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Yang Q, Xue B, Liu F, Lu Y, Tang J, Yan M, Wu Q, Chen R, Zhou A, Liu L, Liu J, Qu C, Wu Q, Fu M, Zhong J, Dong J, Chen S, Wang F, Zhou Y, Zheng J, Peng W, Shang J, Chen X. Farnesyltransferase inhibitor lonafarnib suppresses respiratory syncytial virus infection by blocking conformational change of fusion glycoprotein. Signal Transduct Target Ther 2024; 9:144. [PMID: 38853183 PMCID: PMC11163014 DOI: 10.1038/s41392-024-01858-5] [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: 12/07/2023] [Revised: 04/28/2024] [Accepted: 05/09/2024] [Indexed: 06/11/2024] Open
Abstract
Respiratory syncytial virus (RSV) is the major cause of bronchiolitis and pneumonia in young children and the elderly. There are currently no approved RSV-specific therapeutic small molecules available. Using high-throughput antiviral screening, we identified an oral drug, the prenylation inhibitor lonafarnib, which showed potent inhibition of the RSV fusion process. Lonafarnib exhibited antiviral activity against both the RSV A and B genotypes and showed low cytotoxicity in HEp-2 and human primary bronchial epithelial cells (HBEC). Time-of-addition and pseudovirus assays demonstrated that lonafarnib inhibits RSV entry, but has farnesyltransferase-independent antiviral efficacy. Cryo-electron microscopy revealed that lonafarnib binds to a triple-symmetric pocket within the central cavity of the RSV F metastable pre-fusion conformation. Mutants at the RSV F sites interacting with lonafarnib showed resistance to lonafarnib but remained fully sensitive to the neutralizing monoclonal antibody palivizumab. Furthermore, lonafarnib dose-dependently reduced the replication of RSV in BALB/c mice. Collectively, lonafarnib could be a potential fusion inhibitor for RSV infection.
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Affiliation(s)
- Qi Yang
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Bao Xue
- Guangzhou National Laboratory, Guangzhou, 510005, China
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Fengjiang Liu
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Yongzhi Lu
- Guangzhou National Laboratory, Guangzhou, 510005, China
- School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, 511436, China
| | - Jielin Tang
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Mengrong Yan
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Qiong Wu
- Guangzhou National Laboratory, Guangzhou, 510005, China
- School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, 511436, China
| | - Ruyi Chen
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Anqi Zhou
- GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 511436, China
| | - Lijie Liu
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Junjun Liu
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Changbin Qu
- Guangzhou National Laboratory, Guangzhou, 510005, China
| | - Qingxin Wu
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Muqing Fu
- Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Jiayi Zhong
- Guangzhou National Laboratory, Guangzhou, 510005, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China
| | - Jianwei Dong
- Guangzhou National Laboratory, Guangzhou, 510005, China
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Sijie Chen
- GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 511436, China
| | - Fan Wang
- GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 511436, China
| | - Yuan Zhou
- Guangzhou National Laboratory, Guangzhou, 510005, China
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Jie Zheng
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- School of Pharmaceutical Science and Technology, Hangzhou lnstitute for Advanced Study, UCAS, Hangzhou, 310024, China
| | - Wei Peng
- Guangzhou National Laboratory, Guangzhou, 510005, China.
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China.
| | - Jinsai Shang
- Guangzhou National Laboratory, Guangzhou, 510005, China.
- School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, 511436, China.
| | - Xinwen Chen
- Guangzhou National Laboratory, Guangzhou, 510005, China.
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, 511436, China.
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Huong TN, Lee ZQ, Lai SK, Lee HY, Tan BH, Sugrue RJ. Evidence that an interaction between the respiratory syncytial virus F and G proteins at the distal ends of virus filaments mediates efficient multiple cycle infection. Virology 2024; 591:109985. [PMID: 38227992 DOI: 10.1016/j.virol.2024.109985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 11/29/2023] [Accepted: 01/04/2024] [Indexed: 01/18/2024]
Abstract
Evidence for a stable interaction between the respiratory syncytial virus (RSV) F and G proteins on the surface of virus filaments was provided using antibody immunoprecipitation studies on purified RSV particles, and by the in situ analysis on the surface of RSV-infected cells using the proximity ligation assay. Imaging of the F and G protein distribution on virus filaments suggested that this protein complex was localised at the distal ends of the virus filaments, and suggested that this protein complex played a direct role in mediating efficient localised cell-to-cell virus transmission. G protein expression was required for efficient localised cell-to-cell transmission of RSV in cell monolayers which provided evidence that this protein complex mediates efficient multiple cycle infection. Collectively, these data provide evidence that F and G proteins form a complex on the surface of RSV particles, and that a role for this protein complex in promoting virus transmission is suggested.
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Affiliation(s)
- Tra Nguyen Huong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Zhi Qi Lee
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Soak Kuan Lai
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Hsin Yee Lee
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Boon Huan Tan
- LKC School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore, 308232, Republic of Singapore
| | - Richard J Sugrue
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore.
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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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Kembou-Ringert JE, Steinhagen D, Thompson KD, Daly JM, Adamek M. Immune responses to Tilapia lake virus infection: what we know and what we don't know. Front Immunol 2023; 14:1240094. [PMID: 37622112 PMCID: PMC10445761 DOI: 10.3389/fimmu.2023.1240094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 07/20/2023] [Indexed: 08/26/2023] Open
Abstract
Tilapia lake virus (TiLV) is a novel contagious pathogen associated with a lethal disease affecting and decimating tilapia populations on several continents across the globe. Fish viral diseases, such as Tilapia lake virus disease (TiLVD), represent a serious threat to tilapia aquaculture. Therefore, a better understanding of the innate immune responses involved in establishing an antiviral state can help shed light on TiLV disease pathogenesis. Moreover, understanding the adaptive immune mechanisms involved in mounting protection against TiLV could greatly assist in the development of vaccination strategies aimed at controlling TiLVD. This review summarizes the current state of knowledge on the immune responses following TiLV infection. After describing the main pathological findings associated with TiLVD, both the innate and adaptive immune responses and mechanisms to TiLV infection are discussed, in both disease infection models and in vitro studies. In addition, our work, highlights research questions, knowledge gaps and research areas in the immunology of TiLV infection where further studies are needed to better understand how disease protection against TiLV is established.
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Affiliation(s)
- Japhette E. Kembou-Ringert
- Department of Infection, Immunity and Inflammation, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Dieter Steinhagen
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Kim D. Thompson
- Moredun Research Institute, Pentlands Science Park, Penicuik, United Kingdom
| | - Janet M. Daly
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, United Kingdom
| | - Mikolaj Adamek
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
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5
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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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6
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Céspedes-Tenorio D, Arias-Arias JL. The Virus-Induced Cytopathic Effect. Subcell Biochem 2023; 106:197-210. [PMID: 38159228 DOI: 10.1007/978-3-031-40086-5_7] [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
The cytopathic effect comprises the set of cellular alterations produced by a viral infection. It is of great relevance since it constitutes a direct marker of infection. Likewise, these alterations are often virus-specific which makes them a phenotypic marker for many viral species. All these characteristics have been used to complement the study of the dynamics of virus-cell interactions through the kinetic study of the progression of damage produced by the infection. Various approaches have been used to monitor the cytopathic effect, ranging from light microscopy, immunofluorescence assays, and direct labeling with fluorescent dyes, to plaque assay for the characterization of the infection over time. Here we address the relevance of the study of cytopathic effect and describe different experimental alternatives for its application.
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Affiliation(s)
- Daniel Céspedes-Tenorio
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Jorge L Arias-Arias
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
- Dulbecco Lab Studio, Residencial Lisboa 2G, Alajuela, Costa Rica.
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7
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PIK-24 Inhibits RSV-Induced Syncytium Formation via Direct Interaction with the p85α Subunit of PI3K. J Virol 2022; 96:e0145322. [PMID: 36416586 PMCID: PMC9749462 DOI: 10.1128/jvi.01453-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Phosphoinositide-3 kinase (PI3K) signaling regulates many cellular processes, including cell survival, differentiation, proliferation, cytoskeleton reorganization, and apoptosis. The actin cytoskeleton regulated by PI3K signaling plays an important role in plasma membrane rearrangement. Currently, it is known that respiratory syncytial virus (RSV) infection requires PI3K signaling. However, the regulatory pattern or corresponding molecular mechanism of PI3K signaling on cell-to-cell fusion during syncytium formation remains unclear. This study synthesized a novel PI3K inhibitor PIK-24 designed with PI3K as a target and used it as a molecular probe to investigate the involvement of PI3K signaling in syncytium formation during RSV infection. The results of the antiviral mechanism revealed that syncytium formation required PI3K signaling to activate RHO family GTPases Cdc42, to upregulate the inactive form of cofilin, and to increase the amount of F-actin in cells, thereby causing actin cytoskeleton reorganization and membrane fusion between adjacent cells. PIK-24 treatment significantly abolished the generation of these events by blocking the activation of PI3K signaling. Moreover, PIK-24 had an obvious binding activity with the p85α regulatory subunit of PI3K. The anti-RSV effect similar to PIK-24 was obtained after knockdown of p85α in vitro or knockout of p85α in vivo, suggesting that PIK-24 inhibited RSV infection by targeting PI3K p85α. Most importantly, PIK-24 exerted a potent anti-RSV activity, and its antiviral effect was stronger than that of the classic PI3K inhibitor LY294002, PI-103, and broad-spectrum antiviral drug ribavirin. Thus, PIK-24 has the potential to be developed into a novel anti-RSV agent targeting cellular PI3K signaling. IMPORTANCE PI3K protein has many functions and regulates various cellular processes. As an important regulatory subunit of PI3K, p85α can regulate the activity of PI3K signaling. Therefore, it serves as the key target for virus infection. Indeed, p85α-regulated PI3K signaling facilitates various intracellular plasma membrane rearrangement events by modulating the actin cytoskeleton, which may be critical for RSV-induced syncytium formation. In this study, we show that a novel PI3K inhibitor inhibits RSV-induced PI3K signaling activation and actin cytoskeleton reorganization by targeting the p85α protein, thereby inhibiting syncytium formation and exerting a potent antiviral effect. Respiratory syncytial virus (RSV) is one of the most common respiratory pathogens, causing enormous morbidity, mortality, and economic burden. Currently, no effective antiviral drugs or vaccines exist for RSV infection. This study contributes to understanding the molecular mechanism by which PI3K signaling regulates syncytium formation and provides a leading compound for anti-RSV infection drug development.
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Bergeron HC, Tripp RA. RSV Replication, Transmission, and Disease Are Influenced by the RSV G Protein. Viruses 2022; 14:v14112396. [PMID: 36366494 PMCID: PMC9692685 DOI: 10.3390/v14112396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/24/2022] [Accepted: 10/28/2022] [Indexed: 01/31/2023] Open
Abstract
It is important to understand the features affecting virus replication, fitness, and transmissibility as they contribute to the outcome of infection and affect disease intervention approaches. Respiratory syncytial virus (RSV) is a major contributor to respiratory disease, particularly in the infant and elderly populations. Although first described over 60 years ago, there are no approved vaccines and there are limited specific antiviral treatments due in part to our incomplete understanding of the features affecting RSV replication, immunity, and disease. RSV studies have typically focused on using continuous cell lines and conventional RSV strains to establish vaccine development and various antiviral countermeasures. This review outlines how the RSV G protein influences viral features, including replication, transmission, and disease, and how understanding the role of the G protein can improve the understanding of preclinical studies.
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9
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A Virus Is a Community: Diversity within Negative-Sense RNA Virus Populations. Microbiol Mol Biol Rev 2022; 86:e0008621. [PMID: 35658541 DOI: 10.1128/mmbr.00086-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Negative-sense RNA virus populations are composed of diverse viral components that interact to form a community and shape the outcome of virus infections. At the genomic level, RNA virus populations consist not only of a homogeneous population of standard viral genomes but also of an extremely large number of genome variants, termed viral quasispecies, and nonstandard viral genomes, which include copy-back viral genomes, deletion viral genomes, mini viral RNAs, and hypermutated RNAs. At the particle level, RNA virus populations are composed of pleomorphic particles, particles missing or having additional genomes, and single particles or particle aggregates. As we continue discovering more about the components of negative-sense RNA virus populations and their crucial functions during virus infection, it will become more important to study RNA virus populations as a whole rather than their individual parts. In this review, we will discuss what is known about the components of negative-sense RNA virus communities, speculate how the components of the virus community interact, and summarize what vaccines and antiviral therapies are being currently developed to target or harness these components.
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10
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Manti S, Piedimonte G. An overview on the RSV-mediated mechanisms in the onset of non-allergic asthma. Front Pediatr 2022; 10:998296. [PMID: 36204661 PMCID: PMC9530042 DOI: 10.3389/fped.2022.998296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/19/2022] [Indexed: 12/13/2022] Open
Abstract
Respiratory syncytial virus (RSV) infection is recognized as an important risk factor for wheezing and asthma, since it commonly affects babies during lung development. While the role of RSV in the onset of atopic asthma is widely recognized, its impact on the onset of non-atopic asthma, mediated via other and independent causal pathways, has long been also suspected, but the association is less clear. Following RSV infection, the release of local pro-inflammatory molecules, the dysfunction of neural pathways, and the compromised epithelial integrity can become chronic and influence airway development, leading to bronchial hyperreactivity and asthma, regardless of atopic status. After a brief review of the RSV structure and its interaction with the immune system and neuronal pathways, this review summarizes the current evidence about the RSV-mediated pathogenic pathways in predisposing and inducing airway dysfunction and non-allergic asthma development.
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Affiliation(s)
- Sara Manti
- Pediatric Pulmonology Unit, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy.,Pediatric Unit, Department of Human Pathology of Adult and Childhood Gaetano Barresi, University of Messina, Messina, Italy
| | - Giovanni Piedimonte
- Department of Pediatrics, Biochemistry and Molecular Biology, Tulane University, New Orleans, LA, United States
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11
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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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12
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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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13
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Indicators of the molecular pathogenesis of virulent Newcastle disease virus in chickens revealed by transcriptomic profiling of spleen. Sci Rep 2021; 11:17570. [PMID: 34475461 PMCID: PMC8413450 DOI: 10.1038/s41598-021-96929-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 08/18/2021] [Indexed: 02/07/2023] Open
Abstract
Newcastle disease virus (NDV) has caused significant outbreaks in South-East Asia, particularly in Indonesia in recent years. Recently emerged genotype VII NDVs (NDV-GVII) have shifted their tropism from gastrointestinal/respiratory tropism to a lymphotropic virus, invading lymphoid organs including spleen and bursa of Fabricius to cause profound lymphoid depletion. In this study, we aimed to identify candidate genes and biological pathways that contribute to the disease caused by this velogenic NDV-GVII. A transcriptomic analysis based on RNA-Seq of spleen was performed in chickens challenged with NDV-GVII and a control group. In total, 6361 genes were differentially expressed that included 3506 up-regulated genes and 2855 down-regulated genes. Real-Time PCR of ten selected genes validated the RNA-Seq results as the correlation between them is 0.98. Functional and network analysis of Differentially Expressed Genes (DEGs) showed altered regulation of ElF2 signalling, mTOR signalling, proliferation of cells of the lymphoid system, signalling by Rho family GTPases and synaptogenesis signalling in spleen. We have also identified modified expression of IFIT5, PI3K, AGT and PLP1 genes in NDV-GVII infected chickens. Our findings in activation of autophagy-mediated cell death, lymphotropic and synaptogenesis signalling pathways provide new insights into the molecular pathogenesis of this newly emerged NDV-GVII.
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14
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Monson EA, Trenerry AM, Laws JL, Mackenzie JM, Helbig KJ. Lipid droplets and lipid mediators in viral infection and immunity. FEMS Microbiol Rev 2021; 45:fuaa066. [PMID: 33512504 PMCID: PMC8371277 DOI: 10.1093/femsre/fuaa066] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/02/2020] [Indexed: 12/14/2022] Open
Abstract
Lipid droplets (LDs) contribute to key pathways important for the physiology and pathophysiology of cells. In a homeostatic view, LDs regulate the storage of neutral lipids, protein sequestration, removal of toxic lipids and cellular communication; however, recent advancements in the field show these organelles as essential for various cellular stress response mechanisms, including inflammation and immunity, with LDs acting as hubs that integrate metabolic and inflammatory processes. The accumulation of LDs has become a hallmark of infection, and is often thought to be virally driven; however, recent evidence is pointing to a role for the upregulation of LDs in the production of a successful immune response to viral infection. The fatty acids housed in LDs are also gaining interest due to the role that these lipid species play during viral infection, and their link to the synthesis of bioactive lipid mediators that have been found to have a very complex role in viral infection. This review explores the role of LDs and their subsequent lipid mediators during viral infections and poses a paradigm shift in thinking in the field, whereby LDs may play pivotal roles in protecting the host against viral infection.
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Affiliation(s)
- Ebony A Monson
- School of Life Sciences, La Trobe University, Melbourne, Australia, 3083
| | - Alice M Trenerry
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia, 3000
| | - Jay L Laws
- School of Life Sciences, La Trobe University, Melbourne, Australia, 3083
| | - Jason M Mackenzie
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia, 3000
| | - Karla J Helbig
- School of Life Sciences, La Trobe University, Melbourne, Australia, 3083
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15
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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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16
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Reverse genetics systems for contemporary isolates of respiratory syncytial virus enable rapid evaluation of antibody escape mutants. Proc Natl Acad Sci U S A 2021; 118:2026558118. [PMID: 33811145 DOI: 10.1073/pnas.2026558118] [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] [Indexed: 11/18/2022] Open
Abstract
Human respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infection in children under 5 y of age. In the absence of a safe and effective vaccine and with limited options for therapeutic interventions, uncontrolled epidemics of RSV occur annually worldwide. Existing RSV reverse genetics systems have been predominantly based on older laboratory-adapted strains such as A2 or Long. These strains are not representative of currently circulating genotypes and have a convoluted passage history, complicating their use in studies on molecular determinants of viral pathogenesis and intervention strategies. In this study, we have generated reverse genetics systems for clinical isolates of RSV-A (ON1, 0594 strain) and RSV-B (BA9, 9671 strain) in which the full-length complementary DNA (cDNA) copy of the viral antigenome is cloned into a bacterial artificial chromosome (BAC). Additional recombinant (r) RSVs were rescued expressing enhanced green fluorescent protein (EGFP), mScarlet, or NanoLuc luciferase from an additional transcription unit inserted between the P and M genes. Mutations in antigenic site II of the F protein conferring escape from palivizumab neutralization (K272E, K272Q, S275L) were investigated using quantitative cell-fusion assays and rRSVs via the use of BAC recombineering protocols. These mutations enabled RSV-A and -B to escape palivizumab neutralization but had differential impacts on cell-to-cell fusion, as the S275L mutation resulted in an almost-complete ablation of syncytium formation. These reverse genetics systems will facilitate future cross-validation efficacy studies of novel RSV therapeutic intervention strategies and investigations into viral and host factors necessary for virus entry and cell-to-cell spread.
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17
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Sood N, Verma DK, Paria A, Yadav SC, Yadav MK, Bedekar MK, Kumar S, Swaminathan TR, Mohan CV, Rajendran KV, Pradhan PK. Transcriptome analysis of liver elucidates key immune-related pathways in Nile tilapia Oreochromis niloticus following infection with tilapia lake virus. FISH & SHELLFISH IMMUNOLOGY 2021; 111:208-219. [PMID: 33577877 DOI: 10.1016/j.fsi.2021.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Nile tilapia (Oreochromis niloticus) is one of the most important aquaculture species farmed worldwide. However, the recent emergence of tilapia lake virus (TiLV) disease, also known as syncytial hepatitis of tilapia, has threatened the global tilapia industry. To gain more insight regarding the host response against the disease, the transcriptional profiles of liver in experimentally-infected and control tilapia were compared. Analysis of RNA-Seq data identified 4640 differentially expressed genes (DEGs), which were involved among others in antigen processing and presentation, MAPK, apoptosis, necroptosis, chemokine signaling, interferon, NF-kB, acute phase response and JAK-STAT pathways. Enhanced expression of most of the DEGs in the above pathways suggests an attempt by tilapia to resist TiLV infection. However, upregulation of some of the key genes such as BCL2L1 in apoptosis pathway; NFKBIA in NF-kB pathway; TRFC in acute phase response; and SOCS, EPOR, PI3K and AKT in JAK-STAT pathway and downregulation of the genes, namely MAP3K7 in MAPK pathway; IFIT1 in interferon; and TRIM25 in NF-kB pathway suggested that TiLV was able to subvert the host immune response to successfully establish the infection. The study offers novel insights into the cellular functions that are affected following TiLV infection and will serve as a valuable genomic resource towards our understanding of susceptibility of tilapia to TiLV infection.
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Affiliation(s)
- Neeraj Sood
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Dev Kumar Verma
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Anutosh Paria
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Shrish Chandra Yadav
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Manoj Kumar Yadav
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Megha Kadam Bedekar
- ICAR-Central Institute of Fisheries Education, Versova, Andheri (W), Mumbai, 400 061, Maharashtra, India
| | - Saurav Kumar
- ICAR-Central Institute of Fisheries Education, Versova, Andheri (W), Mumbai, 400 061, Maharashtra, India
| | - Thangaraj Raja Swaminathan
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, 682 018, Kerala, India
| | | | - K V Rajendran
- ICAR-Central Institute of Fisheries Education, Versova, Andheri (W), Mumbai, 400 061, Maharashtra, India
| | - Pravata Kumar Pradhan
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India.
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18
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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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19
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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: 59] [Impact Index Per Article: 14.8] [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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20
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Abstract
A critical step in the life cycle of a virus is spread to a new target cell, which generally involves the release of new viral particles from the infected cell which can then initiate infection in the next target cell. While cell-free viral particles released into the extracellular environment are necessary for long distance spread, there are disadvantages to this mechanism. These include the presence of immune system components, the low success rate of infection by single particles, and the relative fragility of viral particles in the environment. Several mechanisms of direct cell-to-cell spread have been reported for animal viruses which would avoid the issues associated with cell-free particles. A number of viruses can utilize several different mechanisms of direct cell-to-cell spread, but our understanding of the differential usage by these pathogens is modest. Although the mechanisms of cell-to-cell spread differ among viruses, there is a common exploitation of key pathways and components of the cellular cytoskeleton. Remarkably, some of the viral mechanisms of cell-to-cell spread are surprisingly similar to those used by bacteria. Here we summarize the current knowledge of the conventional and non-conventional mechanisms of viral spread, the common methods used to detect viral spread, and the impact that these mechanisms can have on viral pathogenesis.
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Affiliation(s)
- Nicolas Cifuentes-Munoz
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, San Miguel, Santiago, Chile
| | - Farah El Najjar
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Rebecca Ellis Dutch
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, United States.
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21
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Transcriptome Analysis Reveals Inhibitory Effects of Lentogenic Newcastle Disease Virus on Cell Survival and Immune Function in Spleen of Commercial Layer Chicks. Genes (Basel) 2020; 11:genes11091003. [PMID: 32859030 PMCID: PMC7565929 DOI: 10.3390/genes11091003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/19/2020] [Accepted: 08/25/2020] [Indexed: 01/05/2023] Open
Abstract
As a major infectious disease in chickens, Newcastle disease virus (NDV) causes considerable economic losses in the poultry industry, especially in developing countries where there is limited access to effective vaccination. Therefore, enhancing resistance to the virus in commercial chickens through breeding is a promising way to promote poultry production. In this study, we investigated gene expression changes at 2 and 6 days post inoculation (dpi) at day 21 with a lentogenic NDV in a commercial egg-laying chicken hybrid using RNA sequencing analysis. By comparing NDV-challenged and non-challenged groups, 526 differentially expressed genes (DEGs) (false discovery rate (FDR) < 0.05) were identified at 2 dpi, and only 36 at 6 dpi. For the DEGs at 2 dpi, Ingenuity Pathway Analysis predicted inhibition of multiple signaling pathways in response to NDV that regulate immune cell development and activity, neurogenesis, and angiogenesis. Up-regulation of interferon induced protein with tetratricopeptide repeats 5 (IFIT5) in response to NDV was consistent between the current and most previous studies. Sprouty RTK signaling antagonist 1 (SPRY1), a DEG in the current study, is in a significant quantitative trait locus associated with virus load at 6 dpi in the same population. These identified pathways and DEGs provide potential targets to further study breeding strategy to enhance NDV resistance in chickens.
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Abstract
Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract disease in young children and elderly people. Although the virus was isolated in 1955, an effective RSV vaccine has not been developed, and the only licensed intervention is passive immunoprophylaxis of high-risk infants with a humanized monoclonal antibody. During the past 5 years, however, there has been substantial progress in our understanding of the structure and function of the RSV glycoproteins and their interactions with host cell factors that mediate entry. This period has coincided with renewed interest in developing effective interventions, including the isolation of potent monoclonal antibodies and small molecules and the design of novel vaccine candidates. In this Review, we summarize the recent findings that have begun to elucidate RSV entry mechanisms, describe progress on the development of new interventions and conclude with a perspective on gaps in our knowledge that require further investigation. Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract disease in young children and elderly people. In this Review, Battles and McLellan summarize our current understanding of RSV entry, describe progress on the development of new interventions and conclude with a perspective on gaps in our knowledge that require further investigation.
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Affiliation(s)
- Michael B Battles
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA.
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23
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Meshram CD, Oomens AGP. Identification of a human respiratory syncytial virus phosphoprotein domain required for virus-like-particle formation. Virology 2019; 532:48-54. [PMID: 31009855 DOI: 10.1016/j.virol.2019.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 04/03/2019] [Accepted: 04/04/2019] [Indexed: 10/27/2022]
Abstract
Perceived inefficiency and inadequate knowledge of the human respiratory syncytial virus (hRSV) assembly process present a hurdle for large-scale production of authentic hRSV virus-like particles (VLPs) for vaccine purposes. We previously established that the matrix protein, phosphoprotein (P), and fusion protein carboxy-terminus were sufficient to generate VLPs that resemble filamentous wildtype hRSV. Here, the contribution of P was examined. By co-expressing matrix, fusion, and modified P proteins, a ser/thr-rich P region (residues 39-57) was found to be critical for VLP formation, whereas the oligomerization domain was not. Substitutions throughout region 39-57 inhibited VLP formation and relevant amino acids were identified. Phosphomimetic substitutions of serines and threonines inhibited VLP formation; Phosphoblatant substitutions did not. The data show that P not only co-regulates replication and transcription but also has an important role in assembly, mediated by a separate domain that likely interacts with M and/or F and is highly regulated by phosphorylation.
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Affiliation(s)
- Chetan D Meshram
- Department of Microbiology. University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Antonius G P Oomens
- Center for Veterinary Health Sciences, Oklahoma State University, 250 McElroy Hall, Stillwater, OK, 74078, USA.
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24
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Monette A, Mouland AJ. T Lymphocytes as Measurable Targets of Protection and Vaccination Against Viral Disorders. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 342:175-263. [PMID: 30635091 PMCID: PMC7104940 DOI: 10.1016/bs.ircmb.2018.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Continuous epidemiological surveillance of existing and emerging viruses and their associated disorders is gaining importance in light of their abilities to cause unpredictable outbreaks as a result of increased travel and vaccination choices by steadily growing and aging populations. Close surveillance of outbreaks and herd immunity are also at the forefront, even in industrialized countries, where previously eradicated viruses are now at risk of re-emergence due to instances of strain recombination, contractions in viral vector geographies, and from their potential use as agents of bioterrorism. There is a great need for the rational design of current and future vaccines targeting viruses, with a strong focus on vaccine targeting of adaptive immune effector memory T cells as the gold standard of immunity conferring long-lived protection against a wide variety of pathogens and malignancies. Here, we review viruses that have historically caused large outbreaks and severe lethal disorders, including respiratory, gastric, skin, hepatic, neurologic, and hemorrhagic fevers. To observe trends in vaccinology against these viral disorders, we describe viral genetic, replication, transmission, and tropism, host-immune evasion strategies, and the epidemiology and health risks of their associated syndromes. We focus on immunity generated against both natural infection and vaccination, where a steady shift in conferred vaccination immunogenicity is observed from quantifying activated and proliferating, long-lived effector memory T cell subsets, as the prominent biomarkers of long-term immunity against viruses and their associated disorders causing high morbidity and mortality rates.
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25
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Ohta K, Matsumoto Y, Yumine N, Nishio M. The V protein of human parainfluenza virus type 2 promotes RhoA-induced filamentous actin formation. Virology 2018; 524:90-96. [DOI: 10.1016/j.virol.2018.08.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 10/28/2022]
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26
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Abstract
Respiratory syncytial virus (RSV) is the most common cause of infant hospitalization and causes a high burden of disease in the elderly, too. This enveloped negative-stranded RNA virus has been recently reclassified in the Pneumoviridae family. Infections of the respiratory cells happens when the two major surface glycoproteins, G and F, take contact with the cell receptor CX3CR1 and mediate entry by fusion, respectively. Viral mRNA transcription, genomic RNA synthesis and nucleocapsid formation occur in large cytoplasmic inclusion bodies to avoid recognition by the host innate immune response. Most progeny virions remain associated to the infected cell surface; fusion of infected with adjacent cells results in the formation of large multinucleated syncytia that eventually undergo apoptosis. Desquamated epithelial cells form the plugs that with mucus and fibrin may cause lower airway obstructions. Pathogenetic mechanism of severe RSV disease likely involve both the extent of viral replication and the host immune response. Regarding the latter, single nucleotide polymorphism analysis and genome-wide association studies showed that genetic susceptibility to severe RSV infection is likely a complex trait, in which many different host genetic variants contribute. Recent studies pointed to the fact that bronchiolitis severity depends more on the specific infecting RSV genotypes than on the amount of viral loads. A population-based surveillance system to better define RSV burden of disease would be of valuable help for implementing future vaccination programs.
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Affiliation(s)
- Alessandra Pierangeli
- Laboratory of Virology, Department of Molecular Medicine, Sapienza University, Rome, Italy -
| | - Carolina Scagnolari
- Laboratory of Virology, Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Guido Antonelli
- Laboratory of Virology, Department of Molecular Medicine, Sapienza University, Rome, Italy
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Huong TN, Yan Y, Jumat MR, Lui J, Tan BH, Wang DY, Sugrue RJ. A sustained antiviral host response in respiratory syncytial virus infected human nasal epithelium does not prevent progeny virus production. Virology 2018; 521:20-32. [PMID: 29870884 DOI: 10.1016/j.virol.2018.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/09/2018] [Accepted: 05/18/2018] [Indexed: 12/01/2022]
Abstract
Respiratory syncytial virus infection was examined using a human nasal epithelial cell model. Maximum levels of shed-virus were produced at between 3 and 5 days post-infection (dpi), and the infectivity of the shed-virus was stable up to 10 dpi. The highest levels of interferon signalling were recorded at 2dpi, and infection induced a widespread antivirus response in the nasal epithelium, involving both infected cells and non-infected cells. Although these cellular responses were associated with reduced levels of progeny virus production and restricted virus spread, they did not inhibit the infectivity virus that is shed early in infection. In the clinical context these data suggest that although the host cell response in the nasal epithelium may restrict the levels of progeny virus particles produced, the stability of the shed-virus in the nasal mucosa may be an important factor in both disease progression and virus transmission.
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Affiliation(s)
- Tra Nguyen Huong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Yan Yan
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228, Republic of Singapore
| | - Muhammad Raihan Jumat
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Jing Lui
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228, Republic of Singapore
| | - Boon Huan Tan
- Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510, Republic of Singapore
| | - De Yun Wang
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228, Republic of Singapore
| | - Richard J Sugrue
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore.
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RSV glycoprotein and genomic RNA dynamics reveal filament assembly prior to the plasma membrane. Nat Commun 2017; 8:667. [PMID: 28939853 PMCID: PMC5610308 DOI: 10.1038/s41467-017-00732-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 07/20/2017] [Indexed: 11/25/2022] Open
Abstract
The human respiratory syncytial virus G protein plays an important role in the entry and assembly of filamentous virions. Here, we report the use of fluorescently labeled soybean agglutinin to selectively label the respiratory syncytial virus G protein in living cells without disrupting respiratory syncytial virus infectivity or filament formation and allowing for interrogations of respiratory syncytial virus virion assembly. Using this approach, we discovered that plasma membrane-bound respiratory syncytial virus G rapidly recycles from the membrane via clathrin-mediated endocytosis. This event is then followed by the dynamic formation of filamentous and branched respiratory syncytial virus particles, and assembly with genomic ribonucleoproteins and caveolae-associated vesicles prior to re-insertion into the plasma membrane. We demonstrate that these processes are halted by the disruption of microtubules and inhibition of molecular motors. Collectively, our results show that for respiratory syncytial virus assembly, viral filaments are produced and loaded with genomic RNA prior to insertion into the plasma membrane. Assembly of filamentous RSV particles is incompletely understood due to a lack of techniques suitable for live-cell imaging. Here Vanover et al. use labeled soybean agglutinin to selectively label RSV G protein and show how filamentous RSV assembly, initiated in the cytoplasm, uses G protein recycled from the plasma membrane.
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Respiratory Syncytial Virus: Infection, Detection, and New Options for Prevention and Treatment. Clin Microbiol Rev 2017; 30:277-319. [PMID: 27903593 DOI: 10.1128/cmr.00010-16] [Citation(s) in RCA: 336] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Respiratory syncytial virus (RSV) infection is a significant cause of hospitalization of children in North America and one of the leading causes of death of infants less than 1 year of age worldwide, second only to malaria. Despite its global impact on human health, there are relatively few therapeutic options available to prevent or treat RSV infection. Paradoxically, there is a very large volume of information that is constantly being refined on RSV replication, the mechanisms of RSV-induced pathology, and community transmission. Compounding the burden of acute RSV infections is the exacerbation of preexisting chronic airway diseases and the chronic sequelae of RSV infection. A mechanistic link is even starting to emerge between asthma and those who suffer severe RSV infection early in childhood. In this article, we discuss developments in the understanding of RSV replication, pathogenesis, diagnostics, and therapeutics. We attempt to reconcile the large body of information on RSV and why after many clinical trials there is still no efficacious RSV vaccine and few therapeutics.
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Bilawchuk LM, Griffiths CD, Jensen LD, Elawar F, Marchant DJ. The Susceptibilities of Respiratory Syncytial Virus to Nucleolin Receptor Blocking and Antibody Neutralization are Dependent upon the Method of Virus Purification. Viruses 2017; 9:E207. [PMID: 28771197 PMCID: PMC5580464 DOI: 10.3390/v9080207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 12/12/2022] Open
Abstract
Respiratory Syncytial Virus (RSV) that is propagated in cell culture is purified from cellular contaminants that can confound experimental results. A number of different purification methods have been described, including methods that utilize fast protein liquid chromatography (FPLC) and gradient ultracentrifugation. Thus, the constituents and experimental responses of RSV stocks purified by ultracentrifugation in sucrose and by FPLC were analyzed and compared by infectivity assay, Coomassie stain, Western blot, mass spectrometry, immuno-transmission electron microscopy (TEM), and ImageStream flow cytometry. The FPLC-purified RSV had more albumin contamination, but there was less evidence of host-derived exosomes when compared to ultracentrifugation-purified RSV as detected by Western blot and mass spectrometry for the exosome markers superoxide dismutase [Cu-Zn] (SOD1) and the tetraspanin CD63. Although the purified virus stocks were equally susceptible to nucleolin-receptor blocking by the DNA aptamer AS1411, the FPLC-purified RSV was significantly less susceptible to anti-RSV polyclonal antibody neutralization; there was 69% inhibition (p = 0.02) of the sucrose ultracentrifugation-purified RSV, 38% inhibition (p = 0.03) of the unpurified RSV, but statistically ineffective neutralization in the FPLC-purified RSV (22% inhibition; p = 0.30). The amount of RSV neutralization of the purified RSV stocks was correlated with anti-RSV antibody occupancy on RSV particles observed by immuno-TEM. RSV purified by different methods alters the stock composition and morphological characteristics of virions that can lead to different experimental responses.
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Affiliation(s)
- Leanne M Bilawchuk
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Cameron D Griffiths
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Lionel D Jensen
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Farah Elawar
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - David J Marchant
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada.
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Mehedi M, McCarty T, Martin SE, Le Nouën C, Buehler E, Chen YC, Smelkinson M, Ganesan S, Fischer ER, Brock LG, Liang B, Munir S, Collins PL, Buchholz UJ. Actin-Related Protein 2 (ARP2) and Virus-Induced Filopodia Facilitate Human Respiratory Syncytial Virus Spread. PLoS Pathog 2016; 12:e1006062. [PMID: 27926942 PMCID: PMC5142808 DOI: 10.1371/journal.ppat.1006062] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/14/2016] [Indexed: 11/19/2022] Open
Abstract
Human respiratory syncytial virus (RSV) is an enveloped RNA virus that is the most important viral cause of acute pediatric lower respiratory tract illness worldwide, and lacks a vaccine or effective antiviral drug. The involvement of host factors in the RSV replicative cycle remains poorly characterized. A genome-wide siRNA screen in human lung epithelial A549 cells identified actin-related protein 2 (ARP2) as a host factor involved in RSV infection. ARP2 knockdown did not reduce RSV entry, and did not markedly reduce gene expression during the first 24 hr of infection, but decreased viral gene expression thereafter, an effect that appeared to be due to inhibition of viral spread to neighboring cells. Consistent with reduced spread, there was a 10-fold reduction in the release of infectious progeny virions in ARP2-depleted cells at 72 hr post-infection. In addition, we found that RSV infection induced filopodia formation and increased cell motility in A549 cells and that this phenotype was ARP2 dependent. Filopodia appeared to shuttle RSV to nearby uninfected cells, facilitating virus spread. Expression of the RSV F protein alone from a plasmid or heterologous viral vector in A549 cells induced filopodia, indicating a new role for the RSV F protein, driving filopodia induction and virus spread. Thus, this study identified roles for ARP2 and filopodia in RSV-induced cell motility, RSV production, and RSV cell-to-cell spread. RSV is the most common viral cause of severe acute pediatric lower respiratory tract illness, including pneumonia and bronchiolitis, in young children worldwide. In a genome-wide siRNA screen in human lung epithelial A549 cells infected with RSV expressing green fluorescent protein (RSV-GFP), we identified ARP2 as a cellular factor with a role in the RSV replicative cycle. ARP2 is part of the actin-related protein 2/3 (ARP2/3) complex, which contributes to cell shape and motility through its role in actin polymerization. ARP2 depletion reduced the production and spread of RSV in human lung epithelial cell cultures, with the most noticeable effects at late time points after RSV infection. RSV infection induced the formation of slender actin-rich cell protrusions, called filopodia and increased cell motility. Filopodia formation and cell motility were inhibited by ARP2 knockdown. The filopodia appeared to shuttle RSV to neighboring cells, facilitating virus spread. Thus, RSV uses two previously unrecognized ARP2 dependent features to facilitate viral spread, namely cell motility and filopodia formation.
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Affiliation(s)
- Masfique Mehedi
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Thomas McCarty
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Scott E. Martin
- Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America
| | - Cyril Le Nouën
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Eugen Buehler
- Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America
| | - Yu-Chi Chen
- Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America
| | - Margery Smelkinson
- Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sundar Ganesan
- Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Elizabeth R. Fischer
- Microscopy Unit, Rocky Mountain Laboratories, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Linda G. Brock
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Bo Liang
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Shirin Munir
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Peter L. Collins
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ursula J. Buchholz
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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The Respiratory Syncytial Virus Phosphoprotein, Matrix Protein, and Fusion Protein Carboxy-Terminal Domain Drive Efficient Filamentous Virus-Like Particle Formation. J Virol 2016; 90:10612-10628. [PMID: 27654298 DOI: 10.1128/jvi.01193-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 09/01/2016] [Indexed: 12/31/2022] Open
Abstract
Virus-like particles (VLPs) are attractive as a vaccine concept. For human respiratory syncytial virus (hRSV), VLP assembly is poorly understood and appears inefficient. Hence, hRSV antigens are often incorporated into foreign VLP systems to generate anti-RSV vaccine candidates. To better understand the assembly, and ultimately to enable efficient production, of authentic hRSV VLPs, we examined the associated requirements and mechanisms. In a previous analysis in HEp-2 cells, the nucleoprotein (N), phosphoprotein (P), matrix protein (M), and fusion protein (F) were required for formation of filamentous VLPs, which, similar to those of wild-type virus, were associated with the cell surface. Using fluorescence and electron microscopy combined with immunogold labeling, we examined the surfaces of transfected HEp-2 cells and further dissected the process of filamentous VLP formation. Our results show that N is not required. Coexpression of P plus M plus F, but not P plus M, M plus F, or P plus F, induced both viral protein coalescence and formation of filamentous VLPs that resembled wild-type virions. Despite suboptimal coalescence in the absence of P, the M and F proteins, when coexpressed, formed cell surface-associated filaments with abnormal morphology, appearing longer and thinner than wild-type virions. For F, only the carboxy terminus (Fstem) was required, and addition of foreign protein sequences to Fstem allowed incorporation into VLPs. Together, the data show that P, M, and the F carboxy terminus are sufficient for robust viral protein coalescence and filamentous VLP formation and suggest that M-F interaction drives viral filament formation, with P acting as a type of cofactor facilitating the process and exerting control over particle morphology. IMPORTANCE hRSV is responsible for >100,000 deaths in children worldwide, and a vaccine is not available. Among the potential anti-hRSV approaches are virus-like particle (VLP) vaccines, which, based on resemblance to virus or viral components, can induce protective immunity. For hRSV, few reports are available concerning authentic VLP production or testing, in large part because VLP production is inefficient and the mechanisms underlying particle assembly are poorly understood. Here, we took advantage of the cell-associated nature of RSV particles and used high-resolution microscopy analyses to examine the viral proteins required for formation of wild-type-virus-resembling VLPs, the contributions of these proteins to morphology, and the domains involved in incorporation of the antigenically important viral F protein. The results provide new insights that will facilitate future production of hRSV VLPs with defined shapes and compositions and may translate into improved manufacture of live-attenuated hRSV vaccines.
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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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El Najjar F, Cifuentes-Muñoz N, Chen J, Zhu H, Buchholz UJ, Moncman CL, Dutch RE. Human metapneumovirus Induces Reorganization of the Actin Cytoskeleton for Direct Cell-to-Cell Spread. PLoS Pathog 2016; 12:e1005922. [PMID: 27683250 PMCID: PMC5040343 DOI: 10.1371/journal.ppat.1005922] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 09/08/2016] [Indexed: 11/22/2022] Open
Abstract
Paramyxovirus spread generally involves assembly of individual viral particles which then infect target cells. We show that infection of human bronchial airway cells with human metapneumovirus (HMPV), a recently identified paramyxovirus which causes significant respiratory disease, results in formation of intercellular extensions and extensive networks of branched cell-associated filaments. Formation of these structures is dependent on actin, but not microtubule, polymerization. Interestingly, using a co-culture assay we show that conditions which block regular infection by HMPV particles, including addition of neutralizing antibodies or removal of cell surface heparan sulfate, did not prevent viral spread from infected to new target cells. In contrast, inhibition of actin polymerization or alterations to Rho GTPase signaling pathways significantly decreased cell-to-cell spread. Furthermore, viral proteins and viral RNA were detected in intercellular extensions, suggesting direct transfer of viral genetic material to new target cells. While roles for paramyxovirus matrix and fusion proteins in membrane deformation have been previously demonstrated, we show that the HMPV phosphoprotein extensively co-localized with actin and induced formation of cellular extensions when transiently expressed, supporting a new model in which a paramyxovirus phosphoprotein is a key player in assembly and spread. Our results reveal a novel mechanism for HMPV direct cell-to-cell spread and provide insights into dissemination of respiratory viruses. Human metapneumovirus (HMPV) is an important human respiratory pathogen that affects all age groups worldwide. There are currently no vaccines or treatments available for HMPV, and key aspects of its life cycle remain unknown. We examined the late events of the HMPV infection cycle in human bronchial epithelial cells. Our data demonstrate that HMPV infection leads to formation of unique structures, including intercellular extensions connecting cells, and large networks of branched cell-associated filaments. Viral modulation of the cellular cytoskeleton and cellular signaling pathways are important for formation of these structures. Our results are consistent with the intercellular extensions playing a role in direct spread of virus from cell-to-cell, potentially by transfer of virus genetic material without particle formation. We also show that the HMPV phosphoprotein localizes with actin and can promote membrane deformations, suggesting a novel role in viral assembly or spread for paramyxovirus phosphoproteins.
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Affiliation(s)
- Farah El Najjar
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Nicolás Cifuentes-Muñoz
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Jing Chen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Haining Zhu
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ursula J. Buchholz
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Carole L. Moncman
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Rebecca Ellis Dutch
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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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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Makris S, Bajorek M, Culley FJ, Goritzka M, Johansson C. Alveolar Macrophages Can Control Respiratory Syncytial Virus Infection in the Absence of Type I Interferons. J Innate Immun 2016; 8:452-63. [PMID: 27423203 PMCID: PMC5322584 DOI: 10.1159/000446824] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 05/16/2016] [Indexed: 12/19/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infections. Immunity to RSV is initiated upon detection of the virus by pattern recognition receptors, such as RIG-I-like receptors. RIG-I-like receptors signal via MAVS to induce the synthesis of proinflammatory mediators, including type I interferons (IFNs), which trigger and shape antiviral responses and protect cells from infection. Alveolar macrophages (AMs) are amongst the first cells to encounter invading viruses and the ones producing type I IFNs. However, it is unclear whether IFNs act to prevent AMs from serving as vehicles for viral replication. In this study, primary AMs from MAVS (Mavs-/-)- or type I IFN receptor (Ifnar1-/-)-deficient mice were exposed to RSV ex vivo. Wild-type (wt) AMs but not Mavs-/- and Ifnar1-/- AMs produced inflammatory mediators in response to RSV. Furthermore, Mavs-/- and Ifnar1-/- AMs accumulated more RSV proteins than wt AMs, but the infection was abortive. Thus, RIG-I-like receptor-MAVS and IFNAR signalling are important for the induction of proinflammatory mediators from AMs upon RSV infection, but this signalling is not central for controlling viral replication. The ability to restrict viral replication makes AMs ideal sensors of RSV infection and important initiators of immune responses in the lung.
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Affiliation(s)
- Spyridon Makris
- Respiratory Infections Section, St. Mary's Campus, National Heart and Lung Institute, Imperial College London, London, UK
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Graham BS. Vaccines against respiratory syncytial virus: The time has finally come. Vaccine 2016; 34:3535-41. [PMID: 27182820 DOI: 10.1016/j.vaccine.2016.04.083] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/11/2016] [Accepted: 04/15/2016] [Indexed: 11/27/2022]
Abstract
Respiratory syncytial virus causes a significant public health burden, particularly in very young infants and the frail elderly. The legacy of enhanced RSV disease (ERD) from a whole formalin-inactivated RSV vaccine, and the complex biology of the virus and the neonate have delayed the development of effective vaccines. However, new insights into factors associated with ERD and breakthroughs in understanding the antigenic structure of the fusion (F) glycoprotein have increased optimism that vaccine development is possible. This has led to investment of time and resources by industry, regulatory authorities, governments, and nonprofit organizations to develop the infrastructure needed to make the advanced clinical development of RSV vaccine candidates a reality.
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Affiliation(s)
- Barney S Graham
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States.
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38
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Jans J, elMoussaoui H, de Groot R, de Jonge MI, Ferwerda G. Actin- and clathrin-dependent mechanisms regulate interferon gamma release after stimulation of human immune cells with respiratory syncytial virus. Virol J 2016; 13:52. [PMID: 27004689 PMCID: PMC4802911 DOI: 10.1186/s12985-016-0506-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 03/14/2016] [Indexed: 12/02/2022] Open
Abstract
Background Respiratory syncytial virus (RSV) can cause recurrent and severe respiratory tract infections. Cytoskeletal proteins are often involved during viral infections, either for cell entry or the initiation of the immune response. The importance of actin and clathrin dynamics for cell entry and the initiation of the cellular immune response against RSV in human immune cells is not known yet. The aim of this study was to investigate the role of actin and clathrin on cell entry of RSV and the subsequent effect on T cell activation and interferon gamma release in human immune cells. Methods Peripheral blood mononuclear cells and purified monocytes were isolated from healthy adults and stimulated in vitro with RSV. Actin and clathrin dynamics were inhibited with respectively cytochalasin D and chlorpromazine. T cell receptor signaling was inhibited with cyclosporin A. Flow cytometry was used to determine the role of actin and clathrin on cell entry and T cell activation by RSV. Enzyme-linked immunosorbent assays were used to investigate the contribution of actin and clathrin on the release of interferon gamma. Results Cell entry, virus gene transcription and interferon gamma release are actin-dependent. Post-endocytic processes like the increased expression of major histocompatibility complex II on monocytes , T cell activation and the release of interferon gamma are clathrin-dependent. Finally, T cell receptor signaling affects T cell activation, whereas soluble interleukin 18 is dispensable. Conclusion Analysis of cell entry and interferon gamma release after infection with RSV reveals the importance of actin- and clathrin-dependent signaling in human immune cells. Insights into the cellular biology of the human immune response against respiratory syncytial virus will provide a better understanding of disease pathogenesis and may prove useful in the development of preventive strategies.
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Affiliation(s)
- Jop Jans
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Science, Radboud university medical center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Hicham elMoussaoui
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Science, Radboud university medical center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Ronald de Groot
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Science, Radboud university medical center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Marien I de Jonge
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Science, Radboud university medical center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Gerben Ferwerda
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Science, Radboud university medical center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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Dapat C, Oshitani H. Novel insights into human respiratory syncytial virus-host factor interactions through integrated proteomics and transcriptomics analysis. Expert Rev Anti Infect Ther 2016; 14:285-97. [PMID: 26760927 PMCID: PMC4819838 DOI: 10.1586/14787210.2016.1141676] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The lack of vaccine and limited antiviral options against respiratory syncytial virus (RSV) highlights the need for novel therapeutic strategies. One alternative is to develop drugs that target host factors required for viral replication. Several microarray and proteomics studies had been published to identify possible host factors that are affected during RSV replication. In order to obtain a comprehensive understanding of RSV-host interaction, we integrated available proteome and transcriptome datasets and used it to construct a virus-host interaction network. Then, we interrogated the network to identify host factors that are targeted by the virus and we searched for drugs from the DrugBank database that interact with these host factors, which may have potential applications in repositioning for future treatment options of RSV infection.
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Affiliation(s)
- Clyde Dapat
- a Department of Virology , Tohoku University Graduate School of Medicine , Sendai , Miyagi Prefecture , Japan
| | - Hitoshi Oshitani
- a Department of Virology , Tohoku University Graduate School of Medicine , Sendai , Miyagi Prefecture , Japan
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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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Huong TN, Tan BH, Sugrue RJ. A Proteomic-Based Workflow Using Purified Respiratory Syncytial Virus Particles to Identify Cellular Factors as Drug Targets. Methods Mol Biol 2016; 1442:175-194. [PMID: 27464695 DOI: 10.1007/978-1-4939-3687-8_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The identification of cellular factors that play a role in respiratory syncytial virus (RSV) replication is an alternative strategy in the identification of druggable cellular protein that are essential for RSV replication. In this regard experimental strategies that are able to screen relevant proteins from the vast array of proteins in the cellular milieu will facilitate the identification of potential drug targets. In this chapter we describe a procedure where RSV particles are purified from cells that are permissive for RSV infection, and the protein composition of the purified virus particles characterized using a proteomics-based strategy. This procedure revealed that actin, several actin-binding proteins, and the chaperones HSP70 and HSP90 also co-purified with the virus particles. The relevance of the HSP90 protein to virus replication was then further validated using imaging, gene silencing and by using an established small molecule HSP90 inhibitor.
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Affiliation(s)
- Tra Nguyen Huong
- 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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Graham BS, Modjarrad K, McLellan JS. Novel antigens for RSV vaccines. Curr Opin Immunol 2015; 35:30-8. [PMID: 26070108 DOI: 10.1016/j.coi.2015.04.005] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 04/28/2015] [Indexed: 02/07/2023]
Abstract
Respiratory syncytial virus (RSV) remains a leading global cause of infant mortality and adult morbidity. Infection, which recurs throughout life, elicits only short-lived immunity. The development of a safe and efficacious vaccine has, thus far, been elusive. Recent technological advances, however, have yielded promising RSV vaccine candidates that are based on solving atomic-level structures of surface glycoproteins interacting with neutralizing antibodies. The class I fusion glycoprotein, F, serves as the primary antigenic component of most vaccines, and is the target of the only licensed monoclonal antibody product used to reduce the frequency of severe disease in high-risk neonates. However, success of prior F-based vaccines has been limited by the lack of understanding how the conformational rearrangement between a metastable prefusion F (pre-F) and a stable postfusion F (post-F) affected the epitope content. Neutralizing epitopes reside on both conformations, but those specific to pre-F are far more potent than those previously identified and present on post-F. The solution of the pre-F structure and its subsequent characterization and stabilization illustrates the value of a structure-based approach to vaccine development, and provides hope that a safe and effective RSV vaccine is possible.
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Affiliation(s)
- Barney S Graham
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Kayvon Modjarrad
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Jason S McLellan
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, 7200 Vail, Hanover, NH 03755, USA
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Jumat MR, Huong TN, Ravi LI, Stanford R, Tan BH, Sugrue RJ. Viperin protein expression inhibits the late stage of respiratory syncytial virus morphogenesis. Antiviral Res 2015; 114:11-20. [DOI: 10.1016/j.antiviral.2014.11.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 11/05/2014] [Accepted: 11/18/2014] [Indexed: 01/13/2023]
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Deng Z, Huang Z, Yuan M, Yang K, Pang Y. Baculovirus induces host cell aggregation via a Rho/Rok-dependent mechanism. J Gen Virol 2014; 95:2310-2320. [PMID: 24866850 DOI: 10.1099/vir.0.066811-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Several baculoviruses can induce host cell aggregation during infection; however, the molecular basis remains unknown. The Rho family of small GTPases, including Rho1, Racs and Cdc42, plays important roles in cell migration and cell-cell contact. Activated GTPases target actin polymerization to discrete sites on the plasma membrane, thereby inducing membrane protrusions. In this study, we demonstrated that Spodoptera litura nucleopolyhedrovirus (SpltNPV) infection induced the amoeboid movement and aggregation of SpLi-221 cells in vitro. The amount of Rho1-GTP increased in the infected cells, which suggested that Rho1 was activated upon infection. RNA interference and superinfection of dominant-negative recombinants revealed that the SpltNPV-induced SpLi-221 cell aggregation was dependent on the Rho1, but not Racs or Cdc42, signalling pathway. Inhibition of Rho-associated protein kinase (Rok) activity by the inhibitor Y-27632 significantly reduced SpLi-221 cell aggregation. Silencing Rho1 expression with RNA interference decreased SpltNPV propagation by approximately 40 % in vitro, when SpLi-221 cells were infected at a low, but not high, m.o.i., suggesting that the SpltNPV-induced cell aggregation may benefit SpltNPV spread.
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Affiliation(s)
- Zihao Deng
- State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Zhihong Huang
- State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Meijin Yuan
- State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Kai Yang
- State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Yi Pang
- State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
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Structural analysis of respiratory syncytial virus reveals the position of M2-1 between the matrix protein and the ribonucleoprotein complex. J Virol 2014; 88:7602-17. [PMID: 24760890 DOI: 10.1128/jvi.00256-14] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Respiratory syncytial virus (RSV), a member of the Paramyxoviridae family of nonsegmented, negative-sense, single-stranded RNA genome viruses, is a leading cause of lower respiratory tract infections in infants, young children, and the elderly or immunocompromised. There are many open questions regarding the processes that regulate human RSV (hRSV) assembly and budding. Here, using cryo-electron tomography, we identified virus particles that were spherical, filamentous, and asymmetric in structure, all within the same virus preparation. The three particle morphologies maintained a similar organization of the surface glycoproteins, matrix protein (M), M2-1, and the ribonucleoprotein (RNP). RNP filaments were traced in three dimensions (3D), and their total length was calculated. The measurements revealed the inclusion of multiple full-length genome copies per particle. RNP was associated with the membrane whenever the M layer was present. The amount of M coverage ranged from 24% to 86% in the different morphologies. Using fluorescence light microscopy (fLM), direct stochastic optical reconstruction microscopy (dSTORM), and a proximity ligation assay (PLA), we provide evidence illustrating that M2-1 is located between RNP and M in isolated viral particles. In addition, regular spacing of the M2-1 densities was resolved when hRSV viruses were imaged using Zernike phase contrast (ZPC) cryo-electron tomography. Our studies provide a more complete characterization of the hRSV virion structure and substantiation that M and M2-1 regulate virus organization. IMPORTANCE hRSV is a leading cause of lower respiratory tract infections in infants and young children as well as elderly or immunocompromised individuals. We used cryo-electron tomography and Zernike phase contrast cryo-electron tomography to visualize populations of purified hRSV in 3D. We observed the three distinct morphologies, spherical, filamentous, and asymmetric, which maintained comparable organizational profiles. Depending on the virus morphology examined, the amount of M ranged from 24% to 86%. We complemented the cryo-imaging studies with fluorescence microscopy, dSTORM, and a proximity ligation assay to provide additional evidence that M2-1 is incorporated into viral particles and is positioned between M and RNP. The results highlight the impact of M and M2-1 on the regulation of hRSV organization.
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The Thr205 phosphorylation site within respiratory syncytial virus matrix (M) protein modulates M oligomerization and virus production. J Virol 2014; 88:6380-93. [PMID: 24672034 DOI: 10.1128/jvi.03856-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Human respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and pneumonia in infants and the elderly worldwide; however, there is no licensed RSV vaccine or effective drug treatment available. The RSV matrix (M) protein plays key roles in virus assembly and budding, but the protein interactions that govern budding of infectious virus are not known. In this study, we focus on M protein and identify a key phosphorylation site (Thr205) in M that is critical for RSV infectious virus production. Recombinant virus with a nonphosphorylatable alanine (Ala) residue at the site was markedly attenuated, whereas virus with a phosphomimetic aspartate (Asp) resulted in a nonviable virus which could only be recovered with an additional mutation in M (serine to asparagine at position 220), strongly implying that Thr205 is critical for viral infectivity. Experiments in vitro showed that mutation of Thr205 does not affect M stability or the ability to form dimers but implicate an effect on higher-order oligomer assembly. In transfected and infected cells, Asp substitution of Thr205 appeared to impair M oligomerization; typical filamentous structures still formed at the plasma membrane, but M assembly during the ensuing elongation process seemed to be impaired, resulting in shorter and more branched filaments as observed using electron microscopy (EM). Our data thus imply for the first time that M oligomerization, regulated by a negative charge at Thr205, may be critical to production of infectious RSV. IMPORTANCE We show here for the first time that RSV M's role in virus assembly/release is strongly dependent on threonine 205 (Thr205), a consensus site for CK2, which appears to play a key regulatory role in modulating M oligomerization and association with virus filaments. Our analysis indicates that T205 mutations do not impair M dimerization or viruslike filament formation per se but rather the ability of M to assemble in ordered fashion on the viral filaments themselves. This appears to impact in turn upon the infectivity of released virus rather than on virus production or release itself. Thus, M oligomerization would appear to be a target of interest for the development of anti-RSV agents; further, the recombinant T205-substituted mutant viruses described here would appear to be the first RSV mutants affected in viral maturation to our knowledge and hence of considerable interest for vaccine approaches in the future.
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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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Alonas E, Lifland AW, Gudheti M, Vanover D, Jung J, Zurla C, Kirschman J, Fiore VF, Douglas A, Barker TH, Yi H, Wright ER, Crowe JE, Santangelo PJ. Combining single RNA sensitive probes with subdiffraction-limited and live-cell imaging enables the characterization of virus dynamics in cells. ACS NANO 2014; 8:302-15. [PMID: 24351207 PMCID: PMC3906890 DOI: 10.1021/nn405998v] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The creation of fluorescently labeled viruses is currently limited by the length of imaging observation time (e.g., labeling an envelope protein) and the rescue of viral infectivity (e.g., encoding a GFP protein). Using single molecule sensitive RNA hybridization probes delivered to the cytoplasm of infected cells, we were able to isolate individual, infectious, fluorescently labeled human respiratory syncytial virus virions. This was achieved without affecting viral mRNA expression, viral protein expression, or infectivity. Measurements included the characterization of viral proteins and genomic RNA in a single virion using dSTORM, the development of a GFP fusion assay, and the development of a pulse-chase assay for viral RNA production that allowed for the detection of both initial viral RNA and nascent RNA production at designated times postinfection. Live-cell measurements included imaging and characterization of filamentous virion fusion and the quantification of virus replication within the same cell over an eight-hour period. Using probe-labeled viruses, individual viral particles can be characterized at subdiffraction-limited resolution, and viral infections can be quantified in single cells over an entire cycle of replication. The implication of this development is that MTRIP labeling of viral RNA during virus assembly has the potential to become a general methodology for the labeling and study of many important RNA viruses.
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Affiliation(s)
- Eric Alonas
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
| | - Aaron W. Lifland
- Vutara, Inc., 615 Arapeen #304, Salt Lake City, Utah 84108, United States
| | - Manasa Gudheti
- Vutara, Inc., 615 Arapeen #304, Salt Lake City, Utah 84108, United States
| | - Daryll Vanover
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
| | - Jeenah Jung
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
| | - Chiara Zurla
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
| | - Jonathan Kirschman
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
| | - Vincent F. Fiore
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
| | - Alison Douglas
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
| | - Thomas H. Barker
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
| | - Hong Yi
- Robert P. Apkarian Integrated Electron Microscopy Core, College of Medicine, Emory University, Atlanta, Georgia 30322, United States
| | - Elizabeth R. Wright
- Robert P. Apkarian Integrated Electron Microscopy Core, College of Medicine, Emory University, Atlanta, Georgia 30322, United States
- Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, 2015 Uppergate Drive, NE, Suite 548, Atlanta, Georgia 30322, United States
| | - James E. Crowe
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Philip J. Santangelo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, UA Whitaker Bldg, Atlanta, Georgia 30332, United States
- Address correspondence to
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Tiwari PM, Eroglu E, Boyoglu-Barnum S, He Q, Willing GA, Vig K, Dennis VA, Singh SR. Atomic force microscopic investigation of respiratory syncytial virus infection in HEp-2 cells. J Microsc 2013; 253:31-41. [PMID: 24251370 DOI: 10.1111/jmi.12095] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 10/07/2013] [Indexed: 01/14/2023]
Abstract
Respiratory syncytial virus (RSV) primarily causes bronchiolitis and pneumonia in infants. In spite of intense research, no safe and effective vaccine has been developed yet. For understanding its pathogenesis and development of anti-RSV drugs/therapeutics, it is indispensable to study the RSV-host interaction. Although, there are limited studies using electron microscopy to elucidate the infection process of RSV, to our knowledge, no study has reported the morphological impact of RSV infection using atomic force microscopy. We report the cytoplasmic and nuclear changes in human epidermoid cell line type 2 using atomic force microscopy. Human epidermoid cell line type 2 cells, grown on cover slips, were infected with RSV and fixed after various time periods, processed and observed for morphological changes using atomic force microscopy. RSV infected cells showed loss of membrane integrity, with degeneration in the cellular content and cytoskeleton. Nuclear membrane was disintegrated and nuclear volume was decreased. The chromatin of the RSV infected cells was condensed, progressing towards degeneration via pyknosis and apoptosis. Membrane protrusions of ~150-200 nm diameter were observed on RSV infected cells after 6 h, suggestive of prospective RSV budding sites. To our knowledge, this is the first study of RSV infection process using atomic force microscopy. Such morphological studies could help explore viral infection process aiding the development of anti-RSV therapies.
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Affiliation(s)
- P M Tiwari
- Center for NanoBiotechnology Research, Alabama State University, Montgomery, Alabama 36101, U.S.A
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Vlecken DH, Pelgrim RP, Ruminski S, Bakker WA, van der Pol LA. Comparison of initial feasibility of host cell lines for viral vaccine production. J Virol Methods 2013; 193:28-41. [DOI: 10.1016/j.jviromet.2013.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 04/17/2013] [Accepted: 04/29/2013] [Indexed: 12/28/2022]
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