or antivirals approved for LF. The RNA-dependent RNA polymerases (RdRp) of RNA viruses are error-prone. As a negative-sense RNA virus, how LASV copes with errors in RNA synthesis and ensures optimal RNA replication are not well elucidated. LASV nucleoprotein (NP) contains a DEDDH 3'-to-5' exoribonuclease motif (ExoN), which is known to be essential for LASV evasion of the interferon response via its ability to degrade virus-derived double-stranded RNA. Herein, we present evidence that LASV NP ExoN has an additional function important for viral RNA replication. We rescued an ExoN-deficient LASV mutant (ExoN- rLASV) by using a reverse genetics system. Our data indicated that abrogation of NP ExoN led to impaired LASV growth and RNA replication in interferon-deficient cells as compared with wild-type rLASV. By utilizing PacBio Single Molecule, Real-Time (SMRT) long-read sequencing technology, we found that rLASV lacking ExoN activity was prone to producing aberrant viral genomic RNA with structural variations. In addition, NP ExoN deficiency enhanced LASV sensitivity to mutagenic nucleoside analogues in virus titration assay. Next-generation deep sequencing analysis showed increased single nucleotide substitution in ExoN- LASV RNA following mutagenic 5-flurouracil treatment. In conclusion, our study revealed that LASV NP ExoN is required for efficient viral RNA replication and mutation control. Among negative-sense RNA viruses, LASV NP is the first example that a viral protein, other than the RdRp, contributes to reduce errors in RNA replication and maintain genomic RNA integrity. These new findings promote our understanding of the basics of LASV infection and inform antiviral and vaccine development.
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Affiliation(s)
- Cheng Huang
- Department of Pathology, Galveston National Laboratory and
Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston,
TX, USA
| | - Emily Mantlo
- Department of Pathology, Galveston National Laboratory and
Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston,
TX, USA
- Current address: Department of Microbiology & Immunology,
Upstate Medical University, Syracuse, NY, USA
| | - Slobodan Paessler
- Department of Pathology, Galveston National Laboratory and
Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston,
TX, USA
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3
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Sänger L, Williams HM, Yu D, Vogel D, Kosinski J, Rosenthal M, Uetrecht C. RNA to Rule Them All: Critical Steps in Lassa Virus Ribonucleoparticle Assembly and Recruitment. J Am Chem Soc 2023; 145:27958-27974. [PMID: 38104324 PMCID: PMC10755698 DOI: 10.1021/jacs.3c07325] [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: 07/10/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 12/19/2023]
Abstract
Lassa virus is a negative-strand RNA virus with only four structural proteins that causes periodic outbreaks in West Africa. The nucleoprotein (NP) encapsidates the viral genome, forming ribonucleoprotein complexes (RNPs) together with the viral RNA and the L protein. RNPs must be continuously restructured during viral genome replication and transcription. The Z protein is important for membrane recruitment of RNPs, viral particle assembly, and budding and has also been shown to interact with the L protein. However, the interaction of NP, viral RNA, and Z is poorly understood. Here, we characterize the interactions between Lassa virus NP, Z, and RNA using structural mass spectrometry. We identify the presence of RNA as the driver for the disassembly of ring-like NP trimers, a storage form, into monomers to subsequently form higher order RNA-bound NP assemblies. We locate the interaction site of Z and NP and demonstrate that while NP binds Z independently of the presence of RNA, this interaction is pH-dependent. These data improve our understanding of RNP assembly, recruitment, and release in Lassa virus.
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Affiliation(s)
- Lennart Sänger
- Bernhard
Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- Leibniz
Institute of Virology (LIV), Notkestraße 85, 22607 Hamburg, Germany
| | - Harry M. Williams
- Bernhard
Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
| | - Dingquan Yu
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- European
Molecular Biology Laboratory Notkestraße 85, 22607 Hamburg, Germany
| | - Dominik Vogel
- Bernhard
Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
| | - Jan Kosinski
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- European
Molecular Biology Laboratory Notkestraße 85, 22607 Hamburg, Germany
- Structural
and Computational Biology Unit, European
Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Maria Rosenthal
- Bernhard
Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- Fraunhofer
Institute for Translational Medicine and Pharmacology (ITMP), Discovery Research ScreeningPort, Schnackenburgallee 114, 22525 Hamburg, Germany
| | - Charlotte Uetrecht
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- Leibniz
Institute of Virology (LIV), Notkestraße 85, 22607 Hamburg, Germany
- Faculty
V: School of Life Sciences, University of
Siegen, Am Eichenhang 50, 57076 Siegen, Germany
- Deutsches
Elektronen-Synchrotron (DESY), Notkestr. 85, 22607 Hamburg, Germany
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Sabsay KR, te Velthuis AJW. Negative and ambisense RNA virus ribonucleocapsids: more than protective armor. Microbiol Mol Biol Rev 2023; 87:e0008223. [PMID: 37750733 PMCID: PMC10732063 DOI: 10.1128/mmbr.00082-23] [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] [Indexed: 09/27/2023] Open
Abstract
SUMMARYNegative and ambisense RNA viruses are the causative agents of important human diseases such as influenza, measles, Lassa fever, and Ebola hemorrhagic fever. The viral genome of these RNA viruses consists of one or more single-stranded RNA molecules that are encapsidated by viral nucleocapsid proteins to form a ribonucleoprotein complex (RNP). This RNP acts as protection, as a scaffold for RNA folding, and as the context for viral replication and transcription by a viral RNA polymerase. However, the roles of the viral nucleoproteins extend beyond these functions during the viral infection cycle. Recent advances in structural biology techniques and analysis methods have provided new insights into the formation, function, dynamics, and evolution of negative sense virus nucleocapsid proteins, as well as the role that they play in host innate immune responses against viral infection. In this review, we discuss the various roles of nucleocapsid proteins, both in the context of RNPs and in RNA-free states, as well as the open questions that remain.
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Affiliation(s)
- Kimberly R. Sabsay
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, USA
| | - Aartjan J. W. te Velthuis
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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5
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Lee K, Choi MJ, Cho MH, Choi DO, Bhoo SH. Antibody production and characterization of the nucleoprotein of sever fever with thrombocytopenia syndrome virus (SFTSV) for effective diagnosis of SFTSV. Virol J 2023; 20:206. [PMID: 37679757 PMCID: PMC10486111 DOI: 10.1186/s12985-023-02173-1] [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: 01/16/2023] [Accepted: 08/30/2023] [Indexed: 09/09/2023] Open
Abstract
BACKGROUND Severe fever with thrombocytopenia syndrome (SFTS) is an infectious disease caused by the Dabie bandavirus, [or SFTS virus (SFTSV)] that has become increasingly widespread since it was first reported in 2009. The SFTSV comprises three essential single-stranded RNA gene segments, with the S segment encoding the nucleocapsid (N) protein. Since the N protein is the most abundant and stable viral protein, it is a useful diagnostic marker of infection. Various SFTSV N-protein-based detection methods have been developed. However, given the limited research on antibodies of an SFTSV N-protein, here we report the characterization of the antibodies against SFTSV N protein especially their mapping results which is essential for more efficient and optimized detection of SFTSV. METHODS To generate SFTSV-N-protein-specific monoclonal antibodies, recombinant full-length SFTSV N protein was expressed in E. coli, and the purified N protein was immunized to mice. The binding epitope positions of the antibodies generated were identified through binding-domain mapping. An antibody pair test using a lateral flow immunoassay (LFIA) was performed to identify effective diagnostic combinations of paired antibodies. RESULTS Nine monoclonal antibodies specific for the SFTSV N protein were generated. Antibodies #3(B4E2) and #5(B4D9) were specific for sequential epitopes, while the remainder were specific for conformational epitopes. Antibody #4(C2G1) showed the highest affinity for the SFTSV N protein. The binding domain mapping results indicated the binding regions of the antibodies were divided into three groups. The antibody pair test demonstrated that #3(B4E2)/#4(C2G1) and #4(C2G1)/#5(B4D9) were effective antibody pairs for SFTSV diagnosis. CONCLUSIONS Effective virus detection requires at least two strong antibodies recognizing separate epitope binding sites of the virus antigen. Here, we generated SFTSV-N-protein-specific monoclonal antibodies and subsequently performed epitope mapping and an antibody pair test to enhance the diagnostic efficiency and accuracy of SFTSV. Confirmation of epitope mappings and their combination immune response to the N protein provide valuable information for effective detection of SFTSV as well as can respond actively to detect a variant SFTSV.
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Affiliation(s)
- Kyungha Lee
- Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, Korea
| | - Min Ji Choi
- Department of Genetics and Biotechnology, Kyung Hee University, Yongin, 17104, Korea
| | - Man-Ho Cho
- Department of Genetics and Biotechnology, Kyung Hee University, Yongin, 17104, Korea
| | - Dong Ok Choi
- Bore Da Biotech, Seongnam-si, Gyeonggi-do, 13209, Korea
| | - Seong-Hee Bhoo
- Graduate School of Green-Bio Science, Kyung Hee University, Yongin, 17104, Korea.
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Schrauf S, Tomberger Y, Nambulli S, Duprex WP, Tschismarov R, Tauber E, Ramsauer K. Biodistribution and toxicology evaluation of a recombinant measles Schwarz-based Lassa vaccine in cynomolgus macaques. J Appl Toxicol 2023; 43:719-733. [PMID: 36480160 DOI: 10.1002/jat.4421] [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: 11/17/2022] [Revised: 11/25/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
MV-LASV is an investigational measles Schwarz-based vaccine for the prevention of Lassa fever. A repeated-dose toxicity study in cynomolgus macaques was performed to assess the biodistribution and local and systemic toxicological effects. Monkeys received three immunizations of MV-LASV or saline intramuscularly with a 2-week interval. An increase in anti-measles antibodies confirmed the reaction of the immune system to the vaccine backbone. Clinical observations, body weight, body temperature, local tolerance, electrocardiogram parameters, various clinical pathology parameters (hematology, coagulation urinalysis, serum chemistry, and C-reactive protein) were monitored. Gross pathology and histopathology of various tissues were evaluated. MV-LASV induced a mild increase in fibrinogen and C-reactive protein concentrations. This coincided with microscopic inflammation at the injection sites which partially or fully resolved following a 3-week recovery period. Viral RNA was found in secondary lymphoid organs and injection sites and gall bladder. No viral shedding to the environment was observed. Overall, the vaccine was locally and systemically well tolerated, supporting a first-in-human study.
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Affiliation(s)
- Sabrina Schrauf
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
| | - Yvonne Tomberger
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
| | - Sham Nambulli
- Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - W Paul Duprex
- Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Roland Tschismarov
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
| | - Erich Tauber
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
| | - Katrin Ramsauer
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
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Chaperonin TRiC/CCT Participates in Mammarenavirus Multiplication in Human Cells via Interaction with the Viral Nucleoprotein. J Virol 2023; 97:e0168822. [PMID: 36656012 PMCID: PMC9973018 DOI: 10.1128/jvi.01688-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The eukaryotic chaperonin containing tailless complex polypeptide 1 ring complex (CCT, also known as TCP-1 Ring Complex, TRiC/CCT) participates in the folding of 5% to 10% of the cellular proteome and has been involved in the life cycle of several viruses, including dengue, Zika, and influenza viruses, but the mechanisms by which the TRiC/CCT complex contributes to virus multiplication remain poorly understood. Here, we document that the nucleoprotein (NP) of the mammarenavirus lymphocytic choriomeningitis virus (LCMV) is a substrate of the human TRiC/CCT complex, and that pharmacological inhibition of TRiC/CCT complex function, or RNAi-mediated knockdown of TRiC/CCT complex subunits, inhibited LCMV multiplication in human cells. We obtained evidence that the TRiC/CCT complex is required for the production of NP-containing virus-like particles (VLPs), and the activity of the virus ribonucleoprotein (vRNP) responsible for directing replication and transcription of the viral genome. Pharmacological inhibition of the TRIC/CCT complex also restricted multiplication of the live-attenuated vaccine candidates Candid#1 and ML29 of the hemorrhagic fever causing Junin (JUNV) and Lassa (LASV) mammarenaviruses, respectively. Our findings indicate that the TRiC/CCT complex is required for mammarenavirus multiplication and is an attractive candidate for the development of host directed antivirals against human-pathogenic mammarenaviruses. IMPORTANCE Host-directed antivirals have gained great interest as an antiviral strategy to counteract the rapid emergence of drug-resistant viruses. The chaperonin TRiC/CCT complex has been involved in the life cycle of several viruses, including dengue, Zika, and influenza viruses. Here, we have provided evidence that the chaperonin TRiC/CCT complex participates in mammarenavirus infection via its interaction with the viral NP. Importantly, pharmacological inhibition of TRiC/CCT function significantly inhibited multiplication of LCMV and the distantly related mammarenavirus JUNV in human cells. Our findings support that the TRiC/CCT complex is required for multiplication of mammarenaviruses and that the TRiC/CCT complex is an attractive host target for the development of antivirals against human-pathogenic mammarenaviruses.
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8
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Malet H, Williams HM, Cusack S, Rosenthal M. The mechanism of genome replication and transcription in bunyaviruses. PLoS Pathog 2023; 19:e1011060. [PMID: 36634042 PMCID: PMC9836281 DOI: 10.1371/journal.ppat.1011060] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Bunyaviruses are negative sense, single-strand RNA viruses that infect a wide range of vertebrate, invertebrate and plant hosts. WHO lists three bunyavirus diseases as priority diseases requiring urgent development of medical countermeasures highlighting their high epidemic potential. While the viral large (L) protein containing the RNA-dependent RNA polymerase is a key enzyme in the viral replication cycle and therefore a suitable drug target, our knowledge on the structure and activities of this multifunctional protein has, until recently, been very limited. However, in the last few years, facilitated by the technical advances in the field of cryogenic electron microscopy, many structures of bunyavirus L proteins have been solved. These structures significantly enhance our mechanistic understanding of bunyavirus genome replication and transcription processes and highlight differences and commonalities between the L proteins of different bunyavirus families. Here, we provide a review of our current understanding of genome replication and transcription in bunyaviruses with a focus on the viral L protein. Further, we compare within bunyaviruses and with the related influenza virus polymerase complex and highlight open questions.
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Affiliation(s)
- Hélène Malet
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
- Institut Universitaire de France (IUF), Paris, France
| | - Harry M. Williams
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | | | - Maria Rosenthal
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Discovery Research ScreeningPort, Hamburg, Germany
- * E-mail:
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9
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Di D, Huang Q, Ly H, Liang Y. Evaluating the Biological Role of Lassa Viral Z Protein-Mediated RIG-I Inhibition Using a Replication-Competent Trisegmented Pichinde Virus System in an Inducible RIG-IN Expression Cell Line. J Virol 2022; 96:e0075422. [PMID: 35913216 PMCID: PMC9400496 DOI: 10.1128/jvi.00754-22] [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: 05/11/2022] [Accepted: 07/14/2022] [Indexed: 02/03/2023] Open
Abstract
Lassa virus (LASV) is a mammarenavirus that can cause lethal Lassa fever disease with no FDA-approved vaccine and limited treatment options. Fatal LASV infections are associated with innate immune suppression. We have previously shown that the small matrix Z protein of LASV, but not of a nonpathogenic arenavirus Pichinde virus (PICV), can inhibit the cellular RIG-I-like receptors (RLRs), but its biological significance has not been evaluated in an infectious virus due to the multiple essential functions of the Z protein required for the viral life cycle. In this study, we developed a stable HeLa cell line (HeLa-iRIGN) that could be rapidly and robustly induced by doxycycline (Dox) treatment to express RIG-I N-terminal effector, with concomitant production of type I interferons (IFN-Is). We also generated recombinant tri-segmented PICVs, rP18tri-LZ, and rP18tri-PZ, which encode LASV Z and PICV Z, respectively, as an extra mScarlet fusion protein that is nonessential for the viral life cycle. Upon infection, rP18tri-LZ consistently expressed viral genes at a higher level than rP18tri-PZ. rP18tri-LZ also showed a higher level of a viral infection than rP18tri-PZ did in HeLa-iRIGN cells, especially upon Dox induction. The heterologous Z gene did not alter viral growth in Vero and A549 cells by growth curve analysis, while LASV Z strongly increased and prolonged viral gene expression, especially in IFN-competent A549 cells. Our study provides important insights into the biological role of LASV Z-mediated RIG-I inhibition and implicates LASV Z as a potential virulence factor. IMPORTANCE Lassa virus (LASV) can cause lethal hemorrhagic fever disease in humans but other arenaviruses, such as Pichinde virus (PICV), do not cause obvious disease. We have previously shown that the Z protein of LASV but not of PICV can inhibit RIG-I, a cytosolic innate immune receptor. In this study, we developed a stable HeLa cell line that can be induced to express the RIG-I N-terminal effector domain, which allows for timely control of RIG-I activation. We also generated recombinant PICVs encoding LASV Z or PICV Z as an extra gene that is nonessential for the viral life cycle. Compared to PICV Z, LASV Z could increase viral gene expression and viral infection in an infectious arenavirus system, especially when RIG-I signaling is activated. Our study presented a convenient cell system to characterize RIG-I signaling and its antagonists and revealed LASV Z as a possible virulence factor and a potential antiviral target.
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Affiliation(s)
- Da Di
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, Minnesota, USA
| | - Qinfeng Huang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, Minnesota, USA
| | - Hinh Ly
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, Minnesota, USA
| | - Yuying Liang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, Minnesota, USA
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10
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Nguyen THV, Yekwa E, Selisko B, Canard B, Alvarez K, Ferron F. Inhibition of Arenaviridae nucleoprotein exonuclease by bisphosphonate. IUCRJ 2022; 9:468-479. [PMID: 35844481 PMCID: PMC9252148 DOI: 10.1107/s2052252522005061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
Arenaviruses are emerging enveloped negative-sense RNA viruses that cause neurological and hemorrhagic diseases in humans. Currently, no FDA-approved vaccine or therapeutic agent is available except for ribavirin, which must be administered early during infection for optimum efficacy. A hallmark of arenavirus infection is rapid and efficient immune suppression mediated by the exonuclease domain encoded by the nucleoprotein. This exonuclease is therefore an attractive target for the design of novel antiviral drugs since exonuclease inhibitors might not only have a direct effect on the enzyme but could also boost viral clearance through stimulation of the innate immune system of the host cell. Here, in silico screening and an enzymatic assay were used to identify a novel, specific but weak inhibitor of the arenavirus exonuclease, with IC50 values of 65.9 and 68.6 µM for Mopeia virus and Lymphocytic choriomeningitis virus, respectively. This finding was further characterized using crystallographic and docking approaches. This study serves as a proof of concept and may have assigned a new therapeutic purpose for the bisphosphonate family, therefore paving the way for the development of inhibitors against Arenaviridae.
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Affiliation(s)
- Thi Hong Van Nguyen
- Aix-Marseille Université and Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS – UMR-7257, 13288 Marseille, France
| | - Elsie Yekwa
- Aix-Marseille Université and Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS – UMR-7257, 13288 Marseille, France
| | - Barbara Selisko
- Aix-Marseille Université and Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS – UMR-7257, 13288 Marseille, France
| | - Bruno Canard
- Aix-Marseille Université and Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS – UMR-7257, 13288 Marseille, France
- European Virus Bioinformatics Center, Leutragraben 1, 07743 Jena, Germany
| | - Karine Alvarez
- Aix-Marseille Université and Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS – UMR-7257, 13288 Marseille, France
| | - François Ferron
- Aix-Marseille Université and Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS – UMR-7257, 13288 Marseille, France
- European Virus Bioinformatics Center, Leutragraben 1, 07743 Jena, Germany
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11
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Pyle JD, Whelan SPJ, Bloyet LM. Structure and function of negative-strand RNA virus polymerase complexes. Enzymes 2021; 50:21-78. [PMID: 34861938 DOI: 10.1016/bs.enz.2021.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Viruses with negative-strand RNA genomes (NSVs) include many highly pathogenic and economically devastating disease-causing agents of humans, livestock, and plants-highlighted by recent Ebola and measles virus epidemics, and continuously circulating influenza virus. Because of their protein-coding orientation, NSVs face unique challenges for efficient gene expression and genome replication. To overcome these barriers, NSVs deliver a large and multifunctional RNA-dependent RNA polymerase into infected host cells. NSV-encoded polymerases contain all the enzymatic activities required for transcription and replication of their genome-including RNA synthesis and mRNA capping. Here, we review the structures and functions of NSV polymerases with a focus on key domains responsible for viral replication and gene expression. We highlight shared and unique features among polymerases of NSVs from the Mononegavirales, Bunyavirales, and Articulavirales orders.
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Affiliation(s)
- Jesse D Pyle
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States; Ph.D. Program in Virology, Harvard Medical School, Boston, MA, United States
| | - Sean P J Whelan
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States.
| | - Louis-Marie Bloyet
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States.
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12
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Murphy HL, Ly H. Pathogenicity and virulence mechanisms of Lassa virus and its animal modeling, diagnostic, prophylactic, and therapeutic developments. Virulence 2021; 12:2989-3014. [PMID: 34747339 PMCID: PMC8923068 DOI: 10.1080/21505594.2021.2000290] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Lassa fever (LF) is a deadly viral hemorrhagic disease that is endemic to West Africa. The causative agent of LF is Lassa virus (LASV), which causes approximately 300,000 infections and 5,000 deaths annually. There are currently no approved therapeutics or FDA-approved vaccines against LASV. The high genetic variability between LASV strains and immune evasion mediated by the virus complicate the development of effective therapeutics and vaccines. Here, we aim to provide a comprehensive review of the basic biology of LASV and its mechanisms of disease pathogenesis and virulence in various animal models, as well as an update on prospective vaccines, therapeutics, and diagnostics for LF. Until effective vaccines and/or therapeutics are available for use to prevent or treat LF, a better level of understanding of the basic biology of LASV, its natural genetic variations and immune evasion mechanisms as potential pathogenicity factors, and of the rodent reservoir-vector populations and their geographical distributions, is necessary for the development of accurate diagnostics and effective therapeutics and vaccines against this deadly human viral pathogen.
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Affiliation(s)
- Hannah L Murphy
- Department of Veterinary & Biomedical Sciences, Comparative & Molecular Biosciences Graduate Program, College of Veterinary Medicine, University of Minnesota, Twin Cities
| | - Hinh Ly
- Department of Veterinary & Biomedical Sciences, Comparative & Molecular Biosciences Graduate Program, College of Veterinary Medicine, University of Minnesota, Twin Cities
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13
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Neumeier D, Pedrioli A, Genovese A, Sandu I, Ehling R, Hong KL, Papadopoulou C, Agrafiotis A, Kuhn R, Shlesinger D, Robbiani D, Han J, Hauri L, Csepregi L, Greiff V, Merkler D, Reddy ST, Oxenius A, Yermanos A. Profiling the specificity of clonally expanded plasma cells during chronic viral infection by single-cell analysis. Eur J Immunol 2021; 52:297-311. [PMID: 34727578 PMCID: PMC9299196 DOI: 10.1002/eji.202149331] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/02/2021] [Accepted: 10/29/2021] [Indexed: 12/12/2022]
Abstract
Plasma cells and their secreted antibodies play a central role in the long-term protection against chronic viral infection. However, due to experimental limitations, a comprehensive description of linked genotypic, phenotypic, and antibody repertoire features of plasma cells (gene expression, clonal frequency, virus specificity, and affinity) has been challenging to obtain. To address this, we performed single-cell transcriptome and antibody repertoire sequencing of the murine BM plasma cell population following chronic lymphocytic choriomeningitis virus infection. Our single-cell sequencing approach recovered full-length and paired heavy- and light-chain sequence information for thousands of plasma cells and enabled us to perform recombinant antibody expression and specificity screening. Antibody repertoire analysis revealed that, relative to protein immunization, chronic infection led to increased levels of clonal expansion, class-switching, and somatic variants. Furthermore, antibodies from the highly expanded and class-switched (IgG) plasma cells were found to be specific for multiple viral antigens and a subset of clones exhibited cross-reactivity to nonviral and autoantigens. Integrating single-cell transcriptome data with antibody specificity suggested that plasma cell transcriptional phenotype was correlated to viral antigen specificity. Our findings demonstrate that chronic viral infection can induce and sustain plasma cell clonal expansion, combined with significant somatic hypermutation, and can generate cross-reactive antibodies.
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Affiliation(s)
- Daniel Neumeier
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | | | | | - Ioana Sandu
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Roy Ehling
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Kai-Lin Hong
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Chrysa Papadopoulou
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Andreas Agrafiotis
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland.,Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Raphael Kuhn
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | | | - Damiano Robbiani
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Jiami Han
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Laura Hauri
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Lucia Csepregi
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Victor Greiff
- Department of Immunology, University of Oslo, Oslo, Norway
| | - Doron Merkler
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.,Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland
| | - Sai T Reddy
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | | | - Alexander Yermanos
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland.,Institute of Microbiology, ETH Zurich, Zurich, Switzerland.,Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
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14
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Abstract
Arenaviruses initiate infection by delivering a transcriptionally competent ribonucleoprotein (RNP) complex into the cytosol of host cells. The arenavirus RNP consists of the large (L) RNA-dependent RNA polymerase (RdRP) bound to a nucleoprotein (NP)-encapsidated genomic RNA (viral RNA [vRNA]) template. During transcription and replication, L must transiently displace RNA-bound NP to allow for template access into the RdRP active site. Concomitant with RNA replication, new subunits of NP must be added to the nascent complementary RNAs (cRNA) as they emerge from the product exit channel of L. Interactions between L and NP thus play a central role in arenavirus gene expression. We developed an approach to purify recombinant functional RNPs from mammalian cells in culture using a synthetic vRNA and affinity-tagged L and NP. Negative-stain electron microscopy of purified RNPs revealed they adopt diverse and flexible structures, like RNPs of other Bunyavirales members. Monodispersed L-NP and trimeric ring-like NP complexes were also obtained in excess of flexible RNPs, suggesting that these heterodimeric structures self-assemble in the absence of suitable RNA templates. This work allows for further biochemical analysis of the interaction between arenavirus L and NP proteins and provides a framework for future high-resolution structural analyses of this replication-associated complex. IMPORTANCE Arenaviruses are rodent-borne pathogens that can cause severe disease in humans. All arenaviruses begin the infection cycle with delivery of the virus replication machinery into the cytoplasm of the host cell. This machinery consists of an RNA-dependent RNA polymerase-which copies the viral genome segments and synthesizes all four viral mRNAs-bound to the two nucleoprotein-encapsidated genomic RNAs. How this complex assembles remains a mystery. Our findings provide direct evidence for the formation of diverse intracellular arenavirus replication complexes using purification strategies for the polymerase, nucleoprotein, and genomic RNA of Machupo virus, which causes Bolivian hemorrhagic fever in humans. We demonstrate that the polymerase and nucleoprotein assemble into higher-order structures within cells, providing a model for the molecular events of arenavirus RNA synthesis. These findings provide a framework for probing the architectures and functions of the arenavirus replication machinery and thus advancing antiviral strategies targeting this essential complex.
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15
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Simo Tchetgna H, Descorps-Declère S, Selekon B, Kwasiborski A, Vandenbogaert M, Manuguerra JC, Gessain A, Caro V, Nakouné E, Berthet N. Molecular characterization of a new highly divergent Mobala related arenavirus isolated from Praomys sp. rodents. Sci Rep 2021; 11:10188. [PMID: 33986310 PMCID: PMC8119949 DOI: 10.1038/s41598-021-88046-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/06/2021] [Indexed: 12/02/2022] Open
Abstract
Arenaviruses represent a family of viruses that are naturally present in rodents belonging to subfamily Murinae, Neotominae or Sigmodontinae. Except for Lassa virus, little information is available on other Old-World arenaviruses. Here, we describe strain AnRB3214, a virus isolated from a presumed Praomys sp. rodent in the Central African Republic in 1981 and assigned to Ippy virus based on antigenic similarity. The strain was simultaneously sequenced on Illumina NovaSeq 6000 and MinION Mk1B devices and analysed with various bioinformatics tools. We show that the best genome coverage and depth were obtained with the Kaiju and Minimap2 classification and identification tools, on either the MinION or the Illumina reads. The genetic analysis of AnRB3214 fragments showed 68% to 79% similarity with the Mobala and Gairo mammarenaviruses at the nucleic acid level. Strain AnRB3214 had a truncated nucleoprotein smaller than that of other Old World arenaviruses. Molecular clock analysis suggests that this strain diverged from Mobala virus at least 400 years ago. Finally, this study illustrates the importance of genomics in the identification of archived viruses and expands on the diversity of African arenaviruses, because strain AnRB3214 is either a variant or a close relative of Mobala virus, and not Ippy virus.
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Affiliation(s)
- Huguette Simo Tchetgna
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon.,The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai - Chinese Academy of Sciences, Discovery and Molecular Characterization of Pathogens, Shanghai, 200031, China
| | - Stephane Descorps-Declère
- Center of Bioinformatics, Biostatistics and Integrative Biology (C3BI), Institut Pasteur, Paris, France
| | | | - Aurelia Kwasiborski
- Cellule d'Intervention Biologique d'Urgence, Institut Pasteur, Unité Environnement et Risques Infectieux, Paris, France
| | - Mathias Vandenbogaert
- Cellule d'Intervention Biologique d'Urgence, Institut Pasteur, Unité Environnement et Risques Infectieux, Paris, France
| | - Jean-Claude Manuguerra
- Cellule d'Intervention Biologique d'Urgence, Institut Pasteur, Unité Environnement et Risques Infectieux, Paris, France
| | - Antoine Gessain
- Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, Département de Virologie, Institut Pasteur, Paris, France.,Centre National de Recherche Scientifique (CNRS) UMR3569, Paris, France
| | - Valérie Caro
- Cellule d'Intervention Biologique d'Urgence, Institut Pasteur, Unité Environnement et Risques Infectieux, Paris, France
| | | | - Nicolas Berthet
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai - Chinese Academy of Sciences, Discovery and Molecular Characterization of Pathogens, Shanghai, 200031, China. .,Cellule d'Intervention Biologique d'Urgence, Institut Pasteur, Unité Environnement et Risques Infectieux, Paris, France.
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16
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Fearns R. Negative‐strand RNA Viruses. Virology 2021. [DOI: 10.1002/9781119818526.ch3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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Kumar N, Sarma H, Sastry GN. Repurposing of approved drug molecules for viral infectious diseases: a molecular modelling approach. J Biomol Struct Dyn 2021; 40:8056-8072. [PMID: 33810775 DOI: 10.1080/07391102.2021.1905558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The identification of new viral drugs has become a task of paramount significance due to the frequent occurrence of viral infections and especially during the current pandemic. Despite the recent advancements, the development of antiviral drugs has not made parallel progress. Reduction of time frame and cost of the drug development process is the major advantage of drug repurposing. Therefore, in this study, a drug repurposing strategy using molecular modelling techniques, i.e. biological activity prediction, virtual screening, and molecular dynamics simulation was employed to find promising repurposing candidates for viral infectious diseases. The biological activities of non-redundant (4171) drug molecules were predicted using PASS analysis, and 1401 drug molecules were selected which showed antiviral activities in the analysis. These drug molecules were subjected to virtual screening against the selected non-structural viral proteins. A series of filters, i.e. top 10 drug molecules based on binding affinity, mean value of binding affinity, visual inspection of protein-drug complexes, and number of H-bond between protein and drug molecules were used to narrow down the drug molecules. Molecular dynamics simulation analysis was carried out to validate the intrinsic atomic interactions and binding conformations of protein-drug complexes. The binding free energies of drug molecules were assessed by employing MMPBSA analysis. Finally, nine drug molecules were prioritized, as promising repurposing candidates with the potential to inhibit the selected non-structural viral proteins.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Nandan Kumar
- Centre for Molecular Modelling, CSIR-Indian Institute of Chemical Technology, Hyderabad, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Himakshi Sarma
- Advanced Computation and Data Sciences Division, CSIR-North East Institute of Science and Technology, Jorhat, India
| | - G Narahari Sastry
- Centre for Molecular Modelling, CSIR-Indian Institute of Chemical Technology, Hyderabad, India.,Advanced Computation and Data Sciences Division, CSIR-North East Institute of Science and Technology, Jorhat, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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18
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Namineni S, O'Connor T, Faure-Dupuy S, Johansen P, Riedl T, Liu K, Xu H, Singh I, Shinde P, Li F, Pandyra A, Sharma P, Ringelhan M, Muschaweckh A, Borst K, Blank P, Lampl S, Neuhaus K, Durantel D, Farhat R, Weber A, Lenggenhager D, Kündig TM, Staeheli P, Protzer U, Wohlleber D, Holzmann B, Binder M, Breuhahn K, Assmus LM, Nattermann J, Abdullah Z, Rolland M, Dejardin E, Lang PA, Lang KS, Karin M, Lucifora J, Kalinke U, Knolle PA, Heikenwalder M. A dual role for hepatocyte-intrinsic canonical NF-κB signaling in virus control. J Hepatol 2020; 72:960-975. [PMID: 31954207 DOI: 10.1016/j.jhep.2019.12.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 12/02/2019] [Accepted: 12/11/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Hepatic innate immune control of viral infections has largely been attributed to Kupffer cells, the liver-resident macrophages. However, hepatocytes, the parenchymal cells of the liver, also possess potent immunological functions in addition to their known metabolic functions. Owing to their abundance in the liver and known immunological functions, we aimed to investigate the direct antiviral mechanisms employed by hepatocytes. METHODS Using lymphocytic choriomeningitis virus (LCMV) as a model of liver infection, we first assessed the role of myeloid cells by depletion prior to infection. We investigated the role of hepatocyte-intrinsic innate immune signaling by infecting mice lacking canonical NF-κB signaling (IkkβΔHep) specifically in hepatocytes. In addition, mice lacking hepatocyte-specific interferon-α/β signaling-(IfnarΔHep), or interferon-α/β signaling in myeloid cells-(IfnarΔMyel) were infected. RESULTS Here, we demonstrate that LCMV activates NF-κB signaling in hepatocytes. LCMV-triggered NF-κB activation in hepatocytes did not depend on Kupffer cells or TNFR1 signaling but rather on Toll-like receptor signaling. LCMV-infected IkkβΔHep livers displayed strongly elevated viral titers due to LCMV accumulation within hepatocytes, reduced interferon-stimulated gene (ISG) expression, delayed intrahepatic immune cell influx and delayed intrahepatic LCMV-specific CD8+ T cell responses. Notably, viral clearance and ISG expression were also reduced in LCMV-infected primary hepatocytes lacking IKKβ, demonstrating a hepatocyte-intrinsic effect. Similar to livers of IkkβΔHep mice, enhanced hepatocytic LCMV accumulation was observed in livers of IfnarΔHep mice, whereas IfnarΔMyel mice were able to control LCMV infection. Hepatocytic NF-κB signaling was also required for efficient ISG induction in HDV-infected dHepaRG cells and interferon-α/β-mediated inhibition of HBV replication in vitro. CONCLUSIONS Together, these data show that hepatocyte-intrinsic NF-κB is a vital amplifier of interferon-α/β signaling, which is pivotal for strong early ISG responses, immune cell infiltration and hepatic viral clearance. LAY SUMMARY Innate immune cells have been ascribed a primary role in controlling viral clearance upon hepatic infections. We identified a novel dual role for NF-κB signaling in infected hepatocytes which was crucial for maximizing interferon responses and initiating adaptive immunity, thereby efficiently controlling hepatic virus replication.
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Affiliation(s)
- Sukumar Namineni
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany; Institute of Virology, Technical University of Munich and Helmholtz Zentrum München, Schneckenburgerstrasse 8, 81675 Munich, Germany; Institute of Molecular Immunology and Experimental Oncology, Technical University of Munich, Ismaningerstraße 22, 81675 Munich, Germany
| | - Tracy O'Connor
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany; Institute of Molecular Immunology and Experimental Oncology, Technical University of Munich, Ismaningerstraße 22, 81675 Munich, Germany
| | - Suzanne Faure-Dupuy
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Pål Johansen
- Department of Dermatology, University Hospital Zurich and University of Zurich, Gloriastrasse 31, 8091 Zurich, Switzerland
| | - Tobias Riedl
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kaijing Liu
- Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany
| | - Haifeng Xu
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstr. 55, Essen 45147, Germany
| | - Indrabahadur Singh
- Emmy Noether Research Group Epigenetic Machineries and Cancer, Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Prashant Shinde
- Department of Molecular Medicine II, Medical Faculty, Heinrich Heine University, Universitätstr.1, 40225 Düsseldorf, Germany
| | - Fanghui Li
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstr. 55, Essen 45147, Germany
| | - Aleksandra Pandyra
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstr. 55, Essen 45147, Germany
| | - Piyush Sharma
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstr. 55, Essen 45147, Germany; Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, USA, 38105
| | - Marc Ringelhan
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany; Institute of Virology, Technical University of Munich and Helmholtz Zentrum München, Schneckenburgerstrasse 8, 81675 Munich, Germany; Department of Internal Medicine II, University Hospital rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Andreas Muschaweckh
- Klinikum rechts der Isar, Department of Neurology, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Katharina Borst
- Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Hanover Medical School and the Helmholtz Centre for Infection Research, Brunswick, Germany
| | - Patrick Blank
- Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Hanover Medical School and the Helmholtz Centre for Infection Research, Brunswick, Germany
| | - Sandra Lampl
- Institute of Molecular Immunology and Experimental Oncology, Technical University of Munich, Ismaningerstraße 22, 81675 Munich, Germany
| | - Katharina Neuhaus
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - David Durantel
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR 5286, Centre Léon Bérard, Lyon, France
| | - Rayan Farhat
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR 5286, Centre Léon Bérard, Lyon, France
| | - Achim Weber
- Department of Pathology and Molecular Pathology, University Hospital of Zurich, 8091 Zurich, Switzerland
| | - Daniela Lenggenhager
- Department of Pathology and Molecular Pathology, University Hospital of Zurich, 8091 Zurich, Switzerland
| | - Thomas M Kündig
- Department of Dermatology, University Hospital Zurich and University of Zurich, Gloriastrasse 31, 8091 Zurich, Switzerland
| | - Peter Staeheli
- Institute of Virology, University of Freiburg, Freiburg, Germany
| | - Ulrike Protzer
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany; Institute of Virology, Technical University of Munich and Helmholtz Zentrum München, Schneckenburgerstrasse 8, 81675 Munich, Germany
| | - Dirk Wohlleber
- Institute of Molecular Immunology and Experimental Oncology, Technical University of Munich, Ismaningerstraße 22, 81675 Munich, Germany
| | - Bernhard Holzmann
- Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Marco Binder
- Research Group "Dynamics of Early Viral Infection and the Innate Antiviral Response", Division Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Kai Breuhahn
- Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Jacob Nattermann
- Department of Internal Medicine, University of Bonn, Bonn, Germany
| | | | - Maude Rolland
- Laboratory of Molecular Immunology and Signal Transduction, GIGA-Institute, University of Liège, 4000 Liège, Belgium
| | - Emmanuel Dejardin
- Laboratory of Molecular Immunology and Signal Transduction, GIGA-Institute, University of Liège, 4000 Liège, Belgium
| | - Philipp A Lang
- Department of Molecular Medicine II, Medical Faculty, Heinrich Heine University, Universitätstr.1, 40225 Düsseldorf, Germany
| | - Karl S Lang
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstr. 55, Essen 45147, Germany
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California San Diego (UCSD), 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Julie Lucifora
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR 5286, Centre Léon Bérard, Lyon, France
| | - Ulrich Kalinke
- Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Hanover Medical School and the Helmholtz Centre for Infection Research, Brunswick, Germany
| | - Percy A Knolle
- Institute of Molecular Immunology and Experimental Oncology, Technical University of Munich, Ismaningerstraße 22, 81675 Munich, Germany
| | - Mathias Heikenwalder
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany; Institute of Virology, Technical University of Munich and Helmholtz Zentrum München, Schneckenburgerstrasse 8, 81675 Munich, Germany; Institute of Molecular Immunology and Experimental Oncology, Technical University of Munich, Ismaningerstraße 22, 81675 Munich, Germany.
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19
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Mateer EJ, Maruyama J, Card GE, Paessler S, Huang C. Lassa Virus, but Not Highly Pathogenic New World Arenaviruses, Restricts Immunostimulatory Double-Stranded RNA Accumulation during Infection. J Virol 2020; 94:e02006-19. [PMID: 32051278 PMCID: PMC7163147 DOI: 10.1128/jvi.02006-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/09/2020] [Indexed: 12/14/2022] Open
Abstract
The arenaviruses Lassa virus (LASV), Junín virus (JUNV), and Machupo virus (MACV) can cause severe and fatal diseases in humans. Although these pathogens are closely related, the host immune responses to these virus infections differ remarkably, with direct implications for viral pathogenesis. LASV infection is immunosuppressive, with a very low-level interferon response. In contrast, JUNV and MACV infections stimulate a robust interferon (IFN) response in a retinoic acid-inducible gene I (RIG-I)-dependent manner and readily activate protein kinase R (PKR), a known host double-stranded RNA (dsRNA) sensor. In response to infection with RNA viruses, host nonself RNA sensors recognize virus-derived dsRNA as danger signals and initiate innate immune responses. Arenavirus nucleoproteins (NPs) contain a highly conserved exoribonuclease (ExoN) motif, through which LASV NP has been shown to degrade virus-derived immunostimulatory dsRNA in biochemical assays. In this study, we for the first time present evidence that LASV restricts dsRNA accumulation during infection. Although JUNV and MACV NPs also have the ExoN motif, dsRNA readily accumulated in infected cells and often colocalized with dsRNA sensors. Moreover, LASV coinfection diminished the accumulation of dsRNA and the IFN response in JUNV-infected cells. The disruption of LASV NP ExoN with a mutation led to dsRNA accumulation and impaired LASV replication in minigenome systems. Importantly, both LASV NP and RNA polymerase L protein were required to diminish the accumulation of dsRNA and the IFN response in JUNV infection. For the first time, we discovered a collaboration between LASV NP ExoN and L protein in limiting dsRNA accumulation. Our new findings provide mechanistic insights into the differential host innate immune responses to highly pathogenic arenavirus infections.IMPORTANCE Arenavirus NPs contain a highly conserved DEDDh ExoN motif, through which LASV NP degrades virus-derived, immunostimulatory dsRNA in biochemical assays to eliminate the danger signal and inhibit the innate immune response. Nevertheless, the function of NP ExoN in arenavirus infection remains to be defined. In this study, we discovered that LASV potently restricts dsRNA accumulation during infection and minigenome replication. In contrast, although the NPs of JUNV and MACV also harbor the ExoN motif, dsRNA readily formed during JUNV and MACV infections, accompanied by IFN and PKR responses. Interestingly, LASV NP alone was not sufficient to limit dsRNA accumulation. Instead, both LASV NP and L protein were required to restrict immunostimulatory dsRNA accumulation. Our findings provide novel and important insights into the mechanism for the distinct innate immune response to these highly pathogenic arenaviruses and open new directions for future studies.
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Affiliation(s)
- Elizabeth J Mateer
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Junki Maruyama
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Galen E Card
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Slobodan Paessler
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Cheng Huang
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
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20
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Abstract
Atomic structures of the polymerase–endonuclease complex of the orthomyxovirus influenza and the orthobunyavirus La Crosse—two distinct segmented negative-sense (SNS) RNA viruses—demonstrate that binding of the genomic 5′ RNA rearranges the catalytic residues of the RNA-dependent RNA-polymerase (RdRP). Working with the arenavirus, Machupo, we demonstrate that 5′ RNAs from the genomic and antigenomic copies of both segments activate the RdRP in conjunction with a specific promoter. This study builds upon structural studies with two different SNS RNA viruses to reveal a previously unappreciated mechanism of RNA-guided promoter-specific polymerase regulation in SNS RNA viruses. The conservation of activating RNA elements among the polymerase–endonuclease complexes of SNS RNA viruses suggests new avenues for developing antiviral therapeutics. Segmented negative-sense (SNS) RNA viruses initiate infection by delivering into cells a suite of genomic RNA segments, each sheathed by the viral nucleocapsid protein and bound by the RNA-dependent RNA-polymerase (RdRP). For the orthomyxovirus influenza and the bunyavirus La Crosse, the 5′ end of the genomic RNA binds as a hook-like structure proximal to the active site of the RdRP. Using an in vitro assay for the RNA-dependent RNA-polymerase (RdRP) of the arenavirus Machupo (MACV), we demonstrate that the 5′ genomic and antigenomic RNAs of both small and large genome segments stimulate activity in a promoter-specific manner. Functional probing of the activating RNAs identifies intramolecular base-pairing between positions +1 and +7 and a pseudotemplated 5′ terminal guanine residue as key for activation. Binding of structured 5′ RNAs is a conserved feature of all SNS RNA virus polymerases, implying that promoter-specific RdRP activation extends beyond the arenaviruses. The 5′ RNAs and the RNA binding pocket itself represent targets for therapeutic intervention.
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Wang G, Chang H, Jia B, Liu Y, Huang R, Wu W, Hao Y, Yan X, Xia J, Chen Y, Wu C. Nucleocapsid protein-specific IgM antibody responses in the disease progression of severe fever with thrombocytopenia syndrome. Ticks Tick Borne Dis 2019; 10:639-646. [PMID: 30824322 DOI: 10.1016/j.ttbdis.2019.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 12/23/2018] [Accepted: 02/06/2019] [Indexed: 01/10/2023]
Abstract
OBJECTIVES Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that is caused by the SFTS virus (SFTSV) and has a high fatality rate. SFTSV-specific antibody profiles among patients with different clinical outcomes are yet to be described. The nucleocapsid protein (NP) is the most immunogenic viral antigen of the SFTSV. This study, therefore, sought to determine NP-specific antibody responses among SFTS patients with different disease progressions. METHODS In the present study, 43 patients with confirmed SFTS were enrolled in our cohort, and 9 of them deceased. The clinical presentations and key laboratory parameters associated with SFTS fatality were also recorded. Serum samples from each patient were collected every 2 days during their hospitalization. NP-specific IgM and IgG responses as well as Gn or Gc-specific IgM responses were examined by enzyme-linked immunosorbent assay (ELISA), whereas, the dynamic viral loads of SFTSV RNA were quantified via real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS First, 77% of patients generated positive NP-specific IgM antibody responses within two weeks since illness onset, defined as 'N-specific IgM-positive patients', while the rest of the patients were termed as 'N-specific IgM-delayed patients'. Only 17% of the patients generated NP-specific IgG responses. The absence of NP-specific humoral responses was strongly associated with a high risk of fatality and severity of SFTS. IgM-positive patients had significantly lower levels of viral loads, less disturbed coagulopathy, and hepatic and cardiac damage compared to IgM-delayed patients. Moreover, compared to severe or fatal SFTS patients, mild SFTS patients had significantly higher magnitudes of NP-specific IgM responses, but not NP-specific IgG, Gn-specific IgM, or Gc-specific IgM responses. The abundance of NP-specific IgM responses negatively correlated with viral loads, coagulation disturbances, and hepatic injuries among SFTS patients. CONCLUSIONS Our data highlight distinct humoral profiles of NP-specific IgM responses among SFTS patients with different disease progressions and clinical outcomes.
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Affiliation(s)
- Gai Wang
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Haiyan Chang
- Department of Infectious Diseases, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Bei Jia
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yong Liu
- Department of Experimental Medicine, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Rui Huang
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Weihua Wu
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yingying Hao
- Department of Intensive Care Unit, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Xiaomin Yan
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Juan Xia
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yuxin Chen
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
| | - Chao Wu
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
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22
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Ranadheera C, Proulx R, Chaiyakul M, Jones S, Grolla A, Leung A, Rutherford J, Kobasa D, Carpenter M, Czub M. The interaction between the Nipah virus nucleocapsid protein and phosphoprotein regulates virus replication. Sci Rep 2018; 8:15994. [PMID: 30375468 PMCID: PMC6207681 DOI: 10.1038/s41598-018-34484-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/02/2018] [Indexed: 11/29/2022] Open
Abstract
Continued outbreaks of Henipaviruses in South Asia and Australia cause severe and lethal disease in both humans and animals. Together, with evidence of human to human transmission for Nipah virus and the lack of preventative or therapeutic measures, its threat to cause a widespread outbreak and its potential for weaponization has increased. In this study we demonstrate how overexpression of the Nipah virus nucleocapsid protein regulates viral polymerase activity and viral RNA production. By overexpressing the Nipah virus nucleocapsid protein in trans viral transcription was inhibited; however, an increase in viral genome synthesis was observed. Together, the bias of polymerase activity towards genome production led to the severe inhibition of viral progeny. We identified two domains within the nucleocapsid protein, which were each independently capable of binding the viral phosphoprotein. Evident by our data, we propose that the nucleocapsid protein’s ability to interact with the phosphoprotein of the polymerase complex causes a change in polymerase activity and subsequent deficiency in viral replication. This study not only provides insights into the dynamics of Henipavirus RNA synthesis and replication, but also provides insight into potential targets for antiviral drug development.
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Affiliation(s)
- Charlene Ranadheera
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada. .,Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
| | - Roxanne Proulx
- Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Mark Chaiyakul
- Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Shane Jones
- Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Allen Grolla
- Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Anders Leung
- Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - John Rutherford
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Darwyn Kobasa
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada.,Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Michael Carpenter
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada.,Blood Borne Pathogens and Hepatitis, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Markus Czub
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada.,Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.,Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
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23
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Urata S, Kenyon E, Nayak D, Cubitt B, Kurosaki Y, Yasuda J, de la Torre JC, McGavern DB. BST-2 controls T cell proliferation and exhaustion by shaping the early distribution of a persistent viral infection. PLoS Pathog 2018; 14:e1007172. [PMID: 30028868 PMCID: PMC6080785 DOI: 10.1371/journal.ppat.1007172] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 08/07/2018] [Accepted: 06/20/2018] [Indexed: 12/27/2022] Open
Abstract
The interferon inducible protein, BST-2 (or, tetherin), plays an important role in the innate antiviral defense system by inhibiting the release of many enveloped viruses. Consequently, viruses have evolved strategies to counteract the anti-viral activity of this protein. While the mechanisms by which BST-2 prevents viral dissemination have been defined, less is known about how this protein shapes the early viral distribution and immunological defense against pathogens during the establishment of persistence. Using the lymphocytic choriomeningitis virus (LCMV) model of infection, we sought insights into how the in vitro antiviral activity of this protein compared to the immunological defense mounted in vivo. We observed that BST-2 modestly reduced production of virion particles from cultured cells, which was associated with the ability of BST-2 to interfere with the virus budding process mediated by the LCMV Z protein. Moreover, LCMV does not encode a BST-2 antagonist, and viral propagation was not significantly restricted in cells that constitutively expressed BST-2. In contrast to this very modest effect in cultured cells, BST-2 played a crucial role in controlling LCMV in vivo. In BST-2 deficient mice, a persistent strain of LCMV was no longer confined to the splenic marginal zone at early times post-infection, which resulted in an altered distribution of LCMV-specific T cells, reduced T cell proliferation / function, delayed viral control in the serum, and persistence in the brain. These data demonstrate that BST-2 is important in shaping the anatomical distribution and adaptive immune response against a persistent viral infection in vivo. BST-2 (or, tetherin) is an antiviral protein that inhibits the release and spread of many enveloped viruses and is upregulated as part of the innate immune defense against infections. By studying the lymphocytic choriomeningitis virus (LCMV) model of infection, we sought insights into how BST-2 shapes the early viral distribution and immunological defense against a virus during the establishment of persistence. We also studied how the antiviral activity of BST-2 in cell culture compared to the immunological defense mounted by this protein in LCMV-infected mice (in vivo). We observed that BST-2 only modestly affected the production of LCMV in cultured cells by interfering with the viral budding process, but played a crucial role in controlling LCMV in vivo. In the absence of BST-2, a persistent strain of LCMV was ineffectively contained in the spleen at early time points post-infection, resulting in impaired antiviral T cell responses and viral control systemically. These data demonstrate that BST-2 is important in shaping the anatomical distribution and adaptive immune response against a persistent viral infection in vivo.
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Affiliation(s)
- Shuzo Urata
- National Research Center for the Control and Prevention of Infectious Diseases (CCPID), Nagasaki University, Nagasaki, Japan
- Department of Emerging Infectious Diseases, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- Department of Immunology and Microbial Science IMM-6, The Scripps Research Institute, La Jolla, California, United States of America
| | - Elizabeth Kenyon
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Debasis Nayak
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- Center for Bioscience and Biomedical Engineering, Indian Institute of Technology Indore, India
| | - Beatrice Cubitt
- Department of Immunology and Microbial Science IMM-6, The Scripps Research Institute, La Jolla, California, United States of America
| | - Yohei Kurosaki
- Department of Emerging Infectious Diseases, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Jiro Yasuda
- National Research Center for the Control and Prevention of Infectious Diseases (CCPID), Nagasaki University, Nagasaki, Japan
- Department of Emerging Infectious Diseases, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Juan C. de la Torre
- Department of Immunology and Microbial Science IMM-6, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail: (JCdlT); (DBM)
| | - Dorian B. McGavern
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (JCdlT); (DBM)
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24
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Saez-Ayala M, Yekwa EL, Carcelli M, Canard B, Alvarez K, Ferron F. Crystal structures of Lymphocytic choriomeningitis virus endonuclease domain complexed with diketo-acid ligands. IUCRJ 2018; 5:223-235. [PMID: 29765612 PMCID: PMC5947727 DOI: 10.1107/s2052252518001021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/17/2018] [Indexed: 06/08/2023]
Abstract
The Arenaviridae family, together with the Bunyaviridae and Orthomyxoviridae families, is one of the three negative-stranded RNA viral families that encode an endonuclease in their genome. The endonuclease domain is at the N-terminus of the L protein, a multifunctional protein that includes the RNA-dependent RNA polymerase. The synthesis of mRNA in arenaviruses is a process that is primed by capped nucleotides that are 'stolen' from the cellular mRNA by the endonuclease domain in cooperation with other domains of the L protein. This molecular mechanism has been demonstrated previously for the endonuclease of the prototype Lymphocytic choriomeningitis virus (LCMV). However, the mode of action of this enzyme is not fully understood as the original structure did not contain catalytic metal ions. The pivotal role played by the cap-snatching process in the life cycle of the virus and the highly conserved nature of the endonuclease domain make it a target of choice for the development of novel antiviral therapies. Here, the binding affinities of two diketo-acid (DKA) compounds (DPBA and L-742,001) for the endonuclease domain of LCMV were evaluated using biophysical methods. X-ray structures of the LCMV endonuclease domain with catalytic ions in complex with these two compounds were determined, and their efficacies were assessed in an in vitro endonuclease-activity assay. Based on these data and computational simulation, two new DKAs were synthesized. The LCMV endonuclease domain exhibits a good affinity for these DKAs, making them a good starting point for the design of arenavirus endonuclease inhibitors. In addition to providing the first example of an X-ray structure of an arenavirus endonuclease incorporating a ligand, this study provides a proof of concept that the design of optimized inhibitors against the arenavirus endonuclease is possible.
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Affiliation(s)
| | - Elsie Laban Yekwa
- Aix-Marseille Université, AFMB UMR 7257, 13288 Marseille, France
- CNRS, AFMB UMR 7257, 13288 Marseille, France
| | - Mauro Carcelli
- Dipartimento di Scienze Chimiche, della Vita, della Sostenibilità Ambientale, Università Di Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy
| | - Bruno Canard
- Aix-Marseille Université, AFMB UMR 7257, 13288 Marseille, France
- CNRS, AFMB UMR 7257, 13288 Marseille, France
| | - Karine Alvarez
- Aix-Marseille Université, AFMB UMR 7257, 13288 Marseille, France
- CNRS, AFMB UMR 7257, 13288 Marseille, France
| | - François Ferron
- Aix-Marseille Université, AFMB UMR 7257, 13288 Marseille, France
- CNRS, AFMB UMR 7257, 13288 Marseille, France
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25
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Peña Cárcamo JR, Morell ML, Vázquez CA, Vatansever S, Upadhyay AS, Överby AK, Cordo SM, García CC. The interplay between viperin antiviral activity, lipid droplets and Junín mammarenavirus multiplication. Virology 2018; 514:216-229. [DOI: 10.1016/j.virol.2017.10.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 10/10/2017] [Accepted: 10/12/2017] [Indexed: 01/09/2023]
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26
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Ban YH, Ha SJ. Semi-Functional Quantitative Flow Cytometry Assay for Lymphocytic Choriomeningitis Virus Titration. Immune Netw 2017; 17:307-316. [PMID: 29093652 PMCID: PMC5662780 DOI: 10.4110/in.2017.17.5.307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/13/2017] [Accepted: 10/15/2017] [Indexed: 12/25/2022] Open
Abstract
Quantitative PCR and plaque assay are powerful virological techniques used to measure the load of defective or infectious virus in mouse and human. However, these methods display limitations such as cross contamination and long run-time. Here, we describe a novel technique termed as semi-functional quantitative flow cytometry (SFQF) for the accurate estimation of the quantity of infectious lymphocytic choriomeningitis virus (LCMV). LCMV titration method using flow cytometry was previously developed but has technical shortcomings, owing to the less optimized parameters such as cell overgrowth, plate scale, and detection threshold. Therefore, we first established optimized conditions for SFQF assay using LCMV nucleoprotein (NP)-specific antibody to evaluate the threshold of the virus detection range in the plaque assay. We subsequently demonstrated that the optimization of the method increased the sensitivity of virus detection. We revealed several new advantages of SFQF assay, which overcomes some of the previously contentious points, and established an upgraded version of the previously reported flow cytometric titration assay. This method extends the detection scale to the level of single cell, allowing extension of its application for in vivo detection of infected cells and their phenotypic analysis. Thus, SFQF assay may serve as an alternative analytical tool for ensuring the reliability of LCMV titration and can be used with other types of viruses using target-specific antibodies.
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Affiliation(s)
- Young Ho Ban
- Department of Biochemistry, College of Life Science & Biotechnology, Yonsei University Seoul 03722, Korea
| | - Sang-Jun Ha
- Department of Biochemistry, College of Life Science & Biotechnology, Yonsei University Seoul 03722, Korea
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27
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Chen J, Ly H. Immunosuppression by viral N proteins. Oncotarget 2017; 8:50331-50332. [PMID: 28881563 PMCID: PMC5584132 DOI: 10.18632/oncotarget.18597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 06/19/2017] [Indexed: 11/25/2022] Open
Affiliation(s)
- Jidang Chen
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Twin Cities, College of Veterinary Medicine, Saint Paul, MN, USA
| | - Hinh Ly
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Twin Cities, College of Veterinary Medicine, Saint Paul, MN, USA
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28
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Ferron F, Weber F, de la Torre JC, Reguera J. Transcription and replication mechanisms of Bunyaviridae and Arenaviridae L proteins. Virus Res 2017; 234:118-134. [PMID: 28137457 PMCID: PMC7114536 DOI: 10.1016/j.virusres.2017.01.018] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/17/2017] [Accepted: 01/21/2017] [Indexed: 12/15/2022]
Abstract
Bunyavirus and arenavirus are important public health threats. Bunyavirus and arenavirus molecular biology, common and differential features. Implications of LACV L protein structure for understanding viral RNA synthesis. Current state and future perspectives on bunya- and arenavirus antivirals.
Bunyaviridae and Arenaviridae virus families include an important number of highly pathogenic viruses for humans. They are enveloped viruses with negative stranded RNA genomes divided into three (bunyaviruses) or two (arenaviruses) segments. Each genome segment is coated by the viral nucleoproteins (NPs) and the polymerase (L protein) to form a functional ribonucleoprotein (RNP) complex. The viral RNP provides the necessary context on which the L protein carries out the biosynthetic processes of RNA replication and gene transcription. Decades of research have provided a good understanding of the molecular processes underlying RNA synthesis, both RNA replication and gene transcription, for these two families of viruses. In this review we will provide a global view of the common features, as well as differences, of the molecular biology of Bunyaviridae and Arenaviridae. We will also describe structures of protein and protein-RNA complexes so far determined for these viral families, mainly focusing on the L protein, and discuss their implications for understanding the mechanisms of viral RNA replication and gene transcription within the architecture of viral RNPs, also taking into account the cellular context in which these processes occur. Finally, we will discuss the implications of these structural findings for the development of antiviral drugs to treat human diseases caused by members of the Bunyaviridae and Arenaviridae families.
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Affiliation(s)
- François Ferron
- Aix-Marseille Université, AFMB UMR 7257, 13288 Marseille, France; CNRS, AFMB UMR 7257, 13288 Marseille, France
| | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, D-35392 Giessen, Germany
| | | | - Juan Reguera
- Aix-Marseille Université, AFMB UMR 7257, 13288 Marseille, France; CNRS, AFMB UMR 7257, 13288 Marseille, France; INSERM, AFMB UMR 7257, 13288 Marseille, France.
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29
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Guterres A, de Oliveira RC, Fernandes J, de Lemos ERS, Schrago CG. New bunya-like viruses: Highlighting their relations. INFECTION GENETICS AND EVOLUTION 2017; 49:164-173. [PMID: 28111322 DOI: 10.1016/j.meegid.2017.01.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/16/2017] [Accepted: 01/18/2017] [Indexed: 11/18/2022]
Abstract
The standard virus classification scheme for arenaviruses and bunyaviruses shifted dramatically when several groups reported the detection and isolation of divergent groups of viruses in a variety of insect collections. Although these viral families can differ in terms of morphology, structure and genetics, recent findings indicate these viruses may have a shared evolutionary origin. To determine the phylogenetic relations among these families, we inferred phylogenetic trees using three methods. The Maximum Likelihood and Bayesian trees were rooted as suggested by the (molecular clock-rooted) BEAST tree. Our results highlight a noteworthy relation among these viral supergroups of different genome organizations. Our study suggests that the best scenario is the existence of at least three monophyletic supergroups, all of them well supported. The recent data indicate that these viruses are evolutionarily and genetically interconnected. While these supergroups appear to be closely related in our phylogenetic analysis, other viruses should be investigated in future research. In sum, our results also provide insights into the classification scheme, thereby providing a new perspective about the fundamental questions of family origins, diversity and genome evolution.
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Affiliation(s)
- Alexandro Guterres
- Laboratório de Hantaviroses e Rickettsioses, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil; Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Renata Carvalho de Oliveira
- Laboratório de Hantaviroses e Rickettsioses, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Jorlan Fernandes
- Laboratório de Hantaviroses e Rickettsioses, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Elba Regina Sampaio de Lemos
- Laboratório de Hantaviroses e Rickettsioses, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Carlos Guerra Schrago
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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30
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Abstract
Reverse genetics systems encompass a wide array of tools aimed at recapitulating some or all of the virus life cycle. In their most complete form, full-length clone systems allow us to use plasmid-encoded versions of the ribonucleoprotein (RNP) components to initiate the transcription and replication of a plasmid-encoded version of the complete viral genome, thereby initiating the complete virus life cycle and resulting in infectious virus. As such this approach is ideal for the generation of tailor-made recombinant filoviruses, which can be used to study virus biology. In addition, the generation of tagged and particularly fluorescent or luminescent viruses can be applied as tools for both diagnostic applications and for screening to identify novel countermeasures. Here we describe the generation and basic characterization of recombinant Ebola viruses rescued from cloned cDNA using a T7-driven system.
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Affiliation(s)
- Allison Groseth
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany.
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31
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Pattis JG, May ER. Influence of RNA Binding on the Structure and Dynamics of the Lassa Virus Nucleoprotein. Biophys J 2016; 110:1246-54. [PMID: 27028635 DOI: 10.1016/j.bpj.2016.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/03/2016] [Accepted: 02/02/2016] [Indexed: 12/18/2022] Open
Abstract
Lassa virus protects its viral genome through the formation of a ribonucleoprotein complex in which the nucleoprotein (NP) encapsidates the single-stranded RNA genome. Crystal structures provide evidence that a conformational change must occur to allow for RNA binding. In this study, the mechanism by which NP binds to RNA and how the conformational changes in NP are achieved was investigated with molecular-dynamics simulations. NP was structurally characterized in an open configuration when bound to RNA and in a closed form in the absence of RNA. Our results show that when NP is bound to RNA, the protein is highly dynamic and the system undergoes spontaneous deviations away from the open-state configuration. The equilibrium simulations are supported by free-energy calculations that quantify the influence of RNA on the free-energy surface, which governs NP dynamics. We predict that the globally stable states are qualitatively in agreement with the observed crystal structures, but that both open and closed conformations are thermally accessible in the presence of RNA. The free-energy calculations also provide a prediction of the location of the transition state for RNA binding and identify an intermediate metastable state that exhibits correlated motions that could promote RNA binding.
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Affiliation(s)
- Jason G Pattis
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut
| | - Eric R May
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut.
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32
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Wang W, Zhou Z, Zhang L, Wang S, Xiao G. Structure-function relationship of the mammarenavirus envelope glycoprotein. Virol Sin 2016; 31:380-394. [PMID: 27562602 DOI: 10.1007/s12250-016-3815-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/27/2016] [Indexed: 12/29/2022] Open
Abstract
Mammarenaviruses, including lethal pathogens such as Lassa virus and Junín virus, can cause severe hemorrhagic fever in humans. Entry is a key step for virus infection, which starts with binding of the envelope glycoprotein (GP) to receptors on target cells and subsequent fusion of the virus with target cell membranes. The GP precursor is synthesized as a polypeptide, and maturation occurs by two cleavage events, yielding a tripartite GP complex (GPC) formed by a stable signal peptide (SSP), GP1 and GP2. The unique retained SSP interacts with GP2 and plays essential roles in virion maturation and infectivity. GP1 is responsible for binding to the cell receptor, and GP2 is a class I fusion protein. The native structure of the tripartite GPC is unknown. GPC is critical for the receptor binding, membrane fusion and neutralization antibody recognition. Elucidating the molecular mechanisms underlining the structure-function relationship of the three subunits is the key for understanding their function and can facilitate novel avenues for combating virus infections. This review summarizes the basic aspects and recent research of the structure-function relationship of the three subunits. We discuss the structural basis of the receptor-binding domain in GP1, the interaction between SSP and GP2 and its role in virion maturation and membrane fusion, as well as the mechanism by which glycosylation stabilizes the GPC structure and facilitates immune evasion. Understanding the molecular mechanisms involved in these aspects will contribute to the development of novel vaccines and treatment strategies against mammarenaviruses infection.
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Affiliation(s)
- Wei Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
| | - Zheng Zhou
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Leike Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Shaobo Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Gengfu Xiao
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
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Abstract
Hantaviruses are emerging zoonotic pathogens that belong to the Bunyaviridae family. They have been classified as category A pathogens by CDC (centers for disease control and prevention). Hantaviruses pose a serious threat to human health because their infection causes two highly fatal diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). These pathogens are transmitted to humans through aerosolized excreta of their infected rodent hosts. Hantaviruses have a tripartite-segmented negative-sense RNA genome. The three genomic RNA segments, S, M, and L, encode a nucleocapsid protein (N), a precursor glycoprotein that is processed into two envelope glycoproteins (Gn and Gc) and the viral RNA-dependent RNA polymerase (RdRp), respectively. N protein is the major structural component of the virus, its main function is to protect and encapsidate the three genomic RNAs forming three viral ribonucleocapsids. Recent studies have proposed that N in conjunction with RdRp plays important roles in the transcription and replication of viral genome. In addition, N preferentially facilitates the translation of viral mRNA in cells. Glycoproteins, Gn and Gc, play major roles in viral attachment and entry to the host cells, virulence, and assembly and packaging of new virions in infected cells. RdRp functions as RNA replicase and transcriptase to replicate and transcribe the viral RNA and is also thought to have endonuclease activity. Currently, no antiviral therapy or vaccine is available for the treatment of hantavirus-associated diseases. Understanding the molecular details of hantavirus life cycle will help in the identification of targets for antiviral therapeutics and in the design of potential antiviral drug for the treatment of HFRS and HCPS. Due to the alarming fatality of hantavirus diseases, development of an effective vaccine against hantaviruses is a necessity.
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Pasquato A, Kunz S. Novel drug discovery approaches for treating arenavirus infections. Expert Opin Drug Discov 2016; 11:383-93. [PMID: 26882218 DOI: 10.1517/17460441.2016.1153626] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Arenaviruses are enveloped negative stranded viruses endemic in Africa, Europe and the Americas. Several arenaviruses cause severe viral hemorrhagic fever with high mortality in humans and pose serious public health threats. So far, there are no FDA-approved vaccines and therapeutic options are restricted to the off-label use of ribavirin. The major human pathogenic arenaviruses are classified as Category A agents and require biosafety level (BSL)-4 containment. AREAS COVERED Herein, the authors cover the recent progress in the development of BSL2 surrogate systems that recapitulate the entire or specific steps of the arenavirus life cycle and are serving as powerful platforms for drug discovery. Furthermore, they highlight the identification of selected novel drugs that target individual steps of arenavirus multiplication describing their discovery, their targets, and mode of action. EXPERT OPINION The lack of effective drugs against arenaviruses is an unmatched challenge in current medical virology. Novel technologies have provided important insights into the basic biology of arenaviruses and the mechanisms underlying virus-host cell interaction. Significant progress of our understanding of how the virus invades the host cell paved the way to develop powerful novel screening platforms. Recent efforts have provided a range of promising drug candidates currently under evaluation for therapeutic intervention in vivo.
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Affiliation(s)
- Antonella Pasquato
- a Institute of Microbiology , University Hospital Center and University of Lausanne , Lausanne , Switzerland
| | - Stefan Kunz
- a Institute of Microbiology , University Hospital Center and University of Lausanne , Lausanne , Switzerland
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Dhanwani R, Zhou Y, Huang Q, Verma V, Dileepan M, Ly H, Liang Y. A Novel Live Pichinde Virus-Based Vaccine Vector Induces Enhanced Humoral and Cellular Immunity after a Booster Dose. J Virol 2015; 90:2551-60. [PMID: 26676795 PMCID: PMC4810697 DOI: 10.1128/jvi.02705-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/11/2015] [Indexed: 01/24/2023] Open
Abstract
UNLABELLED Pichinde virus (PICV) is a bisegmented enveloped RNA virus that targets macrophages and dendritic cells (DCs) early in infection and induces strong innate and adaptive immunity in mice. We have developed a reverse genetics system to produce live recombinant PICV (strain P18) with a trisegmented RNA genome (rP18tri), which encodes all four PICV gene products and as many as two foreign genes. We have engineered the vector to express the green fluorescent protein (GFP) reporter gene (abbreviated as G in virus designations) and either the hemagglutination (HA [H]) or the nucleoprotein (NP [P]) gene of the influenza A/PR8 virus. The trisegmented viruses rP18tri-G/H and rP18tri-G/P showed slightly reduced growth in vitro and expressed HA and NP, respectively. Mice immunized with rP18tri-G/H were completely protected against lethal influenza virus challenge even 120 days after immunization. These rP18tri-based vectors could efficiently induce both neutralizing antibodies and antigen-specific T cell responses via different immunization routes. Interestingly, the immune responses were significantly increased upon a booster dose and remained at high levels even after three booster doses. In summary, we have developed a novel PICV-based live vaccine vector that can express foreign antigens to induce strong humoral and cell-mediated immunity and is ideal for a prime-and-boost vaccination strategy. IMPORTANCE We have developed a novel Pichinde virus (PICV)-based live viral vector, rP18tri, that packages three RNA segments and encodes as many as two foreign genes. Using the influenza virus HA and NP genes as model antigens, we show that this rP18tri vector can induce strong humoral and cellular immunity via different immunization routes and can lead to protection in mice. Interestingly, a booster dose further enhances the immune responses, a feature that distinguishes this from other known live viral vectors. In summary, our study demonstrates a unique feature of this live rP18tri vector to be used as a novel vaccine platform for a prime-and-boost vaccination strategy.
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MESH Headings
- Animals
- Antibodies, Neutralizing/blood
- Antibodies, Viral/blood
- Disease Models, Animal
- Drug Carriers
- Female
- Gene Expression
- Genes, Reporter
- Genetic Vectors
- Green Fluorescent Proteins/analysis
- Green Fluorescent Proteins/genetics
- Guinea Pigs
- Hemagglutinin Glycoproteins, Influenza Virus/genetics
- Hemagglutinin Glycoproteins, Influenza Virus/immunology
- Influenza Vaccines/administration & dosage
- Influenza Vaccines/genetics
- Influenza Vaccines/immunology
- Male
- Mice, Inbred C57BL
- Nucleocapsid Proteins
- Orthomyxoviridae Infections/prevention & control
- Pichinde virus/genetics
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/immunology
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Survival Analysis
- T-Lymphocytes/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Viral Core Proteins/genetics
- Viral Core Proteins/immunology
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Affiliation(s)
- Rekha Dhanwani
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, Minnesota, USA
| | - Yanqin Zhou
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, Minnesota, USA College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Qinfeng Huang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, Minnesota, USA Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Vikram Verma
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, Minnesota, USA
| | - Mythili Dileepan
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, Minnesota, USA
| | - Hinh Ly
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, Minnesota, USA
| | - Yuying Liang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, Minnesota, USA
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Abstract
Until recently, members of the monogeneric family Arenaviridae (arenaviruses) have been known to infect only muroid rodents and, in one case, possibly phyllostomid bats. The paradigm of arenaviruses exclusively infecting small mammals shifted dramatically when several groups independently published the detection and isolation of a divergent group of arenaviruses in captive alethinophidian snakes. Preliminary phylogenetic analyses suggest that these reptilian arenaviruses constitute a sister clade to mammalian arenaviruses. Here, the members of the International Committee on Taxonomy of Viruses (ICTV) Arenaviridae Study Group, together with other experts, outline the taxonomic reorganization of the family Arenaviridae to accommodate reptilian arenaviruses and other recently discovered mammalian arenaviruses and to improve compliance with the Rules of the International Code of Virus Classification and Nomenclature (ICVCN). PAirwise Sequence Comparison (PASC) of arenavirus genomes and NP amino acid pairwise distances support the modification of the present classification. As a result, the current genus Arenavirus is replaced by two genera, Mammarenavirus and Reptarenavirus, which are established to accommodate mammalian and reptilian arenaviruses, respectively, in the same family. The current species landscape among mammalian arenaviruses is upheld, with two new species added for Lunk and Merino Walk viruses and minor corrections to the spelling of some names. The published snake arenaviruses are distributed among three new separate reptarenavirus species. Finally, a non-Latinized binomial species name scheme is adopted for all arenavirus species. In addition, the current virus abbreviations have been evaluated, and some changes are introduced to unequivocally identify each virus in electronic databases, manuscripts, and oral proceedings.
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Lian K, Yang F, Zhu Z, Cao W, Jin Y, Li D, Zhang K, Guo J, Zheng H, Liu X. Recovery of infectious type Asia1 foot-and-mouth disease virus from suckling mice directly inoculated with an RNA polymerase I/II-driven unidirectional transcription plasmid. Virus Res 2015; 208:73-81. [PMID: 26091821 DOI: 10.1016/j.virusres.2015.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 05/18/2015] [Accepted: 06/05/2015] [Indexed: 11/15/2022]
Abstract
We developed an RNA polymerase (pol) I- and II-driven plasmid-based reverse genetics system to rescue infectious foot-and-mouth disease virus (FMDV) from cloned cDNA. In this plasmid-based transfection, the full-length viral cDNA was flanked by hammerhead ribozyme (HamRz) and hepatitis delta ribozyme (HdvRz) sequences, which were arranged downstream of the two promoters (cytomegalovirus (CMV) and pol I promoter) and upstream of the terminators and polyadenylation signal, respectively. The utility of this method was demonstrated by the recovery of FMDV Asia1 HN/CHA/06 in BHK-21 cells transfected with cDNA plasmids. Furthermore, infectious FMDV Asia1 HN/CHA/06 could be rescued from suckling mice directly inoculated with cDNA plasmids. Thus, this reverse genetics system can be applied to fundamental research and vaccine studies, most notably to rescue those viruses for which there is currently an absence of a suitable cell culture system.
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Affiliation(s)
- Kaiqi Lian
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Fan Yang
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Zixiang Zhu
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Weijun Cao
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ye Jin
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Dan Li
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Keshan Zhang
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Jianhong Guo
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Haixue Zheng
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
| | - Xiangtao Liu
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
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In vitro and in vivo characterizations of pichinde viral nucleoprotein exoribonuclease functions. J Virol 2015; 89:6595-607. [PMID: 25878103 DOI: 10.1128/jvi.00009-15] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 04/03/2015] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Arenaviruses cause severe hemorrhagic fever diseases in humans, and there are limited preventative and therapeutic measures against these diseases. Previous structural and functional analyses of arenavirus nucleoproteins (NPs) revealed a conserved DEDDH exoribonuclease (RNase) domain that is important for type I interferon (IFN) suppression, but the biological roles of the NP RNase in viral replication and host immune suppression have not been well characterized. Infection of guinea pigs with Pichinde virus (PICV), a prototype arenavirus, can serve as a surrogate small animal model for arenavirus hemorrhagic fevers. In this report, we show that mutation of each of the five RNase catalytic residues of PICV NP diminishes the IFN suppression activity and slightly reduces the viral RNA replication activity. Recombinant PICVs with RNase catalytic mutations can induce high levels of IFNs and barely grow in IFN-competent A549 cells, in sharp contrast to the wild-type (WT) virus, while in IFN-deficient Vero cells, both WT and mutant viruses can replicate at relatively high levels. Upon infection of guinea pigs, the RNase mutant viruses stimulate strong IFN responses, fail to replicate productively, and can become WT revertants. Serial passages of the RNase mutants in vitro can also generate WT revertants. Thus, the NP RNase function is essential for the innate immune suppression that allows the establishment of a productive early viral infection, and it may be partly involved in the process of viral RNA replication. IMPORTANCE Arenaviruses, such as Lassa, Lujo, and Machupo viruses, can cause severe and deadly hemorrhagic fever diseases in humans, and there are limited preventative and treatment options against these diseases. Development of broad-spectrum antiviral drugs depends on a better mechanistic understanding of the conserved arenavirus proteins in viral infection. The nucleoprotein (NPs) of all arenaviruses carry a unique exoribonuclease (RNase) domain that has been shown to be critical for the suppression of type I interferons. However, the functional roles of the NP RNase in arenavirus replication and host immune suppression have not been characterized systematically. Using a prototype arenavirus, Pichinde virus (PICV), we characterized the viral growth and innate immune suppression of recombinant RNase-defective mutants in both cell culture and guinea pig models. Our study suggests that the NP RNase plays an essential role in the suppression of host innate immunity, and possibly in viral RNA replication, and that it can serve as a novel target for developing antiviral drugs against arenavirus pathogens.
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Ribosomal protein S19-binding domain provides insights into hantavirus nucleocapsid protein-mediated translation initiation mechanism. Biochem J 2015; 464:109-21. [PMID: 25062117 DOI: 10.1042/bj20140449] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The hantaviral zoonotic diseases pose a significant threat to human health due to the lack of potential antiviral therapeutics or a vaccine against hantaviruses. N (Sin Nombre hantavirus nucleocapsid protein) augments mRNA translation. N binds to both the mRNA 5' cap and 40S ribosomal subunit via RPS19 (ribosomal protein S19). N with the assistance of the viral mRNA 5'-UTR preferentially favours the translation of a downstream ORF. We identified and characterized the RPS19-binding domain at the N-terminus of N. Its deletion did not influence the secondary structure, but affected the conformation of trimeric N molecules. The N variant lacking the RPS19-binding region was able to bind both the mRNA 5' cap and panhandle-like structure, formed by the termini of viral genomic RNA. In addition, the N variant formed stable trimers similar to wild-type N. Use of this variant in multiple experiments provided insights into the mechanism of ribosome loading during N-mediated translation strategy. The present study suggests that N molecules individually associated with the mRNA 5' cap and RPS19 of the 40S ribosomal subunit undergo N-N interaction to facilitate the engagement of N-associated ribosomes at the mRNA 5' cap. This has revealed new targets for therapeutic intervention of hantavirus infection.
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Sullivan BM, Teijaro JR, de la Torre JC, Oldstone MBA. Early virus-host interactions dictate the course of a persistent infection. PLoS Pathog 2015; 11:e1004588. [PMID: 25569216 PMCID: PMC4287607 DOI: 10.1371/journal.ppat.1004588] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/24/2014] [Indexed: 01/12/2023] Open
Abstract
Many persistent viral infections are characterized by a hypofunctional T cell response and the upregulation of negative immune regulators. These events occur days after the initiation of infection. However, the very early host-virus interactions that determine the establishment of viral persistence remain poorly uncharacterized. Here we show that to establish persistence, LCMV must counteract an innate anti-viral immune response within eight hours after infection. While the virus triggers cytoplasmic RNA sensing pathways soon after infection, LCMV counteracts this pathway through a rapid increase in viral titers leading to a dysfunctional immune response characterized by a high cytokine and chemokine expression profile. This altered immune environment allows for viral replication in the splenic white pulp as well as infection of immune cells essential to an effective anti-viral immune response. Our findings illustrate how early events during infection critically dictate the characteristics of the immune response to infection and facilitate either virus control and clearance or persistence. Lymphocytic Choriomenengitis Virus (LCMV) is an important model for the investigation of the pathogenesis of persistent viral infections. As with humans infected with hepatitis C and Human Immunodeficiency Virus-1, adult mice persistently infected with immunosuppressive strains of LCMV express high levels of negative immune regulators that suppress the adaptive T cell immune response thereby facilitating viral persistence. Unknown, however, is whether and how very early interactions between the virus and the infected host affect the establishment of a persistent infection. Here, we describe host-virus interactions within the first 8–12 hours of infection are critical for establishing a persistent infection. While early induction of an anti-viral type-I interferons is essential for the subsequent adaptive immune response required to clear the virus, LCMV is able to overcome the programmed innate immune response by over-stimulating this response early. This affects not only the rate of viral growth in the host, but also the ability to infect specific immune cells that help shape an effective adaptive immune response. We further describe how and where LCMV is sensed by this early immune response, identify the critical timing of early virus-host interactions that lead to a persistent infection, and identify an early dysregulated immune signature associated with a persistent viral infection. Altogether, these observations are critical to understanding how early virus-host interactions determines the course of infection.
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Affiliation(s)
- Brian M. Sullivan
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
| | - John R. Teijaro
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Juan Carlos de la Torre
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Michael B. A. Oldstone
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
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Zhang Y, Chen H, Han JG. Insight into the binding modes of Lassa nucleoprotein complexed with ssRNA by molecular dynamic simulations and free energy calculations. J Biomol Struct Dyn 2014; 33:946-60. [DOI: 10.1080/07391102.2014.923785] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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West BR, Hastie KM, Saphire EO. Structure of the LCMV nucleoprotein provides a template for understanding arenavirus replication and immunosuppression. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:1764-9. [PMID: 24914986 PMCID: PMC4051510 DOI: 10.1107/s1399004714007883] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 04/09/2014] [Indexed: 12/25/2022]
Abstract
The X-ray crystal structure of the Lymphocytic choriomeningitis virus nucleoprotein C-terminal immunosuppressive domain (LCMV NPΔ340) was determined to 2.0 Å resolution. The structure indicates that LCMV NPΔ340, like the other structurally characterized arenaviral nucleoproteins, adopts the fold of an exonuclease. This structure provides a crucial three-dimensional template for functional exploration of the replication and immunosuppression of this prototypic arenavirus.
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Affiliation(s)
- Brandyn R. West
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kathryn M. Hastie
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Erica Ollmann Saphire
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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High-resolution structure of the N-terminal endonuclease domain of the Lassa virus L polymerase in complex with magnesium ions. PLoS One 2014; 9:e87577. [PMID: 24516554 PMCID: PMC3917842 DOI: 10.1371/journal.pone.0087577] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 12/20/2013] [Indexed: 01/18/2023] Open
Abstract
Lassa virus (LASV) causes deadly hemorrhagic fever disease for which there are no vaccines and limited treatments. LASV-encoded L polymerase is required for viral RNA replication and transcription. The functional domains of L–a large protein of 2218 amino acid residues–are largely undefined, except for the centrally located RNA-dependent RNA polymerase (RdRP) motif. Recent structural and functional analyses of the N-terminal region of the L protein from lymphocytic choriomeningitis virus (LCMV), which is in the same Arenaviridae family as LASV, have identified an endonuclease domain that presumably cleaves the cap structures of host mRNAs in order to initiate viral transcription. Here we present a high-resolution crystal structure of the N-terminal 173-aa region of the LASV L protein (LASV L173) in complex with magnesium ions at 1.72 Å. The structure is highly homologous to other known viral endonucleases of arena- (LCMV NL1), orthomyxo- (influenza virus PA), and bunyaviruses (La Crosse virus NL1). Although the catalytic residues (D89, E102 and K122) are highly conserved among the known viral endonucleases, LASV L endonuclease structure shows some notable differences. Our data collected from in vitro endonuclease assays and a reporter-based LASV minigenome transcriptional assay in mammalian cells confirm structural prediction of LASV L173 as an active endonuclease. The high-resolution structure of the LASV L endonuclease domain in complex with magnesium ions should aid the development of antivirals against lethal Lassa hemorrhagic fever.
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Abstract
The attenuated Lassa vaccine candidate ML29 is a laboratory-produced reassortant between Lassa and Mopeia viruses, two Old World arenaviruses that differ by 40% in nucleic acid sequence. In our previous studies, ML29 elicited sterilizing immunity against Lassa virus challenge in guinea pigs and marmosets and virus-specific cell-mediated immunity in both simian immunodeficiency virus (SIV)-infected and uninfected rhesus macaques. Here, we show that ML29 is stable after 12 passages in vitro without losing its plaque morphology or its attenuated phenotype in suckling mice. Additionally, we used deep sequencing to characterize the viral population comprising the original stock of ML29, the stock of ML29 after 12 passages in Vero cells, and the ML29 isolates obtained from vaccinated animals. Twenty-seven isolates bore approximately 77 mutations that exceeded 20% of the single-nucleotide polymorphism (SNP) changes at any single locus. Of these 77 mutations, 5 appeared to be host specific, for example, appearing in mice but not in primates. None of these mutations were reversions of ML29 to the sequences of the parental Lassa and Mopeia viruses. The host-specific mutations indicate viral adaptations to virus-host interactions, and such interactions make reasonable targets for antiviral approaches. Variants capable of chronic infection did not emerge from any of the primate infections, even in immune-deficient animals, indicating that the ML29 reassortant is reasonably stable in vivo. In conclusion, the preclinical studies of ML29 as a Lassa virus vaccine candidate have been advanced, showing high levels of protection in nonhuman primates and acceptable stability both in vitro and in vivo.
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Abstract
Arenaviruses merit significant interest as important human pathogens, since several of them cause severe hemorrhagic fever disease that is associated with high morbidity and significant mortality. Currently, there are no FDA-licensed arenavirus vaccines available, and current antiarenaviral therapy is limited to an off-labeled use of the nucleoside analog ribavirin, which has limited prophylactic efficacy. The pyrimidine biosynthesis inhibitor A3, which was identified in a high-throughput screen for compounds that blocked influenza virus replication, exhibits a broad-spectrum antiviral activity against negative- and positive-sense RNA viruses, retroviruses, and DNA viruses. In this study, we evaluated the antiviral activity of A3 against representative Old World (lymphocytic choriomeningitis virus) and New World (Junin virus) arenaviruses in rodent, monkey, and human cell lines. We show that A3 is significantly more efficient than ribavirin in controlling arenavirus multiplication and that the A3 inhibitory effect is in part due to its ability to interfere with viral RNA replication and transcription. We document an additive antiarenavirus effect of A3 and ribavirin, supporting the potential combination therapy of ribavirin and pyrimidine biosynthesis inhibitors for the treatment of arenavirus infections.
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Zinzula L, Tramontano E. Strategies of highly pathogenic RNA viruses to block dsRNA detection by RIG-I-like receptors: hide, mask, hit. Antiviral Res 2013; 100:615-35. [PMID: 24129118 PMCID: PMC7113674 DOI: 10.1016/j.antiviral.2013.10.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/24/2013] [Accepted: 10/04/2013] [Indexed: 12/24/2022]
Abstract
dsRNA species are byproducts of RNA virus replication and/or transcription. Prompt detection of dsRNA by RIG-I like receptors (RLRs) is a hallmark of the innate immune response. RLRs activation triggers production of the type I interferon (IFN)-based antiviral response. Highly pathogenic RNA viruses encode proteins that block the RLRs pathway. Hide, mask and hit are 3 strategies of RNA viruses to avoid immune system activation.
Double-stranded RNA (dsRNA) is synthesized during the course of infection by RNA viruses as a byproduct of replication and transcription and acts as a potent trigger of the host innate antiviral response. In the cytoplasm of the infected cell, recognition of the presence of viral dsRNA as a signature of “non-self” nucleic acid is carried out by RIG-I-like receptors (RLRs), a set of dedicated helicases whose activation leads to the production of type I interferon α/β (IFN-α/β). To overcome the innate antiviral response, RNA viruses encode suppressors of IFN-α/β induction, which block RLRs recognition of dsRNA by means of different mechanisms that can be categorized into: (i) dsRNA binding and/or shielding (“hide”), (ii) dsRNA termini processing (“mask”) and (iii) direct interaction with components of the RLRs pathway (“hit”). In light of recent functional, biochemical and structural findings, we review the inhibition mechanisms of RLRs recognition of dsRNA displayed by a number of highly pathogenic RNA viruses with different disease phenotypes such as haemorrhagic fever (Ebola, Marburg, Lassa fever, Lujo, Machupo, Junin, Guanarito, Crimean-Congo, Rift Valley fever, dengue), severe respiratory disease (influenza, SARS, Hendra, Hantaan, Sin Nombre, Andes) and encephalitis (Nipah, West Nile).
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Affiliation(s)
- Luca Zinzula
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella di Monserrato, SS554, 09042 Monserrato (Cagliari), Italy.
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Jiao L, Ouyang S, Liang M, Niu F, Shaw N, Wu W, Ding W, Jin C, Peng Y, Zhu Y, Zhang F, Wang T, Li C, Zuo X, Luan CH, Li D, Liu ZJ. Structure of severe fever with thrombocytopenia syndrome virus nucleocapsid protein in complex with suramin reveals therapeutic potential. J Virol 2013; 87:6829-39. [PMID: 23576501 PMCID: PMC3676114 DOI: 10.1128/jvi.00672-13] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Accepted: 04/01/2013] [Indexed: 01/15/2023] Open
Abstract
Severe fever with thrombocytopenia syndrome is an emerging infectious disease caused by a novel bunyavirus (SFTSV). Lack of vaccines and inadequate therapeutic treatments have made the spread of the virus a global concern. Viral nucleocapsid protein (N) is essential for its transcription and replication. Here, we present the crystal structures of N from SFTSV and its homologs from Buenaventura (BUE) and Granada (GRA) viruses. The structures reveal that phleboviral N folds into a compact core domain and an extended N-terminal arm that mediates oligomerization, such as tetramer, pentamer, and hexamer of N assemblies. Structural superimposition indicates that phleboviral N adopts a conserved architecture and uses a similar RNA encapsidation strategy as that of RVFV-N. The RNA binding cavity runs along the inner edge of the ring-like assembly. A triple mutant of SFTSV-N, R64D/K67D/K74D, almost lost its ability to bind RNA in vitro, is deficient in its ability to transcribe and replicate. Structural studies of the mutant reveal that both alterations in quaternary assembly and the charge distribution contribute to the loss of RNA binding. In the screening of inhibitors Suramin was identified to bind phleboviral N specifically. The complex crystal structure of SFTSV-N with Suramin was refined to a 2.30-Å resolution. Suramin was found sitting in the putative RNA binding cavity of SFTSV-N. The inhibitory effect of Suramin on SFTSV replication was confirmed in Vero cells. Therefore, a common Suramin-based therapeutic approach targeting SFTSV-N and its homologs could be developed for containing phleboviral outbreaks.
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Affiliation(s)
- Lianying Jiao
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Songying Ouyang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Mifang Liang
- Key Laboratory of Medical Virology, MOH, National Institute for Viral Diseases Control and Prevention, Beijing, China
| | - Fengfeng Niu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Neil Shaw
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming, China
| | - Wei Wu
- Key Laboratory of Medical Virology, MOH, National Institute for Viral Diseases Control and Prevention, Beijing, China
| | - Wei Ding
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Cong Jin
- Key Laboratory of Medical Virology, MOH, National Institute for Viral Diseases Control and Prevention, Beijing, China
| | - Yao Peng
- Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming, China
| | - Yanping Zhu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Fushun Zhang
- Key Laboratory of Medical Virology, MOH, National Institute for Viral Diseases Control and Prevention, Beijing, China
| | - Tao Wang
- Key Laboratory of Medical Virology, MOH, National Institute for Viral Diseases Control and Prevention, Beijing, China
| | - Chuan Li
- Key Laboratory of Medical Virology, MOH, National Institute for Viral Diseases Control and Prevention, Beijing, China
| | - Xiaobing Zuo
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois, USA
| | - Chi-Hao Luan
- High Throughput Analysis Laboratory, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Center for Structural Genomics of Infectious Diseases, Northwestern University, Illinois, USA
| | - Dexin Li
- Key Laboratory of Medical Virology, MOH, National Institute for Viral Diseases Control and Prevention, Beijing, China
| | - Zhi-Jie Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming, China
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Lennartz F, Hoenen T, Lehmann M, Groseth A, Garten W. The role of oligomerization for the biological functions of the arenavirus nucleoprotein. Arch Virol 2013; 158:1895-905. [PMID: 23553456 DOI: 10.1007/s00705-013-1684-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 02/20/2013] [Indexed: 10/27/2022]
Abstract
The Lassa virus nucleoprotein (NP) is a multifunctional protein that plays an essential role in many aspects of the viral life cycle, including RNA encapsidation, viral transcription and replication, recruitment of ribonucleoprotein complexes to viral budding sites, and inhibition of the host cell interferon response. While it is known that NP is capable of forming oligomers, both the oligomeric state of NP in mammalian cells and the significance of NP oligomerization for its various functions remain unclear. Here, we demonstrate that Lassa virus NP solely forms trimers upon expression in mammalian cells. Using a minigenome assay we show that mutants that are not able to form stable trimers are no longer functional during transcription and/or replication of the minigenome, indicating that NP trimerization is essential for transcription and/or replication of the viral genome. However, mutations leading to destabilization of the NP trimer did not impact the incorporation of NP into virus-like particles or its ability to suppress interferon-induced gene expression, two important functions of arenavirus NP.
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Affiliation(s)
- Frank Lennartz
- Institute of Virology, Philipps University Marburg, Hans-Meerwein-Strasse 2, 35043, Marburg, Germany
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Zapata JC, Salvato MS. Arenavirus variations due to host-specific adaptation. Viruses 2013; 5:241-78. [PMID: 23344562 PMCID: PMC3564120 DOI: 10.3390/v5010241] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 01/11/2013] [Accepted: 01/14/2013] [Indexed: 01/08/2023] Open
Abstract
Arenavirus particles are enveloped and contain two single-strand RNA genomic segments with ambisense coding. Genetic plasticity of the arenaviruses comes from transcription errors, segment reassortment, and permissive genomic packaging, and results in their remarkable ability, as a group, to infect a wide variety of hosts. In this review, we discuss some in vitro studies of virus genetic and phenotypic variation after exposure to selective pressures such as high viral dose, mutagens and antivirals. Additionally, we discuss the variation in vivo of selected isolates of Old World arenaviruses, particularly after infection of different animal species. We also discuss the recent emergence of new arenaviruses in the context of our observations of sequence variations that appear to be host-specific.
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Affiliation(s)
- Juan C Zapata
- Institute of Human Virology-School of Medicine, University of Maryland, Baltimore, MD 21201, USA.
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Ortiz-Riaño E, Cheng BYH, de la Torre JC, Martínez-Sobrido L. D471G mutation in LCMV-NP affects its ability to self-associate and results in a dominant negative effect in viral RNA synthesis. Viruses 2012. [PMID: 23202457 PMCID: PMC3497045 DOI: 10.3390/v4102137] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Arenaviruses merit significant interest because several family members are etiological agents of severe hemorrhagic fevers, representing a major burden to public health. Currently, there are no FDA-licensed vaccines against arenaviruses and the only available antiviral therapy is limited to the use of ribavirin that is partially effective. Arenavirus nucleoprotein (NP) is found associated with the genomic RNA forming the viral ribonucleoproteins (vRNPs) that together with the polymerase (L) direct viral replication and transcription. Virion formation requires the recruitment of vRNPs into budding sites, a process in which the arenavirus matrix-like protein (Z) plays a major role. Therefore, proper NP-NP and NP-Z interactions are required for the generation of infectious progeny. In this work we demonstrate the role of the amino acid residue D471 in the self-association of lymphocytic choriomeningitis virus nucleoprotein (LCMV-NP). Amino acid substitutions at this position abrogate NP oligomerization, affecting its ability to mediate replication and transcription of a minigenome reporter plasmid. However, its ability to interact with the Z protein, counteract the cellular interferon response and bind to dsRNA analogs was retained. Additionally, we also document the dominant negative effect of D471G mutation on viral infection, suggesting that NP self-association is an excellent target for the development of new antivirals against arenaviruses.
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Affiliation(s)
- Emilio Ortiz-Riaño
- Department of Microbiology and Immunology, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642; (E.O-R); (B.Y.H.C); (L. M-S)
| | - Benson Y. H. Cheng
- Department of Microbiology and Immunology, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642; (E.O-R); (B.Y.H.C); (L. M-S)
| | - Juan C. de la Torre
- To whom correspondence should be addressed;
(L.M-S), Tel.: +1-585-276-4733; (J.C. dlT), Tel.: +1-858-784-9462
| | - Luis Martínez-Sobrido
- To whom correspondence should be addressed;
(L.M-S), Tel.: +1-585-276-4733; (J.C. dlT), Tel.: +1-858-784-9462
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