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Bond ACS, Crocker MA, Wilczek MP, DuShane JK, Sandberg AL, Bennett LJ, Leclerc NR, Maginnis MS. High-throughput drug screen identifies calcium and calmodulin inhibitors that reduce JCPyV infection. Antiviral Res 2024; 222:105817. [PMID: 38246207 PMCID: PMC10922812 DOI: 10.1016/j.antiviral.2024.105817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/09/2024] [Accepted: 01/18/2024] [Indexed: 01/23/2024]
Abstract
JC polyomavirus (JCPyV) is a nonenveloped, double-stranded DNA virus that infects the majority of the population. Immunocompetent individuals harbor infection in their kidneys, while severe immunosuppression can result in JCPyV spread to the brain, causing the neurodegenerative disease progressive multifocal leukoencephalopathy (PML). Due to a lack of approved therapies to treat JCPyV and PML, the disease results in rapid deterioration, and is often fatal. In order to identify potential antiviral treatments for JCPyV, a high-throughput, large-scale drug screen was performed using the National Institutes of Health Clinical Collection (NCC). Drugs from the NCC were tested for inhibitory effects on JCPyV infection, and drugs from various classes that reduced JCPyV infection were identified, including receptor agonists and antagonists, calcium signaling modulators, and enzyme inhibitors. Given the role of calcium signaling in viral infection including Merkel cell polyomavirus and simian virus 40 polyomavirus (SV40), calcium signaling inhibitors were further explored for the capacity to impact JCPyV infection. Calcium and calmodulin inhibitors trifluoperazine (TFP), W-7, tetrandrine, and nifedipine reduced JCPyV infection, and TFP specifically reduced viral internalization. Additionally, TFP and W-7 reduced infection by BK polyomavirus, SV40, and SARS-CoV-2. These results highlight specific inhibitors, some FDA-approved, for the possible treatment and prevention of JCPyV and several other viruses, and further illuminate the calcium and calmodulin pathway as a potential target for antiviral drug development.
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Affiliation(s)
- Avery C S Bond
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, 04469, USA
| | - Mason A Crocker
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, 04469, USA
| | - Michael P Wilczek
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, 04469, USA
| | - Jeanne K DuShane
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, 04469, USA
| | - Amanda L Sandberg
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, 04469, USA
| | - Lucas J Bennett
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, 04469, USA
| | - Nicholas R Leclerc
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, 04469, USA
| | - Melissa S Maginnis
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, 04469, USA; Graduate School of Biomedical Science and Engineering, Orono, ME, 04469, USA.
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2
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Tan S, Zhang J, Peng Y, Du W, Yan J, Fang Q. Integrative transcriptome analysis reveals alternative polyadenylation potentially contributes to GCRV early infection. Front Microbiol 2023; 14:1269164. [PMID: 38029205 PMCID: PMC10656684 DOI: 10.3389/fmicb.2023.1269164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 09/28/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Grass carp reovirus (GCRV), a member of the Aquareovirus genus in the Reoviridae family, is considered to be the most pathogenic aquareovirus. Productive viral infection requires extensive interactions between viruses and host cells. However, the molecular mechanisms underlying GCRV early infection remains elusive. Methods In this study we performed transcriptome and DNA methylome analyses with Ctenopharyngodon idellus kidney (CIK) cells infected with GCRV at 0, 4, and 8 h post infection (hpi), respectively. Results We found that at early infection stage the differentially expressed genes related to defense response and immune response in CIK cells are activated. Although DNA methylation pattern of CIK cells 8 hpi is similar to mock-infected cells, we identified a considerable number of genes that selectively utilize alternative polyadenylation sites. Particularly, we found that biological processes of cytoskeleton organization and regulation of microtubule polymerization are statistically enriched in the genes with altered 3'UTRs. Discussion Our results suggest that alternative polyadenylation potentially contributes to GCRV early infection.
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Affiliation(s)
- Sheng Tan
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai, Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jie Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Yonglin Peng
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai, Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wenfei Du
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai, Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jingxuan Yan
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Qin Fang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
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3
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Abad AT, McNamara AJ, Danthi P. Proteasome activity is required for reovirus entry into cells. J Virol 2023; 97:e0134823. [PMID: 37830819 PMCID: PMC10617490 DOI: 10.1128/jvi.01348-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 09/04/2023] [Indexed: 10/14/2023] Open
Abstract
IMPORTANCE Due to their limited genetic capacity, viruses are reliant on multiple host systems to replicate successfully. Mammalian orthoreovirus (reovirus) is commonly used as a model system for understanding host-virus interactions. In this study, we identify that the proteasome system, which is critical for cellular protein turnover, affects reovirus entry. Inhibition of the proteasome using a chemical inhibitor blocks reovirus uncoating. Blocking these events reduces subsequent replication of the virus. This work identifies that additional host factors control reovirus entry.
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Affiliation(s)
- Andrew T. Abad
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | | | - Pranav Danthi
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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4
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Sutton MS, Pletnev S, Callahan V, Ko S, Tsybovsky Y, Bylund T, Casner RG, Cerutti G, Gardner CL, Guirguis V, Verardi R, Zhang B, Ambrozak D, Beddall M, Lei H, Yang ES, Liu T, Henry AR, Rawi R, Schön A, Schramm CA, Shen CH, Shi W, Stephens T, Yang Y, Florez MB, Ledgerwood JE, Burke CW, Shapiro L, Fox JM, Kwong PD, Roederer M. Vaccine elicitation and structural basis for antibody protection against alphaviruses. Cell 2023; 186:2672-2689.e25. [PMID: 37295404 PMCID: PMC10411218 DOI: 10.1016/j.cell.2023.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 03/03/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
Alphaviruses are RNA viruses that represent emerging public health threats. To identify protective antibodies, we immunized macaques with a mixture of western, eastern, and Venezuelan equine encephalitis virus-like particles (VLPs), a regimen that protects against aerosol challenge with all three viruses. Single- and triple-virus-specific antibodies were isolated, and we identified 21 unique binding groups. Cryo-EM structures revealed that broad VLP binding inversely correlated with sequence and conformational variability. One triple-specific antibody, SKT05, bound proximal to the fusion peptide and neutralized all three Env-pseudotyped encephalitic alphaviruses by using different symmetry elements for recognition across VLPs. Neutralization in other assays (e.g., chimeric Sindbis virus) yielded variable results. SKT05 bound backbone atoms of sequence-diverse residues, enabling broad recognition despite sequence variability; accordingly, SKT05 protected mice against Venezuelan equine encephalitis virus, chikungunya virus, and Ross River virus challenges. Thus, a single vaccine-elicited antibody can protect in vivo against a broad range of alphaviruses.
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Affiliation(s)
- Matthew S Sutton
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sergei Pletnev
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Victoria Callahan
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sungyoul Ko
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yaroslav Tsybovsky
- Vaccine Research Center Electron Microscopy Unit, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Tatsiana Bylund
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ryan G Casner
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA
| | - Gabriele Cerutti
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA
| | - Christina L Gardner
- Virology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Veronica Guirguis
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Raffaello Verardi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Baoshan Zhang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Ambrozak
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Margaret Beddall
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hong Lei
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eun Sung Yang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tracy Liu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amy R Henry
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Reda Rawi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Arne Schön
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Chaim A Schramm
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chen-Hsiang Shen
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wei Shi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tyler Stephens
- Vaccine Research Center Electron Microscopy Unit, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Yongping Yang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Maria Burgos Florez
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julie E Ledgerwood
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Crystal W Burke
- Virology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Lawrence Shapiro
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA; Aaron Diamond AIDS Research Center, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA
| | - Julie M Fox
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Department of Biochemistry and Molecular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA.
| | - Mario Roederer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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Seo D, Gammon DB. Manipulation of Host Microtubule Networks by Viral Microtubule-Associated Proteins. Viruses 2022; 14:v14050979. [PMID: 35632720 PMCID: PMC9147350 DOI: 10.3390/v14050979] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 12/19/2022] Open
Abstract
Diverse DNA and RNA viruses utilize cytoskeletal networks to efficiently enter, replicate, and exit the host cell, while evading host immune responses. It is well established that the microtubule (MT) network is commonly hijacked by viruses to traffic to sites of replication after entry and to promote egress from the cell. However, mounting evidence suggests that the MT network is also a key regulator of host immune responses to infection. At the same time, viruses have acquired mechanisms to manipulate and/or usurp MT networks to evade these immune responses. Central to most interactions of viruses with the MT network are virally encoded microtubule-associated proteins (MAPs) that bind to MTs directly or indirectly. These MAPs associate with MTs and other viral or cellular MAPs to regulate various aspects of the MT network, including MT dynamics, MT-dependent transport via motor proteins such as kinesins and dyneins, and MT-dependent regulation of innate immune responses. In this review, we examine how viral MAP interactions with the MT network facilitate viral replication and immune evasion.
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Abstract
Zika virus is a mosquito-borne flavivirus known to cause severe birth defects and neuroimmunological disorders. We have previously demonstrated that mosquito transmission of Zika virus decreases with temperature. While transmission was optimized at 29°C, it was limited at cool temperatures (<22°C) due to poor virus establishment in the mosquitoes. Temperature is one of the strongest drivers of vector-borne disease transmission due to its profound effect on ectothermic mosquito vectors, viruses, and their interaction. Although there is substantial evidence of temperature effects on arbovirus replication and dissemination inside mosquitoes, little is known about whether temperature affects virus replication directly or indirectly through mosquito physiology. In order to determine the mechanisms behind temperature-induced changes in Zika virus transmission potential, we investigated different steps of the virus replication cycle in mosquito cells (C6/36) at optimal (28°C) and cool (20°C) temperatures. We found that the cool temperature did not alter Zika virus entry or translation, but it affected genome replication and reduced the amount of double-stranded RNA replication intermediates. If replication complexes were first formed at 28°C and the cells were subsequently shifted to 20°C, the late steps in the virus replication cycle were efficiently completed. These data suggest that cool temperature decreases the efficiency of Zika virus genome replication in mosquito cells. This phenotype was observed in the Asian lineage of Zika virus, while the African lineage Zika virus was less restricted at 20°C. IMPORTANCE With half of the human population at risk, arboviral diseases represent a substantial global health burden. Zika virus, previously known to cause sporadic infections in humans, emerged in the Americas in 2015 and quickly spread worldwide. There was an urgent need to better understand the disease pathogenesis and develop therapeutics and vaccines, as well as to understand, predict, and control virus transmission. In order to efficiently predict the seasonality and geography for Zika virus transmission, we need a deeper understanding of the host-pathogen interactions and how they can be altered by environmental factors such as temperature. Identifying the step in the virus replication cycle that is inhibited under cool conditions can have implications in modeling the temperature suitability for arbovirus transmission as global environmental patterns change. Understanding the link between pathogen replication and environmental conditions can potentially be exploited to develop new vector control strategies in the future.
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7
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Zhao Z, Deng Y, Niu P, Song J, Wang W, Du Y, Huang B, Wang W, Zhang L, Zhao P, Tan W. Co-Immunization With CHIKV VLP and DNA Vaccines Induces a Promising Humoral Response in Mice. Front Immunol 2021; 12:655743. [PMID: 33868299 PMCID: PMC8044884 DOI: 10.3389/fimmu.2021.655743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/09/2021] [Indexed: 11/25/2022] Open
Abstract
Chikungunya fever is an acute infectious disease that is mediated by the mosquito-transmitted chikungunya virus (CHIKV), for which no licensed vaccines are currently available. Here, we explored several immunization protocols and investigated their immunity and protective effects in mice, with DNA- and virus-like particle (VLP)- vaccines, both alone and in combination. Both DNA and VLP vaccine candidates were developed and characterized, which express CHIKV structural genes (C-E3-E2-6K-E1). Mice were immunized twice, with different protocols, followed by immunological detection and CHIKV Ross challenge. The highest antigen-specific IgG and neutralizing activity were induced by DNA and VLP co-immunization, while the highest cellular immunity was induced by DNA vaccination alone. Although all vaccine groups could protect mice from lethal CHIKV challenge, demonstrated as reduced viral load in various tissues, without weight loss, mice co-immunized with DNA and VLP exhibited the mildest histopathological changes and lowest International Harmonization of Nomenclature and Diagnostic Criteria (INHAND) scores, in comparison to mice with either DNA or VLP vaccination alone. We concluded that co-immunization with DNA and VLP is a promising strategy to inducing better protective immunity against CHIKV infection.
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Affiliation(s)
- Zhimin Zhao
- National Health Commission (NHC) Key Laboratory of Medical Virology, National Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Yao Deng
- National Health Commission (NHC) Key Laboratory of Medical Virology, National Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Peihua Niu
- National Health Commission (NHC) Key Laboratory of Medical Virology, National Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Jingdong Song
- National Health Commission (NHC) Key Laboratory of Medical Virology, National Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Wen Wang
- National Health Commission (NHC) Key Laboratory of Medical Virology, National Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Yongping Du
- Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Zhejiang, China
| | - Baoying Huang
- National Health Commission (NHC) Key Laboratory of Medical Virology, National Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Wenling Wang
- National Health Commission (NHC) Key Laboratory of Medical Virology, National Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Leiliang Zhang
- Institute of Basic Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Ping Zhao
- Shanghai Key Laboratory of Biomedical Protection, Department of Biomedical Protection, Faculty of Naval Medicine, Navy Medical University, Shanghai, China
| | - Wenjie Tan
- National Health Commission (NHC) Key Laboratory of Medical Virology, National Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
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Rodríguez Stewart RM, Raghuram V, Berry JTL, Joshi GN, Mainou BA. Noncanonical Cell Death Induction by Reassortant Reovirus. J Virol 2020; 94:e01613-20. [PMID: 32847857 PMCID: PMC7592226 DOI: 10.1128/jvi.01613-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 08/15/2020] [Indexed: 12/12/2022] Open
Abstract
Triple-negative breast cancer (TNBC) constitutes 10 to 15% of all breast cancer and is associated with worse prognosis than other subtypes of breast cancer. Current therapies are limited to cytotoxic chemotherapy, radiation, and surgery, leaving a need for targeted therapeutics to improve outcomes for TNBC patients. Mammalian orthoreovirus (reovirus) is a nonenveloped, segmented, double-stranded RNA virus in the Reoviridae family. Reovirus preferentially kills transformed cells and is in clinical trials to assess its efficacy against several types of cancer. We previously engineered a reassortant reovirus, r2Reovirus, that infects TNBC cells more efficiently and induces cell death with faster kinetics than parental reoviruses. In this study, we sought to understand the mechanisms by which r2Reovirus induces cell death in TNBC cells. We show that r2Reovirus infection of TNBC cells of a mesenchymal stem-like (MSL) lineage downregulates the mitogen-activated protein kinase/extracellular signal-related kinase pathway and induces nonconventional cell death that is caspase-dependent but caspase 3-independent. Infection of different MSL lineage TNBC cells with r2Reovirus results in caspase 3-dependent cell death. We map the enhanced oncolytic properties of r2Reovirus in TNBC to epistatic interactions between the type 3 Dearing M2 gene segment and type 1 Lang genes. These findings suggest that the genetic composition of the host cell impacts the mechanism of reovirus-induced cell death in TNBC. Together, our data show that understanding host and virus determinants of cell death can identify novel properties and interactions between host and viral gene products that can be exploited for the development of improved viral oncolytics.IMPORTANCE TNBC is unresponsive to hormone therapies, leaving patients afflicted with this disease with limited treatment options. We previously engineered an oncolytic reovirus (r2Reovirus) with enhanced infective and cytotoxic properties in TNBC cells. However, how r2Reovirus promotes TNBC cell death is not known. In this study, we show that reassortant r2Reovirus can promote nonconventional caspase-dependent but caspase 3-independent cell death and that the mechanism of cell death depends on the genetic composition of the host cell. We also map the enhanced oncolytic properties of r2Reovirus in TNBC to interactions between a type 3 M2 gene segment and type 1 genes. Our data show that understanding the interplay between the host cell environment and the genetic composition of oncolytic viruses is crucial for the development of efficacious viral oncolytics.
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Affiliation(s)
- Roxana M Rodríguez Stewart
- Emory University, Atlanta, Georgia, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Jameson T L Berry
- Emory University, Atlanta, Georgia, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Bernardo A Mainou
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
- Children's Healthcare of Atlanta, Atlanta, Georgia, USA
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9
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Ins and Outs of Reovirus: Vesicular Trafficking in Viral Entry and Egress. Trends Microbiol 2020; 29:363-375. [PMID: 33008713 PMCID: PMC7523517 DOI: 10.1016/j.tim.2020.09.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/02/2020] [Accepted: 09/04/2020] [Indexed: 12/11/2022]
Abstract
Cell entry and egress are essential steps in the viral life cycle that govern pathogenesis and spread. Mammalian orthoreoviruses (reoviruses) are nonenveloped viruses implicated in human disease that serve as tractable models for studies of pathogen-host interactions. In this review we discuss the function of intracellular vesicular transport systems in reovirus entry, trafficking, and egress and comment on shared themes for diverse viruses. Designing strategic therapeutic interventions that impede these steps in viral replication requires a detailed understanding of mechanisms by which viruses coopt vesicular trafficking. We illuminate such targets, which may foster development of antiviral agents.
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10
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Berry JTL, Muñoz LE, Rodríguez Stewart RM, Selvaraj P, Mainou BA. Doxorubicin Conjugation to Reovirus Improves Oncolytic Efficacy in Triple-Negative Breast Cancer. Mol Ther Oncolytics 2020; 18:556-572. [PMID: 32995480 PMCID: PMC7493048 DOI: 10.1016/j.omto.2020.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 08/18/2020] [Indexed: 12/31/2022] Open
Abstract
Breast cancer is the second leading cause of cancer-related deaths in women in the United States. The triple-negative breast cancer (TNBC) subtype associates with higher rates of relapse, shorter overall survival, and aggressive metastatic disease. Hormone therapy is ineffective against TNBC, leaving patients with limited therapeutic options. Mammalian orthoreovirus (reovirus) preferentially infects and kills transformed cells, and a genetically engineered reassortant reovirus infects and kills TNBC cells more efficiently than prototypical strains. Reovirus oncolytic efficacy is further augmented by combination with topoisomerase inhibitors, including the frontline chemotherapeutic doxorubicin. However, long-term doxorubicin use correlates with toxicity to healthy tissues. Here, we conjugated doxorubicin to reovirus (reo-dox) to control drug delivery and enhance reovirus-mediated oncolysis. Our data indicate that conjugation does not impair viral biology and enhances reovirus oncolytic capacity in TNBC cells. Reo-dox infection promotes innate immune activation, and crosslinked doxorubicin retains DNA-damaging properties within infected cells. Importantly, reovirus and reo-dox significantly reduce primary TNBC tumor burden in vivo, with greater reduction in metastatic burden after reo-dox inoculation. Together, these data demonstrate that crosslinking chemotherapeutic agents to oncolytic viruses facilitates functional drug delivery to cells targeted by the virus, making it a viable approach for combination therapy against TNBC.
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Affiliation(s)
- Jameson T L Berry
- Emory University School of Medicine, Emory University, Atlanta, GA 30032, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30032, USA
| | - Luis E Muñoz
- Emory University School of Medicine, Emory University, Atlanta, GA 30032, USA
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30032, USA
| | - Roxana M Rodríguez Stewart
- Emory University School of Medicine, Emory University, Atlanta, GA 30032, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30032, USA
| | - Periasamy Selvaraj
- Emory University School of Medicine, Emory University, Atlanta, GA 30032, USA
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30032, USA
| | - Bernardo A Mainou
- Emory University School of Medicine, Emory University, Atlanta, GA 30032, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30032, USA
- Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
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11
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Eichwald C, Ackermann M, Fraefel C. Mammalian orthoreovirus core protein μ2 reorganizes host microtubule-organizing center components. Virology 2020; 549:13-24. [PMID: 32805585 PMCID: PMC7402380 DOI: 10.1016/j.virol.2020.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/02/2020] [Accepted: 07/08/2020] [Indexed: 10/26/2022]
Abstract
Filamentous mammalian orthoreovirus (MRV) viral factories (VFs) are membrane-less cytosolic inclusions in which virus transcription, replication of dsRNA genome segments, and packaging of virus progeny into newly synthesized virus cores take place. In infected cells, the MRV μ2 protein forms punctae in the enlarged region of the filamentous VFs that are co-localized with γ-tubulin and resistant to nocodazole treatment, and permitted microtubule (MT)-extension, features common to MT-organizing centers (MTOCs). Using a previously established reconstituted VF model, we addressed the functions of MT-components and MTOCs concerning their roles in the formation of filamentous VFs. Indeed, the MTOC markers γ-tubulin and centrin were redistributed within the VF-like structures (VFLS) in a μ2-dependent manner. Moreover, the MT-nucleation centers significantly increased in numbers, and γ-tubulin was pulled-down in a binding assay when co-expressed with histidine-tagged-μ2 and μNS. Thus, μ2, by interaction with γ-tubulin, can modulate MTOCs localization and function according to viral needs.
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Affiliation(s)
- Catherine Eichwald
- Institute of Virology, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland.
| | - Mathias Ackermann
- Institute of Virology, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland.
| | - Cornel Fraefel
- Institute of Virology, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland.
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12
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Abstract
Alphaviruses are enveloped positive-sense RNA viruses that can cause serious human illnesses such as polyarthritis and encephalitis. Despite their widespread distribution and medical importance, there are no licensed vaccines or antivirals to combat alphavirus infections. Berberine chloride (BBC) is a pan-alphavirus inhibitor that was previously identified in a replicon-based small-molecule screen. This work showed that BBC inhibits alphavirus replication but also suggested that BBC might have additional effects later in the viral life cycle. Here, we show that BBC has late effects that target the virus nucleocapsid (NC) core. Infected cells treated with BBC late in infection were unable to form stable cytoplasmic NCs or assembly intermediates, as assayed by gradient sedimentation. In vitro studies with recombinant capsid protein (Cp) and purified genomic RNA (gRNA) showed that BBC perturbs core-like particle formation and potentially traps the assembly process in intermediate states. Particles produced from BBC-treated cells were less infectious, despite efficient particle production and only minor decreases in genome packaging. In addition, BBC treatment of free virus particles strongly decreased alphavirus infectivity. In contrast, the infectivity of the negative-sense RNA virus vesicular stomatitis virus was resistant to BBC treatment of infected cells or free virus. Together, our data indicate that BBC alters alphavirus Cp-gRNA interactions and oligomerization and suggest that this may cause defects in NC assembly and in disassembly during subsequent virus entry. Thus, BBC may be considered a novel alphavirus NC assembly inhibitor.IMPORTANCE The alphavirus chikungunya virus (CHIKV) is an example of an emerging human pathogen with increased and rapid global spread. Although an acute CHIKV infection is rarely fatal, many patients suffer from debilitating chronic arthralgia for years. Antivirals against chikungunya and other alphaviruses have been identified in vitro, but to date none have been shown to be efficacious and have been licensed for human use. Here, we investigated a small molecule, berberine chloride (BBC), and showed that it inhibited infectious virus production by several alphaviruses including CHIKV. BBC acted on a late step in the alphavirus exit pathway, namely the formation of the nucleocapsid containing the infectious viral RNA. Better understanding of nucleocapsid formation and its inhibition by BBC will provide important information on the mechanisms of infectious alphavirus production and may enable their future targeting in antiviral strategies.
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13
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Kose N, Fox JM, Sapparapu G, Bombardi R, Tennekoon RN, de Silva AD, Elbashir SM, Theisen MA, Humphris-Narayanan E, Ciaramella G, Himansu S, Diamond MS, Crowe JE. A lipid-encapsulated mRNA encoding a potently neutralizing human monoclonal antibody protects against chikungunya infection. Sci Immunol 2020; 4:4/35/eaaw6647. [PMID: 31101672 DOI: 10.1126/sciimmunol.aaw6647] [Citation(s) in RCA: 138] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/28/2019] [Indexed: 12/31/2022]
Abstract
Infection with chikungunya virus (CHIKV) causes an acute illness characterized by fever, rash, and arthralgia. However, CHIKV infection can sometimes progress to chronic arthritis or even lethal disease. CHIKV continues to cause substantial morbidity worldwide as its vector mosquitoes expand and spread. There are currently no approved vaccines or antiviral drugs available for the prevention or treatment of CHIKV. Although antibody therapy has shown promise in the prevention or treatment of CHIKV disease in preclinical models, challenges remain for implementing such therapies. Here, from the B cells of a survivor of natural CHIKV infection, we isolated ultrapotent neutralizing human monoclonal antibodies (mAbs) and encoded their sequences into mRNA molecules delivered by infusion. One human mAb, CHKV-24, was expressed to biologically significant levels in vivo after infusion of mRNAs in lipid nanoparticles in mice. We evaluated the protective capacity of CHKV-24 mAb immunoglobulin G protein or mRNA in mouse models of CHIKV infection. Treatment with CHKV-24 mRNA protected mice from arthritis, musculoskeletal tissue infection, and lethality and reduced viremia to undetectable levels at 2 days after inoculation. Infusion of macaques with CHKV-24 mRNA achieved a mean maximal mAb concentration of 10.1 to 35.9 micrograms per milliliter, with a half-life of 23 days, a level well above what is needed for protection in mice. Studies with CHKV-24 mRNA in macaques demonstrated a dose-response effect after the first dose of mRNA and maintained levels after second dose. These preclinical data with CHKV-24 mRNA suggest that it might be useful to prevent human disease.
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Affiliation(s)
- Nurgun Kose
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Julie M Fox
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Gopal Sapparapu
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Robin Bombardi
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - A Dharshan de Silva
- Genetech Research Institute, Colombo, Sri Lanka.,Department of Paraclinical Sciences, Faculty of Medicine, Kotelawala Defence University, Sri Lanka
| | | | | | | | | | | | - Michael S Diamond
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.,Department of Molecular Microbiology, Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - James E Crowe
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA. .,Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
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14
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Noll KE, Whitmore AC, West A, McCarthy MK, Morrison CR, Plante KS, Hampton BK, Kollmus H, Pilzner C, Leist SR, Gralinski LE, Menachery VD, Schäfer A, Miller D, Shaw G, Mooney M, McWeeney S, Pardo-Manuel de Villena F, Schughart K, Morrison TE, Baric RS, Ferris MT, Heise MT. Complex Genetic Architecture Underlies Regulation of Influenza-A-Virus-Specific Antibody Responses in the Collaborative Cross. Cell Rep 2020; 31:107587. [PMID: 32348764 PMCID: PMC7195006 DOI: 10.1016/j.celrep.2020.107587] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/20/2020] [Accepted: 04/08/2020] [Indexed: 02/07/2023] Open
Abstract
Host genetic factors play a fundamental role in regulating humoral immunity to viral infection, including influenza A virus (IAV). Here, we utilize the Collaborative Cross (CC), a mouse genetic reference population, to study genetic regulation of variation in antibody response following IAV infection. CC mice show significant heritable variation in the magnitude, kinetics, and composition of IAV-specific antibody response. We map 23 genetic loci associated with this variation. Analysis of a subset of these loci finds that they broadly affect the antibody response to IAV as well as other viruses. Candidate genes are identified based on predicted variant consequences and haplotype-specific expression patterns, and several show overlap with genes identified in human mapping studies. These findings demonstrate that the host antibody response to IAV infection is under complex genetic control and highlight the utility of the CC in modeling and identifying genetic factors with translational relevance to human health and disease.
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Affiliation(s)
- Kelsey E Noll
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alan C Whitmore
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ande West
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mary K McCarthy
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA
| | | | - Kenneth S Plante
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Brea K Hampton
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Heike Kollmus
- Department of Infection Genetics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Carolin Pilzner
- Department of Infection Genetics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sarah R Leist
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Infection Genetics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Lisa E Gralinski
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Vineet D Menachery
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Alexandra Schäfer
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Darla Miller
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ginger Shaw
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Michael Mooney
- Division of Bioinformatics and Computational Biology, Department of Medical Informatics and Clinical Epidemiology, Oregon Health and Science University, Portland, OR, USA; OHSU Knight Cancer Center Institute, Oregon Health and Science University, Portland, OR, USA
| | - Shannon McWeeney
- Division of Bioinformatics and Computational Biology, Department of Medical Informatics and Clinical Epidemiology, Oregon Health and Science University, Portland, OR, USA; OHSU Knight Cancer Center Institute, Oregon Health and Science University, Portland, OR, USA; Oregon Clinical and Translational Research Institute, Oregon Health and Science University, Portland, OR, USA
| | - Fernando Pardo-Manuel de Villena
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Klaus Schughart
- Department of Infection Genetics, Helmholtz Centre for Infection Research, Braunschweig, Germany; University of Veterinary Medicine Hannover, Hannover, Germany; Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Thomas E Morrison
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ralph S Baric
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Martin T Ferris
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mark T Heise
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA.
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15
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Aravamudhan P, Raghunathan K, Konopka-Anstadt J, Pathak A, Sutherland DM, Carter BD, Dermody TS. Reovirus uses macropinocytosis-mediated entry and fast axonal transport to infect neurons. PLoS Pathog 2020; 16:e1008380. [PMID: 32109948 PMCID: PMC7065821 DOI: 10.1371/journal.ppat.1008380] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/11/2020] [Accepted: 02/04/2020] [Indexed: 12/12/2022] Open
Abstract
Several barriers protect the central nervous system (CNS) from pathogen invasion. Yet viral infections of the CNS are common and often debilitating. Understanding how neurotropic viruses co-opt host machinery to overcome challenges to neuronal entry and transmission is important to combat these infections. Neurotropic reovirus disseminates through neural routes and invades the CNS to cause lethal encephalitis in newborn animals. To define mechanisms of reovirus neuronal entry and directional transport, we used primary neuron cultures, which reproduce in vivo infection patterns displayed by different reovirus serotypes. Treatment of neurons with small-molecule inhibitors of different endocytic uptake pathways allowed us to discover that the cellular machinery mediating macropinocytosis is required for reovirus neuronal entry. This mechanism of reovirus entry differs from clathrin-mediated endocytosis, which is used by reovirus to invade non-neuronal cells. Analysis of reovirus transport and release from isolated soma or axonal termini of neurons cultivated in microfluidic devices indicates that reovirus is capable of retrograde but only limited anterograde neuronal transmission. The dynamics of retrograde reovirus movement are consistent with fast axonal transport coordinated by dynein along microtubules. Further analysis of viral transport revealed that multiple virions are transported together in axons within non-acidified vesicles. Reovirus-containing vesicles acidify after reaching the soma, where disassembly of virions and release of the viral core into the cytoplasm initiates replication. These results define mechanisms of reovirus neuronal entry and transport and establish a foundation to identify common host factors used by neuroinvasive viruses. Furthermore, our findings emphasize consideration of cell type-specific entry mechanisms in the tailored design of neurotropic viruses as tracers, oncolytic agents, and delivery vectors. Viral infections of the central nervous system (CNS) cause a significant health burden globally and compel a better mechanistic understanding of neural invasion by viruses to develop effective interventions. Neurotropic reovirus disseminates through neural routes to infect the CNS and serves as a tractable model to study neural invasion by viruses. Despite knowledge of reovirus neurotropism for decades, mechanisms mediating reovirus neuronal infection remain undefined. We used primary neurons cultured in microfluidic devices to study entry and directional transport of reovirus. We discovered that reovirus uses macropinocytosis for neuronal entry as opposed to the use of a clathrin-mediated pathway in non-neuronal cells. We are unaware of another virus using macropinocytosis to enter neurons. Following internalization, reovirus spreads in the retrograde direction using dynein-mediated fast axonal transport but exhibits limited anterograde spread. We further demonstrate that reovirus disassembly and replication occur in the neuronal soma subsequent to axonal transport. Remarkably, these entry and transport mechanisms mirror those used by misfolded proteins implicated in neurodegenerative diseases. Our findings establish the mechanics of reovirus neuronal uptake and spread and provide clues about therapeutic targets to limit neuropathology inflicted by pathogens and misfolded proteins.
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Affiliation(s)
- Pavithra Aravamudhan
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Krishnan Raghunathan
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jennifer Konopka-Anstadt
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Amrita Pathak
- Department of Biochemistry and Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Danica M. Sutherland
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Bruce D. Carter
- Department of Biochemistry and Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Terence S. Dermody
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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16
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Polymorphisms in the Most Oncolytic Reovirus Strain Confer Enhanced Cell Attachment, Transcription, and Single-Step Replication Kinetics. J Virol 2020; 94:JVI.01937-19. [PMID: 31776267 DOI: 10.1128/jvi.01937-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 11/19/2019] [Indexed: 12/31/2022] Open
Abstract
Reovirus serotype 3 Dearing (T3D) replicates preferentially in transformed cells and is in clinical trials as a cancer therapy. Laboratory strains of T3D, however, exhibit differences in plaque size on cancer cells and differences in oncolytic activity in vivo This study aimed to determine why the most oncolytic T3D reovirus lab strain, the Patrick Lee laboratory strain (T3DPL), replicates more efficiently in cancer cells than other commonly used laboratory strains, the Kevin Coombs laboratory strain (T3DKC) and Terence Dermody laboratory (T3DTD) strain. In single-step growth curves, T3DPL titers increased at higher rates and produced ∼9-fold higher burst size. Furthermore, the number of reovirus antigen-positive cells increased more rapidly for T3DPL than for T3DTD In conclusion, the most oncolytic T3DPL possesses replication advantages in a single round of infection. Two specific mechanisms for enhanced infection by T3DPL were identified. First, T3DPL exhibited higher cell attachment, which was attributed to a higher proportion of virus particles with insufficient (≤3) σ1 cell attachment proteins. Second, T3DPL transcribed RNA at rates superior to those of the less oncolytic T3D strains, which is attributed to polymorphisms in M1-encoding μ2 protein, as confirmed in an in vitro transcription assay, and which thus demonstrates that T3DPL has an inherent transcription advantage that is cell type independent. Accordingly, T3DPL established rapid onset of viral RNA and protein synthesis, leading to more rapid kinetics of progeny virus production, larger virus burst size, and higher levels of cell death. Together, these results emphasize the importance of paying close attention to genomic divergence between virus laboratory strains and, mechanistically, reveal the importance of the rapid onset of infection for reovirus oncolysis.IMPORTANCE Reovirus serotype 3 Dearing (T3D) is in clinical trials for cancer therapy. Recently, it was discovered that highly related laboratory strains of T3D exhibit large differences in their abilities to replicate in cancer cells in vitro, which correlates with oncolytic activity in a murine model of melanoma. The current study reveals two mechanisms for the enhanced efficiency of T3DPL in cancer cells. Due to polymorphisms in two viral genes, within the first round of reovirus infection, T3DPL binds to cells more efficiency and more rapidly produces viral RNAs; this increased rate of infection relative to that of the less oncolytic strains gives T3DPL a strong inherent advantage that culminates in higher virus production, more cell death, and higher virus spread.
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17
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Zhang F, Guo H, Chen Q, Ruan Z, Fang Q. Endosomes and Microtubles are Required for Productive Infection in Aquareovirus. Virol Sin 2019; 35:200-211. [PMID: 31858455 DOI: 10.1007/s12250-019-00178-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 09/18/2019] [Indexed: 12/20/2022] Open
Abstract
Grass carp reovirus (GCRV), the genus Aquareovirus in family Reoviridae, is viewed as the most pathogenic aquareovirus. To understand the molecular mechanism of how aquareovirus initiates productive infection, the roles of endosome and microtubule in cell entry of GCRV are investigated by using quantum dots (QDs)-tracking in combination with biochemical approaches. We found that GCRV infection and viral protein synthesis were significantly inhibited by pretreating host cells with endosome acidification inhibitors NH4Cl, chloroquine and bafilomycin A1 (Bafi). Confocal images indicated that GCRV particles could colocalize with Rab5, Rab7 and lysosomes in host cells. Further ultrastructural examination validated that viral particle was found in late endosomes. Moreover, disruption of microtubules with nocodazole clearly blocked GCRV entry, while no inhibitory effects were observed with cytochalasin D treated cells in viral infection, hinting that intracellular transportation of endocytic uptake in GCRV infected cells is via microtubules but not actin filament. Notably, viral particles were observed to transport along microtubules by using QD-labeled GCRV. Altogether, our results suggest that GCRV can use endosomes and microtubules to initiate productive infection.
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Affiliation(s)
- Fuxian Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
- Wuhan Center for Animal Diseases Prevention and Control, Wuhan, 430071, China
| | - Hong Guo
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Qingxiu Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Zheng Ruan
- Wuhan Center for Animal Diseases Prevention and Control, Wuhan, 430071, China
| | - Qin Fang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
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18
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Enhanced Killing of Triple-Negative Breast Cancer Cells by Reassortant Reovirus and Topoisomerase Inhibitors. J Virol 2019; 93:JVI.01411-19. [PMID: 31511390 DOI: 10.1128/jvi.01411-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 09/09/2019] [Indexed: 12/12/2022] Open
Abstract
Breast cancer is the second leading cause of cancer-related deaths in women in the United States. Triple-negative breast cancer constitutes a subset of breast cancer that is associated with higher rates of relapse, decreased survival, and limited therapeutic options for patients afflicted with this type of breast cancer. Mammalian orthoreovirus (reovirus) selectively infects and kills transformed cells, and a serotype 3 reovirus is in clinical trials to assess its efficacy as an oncolytic agent against several cancers. It is unclear if reovirus serotypes differentially infect and kill triple-negative breast cancer cells and if reovirus-induced cytotoxicity of breast cancer cells can be enhanced by modulating the activity of host molecules and pathways. Here, we generated reassortant reoviruses by forward genetics with enhanced infective and cytotoxic properties in triple-negative breast cancer cells. From a high-throughput screen of small-molecule inhibitors, we identified topoisomerase inhibitors as a class of drugs that enhance reovirus infectivity and cytotoxicity of triple-negative breast cancer cells. Treatment of triple-negative breast cancer cells with topoisomerase inhibitors activates DNA damage response pathways, and reovirus infection induces robust production of type III, but not type I, interferon (IFN). Although type I and type III IFNs can activate STAT1 and STAT2, triple-negative breast cancer cellular proliferation is only negatively affected by type I IFN. Together, these data show that reassortant viruses with a novel genetic composition generated by forward genetics in combination with topoisomerase inhibitors more efficiently infect and kill triple-negative breast cancer cells.IMPORTANCE Patients afflicted by triple-negative breast cancer have decreased survival and limited therapeutic options. Reovirus infection results in cell death of a variety of cancers, but it is unknown if different reovirus types lead to triple-negative breast cancer cell death. In this study, we generated two novel reoviruses that more efficiently infect and kill triple-negative breast cancer cells. We show that infection in the presence of DNA-damaging agents enhances infection and triple-negative breast cancer cell killing by reovirus. These data suggest that a combination of a genetically engineered oncolytic reovirus and topoisomerase inhibitors may provide a potent therapeutic option for patients afflicted with triple-negative breast cancer.
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19
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Geng Y, Yan H, Li P, Ren G, Guo X, Yin P, Zhang L, Qian Z, Zhao Z, Sun YC. A highly efficient in vivo plasmid editing tool based on CRISPR-Cas12a and phage λ Red recombineering. J Genet Genomics 2019; 46:455-458. [PMID: 31607505 PMCID: PMC7172145 DOI: 10.1016/j.jgg.2019.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 06/16/2019] [Accepted: 07/04/2019] [Indexed: 12/03/2022]
Affiliation(s)
- Yiman Geng
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Haiqin Yan
- Department of Basic Medical Sciences, Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, 233030, China
| | - Pei Li
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Gaixian Ren
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Xiaopeng Guo
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Peiqi Yin
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Leiliang Zhang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Zhaohui Qian
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China.
| | - Zhendong Zhao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China.
| | - Yi-Cheng Sun
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China.
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20
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Abstract
Viruses must navigate the complex endomembranous network of the host cell to cause infection. In the case of a non-enveloped virus that lacks a surrounding lipid bilayer, endocytic uptake from the plasma membrane is not sufficient to cause infection. Instead, the virus must travel within organelle membranes to reach a specific cellular destination that supports exposure or arrival of the virus to the cytosol. This is achieved by viral penetration across a host endomembrane, ultimately enabling entry of the virus into the nucleus to initiate infection. In this review, we discuss the entry mechanisms of three distinct non-enveloped DNA viruses-adenovirus (AdV), human papillomavirus (HPV), and polyomavirus (PyV)-highlighting how each exploit different intracellular transport machineries and membrane penetration apparatus associated with the endosome, Golgi, and endoplasmic reticulum (ER) membrane systems to infect a host cell. These processes not only illuminate a highly-coordinated interplay between non-enveloped viruses and their host, but may provide new strategies to combat non-enveloped virus-induced diseases.
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Affiliation(s)
- Chelsey C Spriggs
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Mara C Harwood
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States; Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States; Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, United States.
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21
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Song H, Zhao Z, Chai Y, Jin X, Li C, Yuan F, Liu S, Gao Z, Wang H, Song J, Vazquez L, Zhang Y, Tan S, Morel CM, Yan J, Shi Y, Qi J, Gao F, Gao GF. Molecular Basis of Arthritogenic Alphavirus Receptor MXRA8 Binding to Chikungunya Virus Envelope Protein. Cell 2019; 177:1714-1724.e12. [PMID: 31080063 DOI: 10.1016/j.cell.2019.04.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/07/2019] [Accepted: 04/01/2019] [Indexed: 01/17/2023]
Abstract
Arthritogenic alphaviruses, such as Chikungunya virus (CHIKV), cause severe and debilitating rheumatic diseases worldwide, resulting in severe morbidity and economic costs. Recently, MXRA8 was reported as an entry receptor. Here, we present the crystal structures of the mouse MXRA8, human MXRA8 in complex with the CHIKV E protein, and the cryo-electron microscopy structure of human MXRA8 and CHIKV virus-like particle. MXRA8 has two Ig-like domains with unique structural topologies. This receptor binds in the "canyon" between two protomers of the E spike on the surface of the virion. The atomic details at the interface between the two binding entities reveal that both the two domains and the hinge region of MXRA8 are involved in interaction with CHIKV E1-E2 residues from two protomers. Notably, the stalk region of MXRA8 is critical for CHIKV virus entry. This finding provides important information regarding the development of therapeutic countermeasures against those arthritogenic alphaviruses.
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Affiliation(s)
- Hao Song
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhennan Zhao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Chai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiyue Jin
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Changyao Li
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Fei Yuan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Sheng Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhengrong Gao
- Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Haiyuan Wang
- College of Animal Sciences and Technology, Guangxi University, Nanning 530004, China
| | - Jian Song
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Leonardo Vazquez
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; National Institute of Science and Technology for Innovation on Diseases of Neglected Populations (INCT-IDPN), Center for Technological Development in Health (CDTS), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Rio de Janeiro 21040-361, Brazil
| | - Yanfang Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuguang Tan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Carlos M Morel
- National Institute of Science and Technology for Innovation on Diseases of Neglected Populations (INCT-IDPN), Center for Technological Development in Health (CDTS), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Rio de Janeiro 21040-361, Brazil
| | - Jinghua Yan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yi Shi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China; CAS Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Feng Gao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
| | - George F Gao
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China; School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; CAS Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China; Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing 102206, China.
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Yin H, Yin P, Zhao H, Zhang N, Jian X, Song S, Gao S, Zhang L. Intraviral interactome of Chikungunya virus reveals the homo-oligomerization and palmitoylation of structural protein TF. Biochem Biophys Res Commun 2019; 513:919-924. [PMID: 31005258 PMCID: PMC7092876 DOI: 10.1016/j.bbrc.2019.04.098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 04/13/2019] [Indexed: 12/17/2022]
Abstract
Chikungunya virus (CHIKV) is a re-emerging mosquito-transmitted RNA virus causing joint and muscle pain. Although the protein-protein interactions (PPIs) between nonstructural proteins of CHIKV have been extensively established, the complete CHIKV intraviral interactome remains to be elucidated. In this study, we examined all possible CHIKV intraviral PPIs by immunoprecipitation and constructed the intraviral interactome of CHIKV. We reported 19 novel PPIs including the homo-oligomerization of TF. Disulfide bonds promoted the oligomerization of CHIKV TF protein. 2-BP, a palmitoylation inhibitor reduced the palmitoylation of TF and increased TF oligomerization. A quadruple mutant of Cys33, Cys35, Cys41, and Cys43 in TF blocked its palmitoylation and reduced oligomerization. Furthermore, we determined the association of TF with nsP1 and nsP3 in a palmitoylation-dependent manner. Construction of intraviral interactome of CHIKV provides the basis for further studying the function of CHIKV proteins. An intraviral interactome of CHIKV proteins is constructed. CHIKV TF is homo-oligomerized. CHIKV TF is palmitoylated. TF interacts with nsP1 and nsP3 in a palmitoylation-dependent manner.
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Affiliation(s)
- Han Yin
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, PR China
| | - Peiqi Yin
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, PR China
| | - Hongjian Zhao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, PR China
| | - Na Zhang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, PR China
| | - Xia Jian
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, PR China
| | - Siqi Song
- Institute of Basic Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, 250062, PR China
| | - Shan Gao
- Institute of Basic Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, 250062, PR China
| | - Leiliang Zhang
- Institute of Basic Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, 250062, PR China.
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Selection and Characterization of a Reovirus Mutant with Increased Thermostability. J Virol 2019; 93:JVI.00247-19. [PMID: 30787157 DOI: 10.1128/jvi.00247-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 02/13/2019] [Indexed: 12/26/2022] Open
Abstract
The environment represents a significant barrier to infection. Physical stressors (heat) or chemical agents (ethanol) can render virions noninfectious. As such, discrete proteins are necessary to stabilize the dual-layered structure of mammalian orthoreovirus (reovirus). The outer capsid participates in cell entry: (i) σ3 is degraded to generate the infectious subviral particle, and (ii) μ1 facilitates membrane penetration and subsequent core delivery. μ1-σ3 interactions also prevent inactivation; however, this activity is not fully characterized. Using forward and reverse genetic approaches, we identified two mutations (μ1 M258I and σ3 S344P) within heat-resistant strains. σ3 S344P was sufficient to enhance capsid integrity and to reduce protease sensitivity. Moreover, these changes impaired replicative fitness in a reassortant background. This work reveals new details regarding the determinants of reovirus stability.IMPORTANCE Nonenveloped viruses rely on protein-protein interactions to shield their genomes from the environment. The capsid, or protective shell, must also disassemble during cell entry. In this work, we identified a determinant within mammalian orthoreovirus that regulates heat resistance, disassembly kinetics, and replicative fitness. Together, these findings show capsid function is balanced for optimal replication and for spread to a new host.
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Fatty Acid Synthase Promotes the Palmitoylation of Chikungunya Virus nsP1. J Virol 2019; 93:JVI.01747-18. [PMID: 30404808 DOI: 10.1128/jvi.01747-18] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 10/26/2018] [Indexed: 12/20/2022] Open
Abstract
Chikungunya virus (CHIKV) is transmitted to people by mosquitoes, and CHIKV infection causes fever and joint pain. Fatty acid synthase (FASN) has been identified as a proviral factor for CHIKV. How FASN participates in CHIKV replication remains to be elucidated. In this study, we demonstrated that palmitic acid (PA) can restore the suppression of CHIKV replication by FASN inhibitors. The palmitoylation and plasma membrane localization of CHIKV nsP1 were reduced by FASN inhibitors. Triple mutation of Cys417, Cys418, and Cys419 in nsP1 blocked its palmitoylation and severely disrupted CHIKV replication. Furthermore, two zinc finger DHHC domain-containing palmitoyltransferases (ZDHHCs), ZDHHC2 and ZDHHC19, promoted nsP1 palmitoylation and CHIKV replication. Our results not only identified the key enzymes for the palmitoylation of nsP1 but also provided mechanistic insights into the roles of FASN in CHIKV replication.IMPORTANCE S-palmitoylation is an important form of lipid posttranslational modification, which affects the function of proteins by regulating their transport, stability, and localization. Previous studies have shown that FASN is critical for CHIKV replication; however, the mechanism for this function of FASN remains unknown. The key zinc finger DHHC domain-containing palmitoyltransferases involved in the palmitoylation of nsP1 are not clear. We demonstrated that FASN promoted CHIKV replication through nsP1 palmitoylation. ZDHHC2 and ZDHHC19 were identified as the major enzymes for nsP1 palmitoylation. Since nsP1 proteins are conserved in alphaviruses, our results highlight the mechanisms by which alphavirus nsP1 is palmitoylated.
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25
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Components of the Reovirus Capsid Differentially Contribute to Stability. J Virol 2019; 93:JVI.01894-18. [PMID: 30381491 DOI: 10.1128/jvi.01894-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 10/24/2018] [Indexed: 12/13/2022] Open
Abstract
The mammalian orthoreovirus (reovirus) outer capsid is composed of 200 μ1-σ3 heterohexamers and a maximum of 12 σ1 trimers. During cell entry, σ3 is degraded by luminal or intracellular proteases to generate the infectious subviral particle (ISVP). When ISVP formation is prevented, reovirus fails to establish a productive infection, suggesting proteolytic priming is required for entry. ISVPs are then converted to ISVP*s, which is accompanied by μ1 rearrangements. The μ1 and σ3 proteins confer resistance to inactivating agents; however, neither the impact on capsid properties nor the mechanism (or basis) of inactivation is fully understood. Here, we utilized T1L/T3D M2 and T3D/T1L S4 to investigate the determinants of reovirus stability. Both reassortants encode mismatched subunits. When μ1-σ3 were derived from different strains, virions resembled wild-type particles in structure and protease sensitivity. T1L/T3D M2 and T3D/T1L S4 ISVPs were less thermostable than wild-type ISVPs. In contrast, virions were equally susceptible to heating. Virion associated μ1 adopted an ISVP*-like conformation concurrent with inactivation; σ3 preserves infectivity by preventing μ1 rearrangements. Moreover, thermostability was enhanced by a hyperstable variant of μ1. Unlike the outer capsid, the inner capsid (core) was highly resistant to elevated temperatures. The dual layered architecture allowed for differential sensitivity to inactivating agents.IMPORTANCE Nonenveloped and enveloped viruses are exposed to the environment during transmission to a new host. Protein-protein and/or protein-lipid interactions stabilize the particle and protect the viral genome. Mammalian orthoreovirus (reovirus) is composed of two concentric, protein shells. The μ1 and σ3 proteins form the outer capsid; contacts between neighboring subunits are thought to confer resistance to inactivating agents. We further investigated the determinants of reovirus stability. The outer capsid was disrupted concurrent with the loss of infectivity; virion associated μ1 rearranged into an altered conformation. Heat sensitivity was controlled by σ3; however, particle integrity was enhanced by a single μ1 mutation. In contrast, the inner capsid (core) displayed superior resistance to heating. These findings reveal structural components that differentially contribute to reovirus stability.
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26
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Hwang J, Jiang A, Fikrig E. A potent prolyl tRNA synthetase inhibitor antagonizes Chikungunya and Dengue viruses. Antiviral Res 2018; 161:163-168. [PMID: 30521835 DOI: 10.1016/j.antiviral.2018.11.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/26/2018] [Accepted: 11/30/2018] [Indexed: 12/31/2022]
Abstract
Arboviruses represent a group of pathogens that can spread efficiently throughout human populations by hematophagous arthropod vectors. The mosquito-borne (re)emerging Chikungunya and Dengue viruses belong to the alphavirus and flavivirus genus, respectively, with no approved therapeutics or safe vaccines for humans. Transmitted by the same vector Aedes spp., these viruses cause significant morbidity and mortality in endemic areas. Due to the increasing likelihood of co-circulation and co-infection with viruses, we aimed to identify a pharmacologically targetable host factor that can inhibit multiple viruses and show that a potent antagonist of prolyl tRNA synthetase (halofuginone) suppresses both Chikungunya and Dengue viruses. Host tRNA synthetase inhibition may signify an additional approach to combat present and future epidemic pathogens.
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Affiliation(s)
- Jesse Hwang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.
| | - Alfred Jiang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Erol Fikrig
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
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27
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Liu J, Yu C, Gui JF, Pang DW, Zhang QY. Real-Time Dissecting the Entry and Intracellular Dynamics of Single Reovirus Particle. Front Microbiol 2018; 9:2797. [PMID: 30515143 PMCID: PMC6256031 DOI: 10.3389/fmicb.2018.02797] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/31/2018] [Indexed: 12/17/2022] Open
Abstract
Reoviruses are non-enveloped viruses with wide host range, can cause serious infections in animals, plants and microorganism, e.g., aquareovirus, which is capable of causing serious haemorrhagic in aquatic animals. To date, the entry process of aquareovirus infection remains obscure. Real-time single-virus tracking are effective tools for exploring the details in viral infection process, which are crucial for understanding the pathogenic mechanism. Here, we used quantum dots-based single particle tracking technology combined with biochemical assays and ultrastructural observation to reveal unobservable infection steps and map dynamic interactions between a reovirus, Scophthalmus maximus reovirus (SMReV), and its host cell in real time. The results showed that the single membrane-bound reovirus particle can enter into the cell within several seconds through nascent clathrin-caoted pits, and most of the particles could internalize into cytoplasm within 30 min post-infection. The specific inhibitors analysis also showed that entry of SMREV depended on clathrin-mediated endocytosis rather than cavolin-mediated endocytosis. The motion analysis of internalized single particle indicated that the reovirus initially experienced slow and directed motion in the actin-enriched cell periphery, while it underwent relatively faster and directed movement toward the cell interior, suggesting that transport of SMReV was dependent on the cytoskeleton. Further, dual-labeling of virus and cytoskeleton and inhibitor analysis both demonstrated that transport of internalized SMReV was firstly dependent on actin filaments at the cell periphery, and then on microtubules toward the cell interior. Then visualization of SMReV trafficking in the endosomes revealed that the internalized reovirus particles were sorted from early endosomes to late endosomes, then part of them were delivered to lysosome. This study for the first time revealed the entry pathway, intracellular dynamic and the infection fate of fish reovirus in host cell in real time and in situ, which provided new insights into the infection mechanism of non-enveloped viruses.
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Affiliation(s)
- Jia Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Cong Yu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan, China
| | - Jian-Fang Gui
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Dai-Wen Pang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan, China
| | - Qi-Ya Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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28
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Hwang J, Jiang A, Fikrig E. Rev-erb Agonist Inhibits Chikungunya and O'nyong'nyong Virus Replication. Open Forum Infect Dis 2018; 5:ofy315. [PMID: 30568983 PMCID: PMC6293476 DOI: 10.1093/ofid/ofy315] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 11/16/2018] [Indexed: 01/29/2023] Open
Abstract
Chikungunya virus (CHIKV), an alphavirus spread by Aedes spp. mosquitos, causes severe inflammation and joint pain, progressing to a chronic arthralgic state in a subset of patients. Due to recent global epidemics of CHIKV and the potential for related viruses to cause outbreaks, multiple approaches to combat these pathogens are of interest. We report that SR9009, a synthetic agonist of nuclear receptors Rev-erb α/β, inhibits replication of multiple alphaviruses (CHIKV and O'nyong'nyong virus) mainly by suppressing structural protein synthesis, although viral RNA accumulation is relatively unimpeded. Furthermore, SR9009 reduces the inflammatory response in cultured murine macrophages exposed to alphavirus-infected cells.
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Affiliation(s)
- Jesse Hwang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Alfred Jiang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Erol Fikrig
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.,Howard Hughes Medical Institute, Chevy Chase, Maryland
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Reovirus Nonstructural Protein σNS Acts as an RNA Stability Factor Promoting Viral Genome Replication. J Virol 2018; 92:JVI.00563-18. [PMID: 29769334 DOI: 10.1128/jvi.00563-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 05/07/2018] [Indexed: 12/23/2022] Open
Abstract
Viral nonstructural proteins, which are not packaged into virions, are essential for the replication of most viruses. Reovirus, a nonenveloped, double-stranded RNA (dsRNA) virus, encodes three nonstructural proteins that are required for viral replication and dissemination in the host. The reovirus nonstructural protein σNS is a single-stranded RNA (ssRNA)-binding protein that must be expressed in infected cells for production of viral progeny. However, the activities of σNS during individual steps of the reovirus replication cycle are poorly understood. We explored the function of σNS by disrupting its expression during infection using cells expressing a small interfering RNA (siRNA) targeting the σNS-encoding S3 gene and found that σNS is required for viral genome replication. Using complementary biochemical assays, we determined that σNS forms complexes with viral and nonviral RNAs. We also discovered, using in vitro and cell-based RNA degradation experiments, that σNS increases the RNA half-life. Cryo-electron microscopy revealed that σNS and ssRNAs organize into long, filamentous structures. Collectively, our findings indicate that σNS functions as an RNA-binding protein that increases the viral RNA half-life. These results suggest that σNS forms RNA-protein complexes in preparation for genome replication.IMPORTANCE Following infection, viruses synthesize nonstructural proteins that mediate viral replication and promote dissemination. Viruses from the family Reoviridae encode nonstructural proteins that are required for the formation of progeny viruses. Although nonstructural proteins of different viruses in the family Reoviridae diverge in primary sequence, they are functionally homologous and appear to facilitate conserved mechanisms of dsRNA virus replication. Using in vitro and cell culture approaches, we found that the mammalian reovirus nonstructural protein σNS binds and stabilizes viral RNA and is required for genome synthesis. This work contributes new knowledge about basic mechanisms of dsRNA virus replication and provides a foundation for future studies to determine how viruses in the family Reoviridae assort and replicate their genomes.
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Abstract
Cytoplasmic dynein 1 is an important microtubule-based motor in many eukaryotic cells. Dynein has critical roles both in interphase and during cell division. Here, we focus on interphase cargoes of dynein, which include membrane-bound organelles, RNAs, protein complexes and viruses. A central challenge in the field is to understand how a single motor can transport such a diverse array of cargoes and how this process is regulated. The molecular basis by which each cargo is linked to dynein and its cofactor dynactin has started to emerge. Of particular importance for this process is a set of coiled-coil proteins - activating adaptors - that both recruit dynein-dynactin to their cargoes and activate dynein motility.
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Differential Delivery of Genomic Double-Stranded RNA Causes Reovirus Strain-Specific Differences in Interferon Regulatory Factor 3 Activation. J Virol 2018; 92:JVI.01947-17. [PMID: 29437975 DOI: 10.1128/jvi.01947-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/02/2018] [Indexed: 12/17/2022] Open
Abstract
Serotype 3 (T3) reoviruses induce substantially more type 1 interferon (IFN-I) secretion than serotype 1 (T1) strains. However, the mechanisms underlying differences in IFN-I production between T1 and T3 reoviruses remain undefined. Here, we found that differences in IFN-I production between T1 and T3 reoviruses correlate with activation of interferon regulatory factor 3 (IRF3), a key transcription factor for the production of IFN-I. T3 strain rsT3D activated IRF3 more rapidly and to a greater extent than the T1 strain rsT1L, in simian virus 40 (SV40) immortalized endothelial cells (SVECs). Differences in IRF3 activation between rsT1L and rsT3D were observed in the first hours of infection and were independent of de novo viral RNA and protein synthesis. NF-κB activation mirrored IRF3 activation, with rsT3D inducing more NF-κB activity than rsT1L. We also found that IRF3 and NF-κB are activated in a mitochondrial antiviral-signaling protein (MAVS)-dependent manner. rsT1L does not suppress IRF3 activation, as IRF3 phosphorylation could be induced in rsT1L-infected cells. Transfected rsT1L and rsT3D RNA induced IRF3 phosphorylation, indicating that genomic RNA from both strains has the capacity to activate IRF3. Finally, bypassing the normal route of reovirus entry by transfecting in vitro-generated viral cores revealed that rsT1L and rsT3D core particles induced equivalent IRF3 activation. Taken together, our findings indicate that entry-related events that occur after outer capsid disassembly, but prior to deposition of viral cores into the cytoplasm, influence the efficiency of IFN-I responses to reovirus. This work provides further insight into mechanisms by which nonenveloped viruses activate innate immune responses.IMPORTANCE Detection of viral nucleic acids by the host cell triggers type 1 interferon (IFN-I) responses, which are critical for containing and clearing viral infections. Viral RNA is sensed in the cytoplasm by cellular receptors that initiate signaling pathways, leading to the activation of interferon regulatory factor 3 (IRF3) and NF-κB, key transcription factors required for IFN-I induction. Serotype 3 (T3) reoviruses induce significantly more IFN-I than serotype 1 (T1) strains. In this work, we found that differences in IFN-I production by T1 and T3 reoviruses correlate with differential IRF3 activation. Differences in IRF3 activation are not caused by a blockade of the IRF3 activation by a T1 strain. Rather, differences in events during the late stages of viral entry determine the capacity of reovirus to activate host IFN-I responses. Together, our work provides insight into mechanisms of IFN-I induction by nonenveloped viruses.
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Abstract
Viruses are molecular machines sustained through a life cycle that requires replication within host cells. Throughout the infectious cycle, viral and cellular components interact to advance the multistep process required to produce progeny virions. Despite progress made in understanding the virus-host protein interactome, much remains to be discovered about the cellular factors that function during infection, especially those operating at terminal steps in replication. In an RNA interference screen, we identified the eukaryotic chaperonin T-complex protein-1 (TCP-1) ring complex (TRiC; also called CCT for chaperonin containing TCP-1) as a cellular factor required for late events in the replication of mammalian reovirus. We discovered that TRiC functions in reovirus replication through a mechanism that involves folding the viral σ3 major outer-capsid protein into a form capable of assembling onto virus particles. TRiC also complexes with homologous capsid proteins of closely related viruses. Our data define a critical function for TRiC in the viral assembly process and raise the possibility that this mechanism is conserved in related non-enveloped viruses. These results also provide insight into TRiC protein substrates and establish a rationale for the development of small-molecule inhibitors of TRiC as potential antiviral therapeutics.
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Cleavage of the C-Terminal Fragment of Reovirus μ1 Is Required for Optimal Infectivity. J Virol 2018; 92:JVI.01848-17. [PMID: 29298891 DOI: 10.1128/jvi.01848-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 12/20/2017] [Indexed: 12/12/2022] Open
Abstract
The mammalian orthoreovirus (reovirus) outer capsid, which is composed of 200 μ1/σ3 heterohexamers and a maximum of 12 σ1 trimers, contains all of the proteins that are necessary for attaching to and entering host cells. Following attachment, reovirus is internalized by receptor-mediated endocytosis and acid-dependent cathepsin proteases degrade the σ3 protein. This process generates a metastable intermediate, called infectious subviral particle (ISVP), in which the μ1 membrane penetration protein is exposed. ISVPs undergo a second structural rearrangement to deposit the genome-containing core into the host cytoplasm. The conformationally altered particle is called ISVP*. ISVP-to-ISVP* conversion culminates in the release of μ1 N- and C-terminal fragments, μ1N and Φ, respectively. Released μ1N is thought to facilitate core delivery by generating size-selective pores within the endosomal membrane, whereas the precise role of Φ, particularly in the context of viral entry, is undefined. In this report, we characterize a recombinant reovirus that fails to cleave Φ from μ1 in vitro Φ cleavage, which is not required for ISVP-to-ISVP* conversion, enhances the disruption of liposomal membranes and facilitates the recruitment of ISVP*s to the site of pore formation. Moreover, the Φ cleavage-deficient strain initiates infection of host cells less efficiently than the parental strain. These results indicate that μ1N and Φ contribute to reovirus pore forming activity.IMPORTANCE Host membranes represent a physical barrier that prevents infection. To overcome this barrier, viruses utilize diverse strategies, such as membrane fusion or membrane disruption, to access internal components of the cell. These strategies are characterized by discrete protein-protein and protein-lipid interactions. The mammalian orthoreovirus (reovirus) outer capsid undergoes a series of well-defined conformational changes, which conclude with pore formation and delivery of the viral genetic material. In this report, we characterize the role of the small, reovirus-derived Φ peptide in pore formation. Φ cleavage from the outer capsid enhances membrane disruption and facilitates the recruitment of virions to membrane-associated pores. Moreover, Φ cleavage promotes the initiation of infection. Together, these results reveal an additional component of the reovirus pore forming apparatus and highlight a strategy for penetrating host membranes.
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Berger AK, Yi H, Kearns DB, Mainou BA. Bacteria and bacterial envelope components enhance mammalian reovirus thermostability. PLoS Pathog 2017; 13:e1006768. [PMID: 29211815 PMCID: PMC5734793 DOI: 10.1371/journal.ppat.1006768] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 12/18/2017] [Accepted: 11/23/2017] [Indexed: 12/24/2022] Open
Abstract
Enteric viruses encounter diverse environments as they migrate through the gastrointestinal tract to infect their hosts. The interaction of eukaryotic viruses with members of the host microbiota can greatly impact various aspects of virus biology, including the efficiency with which viruses can infect their hosts. Mammalian orthoreovirus, a human enteric virus that infects most humans during childhood, is negatively affected by antibiotic treatment prior to infection. However, it is not known how components of the host microbiota affect reovirus infectivity. In this study, we show that reovirus virions directly interact with Gram positive and Gram negative bacteria. Reovirus interaction with bacterial cells conveys enhanced virion thermostability that translates into enhanced attachment and infection of cells following an environmental insult. Enhanced virion thermostability was also conveyed by bacterial envelope components lipopolysaccharide (LPS) and peptidoglycan (PG). Lipoteichoic acid and N-acetylglucosamine-containing polysaccharides enhanced virion stability in a serotype-dependent manner. LPS and PG also enhanced the thermostability of an intermediate reovirus particle (ISVP) that is associated with primary infection in the gut. Although LPS and PG alter reovirus thermostability, these bacterial envelope components did not affect reovirus utilization of its proteinaceous cellular receptor junctional adhesion molecule-A or cell entry kinetics. LPS and PG also did not affect the overall number of reovirus capsid proteins σ1 and σ3, suggesting their effect on virion thermostability is not mediated through altering the overall number of major capsid proteins on the virus. Incubation of reovirus with LPS and PG did not significantly affect the neutralizing efficiency of reovirus-specific antibodies. These data suggest that bacteria enhance reovirus infection of the intestinal tract by enhancing the thermal stability of the reovirus particle at a variety of temperatures through interactions between the viral particle and bacterial envelope components.
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Affiliation(s)
- Angela K. Berger
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Hong Yi
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, Georgia, United States of America
| | - Daniel B. Kearns
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Bernardo A. Mainou
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
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Sutherland DM, Aravamudhan P, Dermody TS. An Orchestra of Reovirus Receptors: Still Searching for the Conductor. Adv Virus Res 2017; 100:223-246. [PMID: 29551138 DOI: 10.1016/bs.aivir.2017.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Viruses are constantly engaged in a molecular arms race with the host, where efficient and tactical use of cellular receptors benefits critical steps in infection. Receptor use dictates initiation, establishment, and spread of viral infection to new tissues and hosts. Mammalian orthoreoviruses (reoviruses) are pervasive pathogens that use multiple receptors to overcome protective host barriers to disseminate from sites of initial infection and cause disease in young mammals. In particular, reovirus invades the central nervous system (CNS) with serotype-dependent tropism and disease. A single viral gene, encoding the attachment protein σ1, segregates with distinct patterns of CNS injury. Despite the identification and characterization of several reovirus receptors, host factors that dictate tropism via interaction with σ1 remain undefined. Here, we summarize the state of the reovirus receptor field and discuss open questions toward understanding how the reovirus attachment protein dictates CNS tropism.
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Affiliation(s)
| | | | - Terence S Dermody
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
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Zhang N, Zhang L. Key components of COPI and COPII machineries are required for chikungunya virus replication. Biochem Biophys Res Commun 2017; 493:1190-1196. [PMID: 28962860 DOI: 10.1016/j.bbrc.2017.09.142] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 09/25/2017] [Indexed: 10/18/2022]
Abstract
The infection of CHIKV is associated with cellular membranes; however whether early secretory pathways are involved in CHIKV replication remains unclear. In the present study, we have provided initial evidences that CHIKV requires both COPI and COPII for its replication. Small interfering RNAs against COPI components, including coatomer, ARFs or GBF1, suppress CHIKV replication. Moreover, CHIKV infection is abolished by the presence of ARF1 inhibitor brefeldin A or GBF1 inhibitor golgicide A. In addition, perturbation of COPII by silencing key components of COPII pathways leads to a reduction in CHIKV replication. Collectively, these observations demonstrate the importance of functional secretory pathways in the infectivity of CHIKV.
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Affiliation(s)
- Na Zhang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100176, China
| | - Leiliang Zhang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100176, China.
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Simon EJ, Howells MA, Stuart JD, Boehme KW. Serotype-Specific Killing of Large Cell Carcinoma Cells by Reovirus. Viruses 2017; 9:v9060140. [PMID: 28587298 PMCID: PMC5490817 DOI: 10.3390/v9060140] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 05/30/2017] [Accepted: 06/01/2017] [Indexed: 12/30/2022] Open
Abstract
Reovirus is under development as a therapeutic for numerous types of cancer. In contrast to other oncolytic viruses, the safety and efficacy of reovirus have not been improved through genetic manipulation. Here, we tested the oncolytic capacity of recombinant strains (rs) of prototype reovirus laboratory strains T1L and T3D (rsT1L and rsT3D, respectively) in a panel of non-small cell lung cancer (NSCLC) cell lines. We found that rsT1L was markedly more cytolytic than rsT3D in the large cell carcinoma cell lines tested, whereas killing of adenocarcinoma cell lines was comparable between rsT1L and rsT3D. Importantly, non-recombinant T1L and T3D phenocopied the kinetics and magnitude of cell death induced by recombinant strains. We identified gene segments L2, L3, and M1 as viral determinants of strain-specific differences cell killing of the large cell carcinoma cell lines. Together, these results indicate that recombinant reoviruses recapitulate the cell killing properties of non-recombinant, tissue culture-passaged strains. These studies provide a baseline for the use of reverse genetics with the specific objective of engineering more effective reovirus oncolytics. This work raises the possibility that type 1 reoviruses may have the capacity to serve as more effective oncolytics than type 3 reoviruses in some tumor types.
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Affiliation(s)
- Emily J Simon
- Department of Microbiology and Immunology and Center for Microbial Pathogenesis and Host Inflammatory Response, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Morgan A Howells
- Department of Microbiology and Immunology and Center for Microbial Pathogenesis and Host Inflammatory Response, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Johnasha D Stuart
- Department of Microbiology and Immunology and Center for Microbial Pathogenesis and Host Inflammatory Response, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Karl W Boehme
- Department of Microbiology and Immunology and Center for Microbial Pathogenesis and Host Inflammatory Response, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Stanifer ML, Rippert A, Kazakov A, Willemsen J, Bucher D, Bender S, Bartenschlager R, Binder M, Boulant S. Reovirus intermediate subviral particles constitute a strategy to infect intestinal epithelial cells by exploiting TGF-β dependent pro-survival signaling. Cell Microbiol 2016; 18:1831-1845. [PMID: 27279006 DOI: 10.1111/cmi.12626] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 06/02/2016] [Accepted: 06/02/2016] [Indexed: 12/24/2022]
Abstract
Intestinal epithelial cells (IECs) constitute the primary barrier that separates us from the outside environment. These cells, lining the surface of the intestinal tract, represent a major challenge that enteric pathogens have to face. How IECs respond to viral infection and whether enteric viruses have developed strategies to subvert IECs innate immune response remains poorly characterized. Using mammalian reovirus (MRV) as a model enteric virus, we found that the intermediate subviral particles (ISVPs), which are formed in the gut during the natural course of infection by proteolytic digestion of the reovirus virion, trigger reduced innate antiviral immune response in IECs. On the contrary, infection of IECs by virions induces a strong antiviral immune response that leads to cellular death. Additionally, we determined that virions can be sensed by both TLR and RLR pathways while ISVPs are sensed by RLR pathways only. Interestingly, we found that ISVP infected cells secrete TGF-β acting as a pro-survival factor that protects IECs against virion induced cellular death. We propose that ISVPs represent a reovirus strategy to initiate primary infection of the gut by subverting IECs innate immune system and by counteracting cellular-death pathways.
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Affiliation(s)
- Megan L Stanifer
- Schaller research group at CellNetworks, Department of Infectious Diseases, Virology, Heidelberg University, Germany
| | - Anja Rippert
- Schaller research group at CellNetworks, Department of Infectious Diseases, Virology, Heidelberg University, Germany
| | - Alexander Kazakov
- Schaller research group at CellNetworks, Department of Infectious Diseases, Virology, Heidelberg University, Germany
| | - Joschka Willemsen
- Research Group 'Dynamics of early viral infection and the innate antiviral response'.,Division Virus-associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Delia Bucher
- Schaller research group at CellNetworks, Department of Infectious Diseases, Virology, Heidelberg University, Germany
| | - Silke Bender
- Division Virus-associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ralf Bartenschlager
- Division Virus-associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marco Binder
- Research Group 'Dynamics of early viral infection and the innate antiviral response'.,Division Virus-associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Steeve Boulant
- Schaller research group at CellNetworks, Department of Infectious Diseases, Virology, Heidelberg University, Germany.,Research Group 'Cellular polarity and viral infection' (F140), German Cancer Research Center (DKFZ), Heidelberg, Germany
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A Universal Next-Generation Sequencing Protocol To Generate Noninfectious Barcoded cDNA Libraries from High-Containment RNA Viruses. mSystems 2016; 1:mSystems00039-15. [PMID: 27822536 PMCID: PMC5069770 DOI: 10.1128/msystems.00039-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 05/05/2016] [Indexed: 02/08/2023] Open
Abstract
This report establishes and validates a standard operating procedure (SOP) for select agents (SAs) and other biosafety level 3 and/or 4 (BSL-3/4) RNA viruses to rapidly generate noninfectious, barcoded cDNA amenable for next-generation sequencing (NGS). This eliminates the burden of testing all processed samples derived from high-consequence pathogens prior to transfer from high-containment laboratories to lower-containment facilities for sequencing. Our established protocol can be scaled up for high-throughput sequencing of hundreds of samples simultaneously, which can dramatically reduce the cost and effort required for NGS library construction. NGS data from this SOP can provide complete genome coverage from viral stocks and can also detect virus-specific reads from limited starting material. Our data suggest that the procedure can be implemented and easily validated by institutional biosafety committees across research laboratories. Several biosafety level 3 and/or 4 (BSL-3/4) pathogens are high-consequence, single-stranded RNA viruses, and their genomes, when introduced into permissive cells, are infectious. Moreover, many of these viruses are select agents (SAs), and their genomes are also considered SAs. For this reason, cDNAs and/or their derivatives must be tested to ensure the absence of infectious virus and/or viral RNA before transfer out of the BSL-3/4 and/or SA laboratory. This tremendously limits the capacity to conduct viral genomic research, particularly the application of next-generation sequencing (NGS). Here, we present a sequence-independent method to rapidly amplify viral genomic RNA while simultaneously abolishing both viral and genomic RNA infectivity across multiple single-stranded positive-sense RNA (ssRNA+) virus families. The process generates barcoded DNA amplicons that range in length from 300 to 1,000 bp, which cannot be used to rescue a virus and are stable to transport at room temperature. Our barcoding approach allows for up to 288 barcoded samples to be pooled into a single library and run across various NGS platforms without potential reconstitution of the viral genome. Our data demonstrate that this approach provides full-length genomic sequence information not only from high-titer virion preparations but it can also recover specific viral sequence from samples with limited starting material in the background of cellular RNA, and it can be used to identify pathogens from unknown samples. In summary, we describe a rapid, universal standard operating procedure that generates high-quality NGS libraries free of infectious virus and infectious viral RNA. IMPORTANCE This report establishes and validates a standard operating procedure (SOP) for select agents (SAs) and other biosafety level 3 and/or 4 (BSL-3/4) RNA viruses to rapidly generate noninfectious, barcoded cDNA amenable for next-generation sequencing (NGS). This eliminates the burden of testing all processed samples derived from high-consequence pathogens prior to transfer from high-containment laboratories to lower-containment facilities for sequencing. Our established protocol can be scaled up for high-throughput sequencing of hundreds of samples simultaneously, which can dramatically reduce the cost and effort required for NGS library construction. NGS data from this SOP can provide complete genome coverage from viral stocks and can also detect virus-specific reads from limited starting material. Our data suggest that the procedure can be implemented and easily validated by institutional biosafety committees across research laboratories.
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Abstract
Chikungunya virus (CHIKV) is a reemerging alphavirus that has caused epidemics of fever, arthralgia, and rash worldwide. There are currently no licensed vaccines or antiviral therapies available for the prevention or treatment of CHIKV disease. We conducted a high-throughput, chemical compound screen that identified digoxin, a cardiac glycoside that blocks the sodium-potassium ATPase, as a potent inhibitor of CHIKV infection. Treatment of human cells with digoxin or a related cardiac glycoside, ouabain, resulted in a dose-dependent decrease in infection by CHIKV. Inhibition by digoxin was cell type-specific, as digoxin treatment of either murine or mosquito cells did not diminish CHIKV infection. Digoxin displayed antiviral activity against other alphaviruses, including Ross River virus and Sindbis virus, as well as mammalian reovirus and vesicular stomatitis virus. The digoxin-mediated block to CHIKV and reovirus infection occurred at one or more postentry steps, as digoxin inhibition was not bypassed by fusion of CHIKV at the plasma membrane or infection with cell surface-penetrating reovirus entry intermediates. Selection of digoxin-resistant CHIKV variants identified multiple mutations in the nonstructural proteins required for replication complex formation and synthesis of viral RNA. These data suggest a role for the sodium-potassium ATPase in promoting postentry steps of CHIKV replication and provide rationale for modulation of this pathway as a broad-spectrum antiviral strategy. Mitigation of disease induced by globally spreading, mosquito-borne arthritogenic alphaviruses requires the development of new antiviral strategies. High-throughput screening of clinically tested compounds provides a rapid means to identify undiscovered, antiviral functions for well-characterized therapeutics and illuminate host pathways required for viral infection. Our study describes the potent inhibition of CHIKV and related alphaviruses by the cardiac glycoside digoxin and demonstrates a function for the sodium-potassium ATPase in CHIKV infection.
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Gong J, Sachdev E, Mita AC, Mita MM. Clinical development of reovirus for cancer therapy: An oncolytic virus with immune-mediated antitumor activity. World J Methodol 2016; 6:25-42. [PMID: 27019795 PMCID: PMC4804250 DOI: 10.5662/wjm.v6.i1.25] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 01/26/2016] [Accepted: 02/17/2016] [Indexed: 02/06/2023] Open
Abstract
Reovirus is a double-stranded RNA virus with demonstrated oncolysis or preferential replication in cancer cells. The oncolytic properties of reovirus appear to be dependent, in part, on activated Ras signaling. In addition, Ras-transformation promotes reovirus oncolysis by affecting several steps of the viral life cycle. Reovirus-mediated immune responses can present barriers to tumor targeting, serve protective functions against reovirus systemic toxicity, and contribute to therapeutic efficacy through antitumor immune-mediated effects via innate and adaptive responses. Preclinical studies have demonstrated the broad anticancer activity of wild-type, unmodified type 3 Dearing strain reovirus (Reolysin®) across a spectrum of malignancies. The development of reovirus as an anticancer agent and available clinical data reported from 22 clinical trials will be reviewed.
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Luethy LN, Erickson AK, Jesudhasan PR, Ikizler M, Dermody TS, Pfeiffer JK. Comparison of three neurotropic viruses reveals differences in viral dissemination to the central nervous system. Virology 2016; 487:1-10. [PMID: 26479325 PMCID: PMC4679581 DOI: 10.1016/j.virol.2015.09.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 11/28/2022]
Abstract
Neurotropic viruses initiate infection in peripheral tissues prior to entry into the central nervous system (CNS). However, mechanisms of dissemination are not completely understood. We used genetically marked viruses to compare dissemination of poliovirus, yellow fever virus 17D (YFV-17D), and reovirus type 3 Dearing in mice from a hind limb intramuscular inoculation site to the sciatic nerve, spinal cord, and brain. While YFV-17D likely entered the CNS via blood, poliovirus and reovirus likely entered the CNS by transport through the sciatic nerve to the spinal cord. We found that dissemination was inefficient in adult immune-competent mice for all three viruses, particularly reovirus. Dissemination of all viruses was more efficient in immune-deficient mice. Although poliovirus and reovirus both accessed the CNS by transit through the sciatic nerve, stimulation of neuronal transport by muscle damage enhanced dissemination only of poliovirus. Our results suggest that these viruses access the CNS using different pathways.
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Affiliation(s)
- Lauren N Luethy
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Andrea K Erickson
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Palmy R Jesudhasan
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Mine Ikizler
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA; Elizabeth B. Lamb Center for Pediatric Research, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Terence S Dermody
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA; Elizabeth B. Lamb Center for Pediatric Research, Vanderbilt University School of Medicine, Nashville, TN, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Julie K Pfeiffer
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Serotonin Receptor Agonist 5-Nonyloxytryptamine Alters the Kinetics of Reovirus Cell Entry. J Virol 2015; 89:8701-12. [PMID: 26109733 DOI: 10.1128/jvi.00739-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 06/17/2015] [Indexed: 01/15/2023] Open
Abstract
UNLABELLED Mammalian orthoreoviruses (reoviruses) are nonenveloped double-stranded RNA viruses that infect most mammalian species, including humans. Reovirus binds to cell surface glycans, junctional adhesion molecule A (JAM-A), and the Nogo-1 receptor (depending on the cell type) and enters cells by receptor-mediated endocytosis. Within the endocytic compartment, reovirus undergoes stepwise disassembly, which is followed by release of the transcriptionally active viral core into the cytoplasm. In a small-molecule screen to identify host mediators of reovirus infection, we found that treatment of cells with 5-nonyloxytryptamine (5-NT), a prototype serotonin receptor agonist, diminished reovirus cytotoxicity. 5-NT also blocked reovirus infection. In contrast, treatment of cells with methiothepin mesylate, a serotonin antagonist, enhanced infection by reovirus. 5-NT did not alter cell surface expression of JAM-A or attachment of reovirus to cells. However, 5-NT altered the distribution of early endosomes with a concomitant impairment of reovirus transit to late endosomes and a delay in reovirus disassembly. Consistent with an inhibition of viral disassembly, 5-NT treatment did not alter infection by in vitro-generated infectious subvirion particles, which bind to JAM-A but bypass a requirement for proteolytic uncoating in endosomes to infect cells. We also found that treatment of cells with 5-NT decreased the infectivity of alphavirus chikungunya virus and coronavirus mouse hepatitis virus. These data suggest that serotonin receptor signaling influences cellular activities that regulate entry of diverse virus families and provides a new, potentially broad-spectrum target for antiviral drug development. IMPORTANCE Identification of well-characterized small molecules that modulate viral infection can accelerate development of antiviral therapeutics while also providing new tools to increase our understanding of the cellular processes that underlie virus-mediated cell injury. We conducted a small-molecule screen to identify compounds capable of inhibiting cytotoxicity caused by reovirus, a prototype double-stranded RNA virus. We found that 5-nonyloxytryptamine (5-NT) impairs reovirus infection by altering viral transport during cell entry. Remarkably, 5-NT also inhibits infection by an alphavirus and a coronavirus. The antiviral properties of 5-NT suggest that serotonin receptor signaling is an important regulator of infection by diverse virus families and illuminate a potential new drug target.
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Lai CM, Boehme KW, Pruijssers AJ, Parekh VV, Van Kaer L, Parkos CA, Dermody TS. Endothelial JAM-A promotes reovirus viremia and bloodstream dissemination. J Infect Dis 2014; 211:383-93. [PMID: 25149763 DOI: 10.1093/infdis/jiu476] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Viruses that cause systemic disease often spread through the bloodstream to infect target tissues. Although viremia is an important step in the pathogenesis of many viruses, how viremia is established is not well understood. Reovirus has been used to dissect mechanisms of viral pathogenesis and is being evaluated in clinical trials as an oncolytic agent. After peroral entry into mice, reovirus replicates within the gastrointestinal tract and disseminates systemically via hematogenous or neural routes. Junctional adhesion molecule-A (JAM-A) is a tight junction protein that serves as a receptor for reovirus. JAM-A is required for establishment of viremia and viral spread to sites of secondary replication. JAM-A also is expressed on the surface of circulating hematopoietic cells. To determine contributions of endothelial and hematopoietic JAM-A to reovirus dissemination and pathogenesis, we generated strains of mice with altered JAM-A expression in these cell types and assessed bloodstream spread of reovirus strain type 1 Lang (T1L), which disseminates solely by hematogenous routes. We found that endothelial JAM-A but not hematopoietic JAM-A facilitates reovirus T1L bloodstream entry and egress. Understanding how viruses establish viremia may aid in development of inhibitors of this critical step in viral pathogenesis and foster engineering of improved oncolytic viral vectors.
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Affiliation(s)
- Caroline M Lai
- Department of Pathology, Microbiology, and Immunology Elizabeth B. Lamb Center for Pediatric Research
| | - Karl W Boehme
- Elizabeth B. Lamb Center for Pediatric Research Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Andrea J Pruijssers
- Elizabeth B. Lamb Center for Pediatric Research Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | - Luc Van Kaer
- Department of Pathology, Microbiology, and Immunology
| | - Charles A Parkos
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Terence S Dermody
- Department of Pathology, Microbiology, and Immunology Elizabeth B. Lamb Center for Pediatric Research Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
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Residue 82 of the Chikungunya virus E2 attachment protein modulates viral dissemination and arthritis in mice. J Virol 2014; 88:12180-92. [PMID: 25142598 DOI: 10.1128/jvi.01672-14] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that has reemerged to cause profound epidemics of fever, rash, and arthralgia throughout sub-Saharan Africa, Southeast Asia, and the Caribbean. Like other arthritogenic alphaviruses, mechanisms of CHIKV pathogenesis are not well defined. Using the attenuated CHIKV strain 181/25 and virulent strain AF15561, we identified a residue in the E2 viral attachment protein that is a critical determinant of viral replication in cultured cells and pathogenesis in vivo. Viruses containing an arginine at E2 residue 82 displayed enhanced infectivity in mammalian cells but reduced infectivity in mosquito cells and diminished virulence in a mouse model of CHIKV disease. Mice inoculated with virus containing an arginine at this position exhibited reduced swelling at the site of inoculation with a concomitant decrease in the severity of necrosis in joint-associated tissues. Viruses containing a glycine at E2 residue 82 produced higher titers in the spleen and serum at early times postinfection. Using wild-type and glycosaminoglycan (GAG)-deficient Chinese hamster ovary (CHO) cell lines and soluble GAGs, we found that an arginine at residue 82 conferred greater dependence on GAGs for infection of mammalian cells. These data suggest that CHIKV E2 interactions with GAGs diminish dissemination to lymphoid tissue, establishment of viremia, and activation of inflammatory responses early in infection. Collectively, these results suggest a function for GAG utilization in regulating CHIKV tropism and host responses that contribute to arthritis. IMPORTANCE CHIKV is a reemerging alphavirus of global significance with high potential to spread into new, immunologically naive populations. The severity of CHIKV disease, particularly its propensity for chronic musculoskeletal manifestations, emphasizes the need for identification of genetic determinants that dictate CHIKV virulence in the host. To better understand mechanisms of CHIKV pathogenesis, we probed the function of an amino acid polymorphism in the E2 viral attachment protein using a mouse model of CHIKV musculoskeletal disease. In addition to influencing glycosaminoglycan utilization, we identified roles for this polymorphism in differential infection of mammalian and mosquito cells and targeting of CHIKV to specific tissues within infected mice. These studies demonstrate a correlation between CHIKV tissue tropism and virus-induced pathology modulated by a single polymorphism in E2, which in turn illuminates potential targets for vaccine and antiviral drug development.
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Gong J, Mita MM. Activated ras signaling pathways and reovirus oncolysis: an update on the mechanism of preferential reovirus replication in cancer cells. Front Oncol 2014; 4:167. [PMID: 25019061 PMCID: PMC4071564 DOI: 10.3389/fonc.2014.00167] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 06/11/2014] [Indexed: 12/31/2022] Open
Abstract
The development of wild-type, unmodified Type 3 Dearing strain reovirus as an anticancer agent has currently expanded to 32 clinical trials (both completed and ongoing) involving reovirus in the treatment of cancer. It has been more than 30 years since the potential of reovirus as an anticancer agent was first identified in studies that demonstrated the preferential replication of reovirus in transformed cell lines but not in normal cells. Later investigations have revealed the involvement of activated Ras signaling pathways (both upstream and downstream) and key steps of the reovirus infectious cycle in promoting preferential replication in cancer cells with reovirus-induced cancer cell death occurring through necrotic, apoptotic, and autophagic pathways. There is increasing evidence that reovirus-induced antitumor immunity involving both innate and adaptive responses also contributes to therapeutic efficacy though this discussion is beyond the scope of this article. Here, we review our current understanding of the mechanism of oncolysis contributing to the broad anticancer activity of reovirus. Further understanding of reovirus oncolysis is critical in enhancing the clinical development and efficacy of reovirus.
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Affiliation(s)
- Jun Gong
- Department of Medicine, Cedars-Sinai Medical Center , Los Angeles, CA , USA
| | - Monica M Mita
- Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA
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A single-amino-acid polymorphism in Chikungunya virus E2 glycoprotein influences glycosaminoglycan utilization. J Virol 2013; 88:2385-97. [PMID: 24371059 DOI: 10.1128/jvi.03116-13] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Chikungunya virus (CHIKV) is a reemerging arbovirus responsible for outbreaks of infection throughout Asia and Africa, causing an acute illness characterized by fever, rash, and polyarthralgia. Although CHIKV infects a broad range of host cells, little is known about how CHIKV binds and gains access to the target cell interior. In this study, we tested whether glycosaminoglycan (GAG) binding is required for efficient CHIKV replication using CHIKV vaccine strain 181/25 and clinical isolate SL15649. Preincubation of strain 181/25, but not SL15649, with soluble GAGs resulted in dose-dependent inhibition of infection. While parental Chinese hamster ovary (CHO) cells are permissive for both strains, neither strain efficiently bound to or infected mutant CHO cells devoid of GAG expression. Although GAGs appear to be required for efficient binding of both strains, they exhibit differential requirements for GAGs, as SL15649 readily infected cells that express excess chondroitin sulfate but that are devoid of heparan sulfate, whereas 181/25 did not. We generated a panel of 181/25 and SL15649 variants containing reciprocal amino acid substitutions at positions 82 and 318 in the E2 glycoprotein. Reciprocal exchange at residue 82 resulted in a phenotype switch; Gly(82) results in efficient infection of mutant CHO cells but a decrease in heparin binding, whereas Arg(82) results in reduced infectivity of mutant cells and an increase in heparin binding. These results suggest that E2 residue 82 is a primary determinant of GAG utilization, which likely mediates attenuation of vaccine strain 181/25. IMPORTANCE Chikungunya virus (CHIKV) infection causes a debilitating rheumatic disease that can persist for months to years, and yet there are no licensed vaccines or antiviral therapies. Like other alphaviruses, CHIKV displays broad tissue tropism, which is thought to be influenced by virus-receptor interactions. In this study, we determined that cell-surface glycosaminoglycans are utilized by both a vaccine strain and a clinical isolate of CHIKV to mediate virus binding. We also identified an amino acid polymorphism in the viral E2 attachment protein that influences utilization of glycosaminoglycans. These data enhance an understanding of the viral and host determinants of CHIKV cell entry, which may foster development of new antivirals that act by blocking this key step in viral infection.
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The μ1 72-96 loop controls conformational transitions during reovirus cell entry. J Virol 2013; 87:13532-42. [PMID: 24089575 DOI: 10.1128/jvi.01899-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The reovirus outer capsid protein μ1 forms a lattice surrounding the viral core. In the native state, μ1 determines the environmental stability of the viral capsid. Additionally, during cell entry, μ1 undergoes structural rearrangements that facilitate delivery of the viral cores across the membrane. To determine how the capsid-stabilizing functions of μ1 impinge on the capacity of μ1 to undergo conformational changes required for cell entry, we characterized viruses with mutations engineered at charged residues within the μ1 loop formed by residues 72 to 96 (72-96 loop). This loop is proposed to stabilize the capsid by mediating interactions between neighboring μ1 trimers and between trimers and the core. We found that mutations at Glu89 (E89) within this loop produced viruses with compromised efficiency for completing their replication cycle. ISVPs of E89 mutants converted to ISVP*s more readily than those of wild-type viruses. The E89 mutants yielded revertants with second-site substitutions within regions that mediate interaction between μ1 trimers at a site distinct from the 72-96 loop. These viruses also contained changes in regions that control interactions within μ1 trimers. Viruses containing these second-site changes displayed restored plaque phenotypes and were capable of undergoing ISVP-to-ISVP* conversion in a regulated manner. These findings highlight regions of μ1 that stabilize the reovirus capsid and demonstrate that an enhanced propensity to form ISVP*s in an unregulated manner compromises viral fitness.
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