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Swaraj S, Tripathi S. Interference without interferon: interferon-independent induction of interferon-stimulated genes and its role in cellular innate immunity. mBio 2024:e0258224. [PMID: 39302126 DOI: 10.1128/mbio.02582-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2024] Open
Abstract
Interferons (IFNs) are multifaceted proteins that play pivotal roles in orchestrating robust antiviral immune responses and modulating the intricate landscape of host immunity. The major signaling pathway activated by IFNs is the JAK/STAT (Janus kinase/signal transducer and activator of transcription) pathway, which leads to the transcription of a battery of genes, collectively known as IFN-stimulated genes (ISGs). While the well-established role of IFNs in coordinating the innate immune response against viral infections is widely acknowledged, recent years have provided a more distinct comprehension of the functional significance attributed to non-canonical, IFN-independent induction of ISGs. In this review, we summarize the non-conventional signaling pathways of ISG induction. These alternative pathways offer new avenues for developing antiviral strategies or immunomodulation in various diseases.
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Affiliation(s)
- Shachee Swaraj
- Emerging Viral Pathogens Laboratory, Centre for Infectious Disease Research, Indian Institute of Science, Bengaluru, India
- Microbiology & Cell Biology Department, Biological Sciences Division, Indian Institute of Science, Bengaluru, India
| | - Shashank Tripathi
- Emerging Viral Pathogens Laboratory, Centre for Infectious Disease Research, Indian Institute of Science, Bengaluru, India
- Microbiology & Cell Biology Department, Biological Sciences Division, Indian Institute of Science, Bengaluru, India
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2
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Williams EP, Nandi A, Nam V, Allen LJS, Trindade AA, Kosiewicz MM, Jonsson CB. Modeling the Immune Response for Pathogenic and Nonpathogenic Orthohantavirus Infections in Human Lung Microvasculature Endothelial Cells. Viruses 2023; 15:1806. [PMID: 37766212 PMCID: PMC10535571 DOI: 10.3390/v15091806] [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: 06/28/2023] [Revised: 08/18/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
Hantaviruses, genus Orthohantavirus, family Hantaviridae, order Bunyavirales, are negative-sense, single-stranded, tri-segmented RNA viruses that persistently infect rodents, shrews, and moles. Of these, only certain virus species harbored by rodents are pathogenic to humans. Infection begins with inhalation of virus particles into the lung and trafficking to the lung microvascular endothelial cells (LMVEC). The reason why certain rodent-borne hantavirus species are pathogenic has long been hypothesized to be related to their ability to downregulate and dysregulate the immune response as well as increase vascular permeability of infected endothelial cells. We set out to study the temporal dynamics of host immune response modulation in primary human LMVECs following infection by Prospect Hill (nonpathogenic), Andes (pathogenic), and Hantaan (pathogenic) viruses. We measured the level of RNA transcripts for genes representing antiviral, proinflammatory, anti-inflammatory, and metabolic pathways from 12 to 72 h with time points every 12 h. Gene expression analysis in conjunction with mathematical modeling revealed a similar profile for all three viruses in terms of upregulated genes that partake in interferon signaling (TLR3, IRF7, IFNB1), host immune cell recruitment (CXCL10, CXCL11, and CCL5), and host immune response modulation (IDO1). We examined secreted protein levels of IFN-β, CXCL10, CXCL11, CCL5, and IDO in two male and two female primary HLMVEC donors at 48 and 60 h post infection. All three viruses induced similar levels of CCL5, CXCL10, and CXCL11 within a particular donor, and the levels were similar in three of the four donors. All three viruses induced different protein secretion levels for both IFN-β and IDO and secretion levels differed between donors. In conclusion, we show that there was no difference in the transcriptional profiles of key genes in primary HLMVECs following infection by pathogenic and nonpathogenic hantaviruses, with protein secretion levels being more donor-specific than virus-specific.
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Affiliation(s)
- Evan P. Williams
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA;
| | - Aadrita Nandi
- Department of Mathematics and Statistics, Texas Tech University, Lubbock, TX 79409, USA; (A.N.); (V.N.); (L.J.S.A.); (A.A.T.)
| | - Victoria Nam
- Department of Mathematics and Statistics, Texas Tech University, Lubbock, TX 79409, USA; (A.N.); (V.N.); (L.J.S.A.); (A.A.T.)
| | - Linda J. S. Allen
- Department of Mathematics and Statistics, Texas Tech University, Lubbock, TX 79409, USA; (A.N.); (V.N.); (L.J.S.A.); (A.A.T.)
| | - A. Alexandre Trindade
- Department of Mathematics and Statistics, Texas Tech University, Lubbock, TX 79409, USA; (A.N.); (V.N.); (L.J.S.A.); (A.A.T.)
| | - Michele M. Kosiewicz
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202, USA;
| | - Colleen B. Jonsson
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA;
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3
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Ter Horst S, Conceição-Neto N, Neyts J, Rocha-Pereira J. Structural and functional similarities in bunyaviruses: Perspectives for pan-bunya antivirals. Rev Med Virol 2019; 29:e2039. [PMID: 30746831 PMCID: PMC7169261 DOI: 10.1002/rmv.2039] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 11/29/2018] [Accepted: 01/17/2019] [Indexed: 01/03/2023]
Abstract
The order of Bunyavirales includes numerous (re)emerging viruses that collectively have a major impact on human and animal health worldwide. There are no vaccines for human use or antiviral drugs available to prevent or treat infections with any of these viruses. The development of efficacious and safe drugs and vaccines is a pressing matter. Ideally, such antivirals possess pan‐bunyavirus antiviral activity, allowing the containment of every bunya‐related threat. The fact that many bunyaviruses need to be handled in laboratories with biosafety level 3 or 4, the great variety of species and the frequent emergence of novel species complicate such efforts. We here examined the potential druggable targets of bunyaviruses, together with the level of conservation of their biological functions, structure, and genetic similarity by means of heatmap analysis. In the light of this, we revised the available models and tools currently available, pointing out directions for antiviral drug discovery.
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Affiliation(s)
- Sebastiaan Ter Horst
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, KU Leuven, Leuven, Belgium
| | - Nádia Conceição-Neto
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Clinical and Epidemiological Virology, KU Leuven, Leuven, Belgium
| | - Johan Neyts
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, KU Leuven, Leuven, Belgium
| | - Joana Rocha-Pereira
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, KU Leuven, Leuven, Belgium
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4
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Buranda T, Gineste C, Wu Y, Bondu V, Perez D, Lake KR, Edwards BS, Sklar LA. A High-Throughput Flow Cytometry Screen Identifies Molecules That Inhibit Hantavirus Cell Entry. SLAS DISCOVERY 2018; 23:634-645. [PMID: 29608398 DOI: 10.1177/2472555218766623] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hantaviruses cause hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS), which infects more than 200,000 people worldwide. Sin Nombre virus (SNV) and Andes virus (ANDV) cause the most severe form of HCPS, with case fatality ratios of 30%-40%. There are no specific therapies or vaccines for SNV. Using high-throughput flow cytometry, we screened the Prestwick Chemical Library for small-molecule inhibitors of the binding interaction between UV-inactivated and fluorescently labeled SNVR18 particles, and decay-accelerating factor (DAF) expressed on Tanoue B cells. Eight confirmed hit compounds from the primary screen were investigated further in secondary screens that included infection inhibition, cytotoxicity, and probe interference. Antimycin emerged as a bona fide hit compound that inhibited cellular infection of the major HCPS (SNV)- and HCPS (Hantaan)-causing viruses. Confirming our assay's ability to detect active compounds, orthogonal testing of the hit compound showed that antimycin binds directly to the virus particle and blocks recapitulation of physiologic integrin activation caused by SNV binding to the integrin PSI domain.
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Affiliation(s)
- Tione Buranda
- 1 Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM, USA, and in revised form Feb 15, 2018. Accepted for publication Mar 1, 2018.,2 Center for Infectious Diseases and Immunity, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Catherine Gineste
- 3 University of New Mexico Center for Molecular Discovery, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Yang Wu
- 1 Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM, USA, and in revised form Feb 15, 2018. Accepted for publication Mar 1, 2018
| | - Virginie Bondu
- 1 Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM, USA, and in revised form Feb 15, 2018. Accepted for publication Mar 1, 2018
| | - Dominique Perez
- 1 Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM, USA, and in revised form Feb 15, 2018. Accepted for publication Mar 1, 2018.,4 Department of Cancer Center, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Kaylin R Lake
- 5 Department of Biochemistry, University of New Mexico, Albuquerque, NM, USA
| | - Bruce S Edwards
- 1 Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM, USA, and in revised form Feb 15, 2018. Accepted for publication Mar 1, 2018.,3 University of New Mexico Center for Molecular Discovery, University of New Mexico School of Medicine, Albuquerque, NM, USA.,4 Department of Cancer Center, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Larry A Sklar
- 1 Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM, USA, and in revised form Feb 15, 2018. Accepted for publication Mar 1, 2018.,3 University of New Mexico Center for Molecular Discovery, University of New Mexico School of Medicine, Albuquerque, NM, USA.,4 Department of Cancer Center, University of New Mexico School of Medicine, Albuquerque, NM, USA
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5
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Liu MM, Lei XY, Yu H, Zhang JZ, Yu XJ. Correlation of cytokine level with the severity of severe fever with thrombocytopenia syndrome. Virol J 2017; 14:6. [PMID: 28086978 PMCID: PMC5237221 DOI: 10.1186/s12985-016-0677-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/27/2016] [Indexed: 12/13/2022] Open
Abstract
Background Severe fever with thrombocytopenia syndrome (SFTS) was an emerging hemorrhagic fever that was caused by a tick-borne bunyavirus, SFTSV. Although SFTSV nonstructural protein can inhibit type I interferon (IFN-I) production Ex Vivo and IFN-I played key role in resistance SFTSV infection in animal model, the role of IFN-I in patients is not investigated. Methods We have assayed the concentration of IFN-α, a subtype of IFN-I as well as other cytokines in the sera of SFTS patients and the healthy population with CBA (Cytometric bead array) assay. Results The results showed that IFN-α, tumor necrosis factor (TNF-α), granulocyte colony-stimulating factor (G-CSF), interferon-γ (IFN-γ), macrophage inflammatory protein (MIP-1α), interleukin-6 (IL-6), IL-10, interferon-inducible protein (IP-10), monocyte chemoattractant protein (MCP-1) were significantly higher in SFTS patients than in healthy persons (p < 0.05); the concentrations of IFN-α, IFN-γ, G-CSF, MIP-1α, IL-6, and IP-10 were significant higher in severe SFTS patients than in mild SFTS patients (p < 0.05). Conclusion The concentration of IFN-α as well as other cytokines (IFN-γ, G-CSF, MIP-1α, IL-6, and IP-10) is correlated with the severity of SFTS, suggesting that type I interferon may not be significant in resistance SFTSV infection in humans and it may play an import role in cytokine storm.
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Affiliation(s)
- Miao-Miao Liu
- School of Public Health, Shandong University, Jinan, 250012, China
| | - Xiao-Ying Lei
- School of Public Health, Shandong University, Jinan, 250012, China
| | - Hao Yu
- School of Medicine, Fudan University, Shanghai, 200032, China
| | - Jian-Zhi Zhang
- School of Health Professions, University of Texas Medical Branch, Galveston, Texas, 77555-0609, USA
| | - Xue-Jie Yu
- School of Public Health, Shandong University, Jinan, 250012, China. .,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, 77555-0609, USA.
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6
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Spengler JR, Patel JR, Chakrabarti AK, Zivcec M, García-Sastre A, Spiropoulou CF, Bergeron É. RIG-I Mediates an Antiviral Response to Crimean-Congo Hemorrhagic Fever Virus. J Virol 2015; 89:10219-29. [PMID: 26223644 PMCID: PMC4580164 DOI: 10.1128/jvi.01643-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 07/21/2015] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED In the cytoplasm, the retinoic acid-inducible gene I (RIG-I) senses the RNA genomes of several RNA viruses. RIG-I binds to viral RNA, eliciting an antiviral response via the cellular adaptor MAVS. Crimean-Congo hemorrhagic fever virus (CCHFV), a negative-sense RNA virus with a 5'-monophosphorylated genome, is a highly pathogenic zoonotic agent with significant public health implications. We found that, during CCHFV infection, RIG-I mediated a type I interferon (IFN) response via MAVS. Interfering with RIG-I signaling reduced IFN production and IFN-stimulated gene expression and increased viral replication. Immunostimulatory RNA was isolated from CCHFV-infected cells and from virion preparations, and RIG-I coimmunoprecipitation of infected cell lysates isolated immunostimulatory CCHFV RNA. This report serves as the first description of a pattern recognition receptor for CCHFV and highlights a critical signaling pathway in the antiviral response to CCHFV. IMPORTANCE CCHFV is a tick-borne virus with a significant public health impact. In order for cells to respond to virus infection, they must recognize the virus as foreign and initiate antiviral signaling. To date, the receptors involved in immune recognition of CCHFV are not known. Here, we investigate and identify RIG-I as a receptor involved in initiating an antiviral response to CCHFV. This receptor initially was not expected to play a role in CCHFV recognition because of characteristics of the viral genome. These findings are important in understanding the antiviral response to CCHFV and support continued investigation into the spectrum of potential viruses recognized by RIG-I.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/immunology
- Animals
- Cell Line
- Cell Line, Tumor
- Chlorocebus aethiops
- DEAD Box Protein 58
- DEAD-box RNA Helicases/genetics
- DEAD-box RNA Helicases/immunology
- Epithelial Cells
- Fibroblasts/immunology
- Fibroblasts/virology
- Gene Expression Regulation
- Genome, Viral
- HEK293 Cells
- Hemorrhagic Fever Virus, Crimean-Congo/genetics
- Hemorrhagic Fever Virus, Crimean-Congo/immunology
- Host-Pathogen Interactions
- Humans
- Interferon Type I/genetics
- Interferon Type I/immunology
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- RNA, Viral/genetics
- RNA, Viral/immunology
- Receptors, Immunologic
- Receptors, Virus/genetics
- Receptors, Virus/immunology
- Signal Transduction
- Vero Cells
- Virus Replication
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Affiliation(s)
- Jessica R Spengler
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jenish R Patel
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Ayan K Chakrabarti
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Marko Zivcec
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Christina F Spiropoulou
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Éric Bergeron
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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7
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Morzunov SP, Khaiboullina SF, St Jeor S, Rizvanov AA, Lombardi VC. Multiplex Analysis of Serum Cytokines in Humans with Hantavirus Pulmonary Syndrome. Front Immunol 2015; 6:432. [PMID: 26379668 PMCID: PMC4553709 DOI: 10.3389/fimmu.2015.00432] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/09/2015] [Indexed: 12/11/2022] Open
Abstract
Hantavirus pulmonary syndrome (HPS) is an acute zoonotic disease transmitted primarily through inhalation of virus-contaminated aerosols. Hantavirus infection of endothelial cells leads to increased vascular permeability without a visible cytopathic effect. For this reason, it has been suggested that the pathogenesis of HPS is indirect with immune responses, such as cytokine production, playing a dominant role. In order to investigate their potential contribution to HPS pathogenesis, we analyzed the serum of hantavirus-infected subjects and healthy controls for 68 different cytokines, chemokines, angiogenic, and growth factors. Our analysis identified differential expression of cytokines that promote tissue migration of mononuclear cells including T lymphocytes, natural killer cells, and dendritic cells. Additionally, we observed a significant upregulation of cytokines known to regulate leukocyte migration and subsequent repair of lung tissue, as well as cytokines known to increase endothelial monolayer permeability and facilitate leukocyte transendothelial migration. Conversely, we observed a downregulation of cytokines associated with platelet numbers and function, consistent with the thrombocytopenia observed in subjects with HPS. This study corroborates clinical findings and extends our current knowledge regarding immunological and laboratory findings in subjects with HPS.
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Affiliation(s)
- Sergey P Morzunov
- Department of Pathology, School of Medicine, University of Nevada , Reno, NV , USA
| | - Svetlana F Khaiboullina
- Institute of Fundamental Medicine and Biology, Kazan Federal University , Kazan , Russia ; Whittemore Peterson Institute , Reno, NV , USA
| | - Stephen St Jeor
- Department of Microbiology and Immunology, University of Nevada , Reno, NV , USA
| | - Albert A Rizvanov
- Institute of Fundamental Medicine and Biology, Kazan Federal University , Kazan , Russia
| | - Vincent C Lombardi
- Whittemore Peterson Institute , Reno, NV , USA ; Department of Biochemistry, School of Medicine, University of Nevada , Reno, NV , USA
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Hantaan virus can infect human keratinocytes and activate an interferon response through the nuclear translocation of IRF-3. INFECTION GENETICS AND EVOLUTION 2015; 29:146-55. [DOI: 10.1016/j.meegid.2014.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 11/09/2014] [Accepted: 11/11/2014] [Indexed: 12/11/2022]
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9
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Weber M, Gawanbacht A, Habjan M, Rang A, Borner C, Schmidt AM, Veitinger S, Jacob R, Devignot S, Kochs G, García-Sastre A, Weber F. Incoming RNA virus nucleocapsids containing a 5'-triphosphorylated genome activate RIG-I and antiviral signaling. Cell Host Microbe 2013; 13:336-46. [PMID: 23498958 PMCID: PMC5515363 DOI: 10.1016/j.chom.2013.01.012] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 10/12/2012] [Accepted: 01/25/2013] [Indexed: 12/24/2022]
Abstract
Host defense to RNA viruses depends on rapid intracellular recognition of viral RNA by two cytoplasmic RNA helicases: RIG-I and MDA5. RNA transfection experiments indicate that RIG-I responds to naked double-stranded RNAs (dsRNAs) with a triphosphorylated 5' (5'ppp) terminus. However, the identity of the RIG-I stimulating viral structures in an authentic infection context remains unresolved. We show that incoming viral nucleocapsids containing a 5'ppp dsRNA "panhandle" structure trigger antiviral signaling that commences with RIG-I, is mediated through the adaptor protein MAVS, and terminates with transcription factor IRF-3. Independent of mammalian cofactors or viral polymerase activity, RIG-I bound to viral nucleocapsids, underwent a conformational switch, and homo-oligomerized. Enzymatic probing and superresolution microscopy suggest that RIG-I interacts with the panhandle structure of the viral nucleocapsids. These results define cytoplasmic entry of nucleocapsids as the proximal RIG-I-sensitive step during infection and establish viral nucleocapsids with a 5'ppp dsRNA panhandle as a RIG-I activator.
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Affiliation(s)
- Michaela Weber
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Ali Gawanbacht
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Matthias Habjan
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Andreas Rang
- Institute of Virology, Helmut-Ruska-Haus, University Hospital Charité, Charité Campus Mitte, Berlin, Germany
| | - Christoph Borner
- Institute of Molecular Medicine, Stefan-Meier-Strasse 17, D-79104 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
| | - Anna Mareike Schmidt
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
| | - Sophie Veitinger
- Department of Cell Biology and Cell Pathology, Philipps-University Marburg, Marburg, Germany
| | - Ralf Jacob
- Department of Cell Biology and Cell Pathology, Philipps-University Marburg, Marburg, Germany
| | - Stéphanie Devignot
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Georg Kochs
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Adolfo García-Sastre
- Department of Microbiology, Mount Sinai School of Medicine, New York, NY-10029, USA
- Department of Medicine, Division of Infectious Diseases, Mount Sinai School of Medicine, New York, NY-10029, USA
- Global Health and Emerging Pathogens Institute, Mount Sinai School of Medicine, New York, NY-10029, USA
| | - Friedemann Weber
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
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Noguchi S, Hijikata M, Hamano E, Matsushita I, Ito H, Ohashi J, Nagase T, Keicho N. MxA transcripts with distinct first exons and modulation of gene expression levels by single-nucleotide polymorphisms in human bronchial epithelial cells. Immunogenetics 2012; 65:107-14. [PMID: 23160781 PMCID: PMC7079882 DOI: 10.1007/s00251-012-0663-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 10/22/2012] [Indexed: 12/24/2022]
Abstract
Myxovirus resistance A (MxA) is a major interferon (IFN)-inducible antiviral protein. Promoter single-nucleotide polymorphisms (SNPs) of MxA near the IFN-stimulated response element (ISRE) have been frequently associated with various viral diseases, including emerging respiratory infections. We investigated the expression profile of MxA transcripts with distinct first exons in human bronchial epithelial cells. For primary culture, the bronchial epithelium was isolated from lung tissues with different genotypes, and total RNA was subjected to real-time reverse transcription polymerase chain reaction. The previously reported MxA transcript (T1) and a recently registered transcript with a distinct 5′ first exon (T0) were identified. IFN-β and polyinosinic–polycytidylic acid induced approximately 100-fold higher expression of the T1 transcript than that of the T0 transcript, which also had a potential ISRE motif near its transcription start site. Even without inducers, the T1 transcript accounted for approximately two thirds of the total expression of MxA, levels of which were significantly associated with its promoter and exon 1 SNPs (rs17000900, rs2071430, and rs464138). Our results suggest that MxA observed in respiratory viral infections is possibly dominated by the T1 transcript and partly influenced by relevant 5′ SNPs.
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Affiliation(s)
- Satoshi Noguchi
- Department of Respiratory Diseases, Research Institute, National Center for Global Health and Medicine, Toyama, Shinjuku-ku, Tokyo, Japan
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11
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Hantavirus regulation of type I interferon responses. Adv Virol 2012; 2012:524024. [PMID: 22924041 PMCID: PMC3423653 DOI: 10.1155/2012/524024] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 05/18/2012] [Accepted: 07/04/2012] [Indexed: 11/22/2022] Open
Abstract
Hantaviruses primarily infect human endothelial cells (ECs) and cause two highly lethal human diseases. Early addition of Type I interferon (IFN) to ECs blocks hantavirus replication and thus for hantaviruses to be pathogenic they need to prevent early interferon induction. PHV replication is blocked in human ECs, but not inhibited in IFN deficient VeroE6 cells and consistent with this, infecting ECs with PHV results in the early induction of IFNβ and an array of interferon stimulated genes (ISGs). In contrast, ANDV, HTNV, NY-1V and TULV hantaviruses, inhibit early ISG induction and successfully replicate within human ECs. Hantavirus inhibition of IFN responses has been attributed to several viral proteins including regulation by the Gn proteins cytoplasmic tail (Gn-T). The Gn-T interferes with the formation of STING-TBK1-TRAF3 complexes required for IRF3 activation and IFN induction, while the PHV Gn-T fails to alter this complex or regulate IFN induction. These findings indicate that interfering with early IFN induction is necessary for hantaviruses to replicate in human ECs, and suggest that additional determinants are required for hantaviruses to be pathogenic. The mechanism by which Gn-Ts disrupt IFN signaling is likely to reveal potential therapeutic interventions and suggest protein targets for attenuating hantaviruses.
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12
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Dong C, Zafrullah M, Mixson-Hayden T, Dai X, Liang J, Meng J, Kamili S. Suppression of interferon-α signaling by hepatitis E virus. Hepatology 2012; 55:1324-32. [PMID: 22183878 DOI: 10.1002/hep.25530] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 11/02/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED The interferon (IFN) system is integral to the host response against viruses, and many viruses have developed strategies to overcome its antiviral effects. The effects of hepatitis E virus (HEV), the causative agent of hepatitis E, on IFN signaling have not been investigated primarily because of the nonavailability of an efficient in vitro culture system or small animal models of infection. We report here the generation of A549 cell lines persistently infected with genotype 3 HEV, designated as HEV-A549 cells and the effects HEV has on IFN-α-mediated Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling. Treatment of HEV-A549 cells with 250, 500, and 1000 U/mL of IFN-α for 72 hours showed a dose-dependent reduction in HEV RNA levels by 10%, 20%, and 50%, respectively. IFN-α-stimulated genes coding for the antiviral proteins dsRNA-activated protein kinase (PKR) and 2',5'-oligoadenylate synthetase (2',5'-OAS) were down-regulated in IFN-α-treated HEV-A549 cells. HEV infection also prevented IFN-α-induced phosphorylation of STAT1. Regulation of STAT1 by HEV was specific, as phosphorylation of STAT2, tyrosine kinase (Tyk) 2, and Jak1 by IFN-α was unaltered. Additionally, STAT1 levels were markedly increased in HEV-A549 cells compared with naive A549 cells. Furthermore, binding of HEV open reading frame (ORF)3 protein to STAT1 in HEV-A549 cells was observed. HEV ORF3 protein alone inhibited IFN-α-induced phosphorylation of STAT1 and down-regulated the IFN-α-stimulated genes encoding PKR, 2',5'-OAS, and myxovirus resistance A. CONCLUSION HEV inhibits IFN-α signaling through the regulation of STAT1 phosphorylation in A549 cells. These findings have implications for the development of new strategies against hepatitis E.
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Affiliation(s)
- Chen Dong
- Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Popugaeva E, Witkowski PT, Schlegel M, Ulrich RG, Auste B, Rang A, Krüger DH, Klempa B. Dobrava-Belgrade hantavirus from Germany shows receptor usage and innate immunity induction consistent with the pathogenicity of the virus in humans. PLoS One 2012; 7:e35587. [PMID: 22545121 PMCID: PMC3335829 DOI: 10.1371/journal.pone.0035587] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 03/18/2012] [Indexed: 11/18/2022] Open
Abstract
Background Dobrava-Belgrade virus (DOBV) is a European hantavirus causing hemorrhagic fever with renal syndrome (HFRS) in humans with fatality rates of up to 12%. DOBV-associated clinical cases typically occur also in the northern part of Germany where the virus is carried by the striped field mouse (Apodemus agrarius). However, the causative agent responsible for human illness has not been previously isolated. Methodology/Principal Findings Here we report on characterization of a novel cell culture isolate from Germany obtained from a lung tissue of “spillover” infected yellow necked mouse (A. flavicollis) trapped near the city of Greifswald. Phylogenetic analyses demonstrated close clustering of the new strain, designated Greifswald/Aa (GRW/Aa) with the nucleotide sequence obtained from a northern German HFRS patient. The virus was effectively blocked by specific antibodies directed against β3 integrins and Decay Accelerating Factor (DAF) indicating that the virus uses same receptors as the highly pathogenic Hantaan virus (HTNV). In addition, activation of selected innate immunity markers as interferon β and λ and antiviral protein MxA after viral infection of A549 cells was investigated and showed that the virus modulates the first-line antiviral response in a similar way as HTNV. Conclusions/Significance In summary, our study reveals novel data on DOBV receptor usage and innate immunity induction in relationship to virus pathogenicity and underlines the potency of German DOBV strains to act as human pathogen.
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Affiliation(s)
- Elena Popugaeva
- Institute of Virology, Helmut-Ruska-Haus, Charité Medical School, Berlin, Germany
| | - Peter T. Witkowski
- Institute of Virology, Helmut-Ruska-Haus, Charité Medical School, Berlin, Germany
| | - Mathias Schlegel
- Friedrich-Loeffler-Institut, Institute for Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany
| | - Rainer G. Ulrich
- Friedrich-Loeffler-Institut, Institute for Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany
| | - Brita Auste
- Institute of Virology, Helmut-Ruska-Haus, Charité Medical School, Berlin, Germany
| | - Andreas Rang
- Institute of Virology, Helmut-Ruska-Haus, Charité Medical School, Berlin, Germany
| | - Detlev H. Krüger
- Institute of Virology, Helmut-Ruska-Haus, Charité Medical School, Berlin, Germany
| | - Boris Klempa
- Institute of Virology, Helmut-Ruska-Haus, Charité Medical School, Berlin, Germany
- Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia
- * E-mail:
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14
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Lee MH, Lalwani P, Raftery MJ, Matthaei M, Lütteke N, Kirsanovs S, Binder M, Ulrich RG, Giese T, Wolff T, Krüger DH, Schönrich G. RNA helicase retinoic acid-inducible gene I as a sensor of Hantaan virus replication. J Gen Virol 2011; 92:2191-2200. [PMID: 21632559 DOI: 10.1099/vir.0.032367-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Hantaan virus (HTNV) causes severe human disease. The HTNV genome consists of three ssRNA segments of negative polarity that are complexed with viral nucleocapsid (N) protein. How the human innate immune system detects HTNV is unclear. RNA helicase retinoic acid-inducible gene I (RIG-I) does not sense genomic HTNV RNA. So far it has not been analysed whether pathogen-associated molecular patterns generated during the HTNV replication trigger RIG-I-mediated innate responses. Indeed, we found that knock-down of RIG-I in A549 cells, an alveolar epithelial cell line, increases HTNV replication and prevents induction of 2',5'-oligoadenylate synthetase, an interferon-stimulated gene. Moreover, overexpression of wild-type or constitutive active RIG-I in Huh7.5 cells lacking a functional RIG-I diminished HTNV virion production. Intriguingly, reporter assays revealed that in vitro-transcribed HTNV N RNA and expression of the HTNV N ORF triggers RIG-I signalling. This effect was completely blocked by the RNA-binding domain of vaccinia virus E3 protein, suggesting that dsRNA-like secondary structures of HTNV N RNA stimulate RIG-I. Finally, transfection of HTNV N RNA into A549 cells resulted in a 2 log-reduction of viral titres upon challenge with virus. Our study is the first demonstration that RIG-I mediates antiviral innate responses induced by HTNV N RNA during HTNV replication and interferes with HTNV growth.
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Affiliation(s)
- Min-Hi Lee
- Institute of Medical Virology, Charité - Universitätsmedizin Berlin, D-10098 Berlin, Germany
| | - Pritesh Lalwani
- Institute of Medical Virology, Charité - Universitätsmedizin Berlin, D-10098 Berlin, Germany
| | - Martin J Raftery
- Institute of Medical Virology, Charité - Universitätsmedizin Berlin, D-10098 Berlin, Germany
| | | | - Nina Lütteke
- Institute of Medical Virology, Charité - Universitätsmedizin Berlin, D-10098 Berlin, Germany
| | - Sina Kirsanovs
- Institute of Medical Virology, Charité - Universitätsmedizin Berlin, D-10098 Berlin, Germany
| | - Marco Binder
- Department of Molecular Virology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Rainer G Ulrich
- Friedrich Loeffler Institute, Institute for Novel and Emerging Infectious Diseases, D-17493 Greifswald-Insel Riems, Germany
| | - Thomas Giese
- Institute of Immunology, University of Heidelberg, D-69120 Heidelberg, Germany
| | | | - Detlev H Krüger
- Institute of Medical Virology, Charité - Universitätsmedizin Berlin, D-10098 Berlin, Germany
| | - Günther Schönrich
- Institute of Medical Virology, Charité - Universitätsmedizin Berlin, D-10098 Berlin, Germany
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15
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Wang H, Vaheri A, Weber F, Plyusnin A. Old World hantaviruses do not produce detectable amounts of dsRNA in infected cells and the 5' termini of their genomic RNAs are monophosphorylated. J Gen Virol 2011; 92:1199-1204. [PMID: 21289157 DOI: 10.1099/vir.0.029405-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
dsRNA and 5'-triphosphate RNA are considered critical activators of the innate immune response because of their interaction with pattern recognition receptors. It has been reported that no dsRNA is detected in negative-sense RNA virus-infected cells and that Hantaan virus (HTNV) genomic RNA bears a 5' monophosphate group. In this paper we examine the 5' termini of genomic RNAs of and dsRNA production by two major groups of Old World hantaviruses. No detectable amounts of dsRNA were found in infected cells. Also, the genomic RNAs of these hantaviruses bear a 5' monophosphate group and therefore are unable to trigger interferon induction. Taken together with the earlier data on HTNV, these results suggest that in addition to the dsRNA and genomic RNA, which may be only minimally involved in the induction of innate immunity, other cellular signalling pathways may also be involved and that these await further investigation.
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Affiliation(s)
- Hao Wang
- Department of Virology, Infection Biology Research Program, Haartman Institute, University of Helsinki, Finland
| | - Antti Vaheri
- Department of Virology, Infection Biology Research Program, Haartman Institute, University of Helsinki, Finland
| | - Friedemann Weber
- Institute of Virology, Philipps University Marburg, Marburg, Germany
| | - Alexander Plyusnin
- Department of Virology, Infection Biology Research Program, Haartman Institute, University of Helsinki, Finland
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16
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Hantaviruses in the americas and their role as emerging pathogens. Viruses 2010; 2:2559-86. [PMID: 21994631 PMCID: PMC3185593 DOI: 10.3390/v2122559] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 11/15/2010] [Accepted: 11/24/2010] [Indexed: 12/17/2022] Open
Abstract
The continued emergence and re-emergence of pathogens represent an ongoing, sometimes major, threat to populations. Hantaviruses (family Bunyaviridae) and their associated human diseases were considered to be confined to Eurasia, but the occurrence of an outbreak in 1993–94 in the southwestern United States led to a great increase in their study among virologists worldwide. Well over 40 hantaviral genotypes have been described, the large majority since 1993, and nearly half of them pathogenic for humans. Hantaviruses cause persistent infections in their reservoir hosts, and in the Americas, human disease is manifest as a cardiopulmonary compromise, hantavirus cardiopulmonary syndrome (HCPS), with case-fatality ratios, for the most common viral serotypes, between 30% and 40%. Habitat disturbance and larger-scale ecological disturbances, perhaps including climate change, are among the factors that may have increased the human caseload of HCPS between 1993 and the present. We consider here the features that influence the structure of host population dynamics that may lead to viral outbreaks, as well as the macromolecular determinants of hantaviruses that have been regarded as having potential contribution to pathogenicity.
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17
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Abstract
Evasion of interferon (IFN)-mediated antiviral signaling is a common defense strategy for pathogenic RNA viruses. To date, research on IFN antagonism by hantaviruses is limited and has focused on only a subset of the numerous recognized hantavirus species. The host IFN response has two phases, an initiation phase, resulting in the induction of alpha/beta IFN (IFN-α/β), and an amplification phase, whereby IFN-α/β signals through the Jak/STAT pathway, resulting in the establishment of the cellular antiviral state. We examined interactions between these critical host responses and the New World hantaviruses. We observed delayed cellular responses in both Andes virus (ANDV)- and Sin Nombre virus (SNV)-infected A549 and Huh7-TLR3 cells. We found that IFN-β induction is inhibited by coexpression of ANDV nucleocapsid protein (NP) and glycoprotein precursor (GPC) and is robustly inhibited by SNV GPC alone. Downstream amplification by Jak/STAT signaling is also inhibited by SNV GPC and by either NP or GPC of ANDV. Therefore, ANDV- and SNV-encoded proteins have the potential for inhibiting both IFN-β induction and signaling, with SNV exhibiting the more potent antagonism ability. Herein we identify ANDV NP, a previously unrecognized inhibitor of Jak/STAT signaling, and show that IFN antagonism by ANDV relies on expression of both the glycoproteins and NP, whereas the glycoproteins appear to be sufficient for antagonism by SNV. These data suggest that IFN antagonism strategies by hantaviruses are quite variable, even between species with similar disease phenotypes, and may help to better elucidate species-specific pathogenesis.
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18
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Prescott J, Hall P, Acuna-Retamar M, Ye C, Wathelet MG, Ebihara H, Feldmann H, Hjelle B. New World hantaviruses activate IFNlambda production in type I IFN-deficient vero E6 cells. PLoS One 2010; 5:e11159. [PMID: 20567522 PMCID: PMC2887373 DOI: 10.1371/journal.pone.0011159] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 05/23/2010] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Hantaviruses indigenous to the New World are the etiologic agents of hantavirus cardiopulmonary syndrome (HCPS). These viruses induce a strong interferon-stimulated gene (ISG) response in human endothelial cells. African green monkey-derived Vero E6 cells are used to propagate hantaviruses as well as many other viruses. The utility of the Vero E6 cell line for virus production is thought to owe to their lack of genes encoding type I interferons (IFN), rendering them unable to mount an efficient innate immune response to virus infection. Interferon lambda, a more recently characterized type III IFN, is transcriptionally controlled much like the type I IFNs, and activates the innate immune system in a similar manner. METHODOLOGY/PRINCIPAL FINDINGS We show that Vero E6 cells respond to hantavirus infection by secreting abundant IFNlambda. Three New World hantaviruses were similarly able to induce IFNlambda expression in this cell line. The IFNlambda contained within virus preparations generated with Vero E6 cells independently activates ISGs when used to infect several non-endothelial cell lines, whereas innate immune responses by endothelial cells are specifically due to viral infection. We show further that Sin Nombre virus replicates to high titer in human hepatoma cells (Huh7) without inducing ISGs. CONCLUSIONS/SIGNIFICANCE Herein we report that Vero E6 cells respond to viral infection with a highly active antiviral response, including secretion of abundant IFNlambda. This cytokine is biologically active, and when contained within viral preparations and presented to human epithelioid cell lines, results in the robust activation of innate immune responses. We also show that both Huh7 and A549 cell lines do not respond to hantavirus infection, confirming that the cytoplasmic RNA helicase pathways possessed by these cells are not involved in hantavirus recognition. We demonstrate that Vero E6 actively respond to virus infection and inhibiting IFNlambda production in these cells might increase their utility for virus propagation.
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Affiliation(s)
- Joseph Prescott
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Pamela Hall
- Research Service (151), New Mexico Veterans Affairs Health Care System, Albuquerque, New Mexico, United States of America
| | - Mariana Acuna-Retamar
- Department of Pathology, Center for Infectious Diseases and Immunity, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Chunyan Ye
- Department of Pathology, Center for Infectious Diseases and Immunity, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Marc G. Wathelet
- Department of Pathology, Center for Infectious Diseases and Immunity, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States of America
- Infectious Disease Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Hideki Ebihara
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Heinz Feldmann
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
- * E-mail:
| | - Brian Hjelle
- Department of Pathology, Center for Infectious Diseases and Immunity, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States of America
- Department of Biology, Center for Infectious Diseases and Immunity, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States of America
- Department of Molecular Genetics and Microbiology, Center for Infectious Diseases and Immunity, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States of America
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Abstract
West Nile virus (WNV) infection leads to rapid and sustained Ca(2+) influx. This influx was observed with different strains of WNV and in different types of cells. Entry during virion endocytosis as well as through calcium channels contributed to the Ca(2+) influx observed in WNV-infected cells. Ca(2+) influx was not detected after infection with vesicular stomatitis virus (VSV) and occurred only through endocytosis in Sindbis virus-infected cells. Caspase 3 cleavage and activation of several kinases, including focal adhesion kinase (FAK), mitogen-activated extracellular signal-regulated protein kinase (ERK1/2), and protein-serine kinase B alpha (Akt), at early times after WNV infection were shown to be dependent on Ca(2+) influx. Although the activation of these kinases was sustained in virus-infected cells throughout infection, UV-inactivated WNV induced only a transient activation of FAK and ERK1/2 at early times after infection. The Ca(2+)-dependent FAK activation observed in WNV-infected cells was not mediated by alphavbeta3 integrins. Reduction of Ca(2+) influx at early times of infection by various treatments decreased the viral yield and delayed both the early transient caspase 3 cleavage and the activation of FAK, Akt, and ERK signaling. The results indicate that Ca(2+) influx is required for early infection events needed for efficient viral replication, possibly for virus-induced rearrangement of the endoplasmic reticulum (ER) membrane. Increased caspase 3 cleavage at both early (transient) and late times of infection correlated with decreased activation of the FAK and ERK1/2 pathways, indicating a role for these kinases in extending the survival of flavivirus-infected cells.
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Recognition of decay accelerating factor and alpha(v)beta(3) by inactivated hantaviruses: Toward the development of high-throughput screening flow cytometry assays. Anal Biochem 2010; 402:151-60. [PMID: 20363206 DOI: 10.1016/j.ab.2010.03.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Revised: 03/10/2010] [Accepted: 03/11/2010] [Indexed: 01/02/2023]
Abstract
Hantaviruses cause two severe diseases in humans: hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). The lack of vaccines or specific drugs to prevent or treat HFRS and HCPS and the requirement for conducting experiments in a biosafety level 3 laboratory (BSL-3) limit the ability to probe the mechanism of infection and disease pathogenesis. In this study, we developed a generalizable spectroscopic assay to quantify saturable fluorophore sites solubilized in envelope membranes of Sin Nombre virus (SNV) particles. We then used flow cytometry and live cell confocal fluorescence microscopy imaging to show that ultraviolet (UV)-killed SNV particles bind to the cognate receptors of live virions, namely, decay accelerating factor (DAF/CD55) expressed on Tanoue B cells and alpha(v)beta(3) integrins expressed on Vero E6 cells. SNV binding to DAF is multivalent and of high affinity (K(d) approximately 26pM). Self-exchange competition binding assays between fluorescently labeled SNV and unlabeled SNV are used to evaluate an infectious unit-to-particle ratio of approximately 1:14,000. We configured the assay for measuring the binding of fluorescently labeled SNV to Tanoue B suspension cells using a high-throughput flow cytometer. In this way, we established a proof-of-principle high-throughput screening (HTS) assay for binding inhibition. This is a first step toward developing HTS format assays for small molecule inhibitors of viral-cell interactions as well as dissecting the mechanism of infection in a BSL-2 environment.
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21
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Au RY, Jedlicka AE, Li W, Pekosz A, Klein SL. Seoul virus suppresses NF-kappaB-mediated inflammatory responses of antigen presenting cells from Norway rats. Virology 2010; 400:115-27. [PMID: 20170933 DOI: 10.1016/j.virol.2010.01.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/05/2010] [Accepted: 01/21/2010] [Indexed: 10/19/2022]
Abstract
Hantavirus infection reduces antiviral defenses, increases regulatory responses, and causes persistent infection in rodent hosts. To address whether hantaviruses alter the maturation and functional activity of antigen presenting cells (APCs), rat bone marrow-derived dendritic cells (BMDCs) and macrophages (BMDMs) were generated and infected with Seoul virus (SEOV) or stimulated with TLR ligands. SEOV infected both DCs and macrophages, but copies of viral RNA, viral antigen, and infectious virus titers were higher in macrophages. The expression of MHCII and CD80, production of IL-6, IL-10, and TNF-alpha, and expression of Ifnbeta were attenuated in SEOV-infected APCs. Stimulation of APCs with poly I:C prior to SEOV infection increased the expression of activation markers and production of inflammatory cytokines and suppressed SEOV replication. Infection of APCs with SEOV suppressed LPS-induced activation and innate immune responses. Hantaviruses reduce the innate immune response potential of APCs derived from a natural host, which may influence persistence of these zoonotic viruses in the environment.
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Affiliation(s)
- Rebecca Y Au
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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22
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Bunyaviruses and the type I interferon system. Viruses 2009; 1:1003-21. [PMID: 21994579 PMCID: PMC3185543 DOI: 10.3390/v1031003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 11/11/2009] [Accepted: 11/20/2009] [Indexed: 12/15/2022] Open
Abstract
The family Bunyaviridae contains more than 350 viruses that are distributed throughout the world. Most members of the family are transmitted by arthopods, and several cause disease in man, domesticated animals and crop plants. Despite being recognized as an emerging threat, details of the virulence mechanisms employed by bunyaviruses are scant. In this article we summarise the information currently available on how these viruses are able to establish infection when confronted with a powerful antiviral interferon system.
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Innate and adaptive immune responses to herpes simplex virus. Viruses 2009; 1:979-1002. [PMID: 21994578 PMCID: PMC3185534 DOI: 10.3390/v1030979] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 11/13/2009] [Accepted: 11/16/2009] [Indexed: 12/19/2022] Open
Abstract
Immune responses against HSV-1 and HSV-2 are complex and involve a delicate interplay between innate signaling pathways and adaptive immune responses. The innate response to HSV involves the induction of type I IFN, whose role in protection against disease is well characterized in vitro and in vivo. Cell types such as NK cells and pDCs contribute to innate anti-HSV responses in vivo. Finally, the adaptive response includes both humoral and cellular components that play important roles in antiviral control and latency. This review summarizes the innate and adaptive effectors that contribute to susceptibility, immune control and pathogenesis of HSV, and highlights the delicate interplay between these two important arms of immunity.
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Yu L, Ye L, Zhao R, Liu YF, Yang SJ. HSP70 induced by Hantavirus infection interacts with viral nucleocapsid protein and its overexpression suppresses virus infection in Vero E6 cells. Am J Transl Res 2009; 1:367-380. [PMID: 19956449 PMCID: PMC2780037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Accepted: 07/18/2009] [Indexed: 05/28/2023]
Abstract
Hantavirus (HTV) infection is known to induce innate cellular response, a more specified cellular response in the host cells. However, whether it stimulates synthesis of stress proteins, particularly associations of viral proteins, is entirely unknown. The primary focus of this research is using Vero E6 cells infected with Hantaan 76-118 (HTNV) as an in vitro infection model to examine the individual contribution of HTV infection to heat shock response. This study shows that HTNV infection rapidly induced HSP70 expression in Vero E6 cells, which underwent a nucleo-cytoplasmic shuttle that lasted for more than 3 d. The increased HSP70 was preceded by induction of HSP70 mRNA. The physical association of HSP70 with viral nucleocapsid protein (NP) in infected cells was demonstrated by co-localization and immunoprecipation. Vero E6 cells that constitutively overexpress HSP70 after stable transfection with HSP70 gene, when infected with HTNV, showed selectively reduced NP synthesis. These findings suggest HSP70 is actively involved in the control of the expression level of viral structural proteins and possibly involved in virus assembly by binding of NP to HSP70. Overexpression of HSP70 does not favor viral propagation.
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Affiliation(s)
- Lu Yu
- Department of Pathology, Xi Jing Hospital, Fourth Military Medical University Xi'an, Shaanxi 710032, China
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Cell fusion-induced activation of interferon-stimulated genes is not required for restriction of a herpes simplex virus VP16/ICP0 mutant in heterokarya formed between permissive and restrictive cells. J Virol 2009; 83:8976-9. [PMID: 19535444 DOI: 10.1128/jvi.00142-09] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Herpes simplex virus VP16 and ICP0 mutants replicate efficiently in U2OS osteosarcoma cells but are restricted in other cell types. We previously showed that the restrictive phenotype is dominant in a transient cell fusion assay, suggesting that U2OS cells lack an antiviral mechanism present in other cells. Recent data indicate that unscheduled membrane fusion events can activate the expression of interferon-stimulated genes (ISGs) in fibroblasts, raising the possibility that our earlier results were due to a fusion-induced antiviral state. However, we show here that the permissive phenotype is also extinguished following fusion with Vero cells in the absence of ISG induction.
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Abstract
Specific therapy is not available for hantavirus cardiopulmonary syndrome caused by Andes virus (ANDV). Peptides capable of blocking ANDV infection in vitro were identified using antibodies against ANDV surface glycoproteins Gn and Gc to competitively elute a cyclic nonapeptide-bearing phage display library from purified ANDV particles. Phage was examined for ANDV infection inhibition in vitro, and nonapeptides were synthesized based on the most-potent phage sequences. Three peptides showed levels of viral inhibition which were significantly increased by combination treatment with anti-Gn- and anti-Gc-targeting peptides. These peptides will be valuable tools for further development of both peptide and nonpeptide therapeutic agents.
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27
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Handke W, Oelschlegel R, Franke R, Krüger DH, Rang A. Hantaan virus triggers TLR3-dependent innate immune responses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2009; 182:2849-58. [PMID: 19234180 DOI: 10.4049/jimmunol.0802893] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Immediately after viral infection, innate responses including expression of IFN-alpha/beta and IFN-stimulated genes (ISGs) are elicited ubiquitously by recruitment of specific pathogen recognition receptors. The velocity to induce IFN-alpha/beta and ISGs in response to an infection is often decisive for virulence. Interestingly, in primary endothelial cells ISGs are induced later by hantaviruses pathogenic to humans than those considered to be nonpathogenic or of low virulence. Here we demonstrate that pathogenic Hantaan (HTNV) and putatively nonpathogenic Prospect Hill hantavirus (PHV) differentially activate innate responses in the established cell lines A549 and HuH7. STAT1alpha phosphorylation was detectable 3 h after PHV inoculation but not within the first 2 days after HTNV inoculation. The velocity to induce the ISGs MxA and ISG15 correlated inversely with amounts of virus produced. Moreover, expression of the inflammatory chemokine CCL5 was also induced differentially. Both hantaviruses induced innate responses via TRAF3 (TNF receptor-associated factor 3), and TLR3 was required for HTNV-induced expression of MxA, but not for the MxA induction triggered by PHV. Infection of RIG-I-deficient HuH7.5 cells revealed that RIG-I (retinoic acid receptor I) was not necessary for induction of innate responses by PHV. Taken together, these data suggest that HTNV and PHV elicit different signaling cascades that converge via TRAF3. Early induction of antiviral responses might contribute to efficient elimination of PHV. Subsequent to clearance of the infection, innate responses most likely cease; vice versa, retarded induction of antiviral responses could lead to increased HTNV replication and dissemination, which might cause a prolonged inflammatory response and might contribute to the in vivo virulence.
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Affiliation(s)
- Wiebke Handke
- Institute of Virology, Helmut-Ruska-Haus, University Hospital Charité, Charité Campus Mitte, Berlin, Germany
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Pergam SA, Schmidt DW, Nofchissey RA, Hunt WC, Harford AH, Goade DE. Potential renal sequelae in survivors of hantavirus cardiopulmonary syndrome. Am J Trop Med Hyg 2009; 80:279-285. [PMID: 19190227 PMCID: PMC2706524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Although other hantaviruses are associated with renal manifestations, hantavirus cardiopulmonary syndrome (HCPS) has not been associated with such sequelae. The HCPS survivors were prospectively evaluated for renal complications. Subjects underwent yearly evaluation, laboratory studies, and 24-hour urine collection. Thirty subjects were evaluated after recovery from HCPS with the first follow-up at a median of 7.4 months after discharge. Subjects were a wide age range (18-51) but had an equal gender composition. Eighteen of 30 (60%) returned for > 1 evaluation. Half (15/30) had a 24-hour urine collection with > 150 mg of total protein and 6 had > 300 mg. Seven had a Cockcroft-Gault creatinine clearance (CrClCG) < 90 mL/min/1.73 m2 and 2 were < 60. Fifty-three percent met the definition of chronic kidney disease. Those treated with extracorporeal membrane oxygenation had less renal sequelae (P = 0.035). Our data suggest that renal sequelae may occur in HCPS. Further study of renal complications of New World hantavirus infections are needed.
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Affiliation(s)
- Steven A Pergam
- Department of Medicine, University of Washington, Seattle, Washington, USA.
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Abstract
Hantaviruses, similar to several emerging zoonotic viruses, persistently infect their natural reservoir hosts, without causing overt signs of disease. Spillover to incidental human hosts results in morbidity and mortality mediated by excessive proinflammatory and cellular immune responses. The mechanisms mediating the persistence of hantaviruses and the absence of clinical symptoms in rodent reservoirs are only starting to be uncovered. Recent studies indicate that during hantavirus infection, proinflammatory and antiviral responses are reduced and regulatory responses are elevated at sites of increased virus replication in rodents. The recent discovery of structural and non-structural proteins that suppress type I interferon responses in humans suggests that immune responses in rodent hosts could be mediated directly by the virus. Alternatively, several host factors, including sex steroids, glucocorticoids, and genetic factors, are reported to alter host susceptibility and may contribute to persistence of hantaviruses in rodents. Humans and reservoir hosts differ in infection outcomes and in immune responses to hantavirus infection; thus, understanding the mechanisms mediating viral persistence and the absence of disease in rodents may provide insight into the prevention and treatment of disease in humans. Consideration of the coevolutionary mechanisms mediating hantaviral persistence and rodent host survival is providing insight into the mechanisms by which zoonotic viruses have remained in the environment for millions of years and continue to be transmitted to humans.
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Affiliation(s)
- Judith D. Easterbrook
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Sabra L. Klein
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail:
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Characterization of the interferon regulatory factor 3-mediated antiviral response in a cell line deficient for IFN production. Mol Immunol 2008; 46:393-9. [PMID: 19038458 DOI: 10.1016/j.molimm.2008.10.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Accepted: 10/14/2008] [Indexed: 12/24/2022]
Abstract
The innate cellular response to virus particle entry in non-immune cells requires the transcriptional activity of interferon regulatory factor 3 (IRF-3), but not production of type I interferon (IFN). Here, we characterize the IFN-independent innate cellular response to virus-derived stimuli in Vero cells, a monkey kidney epithelial cell line deficient for IFN production. We provide evidence that Vero cells are deficient in their ability to mount an IRF-3-dependent, IFN-independent antiviral response against either incoming virus particles or polyinosinic:polycytidylic acid (pIC), a dsRNA mimetic. We further demonstrate that abundance of IRF-3 protein is a determinant in the pIC-mediated antiviral signalling pathway. These observations further characterize the permissive nature of Vero cells to viral infection, and highlight the crucial involvement of IRF-3 in the innate antiviral response.
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Hantaan virus nucleocapsid protein binds to importin alpha proteins and inhibits tumor necrosis factor alpha-induced activation of nuclear factor kappa B. J Virol 2008; 83:1271-9. [PMID: 19019947 DOI: 10.1128/jvi.00986-08] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Hantaviruses such as Hantaan virus (HTNV) and Andes virus cause two human diseases, hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome, respectively. For both, disease pathogenesis is thought to be immunologically mediated and there have been numerous reports of patients with elevated levels of proinflammatory and inflammatory cytokines, including tumor necrosis factor alpha (TNF-alpha), in their sera. Multiple viruses have developed evasion strategies to circumvent the host cell inflammatory process, with one of the most prevalent being the disruption of nuclear factor kappa B (NF-kappaB) activation. We hypothesized that hantaviruses might also moderate host inflammation by interfering with this pathway. We report here that the nucleocapsid (N) protein of HTNV was able to inhibit TNF-alpha-induced activation of NF-kappaB, as measured by a reporter assay, and the activation of endogenous p65, an NF-kappaB subunit. Surprisingly, there was no defect in the degradation of the inhibitor of NF-kappaB (IkappaB) protein, nor was there any alteration in the level of p65 expression in HTNV N-expressing cells. However, immunofluorescence antibody staining demonstrated that cells expressing HTNV N protein and a green fluorescent protein-p65 fusion had limited p65 nuclear translocation. Furthermore, we were able to detect an interaction between HTNV N protein and importin alpha, a nuclear import molecule responsible for shuttling NF-kappaB to the nucleus. Collectively, our data suggest that HTNV N protein can sequester NF-kappaB in the cytoplasm, thus inhibiting NF-kappaB activity. These findings, which were obtained using cells transfected with cDNA representing the HTNV N gene, were confirmed using HTNV-infected cells.
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Dinwiddie DL, Harrod KS. Human Metapneumovirus Inhibits IFN-α Signaling through Inhibition of STAT1 Phosphorylation. Am J Respir Cell Mol Biol 2008; 38:661-70. [DOI: 10.1165/rcmb.2007-0285oc] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Multivalent presentation of antihantavirus peptides on nanoparticles enhances infection blockade. Antimicrob Agents Chemother 2008; 52:2079-88. [PMID: 18391034 DOI: 10.1128/aac.01415-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Viral entry into susceptible host cells typically results from multivalent interactions between viral surface proteins and host entry receptors. In the case of Sin Nombre virus (SNV), a New World hantavirus that causes hantavirus cardiopulmonary syndrome, infection involves the interaction between viral membrane surface glycoproteins and the human integrin alpha(v)beta(3). Currently, there are no therapeutic agents available which specifically target SNV. To address this problem, we used phage display selection of cyclic nonapeptides to identify peptides that bound SNV and specifically prevented SNV infection in vitro. We synthesized cyclic nonapeptides based on peptide sequences of phage demonstrating the strongest inhibition of infection, and in all cases, the isolated peptides were less effective at blocking infection (9.0% to 27.6% inhibition) than were the same peptides presented by phage (74.0% to 82.6% inhibition). Since peptides presented by the phage were pentavalent, we determined whether the identified peptides would show greater inhibition if presented in a multivalent format. We used carboxyl linkages to conjugate selected cyclic peptides to multivalent nanoparticles and tested infection inhibition. Two of the peptides, CLVRNLAWC and CQATTARNC, showed inhibition that was improved over that of the free format when presented on nanoparticles at a 4:1 nanoparticle-to-virus ratio (9.0% to 32.5% and 27.6% to 37.6%, respectively), with CQATTARNC inhibition surpassing 50% when nanoparticles were used at a 20:1 ratio versus virus. These data illustrate that multivalent inhibitors may disrupt polyvalent protein-protein interactions, such as those utilized for viral infection of host cells, and may represent a useful therapeutic approach.
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Jääskeläinen KM, Plyusnina A, Lundkvist A, Vaheri A, Plyusnin A. Tula hantavirus isolate with the full-length ORF for nonstructural protein NSs survives for more consequent passages in interferon-competent cells than the isolate having truncated NSs ORF. Virol J 2008; 5:3. [PMID: 18190677 PMCID: PMC2253529 DOI: 10.1186/1743-422x-5-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Accepted: 01/11/2008] [Indexed: 01/02/2023] Open
Abstract
Background The competitiveness of two Tula hantavirus (TULV) isolates, TULV/Lodz and TULV/Moravia, was evaluated in interferon (IFN) -competent and IFN-deficient cells. The two isolates differ in the length of the open reading frame (ORF) encoding the nonstructural protein NSs, which has previously been shown to inhibit IFN response in infected cells. Results In IFN-deficient Vero E6 cells both TULV isolates survived equally well. In contrast, in IFN-competent MRC5 cells TULV/Lodz isolate, that possesses the NSs ORF for the full-length protein of 90 aa, survived for more consequent passages than TULV/Moravia isolate, which contains the ORF for truncated NSs protein (66–67 aa). Conclusion Our data show that expression of a full-length NSs protein is beneficial for the virus survival and competitiveness in IFN-competent cells and not essential in IFN-deficient cells. These results suggest that the N-terminal aa residues are important for the full activity of the NSs protein.
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Affiliation(s)
- Kirsi M Jääskeläinen
- Department of Virology, Haartman Institute, PO Box 21, FIN-00014 University of Helsinki, Helsinki, Finland.
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Jääskeläinen KM, Kaukinen P, Minskaya ES, Plyusnina A, Vapalahti O, Elliott RM, Weber F, Vaheri A, Plyusnin A. Tula and Puumala hantavirus NSs ORFs are functional and the products inhibit activation of the interferon-beta promoter. J Med Virol 2007; 79:1527-36. [PMID: 17705180 DOI: 10.1002/jmv.20948] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The S RNA genome segment of hantaviruses carried by Arvicolinae and Sigmodontinae rodents encodes the nucleocapsid (N) protein and has an overlapping (+1) open reading frame (ORF) for a putative nonstructural protein (NSs). The aim of this study was to determine whether the ORF is functional. A protein corresponding to the predicted size of Tula virus (TULV) NSs was detected using coupled in vitro transcription and translation from a cloned S segment cDNA, and a protein corresponding to the predicted size of Puumala virus (PUUV) NSs was detected in infected cells by Western blotting with an anti-peptide serum. The activities of the interferon beta (IFN-beta) promoter, and nuclear factor kappa B (NF-kappaB)- and interferon regulatory factor-3 (IRF-3) responsive promoters, were inhibited in COS-7 cells transiently expressing TULV or PUUV NSs. Also IFN-beta mRNA levels in IFN-competent MRC5 cells either infected with TULV or transiently expressing NSs were decreased. These data demonstrate that Tula and Puumala hantaviruses have a functional NSs ORF. The findings may explain why the NSs ORF has been preserved in the genome of most hantaviruses during their long evolution and why hantavirus-infected cells secrete relatively low levels of IFNs.
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Affiliation(s)
- Kirsi M Jääskeläinen
- Department of Virology, Haartman Institute, FIN-00014 University of Helsinki, Finland
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Schountz T, Prescott J, Cogswell AC, Oko L, Mirowsky-Garcia K, Galvez AP, Hjelle B. Regulatory T cell-like responses in deer mice persistently infected with Sin Nombre virus. Proc Natl Acad Sci U S A 2007; 104:15496-501. [PMID: 17875986 PMCID: PMC2000535 DOI: 10.1073/pnas.0707454104] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Indexed: 12/11/2022] Open
Abstract
Hantavirus cardiopulmonary syndrome is a zoonotic illness associated with a systemic inflammatory immune response, capillary leak, noncardiogenic pulmonary edema, and shock in humans. Cytokines, including TNF, IFN-gamma, and lymphotoxin, are thought to contribute to its pathogenesis. In contrast, infected rodent reservoirs of hantaviruses experience few or no pathologic changes and the host rodent can remain persistently infected for life. Generally, it is unknown why such dichotomous immune responses occur between humans and reservoir hosts. Thus, we examined CD4(+) T cell responses from one such reservoir, the deer mouse (Peromyscus maniculatus), infected with Sin Nombre virus. Proliferation responses to viral nucleocapsid antigen were relatively weak in T cells isolated from deer mice, regardless of acute or persistent infection. The T cells from acutely infected deer mice synthesized a broad spectrum of cytokines, including IFN-gamma, IL-4, IL-5, and TGF-beta(1), but not TNF, lymphotoxin, or IL-17. However, in T cells from persistently infected deer mice, only TGF-beta(1) was expressed by all lines, whereas some expressed reduced levels of IFN-gamma or IL-5. The Forkhead box P3 transcription factor, a marker of some regulatory T cells, was expressed by most of these cells. Collectively, these data suggest that TGF-beta(1)-expressing regulatory T cells may play an important role in limiting immunopathology in the natural reservoir host, but this response may interfere with viral clearance. Such a response may have arisen as a mutually beneficial coadaptive evolutionary event between hantaviruses and their rodent reservoirs, so as to limit disease while also allowing the virus to persist.
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Affiliation(s)
- Tony Schountz
- School of Biological Sciences, University of Northern Colorado, 1556 Ross Hall, Greeley, CO 80639, USA.
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Stoltz M, Ahlm C, Lundkvist A, Klingström J. Lambda interferon (IFN-lambda) in serum is decreased in hantavirus-infected patients, and in vitro-established infection is insensitive to treatment with all IFNs and inhibits IFN-gamma-induced nitric oxide production. J Virol 2007; 81:8685-91. [PMID: 17522204 PMCID: PMC1951347 DOI: 10.1128/jvi.00415-07] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Accepted: 05/16/2007] [Indexed: 12/22/2022] Open
Abstract
Hantaviruses, causing hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS), are known to be sensitive to nitric oxide (NO) and to pretreatment with type I and II interferons (alpha interferon [IFN-alpha]/IFN-beta and IFN-gamma, respectively). Elevated serum levels of NO and IFN-gamma have been observed in HFRS patients, but little is known regarding the systemic levels of other IFNs and the possible effects of hantaviruses on innate antiviral immune responses. In Puumala virus-infected HFRS patients (n = 18), we report that the levels of IFN-alpha and IFN-beta are similar, whereas the level of IFN-lambda (type III IFN) is significantly decreased, during acute (day of hospitalization) compared to the convalescent phase. The possible antiviral effects of IFN-lambda on the prototypic hantavirus Hantaan virus (HTNV) replication was then investigated. Pretreatment of A549 cells with IFN-lambda alone inhibited HTNV replication, and IFN-lambda combined with IFN-gamma induced additive antiviral effects. We then studied the effect of postinfection treatment with IFNs. Interestingly, an already-established HTNV infection was insensitive to subsequent IFN-alpha, -beta, -gamma, and -lambda stimulation, and HTNV-infected cells produced less NO compared to noninfected cells when stimulated with IFN-gamma and IL-1beta. Furthermore, less phosphorylated STAT1 after IFN treatment was observed in the nuclei of infected cells than in those of noninfected cells. The results suggest that hantavirus can interfere with the activation of antiviral innate immune responses in patients and inhibit the antiviral effects of all IFNs. We believe that future studies addressing the mechanisms by which hantaviruses interfere with the activation and shaping of immune responses may bring more knowledge regarding HFRS and HCPS pathogenesis.
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Affiliation(s)
- Malin Stoltz
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, S-171 77 Stockholm, Sweden
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38
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Prescott JB, Hall PR, Bondu-Hawkins VS, Ye C, Hjelle B. Early innate immune responses to Sin Nombre hantavirus occur independently of IFN regulatory factor 3, characterized pattern recognition receptors, and viral entry. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2007; 179:1796-802. [PMID: 17641046 DOI: 10.4049/jimmunol.179.3.1796] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Sin Nombre virus (SNV) is a highly pathogenic New World virus and etiologic agent of hantavirus cardiopulmonary syndrome. We have previously shown that replication-defective virus particles are able to induce a strong IFN-stimulated gene (ISG) response in human primary cells. RNA viruses often stimulate the innate immune response by interactions between viral nucleic acids, acting as a pathogen-associated molecular pattern, and cellular pattern-recognition receptors (PRRs). Ligand binding to PRRs activates transcription factors which regulate the expression of antiviral genes, and in all systems examined thus far, IFN regulatory factor 3 (IRF3) has been described as an essential intermediate for induction of ISG expression. However, we now describe a model in which IRF3 is dispensable for the induction of ISG transcription in response to viral particles. IRF3-independent ISG transcription in human hepatoma cell lines is initiated early after exposure to SNV virus particles in an entry- and replication-independent fashion. Furthermore, using gene knockdown, we discovered that this activation is independent of the best-characterized RNA- and protein-sensing PRRs including the cytoplasmic caspase recruitment domain-containing RNA helicases and the TLRs. SNV particles engage a heretofore unrecognized PRR, likely located at the cell surface, and engage a novel IRF3-independent pathway that activates the innate immune response.
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Affiliation(s)
- Joseph B Prescott
- Department of Pathology, Center for Infectious Diseases and Immunity, School of Medicine, University of New Mexico, Albuquerque, NM 87131, USA
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Müller S, Geffers R, Günther S. Analysis of gene expression in Lassa virus-infected HuH-7 cells. J Gen Virol 2007; 88:1568-1575. [PMID: 17412988 DOI: 10.1099/vir.0.82529-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The pathogenesis of Lassa fever is poorly understood. As the liver is a major target organ of Lassa virus, gene expression in Lassa virus-infected HuH-7 cells, a differentiated human hepatoma cell line, was studied. Cellular mRNA levels were measured at the late phase of acute infection, when virtually all cells expressed large amounts of nucleoprotein, and virus RNA concentration had reached>10(8) copies (ml supernatant)-1. Two types of transcription array were used: cDNA-based macroarrays with a set of 3500 genes (Atlas Human 1.2 arrays; Clontech) and oligonucleotide-based microarrays covering 18,400 transcripts (Human Genome U133A array; Affymetrix). Data analysis was based on statistical frameworks controlling the false-discovery rate. Atlas array data were considered relevant if they could be verified by U133A array or real-time RT-PCR. According to these criteria, there was no evidence for true changes in gene expression. Considering the precision of the U133A array and the number of replicates tested, potential expression changes due to Lassa virus infection are probably smaller than twofold. To substantiate the array data, beta interferon (IFN-beta) gene expression was studied longitudinally in Lassa virus-infected HuH-7 and FRhK-4 cells by using real-time RT-PCR. IFN-beta mRNA levels increased only twofold upon Lassa virus infection, although there was no evidence that the virus inhibited poly(I:C)-induced IFN-beta gene expression. In conclusion, Lassa virus interferes only minimally with gene expression in HuH-7 cells and poorly induces IFN-beta gene transcription.
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Affiliation(s)
- Stefanie Müller
- Department of Virology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Robert Geffers
- Mucosal Immunity Group, German Research Centre for Biotechnology, 38124 Braunschweig, Germany
| | - Stephan Günther
- Department of Virology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
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Holzinger D, Jorns C, Stertz S, Boisson-Dupuis S, Thimme R, Weidmann M, Casanova JL, Haller O, Kochs G. Induction of MxA gene expression by influenza A virus requires type I or type III interferon signaling. J Virol 2007; 81:7776-85. [PMID: 17494065 PMCID: PMC1933351 DOI: 10.1128/jvi.00546-06] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The human MxA gene belongs to the class of interferon (IFN)-stimulated genes (ISGs) involved in antiviral resistance against influenza viruses. Here, we studied the requirements for MxA induction by influenza A virus infection. MxA is transcriptionally upregulated by type I (alpha and beta) and type III (lambda) IFNs. Therefore, MxA is widely used in gene expression studies as a reliable marker for IFN bioactivity. It is not known, however, whether viruses can directly activate MxA expression in the absence of secreted IFN. By using an NS1-deficient influenza A virus and human cells with defects in IFN production or the STAT1 gene, we studied the induction profile of MxA by real-time reverse transcriptase PCR. The NS1-deficient virus is known to be a strong activator of the IFN system because NS1 acts as a viral IFN-antagonistic protein. Nevertheless, MxA gene expression was not inducible by this virus upon infection of IFN nonproducer cells and STAT1-null cells. Likewise, neither IFN-alpha nor IFN-lambda had a sizeable effect on the STAT1-null cells, indicating that MxA expression requires STAT1 signaling and cannot be triggered directly by virus infection. In contrast, the expression of the IFN-stimulated gene ISG56 was induced by influenza virus in these cells, confirming that ISG56 differs from MxA in being directly inducible by viral triggers in an IFN-independent way. In summary, our study reveals that MxA is a unique marker for the detection of type I and type III IFN activity during virus infections and IFN therapy.
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Affiliation(s)
- Dirk Holzinger
- Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Hermann-Herder-Strasse 11, D-79104 Freiburg, Germany
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Spiropoulou CF, Albariño CG, Ksiazek TG, Rollin PE. Andes and Prospect Hill hantaviruses differ in early induction of interferon although both can downregulate interferon signaling. J Virol 2007; 81:2769-76. [PMID: 17202220 PMCID: PMC1866013 DOI: 10.1128/jvi.02402-06] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hantavirus pulmonary syndrome (HPS) is a severe respiratory disease which is thought to result from a dysregulated immune response to infection with pathogenic hantaviruses, such as Sin Nombre virus or Andes virus (ANDV). Other New World hantaviruses, such as Prospect Hill virus (PHV), have not been associated with human disease. Activation of an antiviral state and cell signaling in response to hantavirus infection were examined using human primary lung endothelial cells, the main target cell infected in HPS patients. PHV, but not ANDV, was found to induce a robust beta interferon (IFN-beta) response early after infection of primary lung endothelial cells. The level of IFN induction correlated with IFN regulatory factor 3 (IRF-3) activation, in that IRF-3 dimerization and nuclear translocation were detected in PHV but not ANDV infection. In addition, phosphorylated Stat-1/2 levels were significantly lower in the ANDV-infected cells relative to PHV. Presumably, this reflects the lower level of IRF-3 activation and initial IFN induced by ANDV relative to PHV. To determine whether, in addition, ANDV interference with IFN signaling also contributed to the low Stat-1/2 activation seen in ANDV infection, the levels of exogenous IFN-beta-induced Stat-1/2 activation detectable in uninfected versus ANDV- or PHV-infected Vero-E6 cells were examined. Surprisingly, both viruses were found to downregulate IFN-induced Stat-1/2 activation. Analysis of cells transiently expressing only ANDV or PHV glycoproteins implicated these proteins in this downregulation. In conclusion, while both viruses can interfere with IFN signaling, there is a major difference in the initial interferon induction via IRF-3 activation between ANDV and PHV in infected primary endothelial cells, and this correlates with the reported differences in pathogenicity of these viruses.
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Affiliation(s)
- Christina F Spiropoulou
- Special Pathogens Branch, G-14, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA.
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42
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Alff PJ, Gavrilovskaya IN, Gorbunova E, Endriss K, Chong Y, Geimonen E, Sen N, Reich NC, Mackow ER. The pathogenic NY-1 hantavirus G1 cytoplasmic tail inhibits RIG-I- and TBK-1-directed interferon responses. J Virol 2006; 80:9676-86. [PMID: 16973572 PMCID: PMC1617216 DOI: 10.1128/jvi.00508-06] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hantaviruses cause two diseases with prominent vascular permeability defects, hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. All hantaviruses infect human endothelial cells, although it is unclear what differentiates pathogenic from nonpathogenic hantaviruses. We observed dramatic differences in interferon-specific transcriptional responses between pathogenic and nonpathogenic hantaviruses at 1 day postinfection, suggesting that hantavirus pathogenesis may in part be determined by viral regulation of cellular interferon responses. In contrast to pathogenic NY-1 virus (NY-1V) and Hantaan virus (HTNV), nonpathogenic Prospect Hill virus (PHV) elicits early interferon responses following infection of human endothelial cells. We determined that PHV replication is blocked in human endothelial cells and that RNA and protein synthesis by PHV, but not NY-1V or HTNV, is inhibited at 2 to 4 days postinfection. The addition of antibodies to beta interferon (IFN-beta) blocked interferon-directed MxA induction by >90% and demonstrated that hantavirus infection induces the secretion of IFN-beta from endothelial cells. Coinfecting endothelial cells with NY-1V and PHV resulted in a 60% decrease in the induction of interferon-responsive MxA transcripts by PHV and further suggested the potential for NY-1V to regulate early IFN responses. Expression of the NY-1V G1 cytoplasmic tail inhibited by >90% RIG-I- and downstream TBK-1-directed transcription from interferon-stimulated response elements or beta-interferon promoters in a dose-dependent manner. In contrast, expression of the NY-1V nucleocapsid or PHV G1 tail had no effect on RIG-I- or TBK-1-directed transcriptional responses. Further, neither the NY-1V nor PHV G1 tails inhibited transcriptional responses directed by a constitutively active form of interferon regulatory factor 3 (IRF-3 5D), and IRF-3 is a direct target of TBK-1 phosphorylation. These findings indicate that the pathogenic NY-1V G1 protein regulates cellular IFN responses upstream of IRF-3 phosphorylation at the level of the TBK-1 complex. These findings further suggest that the G1 cytoplasmic tail contains a virulence element which determines the ability of hantaviruses to bypass innate cellular immune responses and delineates a mechanism for pathogenic hantaviruses to successfully replicate within human endothelial cells.
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Affiliation(s)
- Peter J Alff
- Molecular and Cellular Biology Graduate Program, SUNY at Stony Brook, Stony Brook, NY 11794, USA
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Abstract
PURPOSE OF REVIEW In many cases, the specific pathogen responsible for a respiratory infection is not identified and can lead to improper medical treatment, increased duration of illness, and possibly contributes to the development of antibiotic resistance. Molecular-based diagnostic methodologies have significantly improved our ability to identify common respiratory pathogens; these techniques are not useful, however, when a novel pathogen is responsible for the infection and clinicians must rely on differential diagnosis for the treatment of patients. RECENT FINDINGS New pathogens previously not associated with human infections have been identified in the past few years. In addition, new strains of bacteria and viruses have emerged as the causative agents of pneumonia and acute respiratory distress. Protozoans and saprophytic fungi, which are not normally associated with respiratory infection, have also emerged as respiratory pathogens particularly in individuals with AIDS or in those who are otherwise immunocompromised. SUMMARY This review discusses the recent literature on newly described respiratory pathogens as well as opportunistic pathogens that can infect the respiratory system of immunocompromised individuals. The studies referenced here reveal the need for expanded laboratory tests and highly trained microbiologists in clinical laboratories worldwide.
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Affiliation(s)
- John A Lednicky
- Life Sciences Division, Midwest Research Institute, Kansas City, Missouri, USA.
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