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An H, Yu X, Liu Y, Fang L, Shu M, Zhai Q, Chen J. Downregulation of transcription 1 hinders the replication of Dabie bandavirus by promoting the expression of TLR7, TLR8, and TLR9 signaling pathway. Ticks Tick Borne Dis 2024; 15:102307. [PMID: 38194758 DOI: 10.1016/j.ttbdis.2023.102307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 12/15/2023] [Accepted: 12/28/2023] [Indexed: 01/11/2024]
Abstract
Severe fever with thrombocytopenia syndrome virus (SFTSV) is a bunyavirus that causes SFTS, with a case fatality rate of up to 30 %. The innate immune system plays a crucial role in the defense against SFTSV; however, the impact of viral propagation of STFSV on the innate immune system remains unclear. Although proteomics analysis revealed that the expression of the downregulator of transcription 1 (DR1) increased after SFTSV infection, the specific change trend and the functional role of DR1 during viral infection remain unelucidated. In this study, we demonstrate that DR1 was highly expressed in response to SFTSV infection in HEK 293T cells using qRT-PCR and Western blot analysis. Furthermore, viral replication significantly increased the expression of various TLRs, especially TLR9. Our data indicated that DR1 positively regulated the expression of TLRs in HEK 293T cells, DR1 overexpression highly increased the expression of numerous TLRs, whereas RNAi-mediated DR1 silencing decreased TLR expression. Additionally, the myeloid differentiation primary response gene 88 (MyD88)-dependent or TIR-domain-containing adaptor inducing interferon-β (TRIF)-dependent signaling pathways were highly up- and downregulated by the overexpression and silencing of DR1, respectively. Finally, we report that DR1 stimulates the expression of TLR7, TLR8, and TLR9, thereby upregulating the TRIF-dependent and MyD88-dependent signaling pathways during the SFTSV infection, attenuating viral replication, and enhancing the production of type I interferon and various inflammatory factors, including IL-1β, IL-6, and IL-8. These results imply that DR1 defends against SFTSV replication by inducing the expression of TLR7, TLR8, and TLR9. Collectively, our findings revealed a novel role and mechanism of DR1 in mediating antiviral responses and innate immunity.
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Affiliation(s)
- Hao An
- School of Public Health, Weifang Medical University, Weifang 261053, China
| | - Xiaoli Yu
- School of Public Health, Weifang Medical University, Weifang 261053, China
| | - Yumei Liu
- School of Public Health, Weifang Medical University, Weifang 261053, China
| | - Lei Fang
- School of Public Health, Weifang Medical University, Weifang 261053, China
| | - Ming Shu
- School of Public Health, Weifang Medical University, Weifang 261053, China
| | - Qingfeng Zhai
- School of Public Health, Weifang Medical University, Weifang 261053, China
| | - Junhao Chen
- School of Public Health, Weifang Medical University, Weifang 261053, China.
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2
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Li YH, Wang XH, Huang WW, Tian RR, Pang W, Zheng YT. Severe fever with thrombocytopenia syndrome virus induces platelet activation and apoptosis via a reactive oxygen species-dependent pathway. Redox Biol 2023; 65:102837. [PMID: 37544244 PMCID: PMC10428115 DOI: 10.1016/j.redox.2023.102837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/14/2023] [Accepted: 07/31/2023] [Indexed: 08/08/2023] Open
Abstract
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by the SFTS virus (SFTSV) and with a high fatality rate. Thrombocytopenia is a major clinical manifestation observed in SFTS patients, but the underlying mechanism remains largely unclear. Here, we explored the effects of SFTSV infection on platelet function in vivo in severely infected SFTSV IFNar-/- mice and on mouse and human platelet function in vitro. Results showed that SFTSV-induced platelet clearance acceleration may be the main reason for thrombocytopenia. SFTSV-potentiated platelet activation and apoptosis were also observed in infected mice. Further investigation showed that SFTSV infection induced platelet reactive oxygen species (ROS) production and mitochondrial dysfunction. In vitro experiments revealed that administration of SFTSV or SFTSV glycoprotein (Gn) increased activation, apoptosis, ROS production, and mitochondrial dysfunction in separated mouse platelets, which could be effectively ameliorated by the application of antioxidants (NAC (N-acetyl-l-cysteine), SKQ1 (10-(6'-plastoquinonyl) decyltriphenylphosphonium) and resveratrol). In vivo experiments showed that the antioxidants partially rescued SFTSV infection-induced thrombocytopenia by improving excessive ROS production and mitochondrial dysfunction and down-regulating platelet apoptosis and activation. Furthermore, while SFTSV and Gn directly potentiated human platelet activation, it was completely abolished by antioxidants. This study revealed that SFTSV and Gn can directly trigger platelet activation and apoptosis in an ROS-MAPK-dependent manner, which may contribute to thrombocytopenia and hemorrhage during infection, but can be abolished by antioxidants.
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Affiliation(s)
- Yi-Hui Li
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xue-Hui Wang
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China; Department of Pediatric Intensive Care Unit, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China
| | - Wen-Wu Huang
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China; Office of Science and Technology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Ren-Rong Tian
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Wei Pang
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Yong-Tang Zheng
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China.
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3
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Schwarz MM, Price DA, Ganaie SS, Feng A, Mishra N, Hoehl RM, Fatma F, Stubbs SH, Whelan SPJ, Cui X, Egawa T, Leung DW, Amarasinghe GK, Hartman AL. Oropouche orthobunyavirus infection is mediated by the cellular host factor Lrp1. Proc Natl Acad Sci U S A 2022; 119:e2204706119. [PMID: 35939689 PMCID: PMC9388146 DOI: 10.1073/pnas.2204706119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/17/2022] [Indexed: 11/18/2022] Open
Abstract
Oropouche orthobunyavirus (OROV; Peribunyaviridae) is a mosquito-transmitted virus that causes widespread human febrile illness in South America, with occasional progression to neurologic effects. Host factors mediating the cellular entry of OROV are undefined. Here, we show that OROV uses the host protein low-density lipoprotein-related protein 1 (Lrp1) for efficient cellular infection. Cells from evolutionarily distinct species lacking Lrp1 were less permissive to OROV infection than cells with Lrp1. Treatment of cells with either the high-affinity Lrp1 ligand receptor-associated protein (RAP) or recombinant ectodomain truncations of Lrp1 significantly reduced OROV infection. In addition, chimeric vesicular stomatitis virus (VSV) expressing OROV glycoproteins (VSV-OROV) bound to the Lrp1 ectodomain in vitro. Furthermore, we demonstrate the biological relevance of the OROV-Lrp1 interaction in a proof-of-concept mouse study in which treatment of mice with RAP at the time of infection reduced tissue viral load and promoted survival from an otherwise lethal infection. These results with OROV, along with the recent finding of Lrp1 as an entry factor for Rift Valley fever virus, highlight the broader significance of Lrp1 in cellular infection by diverse bunyaviruses. Shared strategies for entry, such as the critical function of Lrp1 defined here, provide a foundation for the development of pan-bunyaviral therapeutics.
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Affiliation(s)
- Madeline M. Schwarz
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213
- Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15213
| | - David A. Price
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Safder S. Ganaie
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Annie Feng
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Nawneet Mishra
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Ryan M. Hoehl
- Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15213
| | - Farheen Fatma
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Sarah H. Stubbs
- Department of Microbiology, Harvard Medical School, Boston, MA, 02115
| | - Sean P. J. Whelan
- Department of Molecular Microbiology, Washington University, St. Louis, MO, 63110
| | - Xiaoxia Cui
- Genome Engineering & Stem Cell Center (GESC@MGI), Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Takeshi Egawa
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Daisy W. Leung
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Amy L. Hartman
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213
- Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15213
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4
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Abstract
Nuclear scaffold attachment factor A (SAFA) is a novel RNA sensor involved in sensing viral RNA in the nucleus and mediating antiviral immunity. Severe fever with thrombocytopenia syndrome virus (SFTSV) is a bunyavirus that causes SFTS with a high fatality rate of up to 30%. It remains elusive whether and how cytoplasmic SFTSV can be sensed by the RNA sensor SAFA. Here, we demonstrated that SAFA was able to detect SFTSV infection and mediate antiviral interferon and inflammatory responses. Transcription and expression levels of SAFA were strikingly upregulated under SFTSV infection. SAFA was retained in the cytoplasm by interaction with SFTSV nucleocapsid protein (NP). Importantly, SFTSV genomic RNA was recognized by cytoplasmic SAFA, which recruited and promoted activation of the STING-TBK1 signaling axis against SFTSV infection. Of note, the nuclear localization signal (NLS) domain of SAFA was important for interaction with SFTSV NP and recognition of SFTSV RNA in the cytoplasm. In conclusion, our study reveals a novel antiviral mechanism in which SAFA functions as a novel cytoplasmic RNA sensor that directly recognizes RNA virus SFTSV and mediates an antiviral response. Severe fever with thrombocytopenia syndrome virus (SFTSV) is an RNA virus with a high fatality rate of up to 30%, which replicates exclusively in the cytoplasm. To date, many cytoplasmic RNA sensors were known to recognize SFTSV infection and trigger antiviral immune responses. Nuclear scaffold attachment factor A (SAFA) is a novel nuclear RNA sensor which can sense viral RNA in the nucleus and promote activation of antiviral immunity. However, there are no studies to investigate whether SAFA could detect cytoplasmic RNA virus infection. Here, we reported that SAFA was able to detect RNA virus SFTSV invasion. Under SFTSV infection, SAFA was retained in the cytoplasm and recognized SFTSV infection by interaction with SFTSV nucleocapsid protein (NP) and cytoplasmic SFTSV RNA directly. Importantly, SAFA recruited and promoted the activation of the STING-TBK1 signaling pathway-mediated antiviral immunity to suppress SFTSV infection. This study provides a further acquaintance in SAFA-mediated antiviral immune responses, illustrating the novel role of SAFA in sensing cytoplasmic SFTSV and mediates an antiviral response.
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Affiliation(s)
- Bin-yan Liu
- State Key Laboratory of Virology, School of Public Health, Wuhan University, Wuhan, P.R. China
| | - Xue-jie Yu
- State Key Laboratory of Virology, School of Public Health, Wuhan University, Wuhan, P.R. China
- * E-mail: (XY); (C-mZ)
| | - Chuan-min Zhou
- State Key Laboratory of Virology, School of Public Health, Wuhan University, Wuhan, P.R. China
- * E-mail: (XY); (C-mZ)
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5
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Hulswit RJG, Paesen GC, Bowden TA, Shi X. Recent Advances in Bunyavirus Glycoprotein Research: Precursor Processing, Receptor Binding and Structure. Viruses 2021; 13:353. [PMID: 33672327 PMCID: PMC7926653 DOI: 10.3390/v13020353] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 01/04/2023] Open
Abstract
The Bunyavirales order accommodates related viruses (bunyaviruses) with segmented, linear, single-stranded, negative- or ambi-sense RNA genomes. Their glycoproteins form capsomeric projections or spikes on the virion surface and play a crucial role in virus entry, assembly, morphogenesis. Bunyavirus glycoproteins are encoded by a single RNA segment as a polyprotein precursor that is co- and post-translationally cleaved by host cell enzymes to yield two mature glycoproteins, Gn and Gc (or GP1 and GP2 in arenaviruses). These glycoproteins undergo extensive N-linked glycosylation and despite their cleavage, remain associated to the virion to form an integral transmembrane glycoprotein complex. This review summarizes recent advances in our understanding of the molecular biology of bunyavirus glycoproteins, including their processing, structure, and known interactions with host factors that facilitate cell entry.
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Affiliation(s)
- Ruben J. G. Hulswit
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (R.J.G.H.); (G.C.P.)
| | - Guido C. Paesen
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (R.J.G.H.); (G.C.P.)
| | - Thomas A. Bowden
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (R.J.G.H.); (G.C.P.)
| | - Xiaohong Shi
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G61 1QH, UK
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6
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Perez-Sautu U, Gu SH, Caviness K, Song DH, Kim YJ, Paola ND, Lee D, Klein TA, Chitty JA, Nagle E, Kim HC, Chong ST, Beitzel B, Reyes DS, Finch C, Byrum R, Cooper K, Liang J, Kuhn JH, Zeng X, Kuehl KA, Coffin KM, Liu J, Oh HS, Seog W, Choi BS, Sanchez-Lockhart M, Palacios G, Jeong ST. A Model for the Production of Regulatory Grade Viral Hemorrhagic Fever Exposure Stocks: From Field Surveillance to Advanced Characterization of SFTSV. Viruses 2020; 12:v12090958. [PMID: 32872451 PMCID: PMC7552075 DOI: 10.3390/v12090958] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 02/05/2023] Open
Abstract
Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging human pathogen, endemic in areas of China, Japan, and the Korea (KOR). It is primarily transmitted through infected ticks and can cause a severe hemorrhagic fever disease with case fatality rates as high as 30%. Despite its high virulence and increasing prevalence, molecular and functional studies in situ are scarce due to the limited availability of high-titer SFTSV exposure stocks. During the course of field virologic surveillance in 2017, we detected SFTSV in ticks and in a symptomatic soldier in a KOR Army training area. SFTSV was isolated from the ticks producing a high-titer viral exposure stock. Through the use of advanced genomic tools, we present here a complete, in-depth characterization of this viral stock, including a comparison with both the virus in its arthropod source and in the human case, and an in vivo study of its pathogenicity. Thanks to this detailed characterization, this SFTSV viral exposure stock constitutes a quality biological tool for the study of this viral agent and for the development of medical countermeasures, fulfilling the requirements of the main regulatory agencies.
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Affiliation(s)
- Unai Perez-Sautu
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
| | - Se Hun Gu
- The 4th Research & Development Institute, Agency for Defense Development (ADD), Daejeon 34186, Korea; (S.H.G.); (D.H.S.); (D.L.)
| | - Katie Caviness
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
| | - Dong Hyun Song
- The 4th Research & Development Institute, Agency for Defense Development (ADD), Daejeon 34186, Korea; (S.H.G.); (D.H.S.); (D.L.)
| | - Yu-Jin Kim
- Army Headquarters, Gyeryong-si 32800, Korea; (Y.-J.K.); (B.-S.C.)
| | - Nicholas Di Paola
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
| | - Daesang Lee
- The 4th Research & Development Institute, Agency for Defense Development (ADD), Daejeon 34186, Korea; (S.H.G.); (D.H.S.); (D.L.)
| | - Terry A. Klein
- Force Health Protection and Preventive Medicine, Medical Department Activity-Korea/65th Medical Brigade, Unit 15281, APO AP 96271, USA; (T.A.K.); (H.-C.K.); (S.-T.C.)
| | - Joseph A. Chitty
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
| | - Elyse Nagle
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
| | - Heung-Chul Kim
- Force Health Protection and Preventive Medicine, Medical Department Activity-Korea/65th Medical Brigade, Unit 15281, APO AP 96271, USA; (T.A.K.); (H.-C.K.); (S.-T.C.)
| | - Sung-Tae Chong
- Force Health Protection and Preventive Medicine, Medical Department Activity-Korea/65th Medical Brigade, Unit 15281, APO AP 96271, USA; (T.A.K.); (H.-C.K.); (S.-T.C.)
| | - Brett Beitzel
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
| | - Daniel S. Reyes
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
| | - Courtney Finch
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Fort Detrick, Frederick, MD 21702, USA; (C.F.); (R.B.); (K.C.); (J.L.); (J.H.K.)
| | - Russ Byrum
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Fort Detrick, Frederick, MD 21702, USA; (C.F.); (R.B.); (K.C.); (J.L.); (J.H.K.)
| | - Kurt Cooper
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Fort Detrick, Frederick, MD 21702, USA; (C.F.); (R.B.); (K.C.); (J.L.); (J.H.K.)
| | - Janie Liang
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Fort Detrick, Frederick, MD 21702, USA; (C.F.); (R.B.); (K.C.); (J.L.); (J.H.K.)
| | - Jens H. Kuhn
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Fort Detrick, Frederick, MD 21702, USA; (C.F.); (R.B.); (K.C.); (J.L.); (J.H.K.)
| | - Xiankun Zeng
- Pathology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (X.Z.); (K.A.K.); (K.M.C.); (J.L.)
| | - Kathleen A. Kuehl
- Pathology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (X.Z.); (K.A.K.); (K.M.C.); (J.L.)
| | - Kayla M. Coffin
- Pathology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (X.Z.); (K.A.K.); (K.M.C.); (J.L.)
| | - Jun Liu
- Pathology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (X.Z.); (K.A.K.); (K.M.C.); (J.L.)
| | - Hong Sang Oh
- Armed Forces Medical Command, Seongnam-si 13590, Korea; (H.S.O.); (W.S.)
| | - Woong Seog
- Armed Forces Medical Command, Seongnam-si 13590, Korea; (H.S.O.); (W.S.)
| | - Byung-Sub Choi
- Army Headquarters, Gyeryong-si 32800, Korea; (Y.-J.K.); (B.-S.C.)
| | - Mariano Sanchez-Lockhart
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
- Department of Pathology & Microbiology, University of Nebraska Medical Centre, Omaha, NE 68198, USA
- Correspondence: (M.S.-L.); (G.P.); (S.T.J.)
| | - Gustavo Palacios
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA; (U.P.-S.); (K.C.); (N.D.P.); (J.A.C.); (E.N.); (B.B.); (D.S.R.)
- Correspondence: (M.S.-L.); (G.P.); (S.T.J.)
| | - Seong Tae Jeong
- The 4th Research & Development Institute, Agency for Defense Development (ADD), Daejeon 34186, Korea; (S.H.G.); (D.H.S.); (D.L.)
- Correspondence: (M.S.-L.); (G.P.); (S.T.J.)
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7
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Gori Savellini G, Anichini G, Gandolfo C, Prathyumnan S, Cusi MG. Toscana virus non-structural protein NSs acts as E3 ubiquitin ligase promoting RIG-I degradation. PLoS Pathog 2019; 15:e1008186. [PMID: 31815967 PMCID: PMC6901176 DOI: 10.1371/journal.ppat.1008186] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 11/04/2019] [Indexed: 01/04/2023] Open
Abstract
It is known that the non-structural protein (NSs) of Toscana virus (TOSV), an emergent sandfly-borne virus causing meningitis or more severe central nervous system injuries in humans, exerts its function triggering RIG-I for degradation in a proteasome-dependent manner, thus breaking off the IFN-β production. The non-structural protein of different members of Bunyavirales has recently appeared as a fundamental protagonist in immunity evasion through ubiquitination-mediated protein degradation targets. We showed that TOSV NSs has an E3 ubiquitin ligase activity, mapping at the carboxy-terminal domain and also involving the amino-terminal of the protein. Indeed, neither the amino- (NSsΔN) nor the carboxy- (NSsΔC) terminal-deleted mutants of TOSV NSs were able to cause ubiquitin-mediated proteasome degradation of RIG-I. Moreover, the addition of the C-terminus of TOSV NSs to the homologous protein of the Sandfly Fever Naples Virus, belonging to the same genus and unable to inhibit IFN-β activity, conferred new properties to this protein, favoring RIG-I ubiquitination and its degradation. NSs lost its antagonistic activity to IFN when one of the terminal residues was missing. Therefore, we showed that NSs could behave as an atypical RING between RING (RBR) E3 ubiquitin ligases. This is the first report which identified the E3 ubiquitin ligase activity in a viral protein among negative strand RNA viruses.
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Affiliation(s)
| | - Gabriele Anichini
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Claudia Gandolfo
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | | | - Maria Grazia Cusi
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
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8
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Geddes VEV, de Oliveira AS, Tanuri A, Arruda E, Ribeiro-Alves M, Aguiar RS. MicroRNA and cellular targets profiling reveal miR-217 and miR-576-3p as proviral factors during Oropouche infection. PLoS Negl Trop Dis 2018; 12:e0006508. [PMID: 29813068 PMCID: PMC5993330 DOI: 10.1371/journal.pntd.0006508] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 06/08/2018] [Accepted: 05/08/2018] [Indexed: 12/16/2022] Open
Abstract
Oropouche Virus is the etiological agent of an arbovirus febrile disease that affects thousands of people and is widespread throughout Central and South American countries. Although isolated in 1950’s, still there is scarce information regarding the virus biology and its prevalence is likely underestimated. In order to identify and elucidate interactions with host cells factors and increase the understanding about the Oropouche Virus biology, we performed microRNA (miRNA) and target genes screening in human hepatocarcinoma cell line HuH-7. Cellular miRNAs are short non-coding RNAs that regulates gene expression post-transcriptionally and play key roles in several steps of viral infections. The large scale RT-qPCR based screening found 13 differentially expressed miRNAs in Oropouche infected cells. Further validation confirmed that miR-217 and miR-576-3p were 5.5 fold up-regulated at early stages of virus infection (6 hours post-infection). Using bioinformatics and pathway enrichment analysis, we predicted the cellular targets genes for miR-217 and miR-576-3p. Differential expression analysis of RNA from 95 selected targets revealed genes involved in innate immunity modulation, viral release and neurological disorder outcomes. Further analysis revealed the gene of decapping protein 2 (DCP2), a previous known restriction factor for bunyaviruses transcription, as a miR-217 candidate target that is progressively down-regulated during Oropouche infection. Our analysis also showed that activators genes involved in innate immune response through IFN-β pathway, as STING (Stimulator of Interferon Genes) and TRAF3 (TNF-Receptor Associated Factor 3), were down-regulated as the infection progress. Inhibition of miR-217 or miR-576-3p restricts OROV replication, decreasing viral RNA (up to 8.3 fold) and virus titer (3 fold). Finally, we showed that virus escape IFN-β mediated immune response increasing the levels of cellular miR-576-3p resulting in a decreasing of its partners STING and TRAF3. We concluded stating that the present study, the first for a Peribunyaviridae member, gives insights in its prospective pathways that could help to understand virus biology, interactions with host cells and pathogenesis, suggesting that the virus escapes the antiviral cellular pathways increasing the expression of cognates miRNAs. Oropouche Virus causes typical arboviral febrile illness and is widely distributed in tropical region of Americas, mainly Amazon region, associated with cases of encephalitis. 500,000 people are estimated to be infected with Oropouche worldwide and some states in Brazil detected higher number of cases among other arboviruses such as Dengue and Chikungunya. As much as climate change, human migration and vector and host availability might increase the risk of virus transmission. Despite its estimated high prevalence in Central and South America populations, the literature concerning the main aspects of viral biology remain scarce and began to be investigated only in the last two decades. Nonetheless, little is known about virus-host cell interactions and pathogenesis. Virus infection regulates cellular pathways either promoting its replication or escaping from immune response through microRNAs. Knowing which microRNAs and target genes are modulated in infection could give us new insights to understand multiple aspects of infection. Here, we depicted candidate miRNAs, genes and pathways affected by Oropouche Virus infection in hepatocyte cells. We hope this work serve as guideline for prospective studies in order to assess the complexity regarding the orthobunyaviruses infections.
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Affiliation(s)
- Victor Emmanuel Viana Geddes
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Anibal Silva de Oliveira
- Departamento de Biologia Celular e Molecular, Centro de Pesquisa em Virologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Amilcar Tanuri
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Eurico Arruda
- Departamento de Biologia Celular e Molecular, Centro de Pesquisa em Virologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Marcelo Ribeiro-Alves
- Instituto Nacional de Infectologia Evandro Chagas, FIOCRUZ, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Renato Santana Aguiar
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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9
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Hover S, Foster B, Fontana J, Kohl A, Goldstein SAN, Barr JN, Mankouri J. Bunyavirus requirement for endosomal K+ reveals new roles of cellular ion channels during infection. PLoS Pathog 2018; 14:e1006845. [PMID: 29352299 PMCID: PMC5805358 DOI: 10.1371/journal.ppat.1006845] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 02/08/2018] [Accepted: 12/28/2017] [Indexed: 11/18/2022] Open
Abstract
In order to multiply and cause disease a virus must transport its genome from outside the cell into the cytosol, most commonly achieved through the endocytic network. Endosomes transport virus particles to specific cellular destinations and viruses exploit the changing environment of maturing endocytic vesicles as triggers to mediate genome release. Previously we demonstrated that several bunyaviruses, which comprise the largest family of negative sense RNA viruses, require the activity of cellular potassium (K+) channels to cause productive infection. Specifically, we demonstrated a surprising role for K+ channels during virus endosomal trafficking. In this study, we have used the prototype bunyavirus, Bunyamwera virus (BUNV), as a tool to understand why K+ channels are required for progression of these viruses through the endocytic network. We report three major findings: First, the production of a dual fluorescently labelled bunyavirus to visualize virus trafficking in live cells. Second, we show that BUNV traffics through endosomes containing high [K+] and that these K+ ions influence the infectivity of virions. Third, we show that K+ channel inhibition can alter the distribution of K+ across the endosomal system and arrest virus trafficking in endosomes. These data suggest high endosomal [K+] is a critical cue that is required for virus infection, and is controlled by cellular K+ channels resident within the endosome network. This highlights cellular K+ channels as druggable targets to impede virus entry, infection and disease.
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Affiliation(s)
- Samantha Hover
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
| | - Becky Foster
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
| | - Juan Fontana
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Steve A. N. Goldstein
- Loyola University Chicago Stritch School of Medicine, Maywood, Illinois, United States of America
| | - John N. Barr
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
- * E-mail: (JNB); (JM)
| | - Jamel Mankouri
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
- * E-mail: (JNB); (JM)
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10
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Drake MJ, Brennan B, Briley Jr K, Bart SM, Sherman E, Szemiel AM, Minutillo M, Bushman FD, Bates P. A role for glycolipid biosynthesis in severe fever with thrombocytopenia syndrome virus entry. PLoS Pathog 2017; 13:e1006316. [PMID: 28388693 PMCID: PMC5397019 DOI: 10.1371/journal.ppat.1006316] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 04/19/2017] [Accepted: 03/24/2017] [Indexed: 01/01/2023] Open
Abstract
A novel bunyavirus was recently found to cause severe febrile illness with high mortality in agricultural regions of China, Japan, and South Korea. This virus, named severe fever with thrombocytopenia syndrome virus (SFTSV), represents a new group within the Phlebovirus genus of the Bunyaviridae. Little is known about the viral entry requirements beyond showing dependence on dynamin and endosomal acidification. A haploid forward genetic screen was performed to identify host cell requirements for SFTSV entry. The screen identified dependence on glucosylceramide synthase (ugcg), the enzyme responsible for initiating de novo glycosphingolipid biosynthesis. Genetic and pharmacological approaches confirmed that UGCG expression and enzymatic activity were required for efficient SFTSV entry. Furthermore, inhibition of UGCG affected a post-internalization stage of SFTSV entry, leading to the accumulation of virus particles in enlarged cytoplasmic structures, suggesting impaired trafficking and/or fusion of viral and host membranes. These findings specify a role for glucosylceramide in SFTSV entry and provide a novel target for antiviral therapies.
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Affiliation(s)
- Mary Jane Drake
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Benjamin Brennan
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Kenneth Briley Jr
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Stephen M. Bart
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Eric Sherman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Agnieszka M. Szemiel
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Madeleine Minutillo
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Frederic D. Bushman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Paul Bates
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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11
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Zheng B, Wang T, Zhang S, Li AQ, Li C, Zhang QF, Liang MF, Li DX. [Severe fever with thrombocytopenia syndrome virus nucleoprotein specifically binds to 60kD SSA/Ro protein in host cells]. Bing Du Xue Bao 2014; 30:233-237. [PMID: 25118376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This study aims to investigate whether the nucleoprotein (NP) of severe fever with thrombocytopenia syndrome virus (SFTSV) can impact the cellular immunity of host cells. Gene segments that encode the NP and non-structural protein (NSs) of SFTSV were inserted into eukaryotic expression vector VR1012. Host proteins that interact with NP and affect immunity were identified with co-immunoprecipitation (IP), SDS-PAGE, mass spectrometry (MS), and Western blot. Co-localization of NP and the identified host proteins was confirmed by confocal microscopy. A 60kD SSA/Ro, a protein related to immunity, interacted with NP, as found by IP and MS. Confocal microscopy showed that NP and SSA/Ro were co-localized in cytoplasm. These results indicated that SFTSV NP may specifically bind to 60kD SSA/Ro and cause a series of immune responses and clinical symptoms.
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12
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Reguera J, Weber F, Cusack S. Bunyaviridae RNA polymerases (L-protein) have an N-terminal, influenza-like endonuclease domain, essential for viral cap-dependent transcription. PLoS Pathog 2010; 6:e1001101. [PMID: 20862319 PMCID: PMC2940753 DOI: 10.1371/journal.ppat.1001101] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 08/13/2010] [Indexed: 01/17/2023] Open
Abstract
Bunyaviruses are a large family of segmented RNA viruses which, like influenza virus, use a cap-snatching mechanism for transcription whereby short capped primers derived by endonucleolytic cleavage of host mRNAs are used by the viral RNA-dependent RNA polymerase (L-protein) to transcribe viral mRNAs. It was recently shown that the cap-snatching endonuclease of influenza virus resides in a discrete N-terminal domain of the PA polymerase subunit. Here we structurally and functionally characterize a similar endonuclease in La Crosse orthobunyavirus (LACV) L-protein. We expressed N-terminal fragments of the LACV L-protein and found that residues 1-180 have metal binding and divalent cation dependent nuclease activity analogous to that of influenza virus endonuclease. The 2.2 Å resolution X-ray crystal structure of the domain confirms that LACV and influenza endonucleases have similar overall folds and identical two metal binding active sites. The in vitro activity of the LACV endonuclease could be abolished by point mutations in the active site or by binding 2,4-dioxo-4-phenylbutanoic acid (DPBA), a known influenza virus endonuclease inhibitor. A crystal structure with bound DPBA shows the inhibitor chelating two active site manganese ions. The essential role of this endonuclease in cap-dependent transcription was demonstrated by the loss of transcriptional activity in a RNP reconstitution system in cells upon making the same point mutations in the context of the full-length LACV L-protein. Using structure based sequence alignments we show that a similar endonuclease almost certainly exists at the N-terminus of L-proteins or PA polymerase subunits of essentially all known negative strand and cap-snatching segmented RNA viruses including arenaviruses (2 segments), bunyaviruses (3 segments), tenuiviruses (4–6 segments), and orthomyxoviruses (6–8 segments). This correspondence, together with the well-known mapping of the conserved polymerase motifs to the central regions of the L-protein and influenza PB1 subunit, suggests that L-proteins might be architecturally, and functionally equivalent to a concatemer of the three orthomyxovirus polymerase subunits in the order PA-PB1-PB2. Furthermore, our structure of a known influenza endonuclease inhibitor bound to LACV endonuclease suggests that compounds targeting a potentially broad spectrum of segmented RNA viruses, several of which are serious or emerging human, animal and plant pathogens, could be developed using structure-based optimisation. Bunyaviruses are a large family of RNA viruses that include serious human, animal and plant pathogens. The viral RNA-dependent RNA polymerase (L-protein) is responsible for replication and transcription of the viral RNA, but apart from its central polymerase domain, it is poorly characterized. Like influenza virus polymerase, bunyavirus L-proteins employ a cap-snatching mechanism to transcribe viral mRNAs, by which host mRNAs are endonucleolytically cleaved as a source of short capped primers. Influenza polymerase endonuclease has recently been located at the PA subunit N-terminus. Here we show biochemically and by crystal structure determination that a similar two-manganese dependent nuclease exists at the N-terminus of La Crosse orthobunyavirus L-protein, whose function is required for cap-dependent transcription. By sequence analysis we show that similar endonuclease signature motifs exist in almost all known segmented RNA, cap-snatching viruses including arenaviruses, bunyaviruses, tenuiviruses and orthomyxoviruses. This suggests that the polymerases of these viruses might share a conserved global architecture with the L-protein being equivalent to a concatenation of the orthomxyovirus PA-PB1-PB2 subunits. We also propose that broad spectrum drugs targeting the endonuclease domain of such viruses could be developed, as exemplified by our structure of the LACV endonuclease complexed with a known influenza endonuclease inhibitor.
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MESH Headings
- Amino Acid Sequence
- Aminobutyrates/metabolism
- Bunyaviridae/enzymology
- Bunyaviridae/genetics
- Bunyaviridae Infections/genetics
- Bunyaviridae Infections/metabolism
- Bunyaviridae Infections/virology
- Catalytic Domain
- Crystallization
- Crystallography, X-Ray
- DNA-Directed RNA Polymerases/chemistry
- DNA-Directed RNA Polymerases/genetics
- DNA-Directed RNA Polymerases/metabolism
- Endonucleases/chemistry
- Endonucleases/genetics
- Endonucleases/metabolism
- Humans
- Influenza, Human/genetics
- Influenza, Human/virology
- Molecular Sequence Data
- Orthomyxoviridae/genetics
- Orthomyxoviridae/immunology
- Orthomyxoviridae/metabolism
- Phenylbutyrates
- Protein Structure, Tertiary
- RNA Caps/genetics
- RNA Caps/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Sequence Homology, Amino Acid
- Transcription, Genetic
- Viral Proteins/chemistry
- Viral Proteins/genetics
- Viral Proteins/metabolism
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Affiliation(s)
- Juan Reguera
- European Molecular Biology Laboratory, Grenoble Outstation, Grenoble, France
- Unit of Virus Host-Cell Interactions (UMI 3265), UJF-EMBL-CNRS, Grenoble, France
| | - Friedemann Weber
- Department of Virology, Institute for Medical Microbiology and Hygiene, Freiburg, Germany
- Institute for Virology, Philipps University Marburg, Marburg, Germany
| | - Stephen Cusack
- European Molecular Biology Laboratory, Grenoble Outstation, Grenoble, France
- Unit of Virus Host-Cell Interactions (UMI 3265), UJF-EMBL-CNRS, Grenoble, France
- * E-mail:
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13
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Abstract
In 129 mice, infection with the nairovirus Dugbe virus (DUGV) was lethal following intracerebral but not intraperitoneal inoculation. Following both routes of inoculation, immunostaining of tissue sections demonstrated virus-positive cells in the brain, indicating that DUGV is neuroinvasive in mice. Many brain areas were affected and neurones were the main cell type infected. Infected cells showed punctate accumulations of viral nucleoprotein in the cytoplasm, indicative of virus replication sites. Immunostaining for activated caspase 3 demonstrated no evidence of apoptosis. The type I interferon (IFN) system plays a significant role in defence against DUGV, as 129 IFN-alpha/beta R(-/-) mice died rapidly following both intraperitoneal and intracerebral inoculations. Studies were undertaken to determine whether the IFN-inducible proteins, protein kinase R (PKR) and MxA, were important for protection; neither PKR nor constitutively expressed human MxA played significant roles.
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Affiliation(s)
- Amanda Boyd
- Centre for Infectious Diseases, College of Medicine and Veterinary Medicine, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, UK
| | - John K Fazakerley
- Centre for Infectious Diseases, College of Medicine and Veterinary Medicine, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, UK
| | - Anne Bridgen
- Department of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK
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14
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Weber F, Bridgen A, Fazakerley JK, Streitenfeld H, Kessler N, Randall RE, Elliott RM. Bunyamwera bunyavirus nonstructural protein NSs counteracts the induction of alpha/beta interferon. J Virol 2002; 76:7949-55. [PMID: 12133999 PMCID: PMC155133 DOI: 10.1128/jvi.76.16.7949-7955.2002] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Production of alpha/beta interferons (IFN-alpha/beta) in response to viral infection is one of the main defense mechanisms of the innate immune system. Many viruses therefore encode factors that subvert the IFN system to enhance their virulence. Bunyamwera virus (BUN) is the prototype of the Bunyaviridae family. By using reverse genetics, we previously produced a recombinant virus lacking the nonstructural protein NSs (BUNdelNSs) and showed that NSs is a nonessential gene product that contributes to viral pathogenesis. Here we demonstrate that BUNdelNSs is a strong inducer of IFN-alpha/beta, whereas in cells infected with the wild-type counterpart expressing NSs (wild-type BUN), neither IFN nor IFN mRNA could be detected. IFN induction by BUNdelNSs correlated with activation of NF-kappaB and was dependent on virally produced double-stranded RNA and on the IFN transcription factor IRF-3. Furthermore, both in cultured cells and in mice lacking a functional IFN-alpha/beta system, BUNdelNSs replicated to wild-type BUN levels, whereas in IFN-competent systems, wild-type BUN grew more efficiently. These results suggest that BUN NSs is an IFN induction antagonist that blocks the transcriptional activation of IFN-alpha/beta in order to increase the virulence of Bunyamwera virus.
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MESH Headings
- Animals
- Bunyamwera virus/genetics
- Bunyamwera virus/immunology
- Bunyamwera virus/pathogenicity
- Bunyamwera virus/physiology
- Bunyaviridae Infections/genetics
- Bunyaviridae Infections/immunology
- Bunyaviridae Infections/metabolism
- Cells, Cultured
- Chlorocebus aethiops
- DNA-Binding Proteins/metabolism
- Female
- Gene Deletion
- Genes, Viral
- Humans
- Interferon Regulatory Factor-3
- Interferon-alpha/biosynthesis
- Interferon-alpha/genetics
- Interferon-beta/biosynthesis
- Interferon-beta/genetics
- Membrane Proteins
- Mice
- Mice, Knockout
- NF-kappa B/metabolism
- Promoter Regions, Genetic
- RNA, Double-Stranded/genetics
- RNA, Double-Stranded/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, Interferon alpha-beta
- Receptors, Interferon/deficiency
- Receptors, Interferon/genetics
- Transcription Factors/metabolism
- Transcriptional Activation
- Vero Cells
- Viral Nonstructural Proteins/genetics
- Viral Nonstructural Proteins/immunology
- Virulence
- Virus Replication
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Affiliation(s)
- Friedemann Weber
- Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, Germany
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15
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Mead JR, Burger RA, Yonk LJ, Coombs J, Warren RP, Kende M, Huggins J, Sidwell RW. Effect of human, recombinant interleukin 2 on Punta Toro virus infections in C57BL/6 mice. Antiviral Res 1991; 15:331-40. [PMID: 1719936 DOI: 10.1016/0166-3542(91)90014-i] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effect of human recombinant interleukin-2 (rIL-2) on Punta Toro virus (PTV) infection was investigated in C57BL/6 mice. Immunologic and viral parameters were assessed after mice were treated i.p. with rIL-2 for 5 days. Treatment of mice with 25000 and 12500 units/mouse of rIL-2 resulted in significant inhibition of the disease as indicated by increases in survival of mice as well as decreases in liver and serum virus titers. Serum glutamic oxalic acid and pyruvic acid transaminase levels were also lowered indicating reduced liver damage. Murine IL-2 production returned to normal or above-normal levels in rIL-2 treated mice. Natural killer cell activity was also moderately stimulated by rIL-2 treatment. Significant amounts of interferon were not detected in the sera of treated mice. Weight gain and survival rates were similar for both toxicity and normal controls indicating that rIL-2 treatments had no toxic effect.
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Affiliation(s)
- J R Mead
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan 84322-5600
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