1
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Sake SM, Zhang X, Rajak MK, Urbanek-Quaing M, Carpentier A, Gunesch AP, Grethe C, Matthaei A, Rückert J, Galloux M, Larcher T, Le Goffic R, Hontonnou F, Chatterjee AK, Johnson K, Morwood K, Rox K, Elgaher WAM, Huang J, Wetzke M, Hansen G, Fischer N, Eléouët JF, Rameix-Welti MA, Hirsch AKH, Herold E, Empting M, Lauber C, Schulz TF, Krey T, Haid S, Pietschmann T. Drug repurposing screen identifies lonafarnib as respiratory syncytial virus fusion protein inhibitor. Nat Commun 2024; 15:1173. [PMID: 38332002 PMCID: PMC10853176 DOI: 10.1038/s41467-024-45241-y] [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: 12/19/2022] [Accepted: 01/16/2024] [Indexed: 02/10/2024] Open
Abstract
Respiratory syncytial virus (RSV) is a common cause of acute lower respiratory tract infection in infants, older adults and the immunocompromised. Effective directly acting antivirals are not yet available for clinical use. To address this, we screen the ReFRAME drug-repurposing library consisting of 12,000 small molecules against RSV. We identify 21 primary candidates including RSV F and N protein inhibitors, five HSP90 and four IMPDH inhibitors. We select lonafarnib, a licensed farnesyltransferase inhibitor, and phase III candidate for hepatitis delta virus (HDV) therapy, for further follow-up. Dose-response analyses and plaque assays confirm the antiviral activity (IC50: 10-118 nM). Passaging of RSV with lonafarnib selects for phenotypic resistance and fixation of mutations in the RSV fusion protein (T335I and T400A). Lentiviral pseudotypes programmed with variant RSV fusion proteins confirm that lonafarnib inhibits RSV cell entry and that these mutations confer lonafarnib resistance. Surface plasmon resonance reveals RSV fusion protein binding of lonafarnib and co-crystallography identifies the lonafarnib binding site within RSV F. Oral administration of lonafarnib dose-dependently reduces RSV virus load in a murine infection model using female mice. Collectively, this work provides an overview of RSV drug repurposing candidates and establishes lonafarnib as a bona fide fusion protein inhibitor.
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Affiliation(s)
- Svenja M Sake
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Xiaoyu Zhang
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Manoj Kumar Rajak
- Institute of Virology, Hannover Medical School, Hannover, Germany
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, Luebeck, Germany
| | - Melanie Urbanek-Quaing
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Arnaud Carpentier
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Antonia P Gunesch
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Christina Grethe
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Alina Matthaei
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Jessica Rückert
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Marie Galloux
- Université Paris-Saclay, INRAE, UVSQ, VIM, Jouy-en-Josas, France
| | | | - Ronan Le Goffic
- Université Paris-Saclay, INRAE, UVSQ, VIM, Jouy-en-Josas, France
| | | | | | | | | | - Katharina Rox
- Department of Chemical Biology, Helmholtz Center of Infection Research, Braunschweig, Germany
- German Centre for Infection Research, Partner site Braunschweig-Hannover, Braunschweig, Germany
| | - Walid A M Elgaher
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)-HZI, Saarbrücken, Germany
- Department of Pharmacy, Saarland University, Saarbrücken, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Jiabin Huang
- Insitute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin Wetzke
- Department for Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- German Center for Lung Research, Partner Site Hannover, BREATH, Hannover, Germany
| | - Gesine Hansen
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Department for Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- German Center for Lung Research, Partner Site Hannover, BREATH, Hannover, Germany
| | - Nicole Fischer
- Insitute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Marie-Anne Rameix-Welti
- Université Paris-Saclay, Université de Versailles St. Quentin; UMR 1173 (2I), INSERM; Assistance Publique des Hôpitaux de Paris, Hôpital Ambroise Paré, Laboratoire de Microbiologie, DMU15, Versailles, France
| | - Anna K H Hirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)-HZI, Saarbrücken, Germany
- Department of Pharmacy, Saarland University, Saarbrücken, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- Helmholtz International Lab for Anti-infectives, HZI, Braunschweig, Germany
| | - Elisabeth Herold
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, Luebeck, Germany
| | - Martin Empting
- German Centre for Infection Research, Partner site Braunschweig-Hannover, Braunschweig, Germany
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)-HZI, Saarbrücken, Germany
- Department of Pharmacy, Saarland University, Saarbrücken, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Chris Lauber
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Thomas F Schulz
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Partner site Braunschweig-Hannover, Braunschweig, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Thomas Krey
- Institute of Virology, Hannover Medical School, Hannover, Germany
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, Luebeck, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- German Center for Infection Research, Partner Site Hamburg-Luebeck-Borstel-Riems, Luebeck, Germany
| | - Sibylle Haid
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany.
| | - Thomas Pietschmann
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany.
- German Centre for Infection Research, Partner site Braunschweig-Hannover, Braunschweig, Germany.
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany.
- Helmholtz International Lab for Anti-infectives, HZI, Braunschweig, Germany.
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Li XM, Wang SP, Wang JY, Tang T, Wan B, Zeng L, Wang J, Chu BB, Yang GY, Pan JJ. RhoA suppresses pseudorabies virus replication in vitro. Virol J 2023; 20:264. [PMID: 37968757 PMCID: PMC10652432 DOI: 10.1186/s12985-023-02229-2] [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: 08/29/2023] [Accepted: 11/05/2023] [Indexed: 11/17/2023] Open
Abstract
The porcine pseudorabies virus (PRV) is one of the most devastating pathogens and brings great economic losses to the swine industry worldwide. Viruses are intracellular parasites that have evolved numerous strategies to subvert and utilize different host processes for their life cycle. Among the different systems of the host cell, the cytoskeleton is one of the most important which not only facilitate viral invasion and spread into neighboring cells, but also help viruses to evade the host immune system. RhoA is a key regulator of cytoskeleton system that may participate in virus infection. In this study, we characterized the function of RhoA in the PRV replication by chemical drugs treatment, gene knockdown and gene over-expression strategy. Inhibition of RhoA by specific inhibitor and gene knockdown promoted PRV proliferation. On the contrary, overexpression of RhoA or activation of RhoA by chemical drug inhibited PRV infection. Besides, our data demonstrated that PRV infection induced the disruption of actin stress fiber, which was consistent with previous report. In turn, the actin specific inhibitor cytochalasin D markedly disrupted the normal fibrous structure of intracellular actin cytoskeleton and decreased the PRV replication, suggesting that actin cytoskeleton polymerization contributed to PRV replication in vitro. In summary, our data displayed that RhoA was a host restriction factor that inhibited PRV replication, which may deepen our understanding the pathogenesis of PRV and provide further insight into the prevention of PRV infection and the development of anti-viral drugs.
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Affiliation(s)
- Xin-Man Li
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China
| | - Shi-Ping Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China
| | - Jin-Yuan Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China
| | - Ting Tang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China
| | - Bo Wan
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Henan Agricultural University, Zhengzhou, 450046, China
| | - Lei Zeng
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China
| | - Jiang Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Henan Agricultural University, Zhengzhou, 450046, China
| | - Bei-Bei Chu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Henan Agricultural University, Zhengzhou, 450046, China
| | - Guo-Yu Yang
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China
- College of Animal Science and Technology, Henan University of Animal Husbandry and Economy, Zhengzhou, 450047, China
| | - Jia-Jia Pan
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China.
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Zhengzhou, 450046, China.
- Key Laboratory of Animal Growth and Development of Henan Province, Zhengzhou, 450046, China.
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Henan Agricultural University, Zhengzhou, 450046, China.
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3
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Sugrue RJ, Tan BH. Defining the Assembleome of the Respiratory Syncytial Virus. Subcell Biochem 2023; 106:227-249. [PMID: 38159230 DOI: 10.1007/978-3-031-40086-5_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
During respiratory syncytial virus (RSV) particle assembly, the mature RSV particles form as filamentous projections on the surface of RSV-infected cells. The RSV assembly process occurs at the / on the cell surface that is modified by a virus infection, involving a combination of several different host cell factors and cellular processes. This induces changes in the lipid composition and properties of these lipid microdomains, and the virus-induced activation of associated Rho GTPase signaling networks drives the remodeling of the underlying filamentous actin (F-actin) cytoskeleton network. The modified sites that form on the surface of the infected cells form the nexus point for RSV assembly, and in this review chapter, they are referred to as the RSV assembleome. This is to distinguish these unique membrane microdomains that are formed during virus infection from the corresponding membrane microdomains that are present at the cell surface prior to infection. In this article, an overview of the current understanding of the processes that drive the formation of the assembleome during RSV particle assembly is given.
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Affiliation(s)
- Richard J Sugrue
- School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore.
| | - Boon Huan Tan
- LKC School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore
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4
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Mucke HA. Drug Repurposing Patent Applications July–September 2022. Assay Drug Dev Technol 2022; 20:359-366. [DOI: 10.1089/adt.2022.097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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5
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Role of ARP2/3 Complex-Driven Actin Polymerization in RSV Infection. Pathogens 2021; 11:pathogens11010026. [PMID: 35055974 PMCID: PMC8781601 DOI: 10.3390/pathogens11010026] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/14/2021] [Accepted: 12/20/2021] [Indexed: 01/30/2023] Open
Abstract
Respiratory syncytial virus (RSV) is the leading viral agent causing bronchiolitis and pneumonia in children under five years old worldwide. The RSV infection cycle starts with macropinocytosis-based entry into the host airway epithelial cell membrane, followed by virus transcription, replication, assembly, budding, and spread. It is not surprising that the host actin cytoskeleton contributes to different stages of the RSV replication cycle. RSV modulates actin-related protein 2/3 (ARP2/3) complex-driven actin polymerization for a robust filopodia induction on the infected lung epithelial A549 cells, which contributes to the virus’s budding, and cell-to-cell spread. Thus, a comprehensive understanding of RSV-induced cytoskeletal modulation and its role in lung pathobiology may identify novel intervention strategies. This review will focus on the role of the ARP2/3 complex in RSV’s pathogenesis and possible therapeutic targets to the ARP2/3 complex for RSV.
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6
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Malhi M, Norris MJ, Duan W, Moraes TJ, Maynes JT. Statin-mediated disruption of Rho GTPase prenylation and activity inhibits respiratory syncytial virus infection. Commun Biol 2021; 4:1239. [PMID: 34716403 PMCID: PMC8556396 DOI: 10.1038/s42003-021-02754-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 10/06/2021] [Indexed: 11/28/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a leading cause of severe respiratory tract infections in children. To uncover new antiviral therapies, we developed a live cell-based high content screening approach for rapid identification of RSV inhibitors and characterized five drug classes which inhibit the virus. Among the molecular targets for each hit, there was a strong functional enrichment in lipid metabolic pathways. Modulation of lipid metabolites by statins, a key hit from our screen, decreases the production of infectious virus through a combination of cholesterol and isoprenoid-mediated effects. Notably, RSV infection globally upregulates host protein prenylation, including the prenylation of Rho GTPases. Treatment by statins or perillyl alcohol, a geranylgeranyltransferase inhibitor, reduces infection in vitro. Of the Rho GTPases assayed in our study, a loss in Rac1 activity strongly inhibits the virus through a decrease in F protein surface expression. Our findings provide new insight into the importance of host lipid metabolism to RSV infection and highlight geranylgeranyltransferases as an antiviral target for therapeutic development.
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Affiliation(s)
- Manpreet Malhi
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Michael J Norris
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Wenming Duan
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Theo J Moraes
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Paediatrics, Division of Respiratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Jason T Maynes
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
- Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
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7
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Segatori VI, Garona J, Caligiuri LG, Bizzotto J, Lavignolle R, Toro A, Sanchis P, Spitzer E, Krolewiecki A, Gueron G, Alonso DF. Effect of Ivermectin and Atorvastatin on Nuclear Localization of Importin Alpha and Drug Target Expression Profiling in Host Cells from Nasopharyngeal Swabs of SARS-CoV-2- Positive Patients. Viruses 2021; 13:2084. [PMID: 34696514 PMCID: PMC8537229 DOI: 10.3390/v13102084] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/01/2021] [Accepted: 10/11/2021] [Indexed: 01/07/2023] Open
Abstract
Nuclear transport and vesicle trafficking are key cellular functions involved in the pathogenesis of RNA viruses. Among other pleiotropic effects on virus-infected host cells, ivermectin (IVM) inhibits nuclear transport mechanisms mediated by importins and atorvastatin (ATV) affects actin cytoskeleton-dependent trafficking controlled by Rho GTPases signaling. In this work, we first analyzed the response to infection in nasopharyngeal swabs from SARS-CoV-2-positive and -negative patients by assessing the gene expression of the respective host cell drug targets importins and Rho GTPases. COVID-19 patients showed alterations in KPNA3, KPNA5, KPNA7, KPNB1, RHOA, and CDC42 expression compared with non-COVID-19 patients. An in vitro model of infection with Poly(I:C), a synthetic analog of viral double-stranded RNA, triggered NF-κB activation, an effect that was halted by IVM and ATV treatment. Importin and Rho GTPases gene expression was also impaired by these drugs. Furthermore, through confocal microscopy, we analyzed the effects of IVM and ATV on nuclear to cytoplasmic importin α distribution, alone or in combination. Results showed a significant inhibition of importin α nuclear accumulation under IVM and ATV treatments. These findings confirm transcriptional alterations in importins and Rho GTPases upon SARS-CoV-2 infection and point to IVM and ATV as valid drugs to impair nuclear localization of importin α when used at clinically-relevant concentrations.
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Affiliation(s)
- Valeria Inés Segatori
- Centro de Oncología Molecular y Traslacional y Plataforma de Servicios Biotecnológicos, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal B1876BXD, Argentina; (V.I.S.); (J.G.); (L.G.C.)
| | - Juan Garona
- Centro de Oncología Molecular y Traslacional y Plataforma de Servicios Biotecnológicos, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal B1876BXD, Argentina; (V.I.S.); (J.G.); (L.G.C.)
- Centro de Medicina Traslacional, Hospital El Cruce, Florencio Varela B1888AAE, Argentina
| | - Lorena Grisel Caligiuri
- Centro de Oncología Molecular y Traslacional y Plataforma de Servicios Biotecnológicos, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal B1876BXD, Argentina; (V.I.S.); (J.G.); (L.G.C.)
| | - Juan Bizzotto
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Biológica, Intendente Guiraldes 2160, Buenos Aires C1428EGA, Argentina; (J.B.); (R.L.); (A.T.); (P.S.)
- CONICET—Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | - Rosario Lavignolle
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Biológica, Intendente Guiraldes 2160, Buenos Aires C1428EGA, Argentina; (J.B.); (R.L.); (A.T.); (P.S.)
- CONICET—Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | - Ayelén Toro
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Biológica, Intendente Guiraldes 2160, Buenos Aires C1428EGA, Argentina; (J.B.); (R.L.); (A.T.); (P.S.)
- CONICET—Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | - Pablo Sanchis
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Biológica, Intendente Guiraldes 2160, Buenos Aires C1428EGA, Argentina; (J.B.); (R.L.); (A.T.); (P.S.)
- CONICET—Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | - Eduardo Spitzer
- Laboratorio Elea-Phoenix, Los Polvorines B1613AUE, Argentina;
| | - Alejandro Krolewiecki
- Instituto de Investigaciones de Enfermedades Tropicales (IIET-CONICET), Sede Regional Orán, Universidad Nacional de Salta, Orán A4530ANQ, Argentina;
| | - Geraldine Gueron
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Biológica, Intendente Guiraldes 2160, Buenos Aires C1428EGA, Argentina; (J.B.); (R.L.); (A.T.); (P.S.)
- CONICET—Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | - Daniel Fernando Alonso
- Centro de Oncología Molecular y Traslacional y Plataforma de Servicios Biotecnológicos, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal B1876BXD, Argentina; (V.I.S.); (J.G.); (L.G.C.)
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8
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Linfield DT, Gao N, Raduka A, Harford TJ, Piedimonte G, Rezaee F. RSV attenuates epithelial cell restitution by inhibiting actin cytoskeleton-dependent cell migration. Am J Physiol Lung Cell Mol Physiol 2021; 321:L189-L203. [PMID: 34010080 DOI: 10.1152/ajplung.00118.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The airway epithelium's ability to repair itself after injury, known as epithelial restitution, is an essential mechanism enabling the respiratory tract's normal functions. Respiratory Syncytial Virus (RSV) is the leading cause of lower respiratory tract infections worldwide. We sought to determine whether RSV delays the airway epithelium wound repair process both in vitro and in vivo. We found that RSV infection attenuated epithelial cell migration, a step in wound repair, promoted stress fiber formation, and mediated assembly of large focal adhesions (FA). Inhibition of Rho kinase (ROCK), a master regulator of actin function, reversed these effects. There was increased RhoA and phospho-myosin light chain (pMLC2) following RSV infection. In vivo, mice were intraperitoneally inoculated with naphthalene to induce lung injury, followed by RSV infection. RSV infection delayed re-epithelialization. There were increased concentrations of pMLC2 in day 7 naphthalene plus RSV animals which normalized by day 14. This study suggests a key mechanism by which RSV infection delays wound healing.
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Affiliation(s)
| | - Nannan Gao
- Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, United States
| | - Andjela Raduka
- Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, United States
| | - Terri J Harford
- Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, United States
| | | | - Fariba Rezaee
- Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, United States.,Center for Pediatric Pulmonology, Cleveland Clinic Children's, Cleveland, Ohio, United States
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9
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Ravi LI, Tan TJ, Tan BH, Sugrue RJ. Virus-induced activation of the rac1 protein at the site of respiratory syncytial virus assembly is a requirement for virus particle assembly on infected cells. Virology 2021; 557:86-99. [PMID: 33677389 DOI: 10.1016/j.virol.2021.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/17/2020] [Accepted: 02/16/2021] [Indexed: 12/13/2022]
Abstract
The distributions of the rac1, rhoA and cdc42 proteins in respiratory syncytial virus (RSV) infected cells was examined. All three rhoGTPases were detected within inclusion bodies, and while the rhoA and rac1 proteins were associated with virus filaments, only the rac1 protein was localised throughout the virus filaments. RSV infection led to increased rac1 protein activation, and using the rac1 protein inhibitor NS23766 we provided evidence that the increased rac1 activation occurred at the site of RSV assembly and facilitated F-actin remodeling during virus morphogenesis. A non-infectious virus-like particle (VLP) assay showed that the RSV VLPs formed in lipid-raft microdomains containing the rac1 protein, together with F-actin and filamin-1 (cell proteins associated with virus filaments). This provided evidence that the virus envelope proteins are trafficked to membrane microdomains containing the rac1 protein. Collectively, these data provide evidence that the rac1 protein plays a direct role in the RSV assembly process.
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Affiliation(s)
- Laxmi Iyer Ravi
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Timothy J Tan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Boon Huan Tan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore; Defense Medical and Environment Research Institute, DSO National Laboratories, 27 Medical Drive, 117510, Singapore; Infection and Immunity, Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore, 308232, Singapore
| | - Richard J Sugrue
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore.
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Leroy H, Han M, Woottum M, Bracq L, Bouchet J, Xie M, Benichou S. Virus-Mediated Cell-Cell Fusion. Int J Mol Sci 2020; 21:E9644. [PMID: 33348900 PMCID: PMC7767094 DOI: 10.3390/ijms21249644] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 02/07/2023] Open
Abstract
Cell-cell fusion between eukaryotic cells is a general process involved in many physiological and pathological conditions, including infections by bacteria, parasites, and viruses. As obligate intracellular pathogens, viruses use intracellular machineries and pathways for efficient replication in their host target cells. Interestingly, certain viruses, and, more especially, enveloped viruses belonging to different viral families and including human pathogens, can mediate cell-cell fusion between infected cells and neighboring non-infected cells. Depending of the cellular environment and tissue organization, this virus-mediated cell-cell fusion leads to the merge of membrane and cytoplasm contents and formation of multinucleated cells, also called syncytia, that can express high amount of viral antigens in tissues and organs of infected hosts. This ability of some viruses to trigger cell-cell fusion between infected cells as virus-donor cells and surrounding non-infected target cells is mainly related to virus-encoded fusion proteins, known as viral fusogens displaying high fusogenic properties, and expressed at the cell surface of the virus-donor cells. Virus-induced cell-cell fusion is then mediated by interactions of these viral fusion proteins with surface molecules or receptors involved in virus entry and expressed on neighboring non-infected cells. Thus, the goal of this review is to give an overview of the different animal virus families, with a more special focus on human pathogens, that can trigger cell-cell fusion.
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Affiliation(s)
- Héloïse Leroy
- Institut Cochin, Inserm U1016, 75014 Paris, France; (H.L.); (M.H.); (M.W.)
- Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France
- Faculty of Health, University of Paris, 75014 Paris, France
| | - Mingyu Han
- Institut Cochin, Inserm U1016, 75014 Paris, France; (H.L.); (M.H.); (M.W.)
- Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France
- Faculty of Health, University of Paris, 75014 Paris, France
| | - Marie Woottum
- Institut Cochin, Inserm U1016, 75014 Paris, France; (H.L.); (M.H.); (M.W.)
- Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France
- Faculty of Health, University of Paris, 75014 Paris, France
| | - Lucie Bracq
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland;
| | - Jérôme Bouchet
- Laboratory Orofacial Pathologies, Imaging and Biotherapies UR2496, University of Paris, 92120 Montrouge, France;
| | - Maorong Xie
- Division of Infection and Immunity, University College London, London WC1E 6BT, UK;
| | - Serge Benichou
- Institut Cochin, Inserm U1016, 75014 Paris, France; (H.L.); (M.H.); (M.W.)
- Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France
- Faculty of Health, University of Paris, 75014 Paris, France
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11
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Respiratory Syncytial Virus and Human Metapneumovirus Infections in Three-Dimensional Human Airway Tissues Expose an Interesting Dichotomy in Viral Replication, Spread, and Inhibition by Neutralizing Antibodies. J Virol 2020; 94:JVI.01068-20. [PMID: 32759319 DOI: 10.1128/jvi.01068-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/31/2020] [Indexed: 12/14/2022] Open
Abstract
Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) are two of the leading causes of respiratory infections in children and elderly and immunocompromised patients worldwide. There is no approved treatment for HMPV and only one prophylactic treatment against RSV, palivizumab, for high-risk infants. Better understanding of the viral lifecycles in a more relevant model system may help identify novel therapeutic targets. By utilizing three-dimensional (3-D) human airway tissues to examine viral infection in a physiologically relevant model system, we showed that RSV infects and spreads more efficiently than HMPV, with the latter requiring higher multiplicities of infection (MOIs) to yield similar levels of infection. Apical ciliated cells were the target for both viruses, but RSV apical release was significantly more efficient than HMPV. In RSV- or HMPV-infected cells, cytosolic inclusion bodies containing the nucleoprotein, phosphoprotein, and respective viral genomic RNA were clearly observed in human airway epithelial (HAE) culture. In HMPV-infected cells, actin-based filamentous extensions were more common (35.8%) than those found in RSV-infected cells (4.4%). Interestingly, neither RSV nor HMPV formed syncytia in HAE tissues. Palivizumab and nirsevimab effectively inhibited entry and spread of RSV in HAE tissues, with nirsevimab displaying significantly higher potency than palivizumab. In contrast, 54G10 completely inhibited HMPV entry but only modestly reduced viral spread, suggesting HMPV may use alternative mechanisms for spread. These results represent the first comparative analysis of infection by the two pneumoviruses in a physiologically relevant model, demonstrating an interesting dichotomy in the mechanisms of infection, spread, and consequent inhibition of the viral lifecycles by neutralizing monoclonal antibodies.IMPORTANCE Respiratory syncytial virus and human metapneumovirus are leading causes of respiratory illness worldwide, but limited treatment options are available. To better target these viruses, we examined key aspects of the viral life cycle in three-dimensional (3-D) human airway tissues. Both viruses establish efficient infection through the apical surface, but efficient spread and apical release were seen for respiratory syncytial virus (RSV) but not human metapneumovirus (HMPV). Both viruses form inclusion bodies, minimally composed of nucleoprotein (N), phosphoprotein (P), and viral RNA (vRNA), indicating that these structures are critical for replication in this more physiological model. HMPV formed significantly more long, filamentous actin-based extensions in human airway epithelial (HAE) tissues than RSV, suggesting HMPV may promote cell-to-cell spread via these extensions. Lastly, RSV entry and spread were fully inhibited by neutralizing antibodies palivizumab and the novel nirsevimab. In contrast, while HMPV entry was fully inhibited by 54G10, a neutralizing antibody, spread was only modestly reduced, further supporting a cell-to-cell spread mechanism.
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12
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Alonso DF, Farina HG. Repurposing of host-based therapeutic agents for the treatment of coronavirus disease 2019 (COVID-19): a link between antiviral and anticancer mechanisms? Int J Antimicrob Agents 2020; 56:106125. [PMID: 32739476 PMCID: PMC7391054 DOI: 10.1016/j.ijantimicag.2020.106125] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/25/2020] [Accepted: 07/23/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Daniel F Alonso
- Laboratory of Molecular Oncology, Department of Science and Technology, National University of Quilmes, Buenos Aires, Argentina.
| | - Hernán G Farina
- Laboratory of Molecular Oncology, Department of Science and Technology, National University of Quilmes, Buenos Aires, Argentina
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13
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Proteomic composition of Nipah virus-like particles. J Proteomics 2018; 172:190-200. [DOI: 10.1016/j.jprot.2017.10.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/13/2017] [Accepted: 10/22/2017] [Indexed: 01/28/2023]
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14
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Graf1 Controls the Growth of Human Parainfluenza Virus Type 2 through Inactivation of RhoA Signaling. J Virol 2016; 90:9394-405. [PMID: 27512058 DOI: 10.1128/jvi.01471-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 08/01/2016] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED Rho GTPases are involved in a variety of cellular activities and are regulated by guanine nucleotide exchange factors and GTPase-activating proteins (GAPs). We found that the activation of Rho GTPases by lysophosphatidic acid promotes the growth of human parainfluenza virus type 2 (hPIV-2). Furthermore, hPIV-2 infection causes activation of RhoA, a Rho GTPase. We hypothesized that Graf1 (also known as ARHGAP26), a GAP, regulates hPIV-2 growth by controlling RhoA signaling. Immunofluorescence analysis showed that hPIV-2 infection altered Graf1 localization from a homogenous distribution within the cytoplasm to granules. Graf1 colocalized with hPIV-2 P, NP, and L proteins. Graf1 interacts with P and V proteins via their N-terminal common region, and the C-terminal Src homology 3 domain-containing region of Graf1 is important for these interactions. In HEK293 cells constitutively expressing Graf1, hPIV-2 growth was inhibited, and RhoA activation was not observed during hPIV-2 infection. In contrast, Graf1 knockdown restored hPIV-2 growth and RhoA activation. Overexpression of hPIV-2 P and V proteins enhanced hPIV-2-induced RhoA activation. These results collectively suggested that hPIV-2 P and V proteins enhanced hPIV-2 growth by binding to Graf1 and that Graf1 inhibits hPIV-2 growth through RhoA inactivation. IMPORTANCE Robust growth of hPIV-2 requires Rho activation. hPIV-2 infection causes RhoA activation, which is suppressed by Graf1. Graf1 colocalizes with viral RNP (vRNP) in hPIV-2-infected cells. We found that Graf1 interacts with hPIV-2 P and V proteins. We also identified regions in these proteins which are important for this interaction. hPIV-2 P and V proteins enhanced the hPIV-2 growth via binding to Graf1, while Graf1 inhibited hPIV-2 growth through RhoA inactivation.
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Shahriari S, Gordon J, Ghildyal R. Host cytoskeleton in respiratory syncytial virus assembly and budding. Virol J 2016; 13:161. [PMID: 27670781 PMCID: PMC5037899 DOI: 10.1186/s12985-016-0618-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 09/17/2016] [Indexed: 12/02/2022] Open
Abstract
Respiratory syncytial virus (RSV) is one of the major pathogens responsible for lower respiratory tract infections (LRTI) in young children, the elderly, and the immunosuppressed. Currently, there are no antiviral drugs or vaccines available that effectively target RSV infections, proving a significant challenge in regards to prevention and treatment. An in-depth understanding of the host-virus interactions that underlie assembly and budding would inform new targets for antiviral development.Current research suggests that the polymerised form of actin, the filamentous or F-actin, plays a role in RSV assembly and budding. Treatment with cytochalasin D, which disrupts F-actin, has been shown to inhibit virus release. In addition, the actin cytoskeleton has been shown to interact with the RSV matrix (M) protein, which plays a central role in RSV assembly. For this reason, the interaction between these two components is hypothesised to facilitate the movement of viral components in the cytoplasm and to the budding site. Despite increases in our knowledge of RSV assembly and budding, M-actin interactions are not well understood. In this review, we discuss the current literature on the role of actin cytoskeleton during assembly and budding of RSV with the aim to integrate disparate studies to build a hypothetical model of the various molecular interactions between actin and RSV M protein that facilitate RSV assembly and budding.
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Affiliation(s)
- Shadi Shahriari
- Respiratory Virology Group, Health Research Institute, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Canberra, 2617, Australia
| | - James Gordon
- Respiratory Virology Group, Health Research Institute, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Canberra, 2617, Australia
| | - Reena Ghildyal
- Respiratory Virology Group, Health Research Institute, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Canberra, 2617, Australia.
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Abstract
The family Paramyxoviridae includes many viruses that significantly affect human and animal health. An essential step in the paramyxovirus life cycle is viral entry into host cells, mediated by virus-cell membrane fusion. Upon viral entry, infection results in expression of the paramyxoviral glycoproteins on the infected cell surface. This can lead to cell-cell fusion (syncytia formation), often linked to pathogenesis. Thus membrane fusion is essential for both viral entry and cell-cell fusion and an attractive target for therapeutic development. While there are important differences between viral-cell and cell-cell membrane fusion, many aspects are conserved. The paramyxoviruses generally utilize two envelope glycoproteins to orchestrate membrane fusion. Here, we discuss the roles of these glycoproteins in distinct steps of the membrane fusion process. These findings can offer insights into evolutionary relationships among Paramyxoviridae genera and offer future targets for prophylactic and therapeutic development.
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Huong TN, Iyer Ravi L, Tan BH, Sugrue RJ. Evidence for a biphasic mode of respiratory syncytial virus transmission in permissive HEp2 cell monolayers. Virol J 2016; 13:12. [PMID: 26790623 PMCID: PMC4719537 DOI: 10.1186/s12985-016-0467-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/12/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND During respiratory syncytial virus (RSV) infection filamentous virus particles are formed on the cell surface. Although the virus infectivity remains cell-associated, low levels of cell-free virus is detected during advanced infection. It is currently unclear if this cell-free virus infectivity is due to a low-efficiency specific cell-release mechanism, or if it arises due to mechanical breakage following virus-induced cell damage at the advanced stage of infection. Understanding the origin of this cell-free virus is a prerequisite for understanding the mechanism of RSV transmission in permissive cells. In this study we describe a detailed examination of RSV transmission in permissive HEp2 cell monolayers. METHODS HEp2 cell monolayers were infected with RSV using a multiplicity of infection of 0.0002, and the course of infection monitored over 5 days. The progression of the virus infection within the cell monolayers was performed using bright-field microscopy to visualise the cell monolayer and immunofluorescence microscopy to detect virus-infected cells. The cell-associated and cell-free virus infectivity were determined by virus plaque assay, and the virus-induced cell cytotoxicity determined by measuring cell membrane permeability and cellular DNA fragmentation. RESULTS At 2 days-post infection (dpi), large clusters of virus-infected cells could be detected indicating localised transmission in the cell monolayer, and during this stage we failed to detect either cell-free virus or cell cytotoxicity. At 3 dpi the presence of much larger infected cell clusters correlated with the begining of virus-induced changes in cell permeability. The presence of cell-free virus correlated with continued increase in cell permeability and cytotoxicity at 4 and 5 dpi. At 5 dpi extensive cell damage, syncytial formation, and increased cellular DNA fragmentation was noted. However, even at 5 dpi the cell-free virus constituted less than 1 % of the total virus infectivity. CONCLUSIONS Our data supports a model of RSV transmission that initially involves the localised cell-to-cell spread of virus particles within the HEp2 cell monolayer. However, low levels of cell free-virus infectivity was observed at the advanced stages of infection, which correlated with a general loss in cell monolayer integrity due to virus-induced cytotoxicity.
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Affiliation(s)
- Tra Nguyen Huong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore.
| | - Laxmi Iyer Ravi
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore.
| | - Boon Huan Tan
- Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore, 117510, Singapore.
| | - Richard J Sugrue
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore.
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Abstract
Human respiratory syncytial virus (RSV) is understood to be a significant human pathogen in infants, young children, and the elderly and the immunocompromised. Over the last decade many important mechanisms contributing to RSV infection, replication, and disease pathogenesis have been revealed; however, there is still insufficient knowledge which has in part hampered vaccine development. Considerable information is accumulating regarding how RSV proteins modulate molecular signaling and immune responses to infection. Understanding how RSV interacts with its host is crucial to facilitate the development of safe and effective vaccines and therapeutic treatments.In this chapter, we provide a brief introduction into RSV replication, pathogenesis, and host immune response, and summarize the state of RSV vaccine and antiviral compounds in clinical stages of development. This chapter frames features of this book and the molecular methods used for understanding RSV interaction with the host.
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Affiliation(s)
- Patricia A Jorquera
- Department of Infectious Diseases, College of Veterinary Medicine, Animal Health Research Center, University of Georgia, 111 Carlton Street, Athens, GA, 30602, USA
| | - Lydia Anderson
- Department of Infectious Diseases, College of Veterinary Medicine, Animal Health Research Center, University of Georgia, 111 Carlton Street, Athens, GA, 30602, USA
| | - Ralph A Tripp
- Department of Infectious Diseases, College of Veterinary Medicine, Animal Health Research Center, University of Georgia, 111 Carlton Street, Athens, GA, 30602, USA.
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19
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Van den Broeke C, Jacob T, Favoreel HW. Rho'ing in and out of cells: viral interactions with Rho GTPase signaling. Small GTPases 2014; 5:e28318. [PMID: 24691164 DOI: 10.4161/sgtp.28318] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Rho GTPases are key regulators of actin and microtubule dynamics and organization. Increasing evidence shows that many viruses have evolved diverse interactions with Rho GTPase signaling and manipulate them for their own benefit. In this review, we discuss how Rho GTPase signaling interferes with many steps in the viral replication cycle, especially entry, replication, and spread. Seen the diversity between viruses, it is not surprising that there is considerable variability in viral interactions with Rho GTPase signaling. However, several largely common effects on Rho GTPases and actin architecture and microtubule dynamics have been reported. For some of these processes, the molecular signaling and biological consequences are well documented while for others we just begin to understand them. A better knowledge and identification of common threads in the different viral interactions with Rho GTPase signaling and their ultimate consequences for virus and host may pave the way toward the development of new antiviral drugs that may target different viruses.
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Affiliation(s)
- Céline Van den Broeke
- Department of Virology, Parasitology, and Immunology; Faculty of Veterinary Medicine; Ghent University; Ghent, Belgium
| | - Thary Jacob
- Department of Virology, Parasitology, and Immunology; Faculty of Veterinary Medicine; Ghent University; Ghent, Belgium
| | - Herman W Favoreel
- Department of Virology, Parasitology, and Immunology; Faculty of Veterinary Medicine; Ghent University; Ghent, Belgium
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20
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Increased hydroxymethylglutaryl coenzyme A reductase activity during respiratory syncytial virus infection mediates actin dependent inter-cellular virus transmission. Antiviral Res 2013; 100:259-68. [PMID: 23994498 DOI: 10.1016/j.antiviral.2013.08.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/26/2013] [Accepted: 08/19/2013] [Indexed: 01/26/2023]
Abstract
We have examined the role that hydroxymethylglutaryl coenzyme A reductase (HMGCR) plays during respiratory syncytial virus (RSV) maturation. Imaging analysis indicated that virus-induced changes in F-actin structure correlated with the formation of virus filaments, and that these virus filaments played a direct role in virus cell-to-cell transmission. Treatment with cytochalasin D (CYD) prevented virus filament formation and virus transmission, but this could be reversed by removal of CYD. This observation, together with the presence of F-actin within the virus filaments suggested that newly polymerised F-actin was required for virus transmission. The virus-induced change in F-actin was inhibited by the HMGCR inhibitor lovastatin, and this correlated with the inhibition of both virus filament formation and the incorporation of F-actin in these virus structures. Furthermore, this inhibitory effect on virus filament formation correlated with a significant reduction in RSV transmission. Collectively these data suggested that HMGCR-mediated changes in F-actin structure play an important role in the inter-cellular transmission of mature RSV particles. These data also highlighted the interplay between cellular metabolism and RSV transmission, and demonstrate that this interaction can be targeted using anti-virus strategies.
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21
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Shaikh FY, Utley TJ, Craven RE, Rogers MC, Lapierre LA, Goldenring JR, Crowe JE. Respiratory syncytial virus assembles into structured filamentous virion particles independently of host cytoskeleton and related proteins. PLoS One 2012; 7:e40826. [PMID: 22808269 PMCID: PMC3396619 DOI: 10.1371/journal.pone.0040826] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 06/13/2012] [Indexed: 12/02/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a single-stranded RNA virus that assembles into viral filaments at the cell surface. Virus assembly often depends on the ability of a virus to use host proteins to accomplish viral tasks. Since the fusion protein cytoplasmic tail (FCT) is critical for viral filamentous assembly, we hypothesized that host proteins important for viral assembly may be recruited by the FCT. Using a yeast two-hybrid screen, we found that filamin A interacted with FCT, and mammalian cell experiments showed it localized to viral filaments but did not affect viral replication. Furthermore, we found that a number of actin-associated proteins also were excluded from viral filaments. Actin or tubulin cytoskeletal rearrangement was not necessary for F trafficking to the cell surface or for viral assembly into filaments, but was necessary for optimal viral replication and may be important for anchoring viral filaments. These findings suggest that RSV assembly into filaments occurs independently of actin polymerization and that viral proteins are the principal drivers for the mechanical tasks involved with formation of complex, structured RSV filaments at the host cell plasma membrane.
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Affiliation(s)
- Fyza Y. Shaikh
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Thomas J. Utley
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Ryan E. Craven
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Meredith C. Rogers
- The Medical Scientist Training Program, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Lynne A. Lapierre
- Department of Surgery and the Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - James R. Goldenring
- Department of Surgery and the Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - James E. Crowe
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
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Small rho GTPases and cholesterol biosynthetic pathway intermediates in African swine fever virus infection. J Virol 2011; 86:1758-67. [PMID: 22114329 DOI: 10.1128/jvi.05666-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The integrity of the cholesterol biosynthesis pathway is required for efficient African swine fever virus (ASFV) infection. Incorporation of prenyl groups into Rho GTPases plays a key role in several stages of ASFV infection, since both geranylgeranyl and farnesyl pyrophosphates are required at different infection steps. We found that Rho GTPase inhibition impaired virus morphogenesis and resulted in an abnormal viral factory size with the accumulation of envelope precursors and immature virions. Furthermore, abundant defective virions reached the plasma membrane, and filopodia formation in exocytosis was abrogated. Rac1 was activated at early ASFV infection stages, coincident with microtubule acetylation, a process that stabilizes microtubules for virus transport. Rac1 inhibition did not affect the viral entry step itself but impaired subsequent virus production. We found that specific Rac1 inhibition impaired viral induced microtubule acetylation and viral intracellular transport. These findings highlight that viral infection is the result of a carefully orchestrated modulation of Rho family GTPase activity within the host cell; this modulation results critical for virus morphogenesis and in turn, triggers cytoskeleton remodeling, such as microtubule stabilization for viral transport during early infection.
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Chang TH, Segovia J, Sabbah A, Mgbemena V, Bose S. Cholesterol-rich lipid rafts are required for release of infectious human respiratory syncytial virus particles. Virology 2011; 422:205-13. [PMID: 22088217 DOI: 10.1016/j.virol.2011.10.029] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 10/24/2011] [Accepted: 10/28/2011] [Indexed: 11/26/2022]
Abstract
Cholesterol and sphingolipid enriched lipid raft micro-domains in the plasma membrane play an important role in the life-cycle of numerous enveloped viruses. Although human respiratory syncytial virus (RSV) proteins associate with the raft domains of infected cells and rafts are incorporated in RSV virion particles, the functional role of raft during RSV infection was unknown. In the current study we have identified rafts as an essential component of host cell that is required for RSV infection. Treatment of human lung epithelial cells with raft disrupting agent methyl-beta-cyclodextrin (MBCD) led to drastic loss of RSV infectivity due to diminished release of infectious progeny RSV virion particles from raft disrupted cells. RSV infection of raft deficient Niemann-Pick syndrome type C human fibroblasts and normal human embryonic lung fibroblasts revealed that during productive RSV infection, raft is required for release of infectious RSV particles.
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Affiliation(s)
- Te-Hung Chang
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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24
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Masaki T, Kojima T, Okabayashi T, Ogasawara N, Ohkuni T, Obata K, Takasawa A, Murata M, Tanaka S, Hirakawa S, Fuchimoto J, Ninomiya T, Fujii N, Tsutsumi H, Himi T, Sawada N. A nuclear factor-κB signaling pathway via protein kinase C δ regulates replication of respiratory syncytial virus in polarized normal human nasal epithelial cells. Mol Biol Cell 2011; 22:2144-56. [PMID: 21562222 PMCID: PMC3128518 DOI: 10.1091/mbc.e10-11-0875] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We established a respiratory syncytial virus (RSV)-infected model in polarized normal human nasal epithelial cells and found that the replication of RSV and the epithelial cell responses including induction of tight junctions were regulated via a protein kinase C δ/hypoxia-inducible factor-1α/nuclear factor-κβ pathway. The control of this pathway may be useful in therapy for RSV-induced respiratory pathogenesis. Respiratory syncytial virus (RSV) is the major cause of bronchitis, asthma, and severe lower respiratory tract disease in infants and young children. The airway epithelium, which has a well-developed barrier regulated by tight junctions, is the first line of defense during respiratory virus infection. In upper airway human nasal epithelial cells (HNECs), however, the primary site of RSV infection, the mechanisms of replication and budding of RSV, and the epithelial cell responses, including the tight junctional barrier, remain unknown. To investigate the detailed mechanisms of replication and budding of RSV in HNECs and the epithelial cell responses, we established an RSV-infected model using human telomerase reverse transcriptase–-transfected HNECs. We first found that the expression and barrier function of tight junction molecules claudin-4 and occludin were markedly induced together with production of proinflammatory cytokines interleukin 8 and tumor necrosis factor-α in HNECs after RSV infection, and the induction of tight junction molecules possibly contributed to budding of RSV. Furthermore, the replication and budding of RSV and the epithelial cell responses in HNECs were regulated via a protein kinase C δ/hypoxia-inducible factor-1α/nuclear factor-κB pathway. The control of this pathway in HNECs may be useful not only for prevention of replication and budding of RSV, but also in therapy for RSV-induced respiratory pathogenesis.
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Affiliation(s)
- Tomoyuki Masaki
- Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo, Japan
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Tikhmyanova N, Little JL, Golemis EA. CAS proteins in normal and pathological cell growth control. Cell Mol Life Sci 2010; 67:1025-48. [PMID: 19937461 PMCID: PMC2836406 DOI: 10.1007/s00018-009-0213-1] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 11/03/2009] [Accepted: 11/09/2009] [Indexed: 12/20/2022]
Abstract
Proteins of the CAS (Crk-associated substrate) family (BCAR1/p130Cas, NEDD9/HEF1/Cas-L, EFS/SIN and CASS4/HEPL) are integral players in normal and pathological cell biology. CAS proteins act as scaffolds to regulate protein complexes controlling migration and chemotaxis, apoptosis, cell cycle, and differentiation, and have more recently been linked to a role in progenitor cell function. Reflecting these complex functions, over-expression of CAS proteins has now been strongly linked to poor prognosis and increased metastasis in cancer, as well as resistance to first-line chemotherapeutics in multiple tumor types including breast and lung cancers, glioblastoma, and melanoma. Further, CAS proteins have also been linked to additional pathological conditions including inflammatory disorders, Alzheimer's and Parkinson's disease, as well as developmental defects. This review will explore the roles of the CAS proteins in normal and pathological states in the context of the many mechanistic insights into CAS protein function that have emerged in the past decade.
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Affiliation(s)
- Nadezhda Tikhmyanova
- Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111 USA
- Department of Biochemistry, Drexel University Medical School, Philadelphia, PA 19102 USA
| | - Joy L. Little
- Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111 USA
| | - Erica A. Golemis
- Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111 USA
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Shao HY, Yu SL, Sia C, Chen Y, Chitra E, Chen IH, Venkatesan N, Leng CH, Chong P, Chow YH. Immunogenic properties of RSV-B1 fusion (F) protein gene-encoding recombinant adenoviruses. Vaccine 2009; 27:5460-71. [PMID: 19622401 DOI: 10.1016/j.vaccine.2009.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 06/16/2009] [Accepted: 07/01/2009] [Indexed: 12/29/2022]
Abstract
Two recombinant adenoviruses designated rAd-F0DeltaTM and rAd-F0 carrying the transmembrane truncated and full length of the F gene of the RSV-B1 strain, respectively, were engineered. Comparative immunogenicity studies in BALB/c mice showed that each vector was capable of inducing RSV-B1-specific antibodies that cross-reacted with the RSV-long and RSV-A2 viruses. The anti-RSV-B1 antibodies were neutralizing, and exhibited strong cross-neutralizing activity against the RSV-long and RSV-A2 isolates as well. Analysis of the cellular responses revealed that animals immunized with rAd-F0DeltaTM and rAd-F0 elicited CD4(+) T-cell responses of the Th1 and Th2 phenotypes, as well as F protein-specific CTLs. Production of Th2 cytokines (IL-4, IL-5 and IL-13) by splenocytes of the rAd-F0DeltaTM and rAd-F0 immunized mice was markedly lower than those released by animals administered with heat-inactivated RSV-B1 (HIRSV-B1). Comparison of the overall humoral and cellular responses suggests that rAd-F0DeltaTM is significantly more immunogenic than rAd-F0. The anti-viral immunity generated by both recombinant adenovirus vectors has conferred protection against live RSV-B1 challenge as judged by the lower viral load recovered in the lungs, a faster rate of recovery of body weight loss, and a lower count of eosinophils as compared to eosinophilia in mice immunized with HIRSV-B1. Results from these studies suggest that rAd-F0DeltaTM or rAd-F0 possess immunogenic properties that meet the requirements expected from potential RSV vaccine candidates.
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Affiliation(s)
- Hsiao-Yun Shao
- Vaccine R&D Center, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan, ROC
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27
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Asada M, Yoshida M, Suzuki T, Hatachi Y, Sasaki T, Yasuda H, Nakayama K, Nishimura H, Nagatomi R, Kubo H, Yamaya M. Macrolide antibiotics inhibit respiratory syncytial virus infection in human airway epithelial cells. Antiviral Res 2009; 83:191-200. [PMID: 19463856 DOI: 10.1016/j.antiviral.2009.05.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 04/28/2009] [Accepted: 05/12/2009] [Indexed: 11/18/2022]
Abstract
To examine the effects of macrolide antibiotics on RS virus infection in airways, human tracheal epithelial cells were pre-treated with bafilomycin A(1) and clarithromycin, and infected with RS virus. Viral titers in supernatant fluids and RNA of RS virus, and concentrations of cytokines in supernatant fluids, including interleukin-6 increased with time after infection. Bafilomycin A(1) and clarithromycin reduced viral titers in supernatant fluids of RS virus, RNA of RS virus, the susceptibility to RS virus infection, and concentrations of cytokines induced by virus infection. N-acetyl-S-geranylgeranyl-L-cysteine, an inhibitor for a small GTP binding protein of RhoA, isoform A of the Ras-homologus (Rho) family, an active form of which is associated with RS virus infection via binding to its fusion protein (F protein), reduced viral titers in supernatant fluids and RNA of RS virus. Bafilomycin A(1) and clarithromycin inhibited RhoA activation induced by lysophosphatidic acid in the cells. Fasudil, an inhibitor of Rho kinase, also reduced viral titers in supernatant fluids and RNA of RS virus. These findings suggest that macrolide antibiotics may inhibit RS virus infection, partly through the reduced expression of F protein receptor, activated RhoA, and the inhibition of subsequent Rho kinase activation in human airway epithelial cells.
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Affiliation(s)
- Masanori Asada
- Department of Geriatrics and Gerontology, Tohoku University School of Medicine, Sendai, Japan
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28
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Yeo DSY, Chan R, Brown G, Ying L, Sutejo R, Aitken J, Tan BH, Wenk MR, Sugrue RJ. Evidence that selective changes in the lipid composition of raft-membranes occur during respiratory syncytial virus infection. Virology 2009; 386:168-82. [DOI: 10.1016/j.virol.2008.12.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 11/19/2008] [Accepted: 12/01/2008] [Indexed: 11/27/2022]
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29
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Fernandes LB, Henry PJ, Goldie RG. Rho kinase as a therapeutic target in the treatment of asthma and chronic obstructive pulmonary disease. Ther Adv Respir Dis 2009; 1:25-33. [PMID: 19124345 DOI: 10.1177/1753465807080740] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Asthma is a complex inflammatory disease of the airways involving reversible bronchoconstriction. Chronic obstructive pulmonary disease is typified by inflammation and airflow limitation that has an irreversible component. There is now substantial evidence that Rho kinase is involved in many of the pathways that contribute to the pathologies associated with these respiratory diseases including bronchoconstriction, airway inflammation, airway remodelling, neuromodulation and exacerbations due to respiratory tract viral infection. Indeed the Rho kinase inhibitor Y-27632 causes bronchodilatation and reduces pulmonary eosinophilia trafficking and airways hyperresponsiveness. Furthermore, accumulating evidence suggests that inhibition of Rho kinase could have a major beneficial impact on symptoms and disease progression in asthma and COPD by modulating several other systems and processes. Thus, the Rho kinase pathway may indeed be a worthwhile therapeutic target in the treatment of asthma and chronic obstructive pulmonary disease.
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Affiliation(s)
- Lynette B Fernandes
- Pharmacology and Anaesthesiology Unit, School of Medicine & Pharmacology, and Western Australian Institute for Medical Research, The University of Western Australia, Perth, Australia
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30
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Effects of hemagglutinin-neuraminidase protein mutations on cell-cell fusion mediated by human parainfluenza type 2 virus. J Virol 2008; 82:8283-95. [PMID: 18562539 DOI: 10.1128/jvi.00460-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The monoclonal antibody M1-1A, specific for the hemagglutinin-neuraminidase (HN) protein of human parainfluenza type 2 virus (HPIV2), blocks virus-induced cell-cell fusion without affecting the hemagglutinating and neuraminidase activities. F13 is a neutralization escape variant selected with M1-1A and contains amino acid mutations N83Y and M186I in the HN protein, with no mutation in the fusion protein. Intriguingly, F13 exhibits reduced ability to induce cell-cell fusion despite its multistep replication. To investigate the potential role of HPIV2 HN protein in the regulation of cell-cell fusion, we introduced these mutations individually or in combination to the HN protein in the context of recombinant HPIV2. Following infection at a low multiplicity, Vero cells infected with the mutant virus H-83/186, which carried both the N83Y and M186I mutations, remained as nonfused single cells at least for 24 h, whereas most of the cells infected with wild-type virus mediated prominent cell-cell fusion within 24 h. On the other hand, the cells infected with the mutant virus, carrying either the H-83 or H-186 mutation, mediated cell-cell fusion but less efficiently than those infected with wild-type virus. Irrespective of the ability to cause cell-cell fusion, however, every virus could infect all the cells in the culture within 48 h after the initial infection. These results indicated that both the N83Y and M186I mutations in the HN protein are involved in the regulation of cell-cell fusion. Notably, the limited cell-cell fusion by H-83/186 virus was greatly promoted by lysophosphatidic acid, a stimulator of the Ras and Rho family GTPases.
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31
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The fusion protein of respiratory syncytial virus triggers p53-dependent apoptosis. J Virol 2008; 82:3236-49. [PMID: 18216092 DOI: 10.1128/jvi.01887-07] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection with respiratory syncytial virus (RSV) frequently causes inflammation and obstruction of the small airways, leading to severe pulmonary disease in infants. We show here that the RSV fusion (F) protein, an integral membrane protein of the viral envelope, is a strong elicitor of apoptosis. Inducible expression of F protein in polarized epithelial cells triggered caspase-dependent cell death, resulting in rigorous extrusion of apoptotic cells from the cell monolayer and transient loss of epithelial integrity. A monoclonal antibody directed against F protein inhibited apoptosis and was also effective if administered to A549 lung epithelial cells postinfection. F protein expression in epithelial cells caused phosphorylation of tumor suppressor p53 at serine 15, activation of p53 transcriptional activity, and conformational activation of proapoptotic Bax. Stable expression of dominant-negative p53 or p53 knockdown by RNA interference inhibited the apoptosis of RSV-infected A549 cells. HEp-2 tumor cells with low levels of p53 were not sensitive to RSV-triggered apoptosis. We propose a new model of RSV disease with the F protein as an initiator of epithelial cell shedding, airway obstruction, secondary necrosis, and consequent inflammation. This makes the RSV F protein a key target for the development of effective postinfection therapies.
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32
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Zhang X, Wang JF, Kunos G, Groopman JE. Cannabinoid modulation of Kaposi's sarcoma-associated herpesvirus infection and transformation. Cancer Res 2007; 67:7230-7. [PMID: 17671191 DOI: 10.1158/0008-5472.can-07-0960] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV; also named human herpesvirus 8) is necessary but not sufficient for the development of Kaposi's sarcoma. A variety of factors may contribute to the pathogenesis of Kaposi's sarcoma in addition to KSHV. Marijuana is a widely used recreational agent, and Delta(9)-tetrahydrocannabinol (Delta(9)-THC), the major active component of marijuana, is prescribed for medicinal use. To evaluate how cannabinoids may affect the pathogenesis of Kaposi's sarcoma, we studied primary human dermal microvascular endothelial cells (HMVEC) exposed to KSHV. There was an increased efficiency of KSHV infection in the presence of low doses of Delta(9)-THC. We also found that Delta(9)-THC increased the viral load in KSHV-infected HMVEC through activation of the KSHV lytic switch gene, the open reading frame 50. Furthermore, we observed that Delta(9)-THC stimulated expression of the KSHV-encoded viral G protein-coupled receptor and Kaposi's sarcoma cell proliferation. Our results indicate that Delta(9)-THC can enhance KSHV infection and replication and foster KSHV-mediated endothelial transformation. Thus, use of cannabinoids may place individuals at greater risk for the development and progression of Kaposi's sarcoma.
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MESH Headings
- Blotting, Western
- Cell Adhesion
- Cell Proliferation/drug effects
- Cell Transformation, Neoplastic/drug effects
- Cells, Cultured
- DNA, Viral/analysis
- Dronabinol/analogs & derivatives
- Dronabinol/pharmacology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/pathology
- Endothelium, Vascular/virology
- Herpesvirus 8, Human/drug effects
- Herpesvirus 8, Human/physiology
- Humans
- Immediate-Early Proteins/metabolism
- Receptors, Chemokine/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Skin/blood supply
- Trans-Activators/metabolism
- Transfection
- Viral Load
- Viral Proteins/metabolism
- Virus Replication/drug effects
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Affiliation(s)
- Xuefeng Zhang
- Division of Experimental Medicine and Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA
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33
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Jeffree CE, Brown G, Aitken J, Su-Yin DY, Tan BH, Sugrue RJ. Ultrastructural analysis of the interaction between F-actin and respiratory syncytial virus during virus assembly. Virology 2007; 369:309-23. [PMID: 17825340 DOI: 10.1016/j.virol.2007.08.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2007] [Revised: 06/06/2007] [Accepted: 08/02/2007] [Indexed: 11/17/2022]
Abstract
During respiratory syncytial virus (RSV) infection there is a close physical interaction between the filamentous actin (F-actin) and the virus, involving both inclusion bodies and the virus filaments. This interaction appears to occur relatively early in the replication cycle, and can be detected from 8 h post-infection. Furthermore, during virus assembly we obtained evidence for the participation of an F-actin-associated signalling pathway involving phosphatidyl-3-kinase (PI3K). Treatment with the PI3K inhibitor LY294002 prevented the formation of virus filaments, although no effect was observed either on virus protein expression, or on trafficking of the virus glycoproteins to the cell surface. Inhibition of the activity of Rac GTPase, a down-stream effector of PI3K, by treatment with the Rac-specific inhibitor NSC23766 gave similar results. These data suggest that an intimate interaction occurs between actin and RSV, and that actin-associated signalling pathway, involving PI3K and Rac GTPase, may play an important role during virus assembly.
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Affiliation(s)
- Chris E Jeffree
- School of Biological Sciences, Daniel Rutherford Building, King's Buildings, Mayfield Road, University of Edinburgh Edinburgh, EH9 3JH, UK
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34
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Rashid-Doubell F, Tannetta D, Redman CWG, Sargent IL, Boyd CAR, Linton EA. Caveolin-1 and Lipid Rafts in Confluent BeWo Trophoblasts: Evidence for Rock-1 Association with Caveolin-1. Placenta 2007; 28:139-51. [PMID: 16480767 DOI: 10.1016/j.placenta.2005.12.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 12/19/2005] [Accepted: 12/21/2005] [Indexed: 11/25/2022]
Abstract
Lipid rafts are detergent-insoluble, low-density membrane domains that are rich in cholesterol and sphingolipids; caveolae are a subdomain of the biochemically defined glycolipid raft whose expression is associated with the protein caveolin-1. This protein associates with numerous signalling molecules, regulating their activity by holding them inactive. Human villous cytotrophoblasts contain caveolin-1, but levels reduce greatly during their differentiation into syncytiotrophoblast. Since caveolin-1 is a known regulator of apoptosis and trophoblast syncytialisation involves the apoptotic cascade, we hypothesised that cytotrophoblast caveolin-1 may also play a role in regulating fusion events involved in syncytium formation. The BeWo choriocarcinoma cell line has previously proved valuable for studying trophoblast syncytialisation, hence the present work was carried out to determine whether BeWo cells could be used as a model for the exploration of caveolin-1's role in regulating the syncytialisation process. Undifferentiated BeWo cells were found to express caveolin-1 in similar amounts to villous cytotrophoblasts isolated from term placenta. Lipid raft fractions prepared from these BeWo cells at confluence contained the raft-associated proteins caveolin-1 and -2, flotillin-1 and -2, stomatin and the heterotrimeric G protein, Galphaq. Confocal immunofluorescence studies revealed that caveolin-1 is internalized to the mitochondria, but not to the Golgi or endoplasmic reticulum, in subconfluent BeWo and that the protein relocates to the plasma membrane upon confluence, an observation confirmed by caveolin-1 and cytochrome c Western blotting of lipid raft fractions and mitochondria purified from confluent and subconfluent cells. Western blotting and immunofluorescence experiments comparing undifferentiated cells and those induced to differentiate using the cAMP analogue, dibutyryl cAMP, showed that BeWo syncytialisation was accompanied by a reduction in caveolin-1 levels, similar to the situation in primary villous cytotrophoblasts. Confluent, undifferentiated BeWo cultures were then used to investigate the cellular localisation of Rock-1, a protein which promotes cytoskeletal re-organisation important for syncytialisation and apoptosis. Its association with caveolin-1 was evidenced by the demonstration that the 160kDa proenzyme form of Rock-1 co-immunoprecipitates with caveolin-1 and vice versa, as well as by the co-localisation of the two proteins at the plasma membrane, as shown in immunofluorescence studies. A proportion of the total cell Rock-1 content was found in BeWo lipid raft fractions, confirming its membrane presence in confluent cells. This close association of plasmalemmal caveolin-1 with Rock-1 protein raises the possibility that caveolin-1 may regulate Rock-1 in these trophoblasts. We conclude that cell-cell contact is required for BeWo trophoblast to exhibit plasmalemmal caveolin-1; BeWo cells at confluence offer a useful model for the study of trophoblast raft behaviour during syncytialisation and for the exploration of the potential Rock-1-regulating role of caveolin-1 in this process.
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Affiliation(s)
- F Rashid-Doubell
- Nuffield Department of Obstetrics and Gynaecology, Women's Centre, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
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35
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Tsurudome M. [Viral fusion mechanisms]. Uirusu 2006; 55:207-19. [PMID: 16557006 DOI: 10.2222/jsv.55.207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The majority of viral fusion proteins can be divided into two classes. The influenza hemagglutinin (HA) belongs to the class I fusion proteins and undergoes a series of conformational changes at acidic pH, leading to membrane fusion. The crystal structures of the prefusion and the postfusion forms of HA have been revealed in 1981 and 1994, respectively. On the basis of these structures, a model for the mechanism of membrane fusion mediated by the conformational changes of HA has been proposed. The flavivirus E and alphavirus E1 proteins belong to the class II fusion proteins and mediate membrane fusion at acidic pH. Their prefusion structures are distinct from that of HA. Last year, however, it has become evident that the postfusion structures of these class I and class II fusion proteins are similar. The paramyxovirus F protein belongs to the class I fusion proteins. In contrast to HA, an interaction between F and its homologous attachment protein is required for F to undergo the conformational changes. Since F mediates fusion at neutral pH, the infected cells can fuse with neighboring uninfected cells. The crystal structures of F and the attachment protein HN have recently been clarified, which will facilitate studies of the molecular mechanism of F-mediated membrane fusion.
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Affiliation(s)
- Masato Tsurudome
- Department of Microbiology, Mie University Graduate School of Medicine, Tsu, Mie, Japan.
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36
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Gower TL, Pastey MK, Peeples ME, Collins PL, McCurdy LH, Hart TK, Guth A, Johnson TR, Graham BS. RhoA signaling is required for respiratory syncytial virus-induced syncytium formation and filamentous virion morphology. J Virol 2005; 79:5326-36. [PMID: 15827147 PMCID: PMC1082718 DOI: 10.1128/jvi.79.9.5326-5336.2005] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2004] [Accepted: 12/21/2004] [Indexed: 11/20/2022] Open
Abstract
Respiratory syncytial virus (RSV) is an important human pathogen that can cause severe and life-threatening respiratory infections in infants, the elderly, and immunocompromised adults. RSV infection of HEp-2 cells induces the activation of RhoA, a small GTPase. We therefore asked whether RhoA signaling is important for RSV replication or syncytium formation. The treatment of HEp-2 cells with Clostridium botulinum C3, an enzyme that ADP-ribosylates and specifically inactivates RhoA, inhibited RSV-induced syncytium formation and cell-to-cell fusion, although similar levels of PFU were released into the medium and viral protein expression levels were equivalent. Treatment with another inhibitor of RhoA signaling, the Rho kinase inhibitor Y-27632, yielded similar results. Scanning electron microscopy of C3-treated infected cells showed reduced numbers of single blunted filaments, in contrast to the large clumps of long filaments in untreated infected cells. These data suggest that RhoA signaling is associated with filamentous virus morphology, cell-to-cell fusion, and syncytium formation but is dispensable for the efficient infection and production of infectious virus in vitro. Next, we developed a semiquantitative method to measure spherical and filamentous virus particles by using sucrose gradient velocity sedimentation. Fluorescence and transmission electron microscopy confirmed the separation of spherical and filamentous forms of infectious virus into two identifiable peaks. The C3 treatment of RSV-infected cells resulted in a shift to relatively more spherical virions than those from untreated cells. These data suggest that viral filamentous protuberances characteristic of RSV infection are associated with RhoA signaling, are important for filamentous virion morphology, and may play a role in initiating cell-to-cell fusion.
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Affiliation(s)
- Tara L Gower
- Vaccine Research Center, Building 40, Room 2502, NIAID, NIH, 40 Convent Dr., MSC 3017, Bethesda, MD 20892-3017, USA
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37
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Huang YCT, Li Z, Brighton LE, Carson JL, Becker S, Soukup JM. 3-nitrotyrosine attenuates respiratory syncytial virus infection in human bronchial epithelial cell line. Am J Physiol Lung Cell Mol Physiol 2005; 288:L988-96. [PMID: 15653711 DOI: 10.1152/ajplung.00378.2004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
3-nitrotyrosine (NO2Tyr), an L-tyrosine derivative during nitrative stress, can substitute the COOH-terminal tyrosine of alpha-tubulin, posttranslationally altering microtubular functions. Because infection of the cells by respiratory syncytial virus (RSV) may require intact microtubules, we tested the hypothesis that NO2Tyr would inhibit RSV infection and intracellular signaling via nitrotyrosination of alpha-tubulin. A human bronchial epithelial cell line (BEAS-2B) was incubated with RSV with or without NO2Tyr. The release of chemokines and viral particles and activation of interferon regulatory factor-3 (IRF-3) were measured. Incubation with NO2Tyr increased nitrotyrosinated alpha-tubulin, and NO2Tyr colocalized with microtubules. RSV-infected cells released viral particles, RANTES, and IL-8 in a time- and dose-dependent manner, and intracellular RSV proteins coprecipitated with alpha-tubulin. NO2Tyr attenuated the RSV-induced release of RANTES, IL-8, and viral particles by 50-90% and decreased alpha-tubulin-associated RSV proteins. 3-chlorotyrosine, another L-tyrosine derivative, had no effects. NO2Tyr also inhibited the RSV-induced shift of the unphosphorylated form I of IRF-3 to the phosphorylated form II. Pre-exposure of the cells to NO(2) (0.15 ppm, 4 h), which produced diffuse protein tyrosine nitration, did not affect RSV-induced release of RANTES, IL-8, or viral particles. NO2Tyr did not affect the potential of viral spreading to the neighboring cells since the RSV titers were not decreased when the uninfected cells were cocultured with the preinfected cells in NO2Tyr-containing medium. These results indicate that NO2Tyr, by replacing the COOH-terminal tyrosine of alpha-tubulin, attenuated RSV infection, and the inhibition appeared to occur at the early stages of RSV infection.
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Affiliation(s)
- Yuh-Chin T Huang
- National Health and Environmental Effects Research Laboratory, Office of Research and Development, Environmental Protection Agency, Research Triangle Park, NC, USA.
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38
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San-Juan-Vergara H, Peeples ME, Lockey RF, Mohapatra SS. Protein kinase C-alpha activity is required for respiratory syncytial virus fusion to human bronchial epithelial cells. J Virol 2004; 78:13717-26. [PMID: 15564481 PMCID: PMC533893 DOI: 10.1128/jvi.78.24.13717-13726.2004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Respiratory syncytial virus (RSV) infection activates protein kinase C (PKC), but the precise PKC isoform(s) involved and its role(s) remain to be elucidated. On the basis of the activation kinetics of different signaling pathways and the effect of various PKC inhibitors, it was reasoned that PKC activation is important in the early stages of RSV infection, especially RSV fusion and/or replication. Herein, the role of PKC-alpha during the early stages of RSV infection in normal human bronchial epithelial cells is determined. The results show that the blocking of PKC-alpha activation by classical inhibitors, pseudosubstrate peptides, or the overexpression of dominant-negative mutants of PKC-alpha in these cells leads to significantly decreased RSV infection. RSV induces phosphorylation, activation, and cytoplasm-to-membrane translocation of PKC-alpha. Also, PKC-alpha colocalizes with virus particles and is required for RSV fusion to the cell membrane. Thus, PKC-alpha could provide a new pharmacological target for controlling RSV infection.
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Affiliation(s)
- Homero San-Juan-Vergara
- The Joy McCann Culverhouse Airways Disease Research Center, Division of Allergy and Immunology, Department of Internal Medicine, College of Medicine, University of South Florida, Tampa, FL 33612, USA
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Budge PJ, Li Y, Beeler JA, Graham BS. RhoA-derived peptide dimers share mechanistic properties with other polyanionic inhibitors of respiratory syncytial virus (RSV), including disruption of viral attachment and dependence on RSV G. J Virol 2004; 78:5015-22. [PMID: 15113882 PMCID: PMC400344 DOI: 10.1128/jvi.78.10.5015-5022.2004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Large polyanionic molecules, such as sulfated polysaccharides (including soluble heparin and dextran sulfate), synthetic polyanionic polymers, and negatively charged proteins, have been shown to broadly inhibit several enveloped viruses. We recently reported the antiviral activity of a peptide derived from amino acids 77 to 95 of a potential binding partner of respiratory syncytial virus F protein (RSV F), the GTPase RhoA. A subsequent study with a truncated peptide (amino acids 80 to 94) revealed that optimal antiviral activity required dimerization via intermolecular disulfide bonds. We report here that the net negative charge of this peptide is also a determining factor for its antiviral activity and that it, like other polyanions, inhibits virus attachment. In a flow cytometry-based binding assay, peptide 80-94, heparin, and dextran sulfate inhibited the attachment of virus to cells at 4 degrees C at the same effective concentrations at which they prevent viral infectivity. Interestingly, time-of-addition experiments revealed that peptide 80-94 and soluble heparin were also able to inhibit the infectivity of a virus that had been prebound to cells at 4 degrees C, as had previously been shown for dextran sulfate, suggesting a potential role for postattachment effects of polyanions on RSV entry. Neutralization experiments with recombinant viruses showed that the antiviral activities of peptide 80-94 and dextran sulfate were diminished in the absence of the RSV attachment glycoprotein (G). Taken together, these data indicate that the antiviral activity of RhoA-derived peptides is functionally similar to that of other polyanions, is dependent on RSV G, and does not specifically relate to a protein-protein interaction between F and RhoA.
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Affiliation(s)
- Philip J Budge
- Department of Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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40
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Hull J, Rowlands K, Lockhart E, Sharland M, Moore C, Hanchard N, Kwiatkowski DP. Haplotype mapping of the bronchiolitis susceptibility locus near IL8. Hum Genet 2004; 114:272-9. [PMID: 14605870 DOI: 10.1007/s00439-003-1038-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2003] [Accepted: 09/15/2003] [Indexed: 10/26/2022]
Abstract
Susceptibility to viral bronchiolitis, the commonest cause of infant admissions to hospital in the industrialised world, is associated with polymorphism at the IL8 locus. Here we map the genomic boundaries of the disease association by case-control analysis and TDT in 580 affected UK infants. Markers for association mapping were chosen after determining patterns of linkage disequilibrium across the surrounding region of chromosome 4q, a 550-kb segment containing nine genes, extending from AFP to PPBP. The region has three major clusters of high linkage disequilibrium and is notable for its low haplotypic diversity. We exclude adjacent chemokine genes as the cause of the association, and identify a disease-associated haplotype that spans a 250-kb region from AFM to IL8. In between these two genes there is only one structural feature of interest, a novel gene RASSF6, which is predicted to encode a Ras effector protein.
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Affiliation(s)
- Jeremy Hull
- University Department of Paediatrics, Level 4, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK.
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41
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Nobiron I, O'Reilly DR, Olszewski JA. Autographa californica nucleopolyhedrovirus infection of Spodoptera frugiperda cells: a global analysis of host gene regulation during infection, using a differential display approach. J Gen Virol 2003; 84:3029-3039. [PMID: 14573808 DOI: 10.1099/vir.0.19270-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Autographa californica nucleopolyhedrovirus (AcMNPV), the type member of the virus family Baculoviridae, infects pest insects and has been the subject of many studies for its development as a biopesticide. It is also the virus upon which most of the commercial baculovirus protein expression systems are based. AcMNPV infection of cultured host Spodoptera frugiperda (Sf9) cells can induce a number of alterations of host cell properties including altering the cellular cytoskeleton, an arrest of the cell cycle in G(2)/M, and the global shutoff of host protein translation. Additionally, several cellular transcripts have been shown to be down-regulated following AcMNPV infection. In this study, we take a differential display approach to address whether a global down-regulation of Sf9 host transcripts occurs at late times of infection. Additionally, we also use this approach to search for host mRNAs which are up-regulated at early times of infection, and may be important for facilitating baculovirus infection. From these experiments we can confirm a global down-regulation of Sf9 mRNA levels at late times of infection. We also found that up-regulation of individual host gene RNA levels at early times of infection did not occur frequently. One host transcript which was found to be transiently up-regulated as a result of AcMNPV infection was an Sf9 Hsc70 gene. Hsc70 proteins have been shown to play a vital role in the life-cycle of other large DNA viruses, which suggests that this protein is also important for baculovirus infection.
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Affiliation(s)
- Isabelle Nobiron
- Department of Biological Sciences, SAF Building, South Kensington Campus, Imperial College, London SW7 2AZ, UK
| | - David R O'Reilly
- Department of Biological Sciences, SAF Building, South Kensington Campus, Imperial College, London SW7 2AZ, UK
| | - Julie A Olszewski
- Department of Biological Sciences, SAF Building, South Kensington Campus, Imperial College, London SW7 2AZ, UK
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42
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Harris J, Werling D. Binding and entry of respiratory syncytial virus into host cells and initiation of the innate immune response. Cell Microbiol 2003; 5:671-80. [PMID: 12969373 DOI: 10.1046/j.1462-5822.2003.00313.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Respiratory syncytial virus (RSV) is the most common cause of severe lower respiratory tract infection in infants and the elderly. There is currently no effective antiviral treatment for the infection, but advances in our understanding of RSV uptake, especially the role of surfactant proteins, the attachment protein G and the fusion protein F, as well as the post-binding events, have revealed potential targets for new therapies and vaccine development. RSV infection triggers an intense inflammatory response, mediated initially by the infected airway epithelial cells and antigen-presenting cells. Humoral and cell-mediated immune responses are important in controlling the extent of infection and promoting viral clearance. The initial innate immune response may play a critical role by influencing the subsequent adaptive response generated. This review summarizes our current understanding of RSV binding and uptake in mammalian cells and how these initial interactions influence the subsequent innate immune response generated.
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Affiliation(s)
- James Harris
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK.
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43
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Bitko V, Oldenburg A, Garmon NE, Barik S. Profilin is required for viral morphogenesis, syncytium formation, and cell-specific stress fiber induction by respiratory syncytial virus. BMC Microbiol 2003; 3:9. [PMID: 12740026 PMCID: PMC156654 DOI: 10.1186/1471-2180-3-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2003] [Accepted: 05/09/2003] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Actin is required for the gene expression and morphogenesis of respiratory syncytial virus (RSV), a clinically important Pneumovirus of the Paramyxoviridae family. In HEp-2 cells, RSV infection also induces actin stress fibers, which may be important in the immunopathology of the RSV disease. Profilin, a major regulator of actin polymerization, stimulates viral transcription in vitro. Thus, we tested the role of profilin in RSV growth and RSV-actin interactions in cultured cells (ex vivo). RESULTS We tested three cell lines: HEp-2 (human), A549 (human), and L2 (rat). In all three, RSV grew well and produced fused cells (syncytium), and two RSV proteins, namely, the phosphoprotein P and the nucleocapsid protein N, associated with profilin. In contrast, induction of actin stress fibers by RSV occurred in HEp-2 and L2 cells, but not in A549. Knockdown of profilin by RNA interference had a small effect on viral macromolecule synthesis but strongly inhibited maturation of progeny virions, cell fusion, and induction of stress fibers. CONCLUSIONS Profilin plays a cardinal role in RSV-mediated cell fusion and viral maturation. In contrast, interaction of profilin with the viral transcriptional proteins P and N may only nominally activate viral RNA-dependent RNA polymerase. Stress fiber formation is a cell-specific response to infection, requiring profilin and perhaps other signaling molecules that are absent in certain cell lines. Stress fibers per se play no role in RSV replication in cell culture. Clearly, the cellular architecture controls multiple steps of host-RSV interaction, some of which are regulated by profilin.
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Affiliation(s)
- Vira Bitko
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Anja Oldenburg
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Nicolle E Garmon
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Sailen Barik
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
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44
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Jeffree CE, Rixon HWM, Brown G, Aitken J, Sugrue RJ. Distribution of the attachment (G) glycoprotein and GM1 within the envelope of mature respiratory syncytial virus filaments revealed using field emission scanning electron microscopy. Virology 2003; 306:254-67. [PMID: 12642099 DOI: 10.1016/s0042-6822(02)00016-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Field emission scanning electron microscopy (FE SEM) was used to visualize the distribution of virus-associated components, the virus-attachment (G) protein, and the host-cell-derived lipid, GM1, in respiratory syncytial virus (RSV) filaments. RSV-infected cells were labeled in situ with a G protein antibody (MAb30) whose presence was detected using a second antibody conjugated to colloidal gold. No bound MAb30 was detected in mock-infected cells, whereas significant quantities bound to viral filaments revealing G protein clusters throughout the filaments. GM1 was detected using cholera toxin B subunit conjugated to colloidal gold. Mock-infected cells revealed numerous GM1 clusters on the cell surface. In RSV-infected cells, these gold clusters were detected on the filaments in low, but significant, amounts, indicating the incorporation of GM1 within the viral envelope. This report describes the first use of FE SEM to map the distribution of specific structural components within the envelope of a Paramyxovirus.
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Affiliation(s)
- Chris E Jeffree
- Institute of Cell and Molecular Biology, Biological Sciences EM Facility, University of Edinburgh, Waddington Building, King's Building, Mayfield Road, EH9 3JN, Edinburgh, UK
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45
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McCurdy LH, Graham BS. Role of plasma membrane lipid microdomains in respiratory syncytial virus filament formation. J Virol 2003; 77:1747-56. [PMID: 12525608 PMCID: PMC140864 DOI: 10.1128/jvi.77.3.1747-1756.2003] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The fusion protein (F) of respiratory syncytial virus (RSV) is the envelope glycoprotein responsible for the characteristic cytopathology of syncytium formation. RSV has been shown to bud from selective areas of the plasma membrane as pleomorphic virions, including both filamentous and round particles. With immunofluorescent microscopy, we demonstrated evidence of RSV filaments incorporating the fusion protein F and colocalizing with a lipid microdomain-specific fluorescent dye, 1,1-dihexadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate. Western blot analysis of Triton X-100 cold-extracted membrane fractions confirmed the presence of RSV proteins within the lipid microdomains. RSV proteins also colocalized with cellular proteins associated with lipid microdomains, caveolin-1, and CD44, as well as with RhoA, a small GTPase. ADP-ribosylation of RhoA by Clostridium botulinum exotoxin inactivated RhoA signaling and resulted in the absence of RSV-induced syncytia despite no significant change in viral titer. We demonstrated an overall decrease in both the number and length of the viral filaments and a shift in the localization of F to nonlipid microdomain regions of the membrane in the presence of C3 toxin. This suggests that the selective incorporation of RSV proteins into lipid microdomains during virus assembly may lead to critical interactions of F with cellular proteins, resulting in microvillus projections necessary for the formation of filamentous virus particles and syncytium formation. Thus, manipulation of membrane lipid microdomains may lead to alterations in the production of viral filaments and RSV pathogenesis and provide a new pharmacologic target for RSV therapy.
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Affiliation(s)
- Lewis H McCurdy
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-3017, USA.
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46
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Brown G, Rixon HWM, Sugrue RJ. Respiratory syncytial virus assembly occurs in GM1-rich regions of the host-cell membrane and alters the cellular distribution of tyrosine phosphorylated caveolin-1. J Gen Virol 2002; 83:1841-1850. [PMID: 12124448 DOI: 10.1099/0022-1317-83-8-1841] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We have previously shown that respiratory syncytial virus (RSV) assembly occurs within regions of the host-cell surface membrane that are enriched in the protein caveolin-1 (cav-1). In this report, we have employed immunofluorescence microscopy to further examine the RSV assembly process. Our results show that RSV matures at regions of the cell surface that, in addition to cav-1, are enriched in the lipid-raft ganglioside GM1. Furthermore, a comparison of mock-infected and RSV-infected cells by confocal microscopy revealed a significant change in the cellular distribution of phosphocaveolin-1 (pcav-1). In mock-infected cells, pcav-1 was located at regions of the cell that interact with the extracellular matrix, termed focal adhesions (FA). In contrast, RSV-infected cells showed both a decrease in the levels of pcav-1 associated with FA and the appearance of pcav-1-containing cytoplasmic vesicles, the latter being absent in mock-infected cells. These cytoplasmic vesicles were clearly visible between 9 and 18 h post-infection and coincided with the formation of RSV filaments, although we did not observe a direct association of pcav-1 with mature virus. In addition, we noted a strong colocalization between pcav-1 and growth hormone receptor binding protein-7 (Grb7), within these cytoplasmic vesicles, which was not observed in mock-infected cells. Collectively, these findings show that the RSV assembly process occurs within specialized lipid-raft structures on the host-cell plasma membrane, induces the cellular redistribution of pcav-1 and results in the formation of cytoplasmic vesicles that contain both pcav-1 and Grb7.
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Affiliation(s)
- Gaie Brown
- MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK1
| | - Helen W McL Rixon
- MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK1
| | - Richard J Sugrue
- MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK1
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47
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Abstract
Respiratory syncytial virus (RSV) is the most important cause of respiratory tract infection in infants. We have an incomplete understanding of the reasons why some infants are more severely affected by RSV than others. There is no effective antiviral treatment for the infection. Advances in our understanding of the biology of RSV, particularly in relation to the attachment protein G and the fusion protein F, have revealed potential targets for new antiviral therapies and vaccine development. In response to RSV infection an intense inflammatory response is triggered, mediated initially by the infected airway epithelial cells. Cell mediated responses are important in controlling the extent of infection and in viral clearance. Humoral responses are important in protection. There is early evidence that genetic variation of the host response can influence the outcome of RSV-induced bronchiolitis.
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Affiliation(s)
- D Hacking
- International Child Health Group, Department of Paediatrics, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK.
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48
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Harris J, Werling D, Hope JC, Taylor G, Howard CJ. Caveolae and caveolin in immune cells: distribution and functions. Trends Immunol 2002; 23:158-64. [PMID: 11864845 DOI: 10.1016/s1471-4906(01)02161-5] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Caveolae are small, cholesterol-rich, hydrophobic membrane domains, characterized by the presence of the protein caveolin and involved in several cellular processes, including clathrin-independent endocytosis, the regulation and transport of cellular cholesterol, and signal transduction. Recently, caveolae have been identified as providing a novel route by which several pathogens are internalized by antigen-presenting cells and as centers for signal transduction. Here, we review the distribution and role of caveolae and caveolin in mammalian immune cells.
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Affiliation(s)
- James Harris
- Sir William Dunn School of Pathology, South Parks Road, OX1 3RE, Oxford, UK.
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49
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Brown G, Aitken J, Rixon HWM, Sugrue RJ. Caveolin-1 is incorporated into mature respiratory syncytial virus particles during virus assembly on the surface of virus-infected cells. J Gen Virol 2002; 83:611-621. [PMID: 11842256 DOI: 10.1099/0022-1317-83-3-611] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have employed immunofluorescence microscopy and transmission electron microscopy to examine the assembly and maturation of respiratory syncytial virus (RSV) in the Vero cell line C1008. RSV matures at the apical cell surface in a filamentous form that extends from the plasma membrane. We observed that inclusion bodies containing viral ribonucleoprotein (RNP) cores predominantly appeared immediately below the plasma membrane, from where RSV filaments form during maturation at the cell surface. A comparison of mock-infected and RSV-infected cells by confocal microscopy revealed a significant change in the pattern of caveolin-1 (cav-1) fluorescence staining. Analysis by immuno-electron microscopy showed that RSV filaments formed in close proximity to cav-1 clusters at the cell surface membrane. In addition, immuno-electron microscopy showed that cav-1 was closely associated with early budding RSV. Further analysis by confocal microscopy showed that cav-1 was subsequently incorporated into the envelope of RSV filaments maturing on the host cell membrane, but was not associated with other virus structures such as the viral RNPs. Although cav-1 was incorporated into the mature virus, it was localized in clusters rather than being uniformly distributed along the length of the viral filaments. Furthermore, when RSV particles in the tissue culture medium from infected cells were examined by immuno-negative staining, the presence of cav-1 on the viral envelope was clearly demonstrated. Collectively, these findings show that cav-1 is incorporated into the envelope of mature RSV particles during egress.
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Affiliation(s)
- Gaie Brown
- MRC Virology Unit1 and Division of Virology, University of Glasgow2, Institute of Virology, Church Street, Glasgow G11 5JR, UK
| | - James Aitken
- MRC Virology Unit1 and Division of Virology, University of Glasgow2, Institute of Virology, Church Street, Glasgow G11 5JR, UK
| | - Helen W McL Rixon
- MRC Virology Unit1 and Division of Virology, University of Glasgow2, Institute of Virology, Church Street, Glasgow G11 5JR, UK
| | - Richard J Sugrue
- MRC Virology Unit1 and Division of Virology, University of Glasgow2, Institute of Virology, Church Street, Glasgow G11 5JR, UK
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