1
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Xie E, Ahmad S, Smyth RP, Sieben C. Advanced fluorescence microscopy in respiratory virus cell biology. Adv Virus Res 2023; 116:123-172. [PMID: 37524480 DOI: 10.1016/bs.aivir.2023.05.002] [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: 08/02/2023]
Abstract
Respiratory viruses are a major public health burden across all age groups around the globe, and are associated with high morbidity and mortality rates. They can be transmitted by multiple routes, including physical contact or droplets and aerosols, resulting in efficient spreading within the human population. Investigations of the cell biology of virus replication are thus of utmost importance to gain a better understanding of virus-induced pathogenicity and the development of antiviral countermeasures. Light and fluorescence microscopy techniques have revolutionized investigations of the cell biology of virus infection by allowing the study of the localization and dynamics of viral or cellular components directly in infected cells. Advanced microscopy including high- and super-resolution microscopy techniques available today can visualize biological processes at the single-virus and even single-molecule level, thus opening a unique view on virus infection. We will highlight how fluorescence microscopy has supported investigations on virus cell biology by focusing on three major respiratory viruses: respiratory syncytial virus (RSV), Influenza A virus (IAV) and SARS-CoV-2. We will review our current knowledge of virus replication and highlight how fluorescence microscopy has helped to improve our state of understanding. We will start by introducing major imaging and labeling modalities and conclude the chapter with a perspective discussion on remaining challenges and potential opportunities.
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Affiliation(s)
- Enyu Xie
- Nanoscale Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Shazeb Ahmad
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg, Germany
| | - Redmond P Smyth
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg, Germany; Faculty of Medicine, University of Würzburg, Würzburg, Germany
| | - Christian Sieben
- Nanoscale Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany; Institute of Genetics, Technische Universität Braunschweig, Braunschweig, Germany.
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2
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Chiu YF, Huang YW, Chen CY, Chen YC, Gong YN, Kuo RL, Huang CG, Shih SR. Visualizing Influenza A Virus vRNA Replication. Front Microbiol 2022; 13:812711. [PMID: 35733972 PMCID: PMC9207383 DOI: 10.3389/fmicb.2022.812711] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Influenza A virus (IAV) has caused recurrent epidemics and severe pandemics. In this study, we adapted an MS2-MCP live-cell imaging system to visualize IAV replication. A reporter plasmid, pHH-PB2-vMSL, was constructed by replacing a part of the PB2-coding sequence in pHH-PB2 with a sequence encoding 24 copies of a stem-loop structure from bacteriophage MS2 (MSL). Binding of MS2 coat protein (MCP) fused to green fluorescent protein (GFP) to MSL enabled the detection of vRNA as fluorescent punctate signals in live-cell imaging. The introduction of pHH-PB2-vMSL into A549 cells transduced to express an MCP-GFP fusion protein lacking the nuclear localization signal (MCP-GFPdN), subsequently allowed tracking of the distribution and replication of PB2-vMSL vRNA after IAV PR8 infection. Spatial and temporal measurements revealed exponential increases in vRNA punctate signal intensity, which was only observed after membrane blebbing in apoptotic cells. Similar signal intensity increases in apoptotic cells were also observed after MDCK cells, transduced to express MCP-GFPdN, were infected with IAV carrying PB2-vMSL vRNA. Notably, PB2-vMSL vRNA replication was observed to occur only in apoptotic cells, at a consistent time after apoptosis initiation. There was a lack of observable PB2-vMSL vRNA replication in non-apoptotic cells, and vRNA replication was suppressed in the presence of apoptosis inhibitors. These findings point to an important role for apoptosis in IAV vRNA replication. The utility of the MS2-imaging system for visualizing time-sensitive processes such as viral replication in live host cells is also demonstrated in this study.
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Affiliation(s)
- Ya-Fang Chiu
- Department of Microbiology and Immunology, Chang Gung University, Taoyuan, Taiwan.,Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan.,Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yi-Wen Huang
- Department of Microbiology and Immunology, Chang Gung University, Taoyuan, Taiwan
| | - Chi-Yuan Chen
- Department of Microbiology and Immunology, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Chia Chen
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yu-Nong Gong
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan.,Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Rei-Lin Kuo
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan
| | - Chung-Guei Huang
- Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Shin-Ru Shih
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan
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3
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Tracking the Replication-Competent Zika Virus with Tetracysteine-Tagged Capsid Protein in Living Cells. J Virol 2022; 96:e0184621. [PMID: 35285687 PMCID: PMC9006885 DOI: 10.1128/jvi.01846-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Zika virus (ZIKV) is the mosquito-borne enveloped flavivirus that causes microcephaly in neonates. While real-time imaging plays a critical role in dissecting viral biology, no fluorescent, genetically engineered ZIKV for single-particle tracking is currently available.
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4
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Tseng YY, Kuan CY, Mibayashi M, Chen CJ, Palese P, Albrecht RA, Hsu WL. Interaction between NS1 and Cellular MAVS Contributes to NS1 Mitochondria Targeting. Viruses 2021; 13:1909. [PMID: 34696339 PMCID: PMC8537625 DOI: 10.3390/v13101909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 11/16/2022] Open
Abstract
Influenza A virus nonstructural protein 1 (NS1) plays an important role in evading host innate immunity. NS1 inhibits interferon (IFN) responses via multiple mechanisms, including sequestering dsRNA and suppressing retinoic acid-inducible gene I (RIG-I) signaling by interacting with RIG-I and tripartite motif-containing protein 25 (TRIM25). In the current study, we demonstrated the mitochondrial localization of NS1 at the early stage of influenza virus infection. Since NS1 does not contain mitochondria-targeting signals, we suspected that there is an association between the NS1 and mitochondrial proteins. This hypothesis was tested by demonstrating the interaction of NS1 with mitochondrial antiviral-signaling protein (MAVS) in a RIG-I-independent manner. Importantly, the association with MAVS facilitated the mitochondrial localization of NS1 and thereby significantly impeded MAVS-mediated Type I IFN production.
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Affiliation(s)
- Yeu-Yang Tseng
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 402, Taiwan; (Y.-Y.T.); (C.-Y.K.)
- WHO Collaborating Centre for Reference and Research on Influenza, Royal Melbourne Hospital, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Chih-Ying Kuan
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 402, Taiwan; (Y.-Y.T.); (C.-Y.K.)
| | - Masaki Mibayashi
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (M.M.); (C.-J.C.); (P.P.); (R.A.A.)
| | - Chi-Jene Chen
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (M.M.); (C.-J.C.); (P.P.); (R.A.A.)
| | - Peter Palese
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (M.M.); (C.-J.C.); (P.P.); (R.A.A.)
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Randy A. Albrecht
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (M.M.); (C.-J.C.); (P.P.); (R.A.A.)
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Wei-Li Hsu
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 402, Taiwan; (Y.-Y.T.); (C.-Y.K.)
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5
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Wang H, Tian Z, Xu Y, Wang Q, Ding SW, Li Y. Altering Intracellular Localization of the RNA Interference Factors by Influenza A Virus Non-structural Protein 1. Front Microbiol 2020; 11:590904. [PMID: 33281788 PMCID: PMC7688628 DOI: 10.3389/fmicb.2020.590904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/19/2020] [Indexed: 11/17/2022] Open
Abstract
Influenza A virus (IAV) causes seasonal infections and periodic pandemics in humans. The non-structural protein 1 (NS1) of IAV is the main viral antagonist of the innate immune responses that play a key role in influenza pathogenesis. However, the mechanism to disrupt the host cell homeostasis by IAV NS1 remains poorly understood. Here, we show that expression of NS1 from the WSN strain, but not PR8 strain, of IAV, markedly induced nuclear import of the host RNA interference (RNAi) factors such as Argonaute-2 and microRNA 16. We found that the single residue substitution of aspartic acid with histidine at position 101 (D101H) of IAV-PR8 NS1 was sufficient to induce the nuclear import process and to enhance the virulence of IAV-PR8 in mice. However, we observed no significant differences between the wild-type and mutant IAV-PR8 in virus titers or induction of the interferon response in lung tissues, indicating a novel role of NS1 in the virulence determination of IAV in a mammalian host. Moreover, our bioinformatic analysis of 69,057 NS1 sequences from all IAV subtypes deposited in the NCBI database revealed that the NS1-H101 gene of IAV-WSN was widespread among H1N1 viruses isolated in 1933 but disappeared completely after 1940. Thus, IAV NS1 (H101) is a mutation selected against during evolution of IAV, suggesting that mutation H101 confers an important biological phenotype.
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Affiliation(s)
- Hua Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Zhonghui Tian
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yan Xu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Qi Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Shou-Wei Ding
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA, United States
| | - Yang Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
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6
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tenOever BR. Synthetic Virology: Building Viruses to Better Understand Them. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a038703. [PMID: 31871242 DOI: 10.1101/cshperspect.a038703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Generally comprised of less than a dozen components, RNA viruses can be viewed as well-designed genetic circuits optimized to replicate and spread within a given host. Understanding the molecular design that enables this activity not only allows one to disrupt these circuits to study their biology, but it provides a reprogramming framework to achieve novel outputs. Recent advances have enabled a "learning by building" approach to better understand virus biology and create valuable tools. Below is a summary of how modifying the preexisting genetic framework of influenza A virus has been used to track viral movement, understand virus replication, and identify host factors that engage this viral circuitry.
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Affiliation(s)
- Benjamin R tenOever
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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7
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Live Visualization of Hemagglutinin Dynamics During Infection by Using a Novel Reporter Influenza A Virus. Viruses 2020; 12:v12060687. [PMID: 32604762 PMCID: PMC7354568 DOI: 10.3390/v12060687] [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: 06/07/2020] [Revised: 06/21/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022] Open
Abstract
Live visualization of influenza A virus (IAV) structural proteins during viral infection in cells is highly sought objective to study different aspects of the viral replication cycle. To achieve this, we engineered an IAV to express a Tetra Cysteine tag (TC tag) from hemagglutinin (HA), which allows intracellular labeling of the engineered HA protein with biarsenic dyes and subsequent fluorescence detection. Using such constructs, we rescued a recombinant IAV with TC tag inserted in HA, in A/Puerto Rico/8/1934(H1N1) background (HA-TC). This recombinant HA-TC tag reporter IAV was replication-competent; however, as compared to wild type PR8 IAV, it was attenuated in multicycle replication. We confirmed expression of TC tag and biarsenical labeling of HA by immunofluorescence assay in cells infected with an HA-TC tag reporter IAV. Further, we used this reporter virus to visualize HA expression and translocation in IAV infected cells by live confocal imaging. We also tested the utility of the HA-TC IAV in testing chemical inhibitors of the HA translocation. Overall, HA-TC IAV is a versatile tool that will be useful for studying viral life cycle events, virus-host interactions, and anti-viral testing.
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8
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Liu SL, Wang ZG, Xie HY, Liu AA, Lamb DC, Pang DW. Single-Virus Tracking: From Imaging Methodologies to Virological Applications. Chem Rev 2020; 120:1936-1979. [PMID: 31951121 PMCID: PMC7075663 DOI: 10.1021/acs.chemrev.9b00692] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Uncovering
the mechanisms of virus infection and assembly is crucial
for preventing the spread of viruses and treating viral disease. The
technique of single-virus tracking (SVT), also known as single-virus
tracing, allows one to follow individual viruses at different parts
of their life cycle and thereby provides dynamic insights into fundamental
processes of viruses occurring in live cells. SVT is typically based
on fluorescence imaging and reveals insights into previously unreported
infection mechanisms. In this review article, we provide the readers
a broad overview of the SVT technique. We first summarize recent advances
in SVT, from the choice of fluorescent labels and labeling strategies
to imaging implementation and analytical methodologies. We then describe
representative applications in detail to elucidate how SVT serves
as a valuable tool in virological research. Finally, we present our
perspectives regarding the future possibilities and challenges of
SVT.
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Affiliation(s)
- Shu-Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, College of Chemistry, and School of Medicine , Nankai University , Tianjin 300071 , P. R. China.,Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry , China University of Geosciences , Wuhan 430074 , P. R. China
| | - Zhi-Gang Wang
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, College of Chemistry, and School of Medicine , Nankai University , Tianjin 300071 , P. R. China
| | - Hai-Yan Xie
- School of Life Science , Beijing Institute of Technology , Beijing 100081 , P. R. China
| | - An-An Liu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, College of Chemistry, and School of Medicine , Nankai University , Tianjin 300071 , P. R. China
| | - Don C Lamb
- Physical Chemistry, Department of Chemistry, Center for Nanoscience (CeNS), and Center for Integrated Protein Science Munich (CIPSM) and Nanosystems Initiative Munich (NIM) , Ludwig-Maximilians-Universität , München , 81377 , Germany
| | - Dai-Wen Pang
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, College of Chemistry, and School of Medicine , Nankai University , Tianjin 300071 , P. R. China.,College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology , Wuhan University , Wuhan 430072 , P. R. China
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9
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Differential Modulation of Innate Immune Responses in Human Primary Cells by Influenza A Viruses Carrying Human or Avian Nonstructural Protein 1. J Virol 2019; 94:JVI.00999-19. [PMID: 31597767 PMCID: PMC6912104 DOI: 10.1128/jvi.00999-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 09/29/2019] [Indexed: 12/22/2022] Open
Abstract
Influenza A viruses (IAVs) cause seasonal epidemics which result in an important health and economic burden. Wild aquatic birds are the natural host of IAV. However, IAV can infect diverse hosts, including humans, domestic poultry, pigs, and others. IAVs circulating in animals occasionally cross the species barrier, infecting humans, which results in mild to very severe disease. In some cases, these viruses can acquire the ability to be transmitted among humans and initiate a pandemic. The nonstructural 1 (NS1) protein of IAV is an important antagonist of the innate immune response. In this study, using recombinant viruses and primary human cells, we show that NS1 proteins from human and avian hosts show intrinsic differences in the modulation of the innate immunity in human dendritic cells and epithelial cells, as well as different cellular localization dynamics in infected cells. The influenza A virus (IAV) nonstructural protein 1 (NS1) contributes to disease pathogenesis through the inhibition of host innate immune responses. Dendritic cells (DCs) release interferons (IFNs) and proinflammatory cytokines and promote adaptive immunity upon viral infection. In order to characterize the strain-specific effects of IAV NS1 on human DC activation, we infected human DCs with a panel of recombinant viruses with the same backbone (A/Puerto Rico/08/1934) expressing different NS1 proteins from human and avian origin. We found that these viruses induced a clearly distinct phenotype in DCs. Specifically, viruses expressing NS1 from human IAV (either H1N1 or H3N2) induced higher levels of expression of type I (IFN-α and IFN-β) and type III (IFN-λ1 to IFNλ3) IFNs than viruses expressing avian IAV NS1 proteins (H5N1, H7N9, and H7N2), but the differences observed in the expression levels of proinflammatory cytokines like tumor necrosis factor alpha (TNF-α) or interleukin-6 (IL-6) were not significant. In addition, using imaging flow cytometry, we found that human and avian NS1 proteins segregate based on their subcellular trafficking dynamics, which might be associated with the different innate immune profile induced in DCs by viruses expressing those NS1 proteins. Innate immune responses induced by our panel of IAV recombinant viruses were also characterized in normal human bronchial epithelial cells, and the results were consistent with those in DCs. Altogether, our results reveal an increased ability of NS1 from avian viruses to antagonize innate immune responses in human primary cells compared to the ability of NS1 from human viruses, which could contribute to the severe disease induced by avian IAV in humans. IMPORTANCE Influenza A viruses (IAVs) cause seasonal epidemics which result in an important health and economic burden. Wild aquatic birds are the natural host of IAV. However, IAV can infect diverse hosts, including humans, domestic poultry, pigs, and others. IAVs circulating in animals occasionally cross the species barrier, infecting humans, which results in mild to very severe disease. In some cases, these viruses can acquire the ability to be transmitted among humans and initiate a pandemic. The nonstructural 1 (NS1) protein of IAV is an important antagonist of the innate immune response. In this study, using recombinant viruses and primary human cells, we show that NS1 proteins from human and avian hosts show intrinsic differences in the modulation of the innate immunity in human dendritic cells and epithelial cells, as well as different cellular localization dynamics in infected cells.
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10
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Vahey MD, Fletcher DA. Low-Fidelity Assembly of Influenza A Virus Promotes Escape from Host Cells. Cell 2018; 176:281-294.e19. [PMID: 30503209 DOI: 10.1016/j.cell.2018.10.056] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 09/05/2018] [Accepted: 10/26/2018] [Indexed: 12/11/2022]
Abstract
Influenza viruses inhabit a wide range of host environments using a limited repertoire of protein components. Unlike viruses with stereotyped shapes, influenza produces virions with significant morphological variability even within clonal populations. Whether this tendency to form pleiomorphic virions is coupled to compositional heterogeneity and whether it affects replicative fitness remains unclear. Here, we address these questions by developing a strain of influenza A virus amenable to rapid compositional characterization through quantitative, site-specific labeling of viral proteins. Using this strain, we find that influenza A produces virions with broad variations in size and composition from even single infected cells. This phenotypic variability contributes to virus survival during environmental challenges, including exposure to antivirals. Complementing genetic adaptations that act over larger populations and longer times, this "low-fidelity" assembly of influenza A virus allows small populations to survive environments that fluctuate over individual replication cycles.
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Affiliation(s)
- Michael D Vahey
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Daniel A Fletcher
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA; University of California, Berkeley/University of California, San Francisco Graduate Group in Bioengineering, Berkeley, CA 94720, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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11
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Gonzàlez-Parra G, De Ridder F, Huntjens D, Roymans D, Ispas G, Dobrovolny HM. A comparison of RSV and influenza in vitro kinetic parameters reveals differences in infecting time. PLoS One 2018; 13:e0192645. [PMID: 29420667 PMCID: PMC5805318 DOI: 10.1371/journal.pone.0192645] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 01/26/2018] [Indexed: 11/19/2022] Open
Abstract
Influenza and respiratory syncytial virus (RSV) cause acute infections of the respiratory tract. Since the viruses both cause illnesses with similar symptoms, researchers often try to apply knowledge gleaned from study of one virus to the other virus. This can be an effective and efficient strategy for understanding viral dynamics or developing treatment strategies, but only if we have a full understanding of the similarities and differences between the two viruses. This study used mathematical modeling to quantitatively compare the viral kinetics of in vitro RSV and influenza virus infections. Specifically, we determined the viral kinetics parameters for RSV A2 and three strains of influenza virus, A/WSN/33 (H1N1), A/Puerto Rico/8/1934 (H1N1), and pandemic H1N1 influenza virus. We found that RSV viral titer increases at a slower rate and reaches its peak value later than influenza virus. Our analysis indicated that the slower increase of RSV viral titer is caused by slower spreading of the virus from one cell to another. These results provide estimates of dynamical differences between influenza virus and RSV and help provide insight into the virus-host interactions that cause observed differences in the time courses of the two illnesses in patients.
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Affiliation(s)
- Gilberto Gonzàlez-Parra
- Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX, United States of America
- Department of Mathematics, New Mexico Tech, Socorro, NM, United States of America
| | | | | | | | | | - Hana M. Dobrovolny
- Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX, United States of America
- * E-mail:
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12
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Tsai CF, Lin HY, Hsu WL, Tsai CH. The novel mitochondria localization of influenza A virus NS1 visualized by FlAsH labeling. FEBS Open Bio 2017; 7:1960-1971. [PMID: 29226082 PMCID: PMC5715299 DOI: 10.1002/2211-5463.12336] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/06/2017] [Accepted: 10/08/2017] [Indexed: 12/11/2022] Open
Abstract
The nonstructural protein 1 (NS1) of the influenza A virus (IAV) is a multifunctional protein that counteracts host cell antiviral responses and inhibits host cell pre‐mRNA processing. NS1 contains two nuclear localization signals that facilitate NS1 shuttling between cytoplasm and nucleus. In this study, we initially observed the novel mitochondria localization of NS1 in a subset of transfected cells. We then further monitored the localization dynamics of the NS1 protein in live cells infected with IAV expressing NS1 with insertion of a tetracysteine‐tag. The resulting mutant virus showed similar levels of infectivity and expression pattern of NS1 to those of wild‐type IAV. Pulse labeling using a biarsenical compound (fluorescein arsenical hairpin binder) allowed us to visualize the dynamic subcellular distribution of NS1 real time. We detected NS1 in mitochondria at a very early infection time point [1.5 h postinfection (hpi)] and observed the formation of a granular structure pattern in the nucleus at 4 hpi. This is the first identification of the novel mitochondria localization of NS1. The possible role of NS1 at an early infection time point is discussed.
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Affiliation(s)
- Chuan-Fu Tsai
- Graduate Institute of Biotechnology National Chung Hsing University Taichung Taiwan
| | - Hsin-Yi Lin
- Graduate Institute of Biotechnology National Chung Hsing University Taichung Taiwan
| | - Wei-Li Hsu
- Graduate Institute of Microbiology and Public Health National Chung Hsing University Taichung Taiwan
| | - Ching-Hsiu Tsai
- Graduate Institute of Biotechnology National Chung Hsing University Taichung Taiwan
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13
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Liu X, Ouyang T, Ouyang H, Ren L. Single particle labeling of RNA virus in live cells. Virus Res 2017; 237:14-21. [PMID: 28506790 DOI: 10.1016/j.virusres.2017.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 12/17/2022]
Abstract
Real-time and visual tracking of viral infection is crucial for elucidating the infectious and pathogenesis mechanisms. To track the virus successfully, an efficient labeling method is necessary. In this review, we first discuss the practical labeling techniques for virus tracking in live cells. We then describe the current knowledge of interactions between RNA viruses (especially influenza viruses, immunodeficiency viruses, and Flaviviruses) and host cellular structures, obtained using single particle labeling techniques combined with real-time fluorescence microscopy. Single particle labeling provides an easy system for understanding the RNA virus life cycle.
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Affiliation(s)
- Xiaohui Liu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Ting Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Hongsheng Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Linzhu Ren
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China.
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14
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Cytokine regulation of lung Th17 response to airway immunization using LPS adjuvant. Mucosal Immunol 2017; 10:361-372. [PMID: 27328989 PMCID: PMC5179326 DOI: 10.1038/mi.2016.54] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/10/2016] [Indexed: 02/04/2023]
Abstract
Infections caused by bacteria in the airway preferentially induce a Th17 response. However, the mechanisms involved in the regulation of CD4 T-cell responses in the lungs are incompletely understood. Here, we have investigated the mechanisms involved in the regulation of Th17 differentiation in the lungs in response to immunization with lipopolysaccharide (LPS) as an adjuvant. Our data show that both Myd88 and TRIF are necessary for Th17 induction. This distinctive fate determination can be accounted for by the pattern of inflammatory cytokines induced by airway administration of LPS. We identified the production of interleukin (IL)-1β and IL-6 by small macrophages and IL-23 by alveolar dendritic cells (DCs), favoring Th17 responses, and IL-10 repressing interferon (IFN)-γ production. Furthermore, we show that exogenous IL-1β can drastically alter Th1 responses driven by influenza and lymphocytic choriomeningitis virus infection models and induce IL-17 production. Thus, the precision of the lung immune responses to potential threats is orchestrated by the cytokine microenvironment, can be repolarized and targeted therapeutically by altering the cytokine milieu. These results indicate that how the development of Th17 responses in the lung is regulated by the cytokines produced by lung DCs and macrophages in response to intranasal immunization with LPS adjuvant.
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Visualization of Oxidative Stress Induced by Experimental Periodontitis in Keap1-Dependent Oxidative Stress Detector-Luciferase Mice. Int J Mol Sci 2016; 17:ijms17111907. [PMID: 27854327 PMCID: PMC5133905 DOI: 10.3390/ijms17111907] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 11/03/2016] [Accepted: 11/07/2016] [Indexed: 12/29/2022] Open
Abstract
The aim of this study was to investigate whether a Keap1-dependent oxidative stress detector-luciferase (OKD-LUC) mouse model would be useful for the visualization of oxidative stress induced by experimental periodontitis. A ligature was placed around the mandibular first molars for seven days to induce periodontitis. Luciferase activity was measured with an intraperitoneal injection of d-luciferin on days 0, 1, and 7. The luciferase activity in the periodontitis group was significantly greater than that in the control group at seven days. The expressions of heme oxygenase-1 (HO-1) and malondialdehyde in periodontal tissue were significantly higher in the periodontitis group than in the control group. Immunofluorescent analysis confirmed that the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) occurred more frequently in the periodontitis group than in the control group. This study found that under oxidative stress induced by experimental periodontitis, the Nrf2/antioxidant defense pathway was activated and could be visualized from the luciferase activity in the OKD-LUC model. Thus, the OKD-LUC mouse model may be useful for exploring the mechanism underlying the relationship between the Nrf2/antioxidant defense pathway and periodontitis by enabling the visualization of oxidative stress over time.
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Applications of Replicating-Competent Reporter-Expressing Viruses in Diagnostic and Molecular Virology. Viruses 2016; 8:v8050127. [PMID: 27164126 PMCID: PMC4885082 DOI: 10.3390/v8050127] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/31/2016] [Accepted: 04/29/2016] [Indexed: 12/13/2022] Open
Abstract
Commonly used tests based on wild-type viruses, such as immunostaining, cannot meet the demands for rapid detection of viral replication, high-throughput screening for antivirals, as well as for tracking viral proteins or virus transport in real time. Notably, the development of replicating-competent reporter-expressing viruses (RCREVs) has provided an excellent option to detect directly viral replication without the use of secondary labeling, which represents a significant advance in virology. This article reviews the applications of RCREVs in diagnostic and molecular virology, including rapid neutralization tests, high-throughput screening systems, identification of viral receptors and virus-host interactions, dynamics of viral infections in vitro and in vivo, vaccination approaches and others. However, there remain various challenges associated with RCREVs, including pathogenicity alterations due to the insertion of a reporter gene, instability or loss of the reporter gene expression, or attenuation of reporter signals in vivo. Despite all these limitations, RCREVs have become powerful tools for both basic and applied virology with the development of new technologies for generating RCREVs, the inventions of novel reporters and the better understanding of regulation of viral replication.
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Thulasi Raman SN, Zhou Y. Networks of Host Factors that Interact with NS1 Protein of Influenza A Virus. Front Microbiol 2016; 7:654. [PMID: 27199973 PMCID: PMC4855030 DOI: 10.3389/fmicb.2016.00654] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 04/19/2016] [Indexed: 11/13/2022] Open
Abstract
Pigs are an important host of influenza A viruses due to their ability to generate reassortant viruses with pandemic potential. NS1 protein of influenza A viruses is a key virulence factor and a major antagonist of innate immune responses. It is also involved in enhancing viral mRNA translation and regulation of virus replication. Being a protein with pleiotropic functions, NS1 has a variety of cellular interaction partners. Hence, studies on swine influenza viruses (SIV) and identification of swine influenza NS1-interacting host proteins is of great interest. Here, we constructed a recombinant SIV carrying a Strep-tag in the NS1 protein and infected primary swine respiratory epithelial cells (SRECs) with this virus. The Strep-tag sequence in the NS1 protein enabled us to purify intact, the NS1 protein and its interacting protein complex specifically. We identified cellular proteins present in the purified complex by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and generated a dataset of these proteins. 445 proteins were identified by LC-MS/MS and among them 192 proteins were selected by setting up a threshold based on MS parameters. The selected proteins were analyzed by bioinformatics and were categorized as belonging to different functional groups including translation, RNA processing, cytoskeleton, innate immunity, and apoptosis. Protein interaction networks were derived using these data and the NS1 interactions with some of the specific host factors were verified by immunoprecipitation. The novel proteins and the networks revealed in our study will be the potential candidates for targeted study of the molecular interaction of NS1 with host proteins, which will provide insights into the identification of new therapeutic targets to control influenza infection and disease pathogenesis.
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Affiliation(s)
- Sathya N Thulasi Raman
- Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, SaskatoonSK, Canada; Vaccinology and Immunotherapeutics Program, School of Public Health, University of Saskatchewan, SaskatoonSK, Canada
| | - Yan Zhou
- Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, SaskatoonSK, Canada; Vaccinology and Immunotherapeutics Program, School of Public Health, University of Saskatchewan, SaskatoonSK, Canada
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Florian PE, Rouillé Y, Ruta S, Nichita N, Roseanu A. Recent advances in human viruses imaging studies. J Basic Microbiol 2016; 56:591-607. [DOI: 10.1002/jobm.201500575] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 02/27/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Paula Ecaterina Florian
- Department of ; Ligand-Receptor Interactions; Institute of Biochemistry of the Romanian Academy; Bucharest Romania
| | - Yves Rouillé
- Center for Infection and Immunity of Lille (CIIL); Inserm U1019; CNRS UMR8204; Institut Pasteur de Lille; Université Lille Nord de France; Lille France
| | - Simona Ruta
- Department of Emergent Diseases; Stefan S. Nicolau Institute of Virology; Bucharest 030304 Romania
| | - Norica Nichita
- Department of Viral Glycoproteins; Institute of Biochemistry of the Romanian Academy; Bucharest Romania
| | - Anca Roseanu
- Department of ; Ligand-Receptor Interactions; Institute of Biochemistry of the Romanian Academy; Bucharest Romania
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Spronken MI, Short KR, Herfst S, Bestebroer TM, Vaes VP, van der Hoeven B, Koster AJ, Kremers GJ, Scott DP, Gultyaev AP, Sorell EM, de Graaf M, Bárcena M, Rimmelzwaan GF, Fouchier RA. Optimisations and Challenges Involved in the Creation of Various Bioluminescent and Fluorescent Influenza A Virus Strains for In Vitro and In Vivo Applications. PLoS One 2015; 10:e0133888. [PMID: 26241861 PMCID: PMC4524686 DOI: 10.1371/journal.pone.0133888] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/03/2015] [Indexed: 01/15/2023] Open
Abstract
Bioluminescent and fluorescent influenza A viruses offer new opportunities to study influenza virus replication, tropism and pathogenesis. To date, several influenza A reporter viruses have been described. These strategies typically focused on a single reporter gene (either bioluminescent or fluorescent) in a single virus backbone. However, whilst bioluminescence is suited to in vivo imaging, fluorescent viruses are more appropriate for microscopy. Therefore, the idea l reporter virus varies depending on the experiment in question, and it is important that any reporter virus strategy can be adapted accordingly. Herein, a strategy was developed to create five different reporter viruses in a single virus backbone. Specifically, enhanced green fluorescent protein (eGFP), far-red fluorescent protein (fRFP), near-infrared fluorescent protein (iRFP), Gaussia luciferase (gLUC) and firefly luciferase (fLUC) were inserted into the PA gene segment of A/PR/8/34 (H1N1). This study provides a comprehensive characterisation of the effects of different reporter genes on influenza virus replication and reporter activity. In vivo reporter gene expression, in lung tissues, was only detected for eGFP, fRFP and gLUC expressing viruses. In vitro, the eGFP-expressing virus displayed the best reporter stability and could be used for correlative light electron microscopy (CLEM). This strategy was then used to create eGFP-expressing viruses consisting entirely of pandemic H1N1, highly pathogenic avian influenza (HPAI) H5N1 and H7N9. The HPAI H5N1 eGFP-expressing virus infected mice and reporter gene expression was detected, in lung tissues, in vivo. Thus, this study provides new tools and insights for the creation of bioluminescent and fluorescent influenza A reporter viruses.
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Affiliation(s)
- Monique I. Spronken
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Kirsty R. Short
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Sander Herfst
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Theo M. Bestebroer
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Vincent P. Vaes
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Barbara van der Hoeven
- Department of Molecular Cell Biology, Section Electron Microscopy, Leiden University Medical Centre, Leiden, the Netherlands
| | - Abraham J. Koster
- Department of Molecular Cell Biology, Section Electron Microscopy, Leiden University Medical Centre, Leiden, the Netherlands
| | - Gert-Jan Kremers
- Erasmus Optical Imaging Centre, Department of Pathology, Erasmus University Medical Centre, Rotterdam, the Netherlands
| | - Dana P. Scott
- Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States of America
| | - Alexander P. Gultyaev
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
- Leiden Institute of Advanced Computer Science, Leiden University, Leiden, the Netherlands
| | - Erin M. Sorell
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
- Milken Institute School of Public Health, Department of Health Policy and Management, George Washington University, Washington, DC, United States of America
| | - Miranda de Graaf
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Montserrat Bárcena
- Department of Molecular Cell Biology, Section Electron Microscopy, Leiden University Medical Centre, Leiden, the Netherlands
| | - Guus F. Rimmelzwaan
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Ron A. Fouchier
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
- * E-mail:
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20
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Li Y, Shen L, Li C, Huang J, Zhao B, Sun Y, Li S, Luo Y, Qiu HJ. Visualization of the Npro protein in living cells using biarsenically labeling tetracysteine-tagged classical swine fever virus. Virus Res 2014; 189:67-74. [PMID: 24815879 DOI: 10.1016/j.virusres.2014.04.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/23/2014] [Accepted: 04/25/2014] [Indexed: 12/20/2022]
Abstract
Real-time fluorescence imaging of viral proteins in living cells is a valuable means to study virus-host interactions, and tetracysteine (TC)-biarsenical technology has been used in several viruses but not in classical swine fever virus (CSFV). Here, we generated CSFV mutants vSMTC385 or vSMTC412 bearing the small TC tag (CCPGCC) in the N-terminal region of the N(pro) protein. The mutants showed growth characteristics indistinguishable from that of the wild-type virus, and retained similar N(pro) subcellular localization to that of the parent virus. Furthermore, labeling with membrane-permeable biarsenical dye resulted in the fluorescent N(pro) protein in the context of virus infection. Finally, we showed that N(pro) was localized in the cytoplasm of CSFV-infected cells at 27 h post-infection (hpi) and present in the nucleus at 48 hpi, and the nuclear import and export was clearly observed from 36.5 to 37 hpi. Interestingly, our results demonstrated that N(pro) transported across the nuclear pores by passive diffusion, which might be prevented by exogenous interferon regulatory factor 3 interacting with N(pro). Taken together, biarsenical labeling allows real-time visualization of the nucleus import and export of the fluorescent N(pro) protein in CSFV-infected living cells.
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Affiliation(s)
- Yongfeng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Liang Shen
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Chao Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Junhua Huang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Bibo Zhao
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Su Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
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Lalime EN, Pekosz A. The R35 residue of the influenza A virus NS1 protein has minimal effects on nuclear localization but alters virus replication through disrupting protein dimerization. Virology 2014; 458-459:33-42. [PMID: 24928037 DOI: 10.1016/j.virol.2014.04.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/05/2014] [Accepted: 04/09/2014] [Indexed: 10/25/2022]
Abstract
The influenza A virus NS1 protein has a nuclear localization sequence (NLS) in the amino terminal region. This NLS overlaps sequences that are important for RNA binding as well as protein dimerization. To assess the significance of the NS1 NLS on influenza virus replication, the NLS amino acids were individually mutated to alanines and recombinant viruses encoding these mutations were rescued. Viruses containing NS1 proteins with mutations at R37, R38 and K41 displayed minimal changes in replication or NS1 protein nuclear localization. Recombinant viruses encoding NS1 R35A were not recovered but viruses containing second site mutations at position D39 in addition to the R35A mutation were isolated. The mutations at position 39 were shown to partially restore NS1 protein dimerization but had minimal effects on nuclear localization. These data indicate that the amino acids in the NS1 NLS region play a more important role in protein dimerization compared to nuclear localization.
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Affiliation(s)
- Erin N Lalime
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe Street, Suite E5132, Baltimore, MD 21205-2103, USA
| | - Andrew Pekosz
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe Street, Suite E5132, Baltimore, MD 21205-2103, USA.
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22
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Forbes N, Selman M, Pelchat M, Jia JJ, Stintzi A, Brown EG. Identification of adaptive mutations in the influenza A virus non-structural 1 gene that increase cytoplasmic localization and differentially regulate host gene expression. PLoS One 2013; 8:e84673. [PMID: 24391972 PMCID: PMC3877356 DOI: 10.1371/journal.pone.0084673] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 11/18/2013] [Indexed: 12/22/2022] Open
Abstract
The NS1 protein of influenza A virus (IAV) is a multifunctional virulence factor. We have previously characterized gain-of-function mutations in the NS1 protein arising from the experimental adaptation of the human isolate A/Hong Kong/1/1968(H3N2) (HK) to the mouse. The majority of these mouse adapted NS1 mutations were demonstrated to increase virulence, viral fitness, and interferon antagonism, but differ in binding to the post-transcriptional processing factor cleavage and polyadenylation specificity factor 30 (CPSF30). Because nuclear trafficking is a major genetic determinant of influenza virus host adaptation, we assessed subcellular localization and host gene expression of NS1 adaptive mutations. Recombinant HK viruses with adaptive mutations in the NS1 gene were assessed for NS1 protein subcellular localization in mouse and human cells using confocal microscopy and cellular fractionation. In human cells the HK wild-type (HK-wt) virus NS1 protein partitioned equivalently between the cytoplasm and nucleus but was defective in cytoplasmic localization in mouse cells. Several adaptive mutations increased the proportion of NS1 in the cytoplasm of mouse cells with the greatest effects for mutations M106I and D125G. The host gene expression profile of the adaptive mutants was determined by microarray analysis of infected mouse cells to show either high or low extents of host-gene regulation (HGR or LGR) phenotypes. While host genes were predominantly down regulated for the HGR group of mutants (D2N, V23A, F103L, M106I+L98S, L98S, M106V, and M106V+M124I), the LGR phenotype mutants (D125G, M106I, V180A, V226I, and R227K) were characterized by a predominant up regulation of host genes. CPSF30 binding affinity of NS1 mutants did not predict effects on host gene expression. To our knowledge this is the first report of roles of adaptive NS1 mutations that impact intracellular localization and regulation of host gene expression.
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Affiliation(s)
- Nicole Forbes
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Mohammed Selman
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Martin Pelchat
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Jian Jun Jia
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Alain Stintzi
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Earl G. Brown
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Zhang Y, Arcia S, Perez B, Fernandez-Funez P, Rincon-Limas DE. p∆TubHA4C, a new versatile vector for constitutive expression in Drosophila. Mol Biol Rep 2013; 40:5407-15. [PMID: 23681549 DOI: 10.1007/s11033-013-2639-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 05/02/2013] [Indexed: 11/27/2022]
Abstract
Several vectors for gene expression are available in Drosophila, a hub for genetics and genomics innovation. However, the vectors for ubiquitous expression have a complex structure, including coding exons, that makes in-frame cloning of cDNAs very complicated. In this report we describe a new Drosophila expression vector (p∆TubHA4C) for ubiquitous expression of coding sequences under the control of a minimal 0.9 kb promoter of α1 tubulin (α1t). This plasmid was designed to include optimized multiple cloning sites (polylinker) to provide flexibility in cloning strategies. We also added the option of double labeling the expressed proteins with two C-terminal tags, the viral epitope hemagglutinin and a synthetic tetracysteine (4C) tag that binds small fluorescent compounds. This dual tag allows both in situ and biochemical detection of the desired protein. In particular, the new 4C tag technology combines easy fluorescent labeling with small arsenical compounds in live or fixed cells and tissues, while producing minimal alterations to the tagged protein due to its small size. To demonstrate the potent and ubiquitous expression under the control of the ∆Tub promoter, bacterial lacZ was expressed and monitored in cell culture and transgenic flies. We found that the modified 0.9 kb ΔTub promoter induced similar expression levels to the intact 2.6 kb α1t promoter, supporting the inclusion of all critical regulatory elements in the new and flexible ∆TubHA4C vector.
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Affiliation(s)
- Yan Zhang
- Department of Neurology, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
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Avilov SV, Moisy D, Naffakh N, Cusack S. Influenza A virus progeny vRNP trafficking in live infected cells studied with the virus-encoded fluorescently tagged PB2 protein. Vaccine 2012; 30:7411-7. [DOI: 10.1016/j.vaccine.2012.09.077] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 04/26/2012] [Accepted: 09/28/2012] [Indexed: 10/27/2022]
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Abstract
The influenza virus is a respiratory pathogen with a negative-sense, segmented RNA genome. Construction of recombinant influenza viruses in the laboratory was reported starting in the 1980s. Within a short period of time, pioneer researchers had devised methods that made it possible to construct influenza viral vectors from cDNA plasmid systems. Herein, we discuss the evolution of influenza virus reverse genetics, from helper virus-dependent systems, to helper virus-independent 17-plasmid systems, and all the way to 3- and 1- plasmid systems. Successes in the modification of different gene segments for various applications, including vaccine and gene therapies are highlighted.
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Affiliation(s)
- Junwei Li
- Center of Excellence for Infectious Diseases, Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA
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Identification of RNA helicase A as a cellular factor that interacts with influenza A virus NS1 protein and its role in the virus life cycle. J Virol 2011; 86:1942-54. [PMID: 22171255 DOI: 10.1128/jvi.06362-11] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Influenza A virus NS1 protein has multiple functions in the infected cell during the virus life cycle. Identification of novel cellular factors that interact with NS1 and understanding their functions in virus infection are of great interest. Recombinant viruses carrying a tagged NS1 are valuable for investigation of interactions between NS1 and cellular factors in the context of virus infection. Here, we report the generation of replication-competent recombinant influenza A viruses bearing a Strep tag in the NS1 protein. Purification of a protein complex associated with Strep-tagged NS1 from virus-infected cells followed by mass spectrometry revealed a number of attractive host factors. Among them, we focused our study on RNA helicase A (RHA) in this report. Through biomedical and functional analyses, we demonstrated that RHA interacts with NS1 in an RNA-dependent manner. Knockdown of RHA resulted in a significant reduction on virus yield and polymerase activity in a minigenome assay. Our cell-free viral genome replication assay showed that viral RNA replication and transcription can be enhanced by addition of RHA, and the enhanced effect of RHA required its ATP-dependent helicase activity. In summary, we established a system to identify cellular factors that interact with NS1 protein during virus infection and furthermore demonstrated that RHA interacts with NS1 and enhances viral replication and transcription.
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Replication-competent influenza A virus that encodes a split-green fluorescent protein-tagged PB2 polymerase subunit allows live-cell imaging of the virus life cycle. J Virol 2011; 86:1433-48. [PMID: 22114331 DOI: 10.1128/jvi.05820-11] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Studies on the intracellular trafficking of influenza virus ribonucleoproteins are currently limited by the lack of a method enabling their visualization during infection in single cells. This is largely due to the difficulty of encoding fluorescent fusion proteins within the viral genome. To circumvent this limitation, we used the split-green fluorescent protein (split-GFP) system (S. Cabantous, T. C. Terwilliger, and G. S. Waldo, Nat. Biotechnol. 23:102-107, 2005) to produce a quasi-wild-type recombinant A/WSN/33/influenza virus which allows expression of individually fluorescent PB2 polymerase subunits in infected cells. The viral PB2 proteins were fused to the 16 C-terminal amino acids of the GFP, whereas the large transcomplementing GFP fragment was supplied by transient or stable expression in cultured cells that were permissive to infection. This system was used to characterize the intranuclear dynamics of PB2 by fluorescence correlation spectroscopy and to visualize the trafficking of viral ribonucleoproteins (vRNPs) by dynamic light microscopy in live infected cells. Following nuclear export, vRNPs showed a transient pericentriolar accumulation and intermittent rapid (∼1 μm/s), directional movements in the cytoplasm, dependent on both microtubules and actin filaments. Our data establish the potential of split-GFP-based recombinant viruses for the tracking of viral proteins during a quasi-wild-type infection. This new virus, or adaptations of it, will be of use in elucidating many aspects of influenza virus host cell interactions as well as in screening for new antiviral compounds. Furthermore, the existence of cell lines stably expressing the complementing GFP fragment will facilitate applications to many other viral and nonviral systems.
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Whitt MA, Mire CE. Utilization of fluorescently-labeled tetracysteine-tagged proteins to study virus entry by live cell microscopy. Methods 2011; 55:127-36. [PMID: 21939769 DOI: 10.1016/j.ymeth.2011.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 09/01/2011] [Accepted: 09/02/2011] [Indexed: 10/24/2022] Open
Abstract
Viruses exploit cellular machinery to gain entry and initiate their replication cycle within host cells. The development of methods to visualize virus entry in live cells has provided new insights to the cellular processes involved in virus entry and the intracellular locations where viral payloads are deposited. The use of fluorescently labeled virus and high-resolution microscopy is currently the method of choice to study virus entry in live cells. While fluorescent protein fusions (e.g. viral proteins fused to GFP) have been used, the labeling of viral proteins that contain a small tetracysteine (tc) tag with biarsenical fluorescent compounds (e.g. FlAsH, ReAsH, Lumio-x) offers several advantages over conventional xFP-fusion constructs. This article describes methods for generating fluorescently labeled viruses encoding tc-tagged proteins that are suitable for the study of virus entry in live cells by fluorescence microscopy. Critical parameters required to quantify fluorescence signals from the labeled, tc-tagged proteins in individual virus particles during the entry process and the subsequent fate of the labeled viral proteins after virus uncoating are also described.
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Affiliation(s)
- Michael A Whitt
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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Pomorski A, Krężel A. Exploration of biarsenical chemistry--challenges in protein research. Chembiochem 2011; 12:1152-67. [PMID: 21538762 DOI: 10.1002/cbic.201100114] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Indexed: 11/07/2022]
Abstract
The fluorescent modification of proteins (with genetically encoded low-molecular-mass fluorophores, affinity probes, or other chemically active species) is extraordinarily useful for monitoring and controlling protein functions in vitro, as well as in cell cultures and tissues. The large sizes of some fluorescent tags, such as fluorescent proteins, often perturb normal activity and localization of the protein of interest, as well as other effects. Of the many fluorescent-labeling strategies applied to in vitro and in vivo studies, one is very promising. This requires a very short (6- to 12-residue), appropriately spaced, tetracysteine sequence (-CCXXCC-); this is either placed at a protein terminus, within flexible loops, or incorporated into secondary structure elements. Proteins that contain the tetracysteine motif become highly fluorescent upon labeling with a nonluminescent biarsenical probe, and form very stable covalent complexes. We focus on the development, growth, and multiple applications of this protein research methodology, both in vitro and in vivo. Its application is not limited to intact-cell protein visualization; it has tremendous potential in other protein research disciplines, such as protein purification and activity control, electron microscopy imaging of cells or tissue, protein-protein interaction studies, protein stability, and aggregation studies.
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Affiliation(s)
- Adam Pomorski
- Department of Protein Engineering, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
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Sivaraman D, Biswas P, Cella LN, Yates MV, Chen W. Detecting RNA viruses in living mammalian cells by fluorescence microscopy. Trends Biotechnol 2011; 29:307-13. [PMID: 21529975 DOI: 10.1016/j.tibtech.2011.02.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 02/20/2011] [Accepted: 02/23/2011] [Indexed: 12/29/2022]
Abstract
Traditional methods that rely on viral isolation and culture techniques continue to be the gold standards used for detection of infectious viral particles. However, new techniques that rely on visualization of live cells can shed light on understanding virus-host interaction for early stage detection and potential drug discovery. Live-cell imaging techniques that incorporate fluorescent probes into viral components provide opportunities for understanding mRNA expression, interaction, and virus movement and localization. Other viral replication events inside a host cell can be exploited for non-invasive detection, such as single-virus tracking, which does not inhibit viral infectivity or cellular function. This review highlights some of the recent advances made using these novel approaches for visualization of viral entry and replication in live cells.
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Affiliation(s)
- Divya Sivaraman
- Department of Chemical Engineering, University of Delaware, Newark, DE 19716, USA
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31
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Pereira CF, Ellenberg PC, Jones KL, Fernandez TL, Smyth RP, Hawkes DJ, Hijnen M, Vivet-Boudou V, Marquet R, Johnson I, Mak J. Labeling of multiple HIV-1 proteins with the biarsenical-tetracysteine system. PLoS One 2011; 6:e17016. [PMID: 21347302 PMCID: PMC3037950 DOI: 10.1371/journal.pone.0017016] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 01/19/2011] [Indexed: 12/01/2022] Open
Abstract
Due to its small size and versatility, the biarsenical-tetracysteine system is an attractive way to label viral proteins for live cell imaging. This study describes the genetic labeling of the human immunodeficiency virus type 1 (HIV-1) structural proteins (matrix, capsid and nucleocapsid), enzymes (protease, reverse transcriptase, RNAse H and integrase) and envelope glycoprotein 120 with a tetracysteine tag in the context of a full-length virus. We measure the impact of these modifications on the natural virus infection and, most importantly, present the first infectious HIV-1 construct containing a fluorescently-labeled nucleocapsid protein. Furthermore, due to the high background levels normally associated with the labeling of tetracysteine-tagged proteins we have also optimized a metabolic labeling system that produces infectious virus containing the natural envelope glycoproteins and specifically labeled tetracysteine-tagged proteins that can easily be detected after virus infection of T-lymphocytes. This approach can be adapted to other viral systems for the visualization of the interplay between virus and host cell during infection.
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Affiliation(s)
- Cândida F. Pereira
- Centre for Virology, Burnet Institute, Melbourne, Victoria, Australia
- Monash Micro Imaging, Monash University, Clayton, Victoria, Australia
- Department of Medicine, Monash University, Clayton, Victoria, Australia
| | - Paula C. Ellenberg
- Centre for Virology, Burnet Institute, Melbourne, Victoria, Australia
- Department of Medicine, Monash University, Clayton, Victoria, Australia
| | - Kate L. Jones
- Centre for Virology, Burnet Institute, Melbourne, Victoria, Australia
| | - Tara L. Fernandez
- Centre for Virology, Burnet Institute, Melbourne, Victoria, Australia
| | - Redmond P. Smyth
- Centre for Virology, Burnet Institute, Melbourne, Victoria, Australia
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, Strasbourg, France
| | - David J. Hawkes
- Centre for Virology, Burnet Institute, Melbourne, Victoria, Australia
| | - Marcel Hijnen
- Centre for Virology, Burnet Institute, Melbourne, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Valérie Vivet-Boudou
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, Strasbourg, France
| | - Roland Marquet
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, Strasbourg, France
| | - Iain Johnson
- Life Technologies Corporation, Eugene, Oregon, United States of America
| | - Johnson Mak
- Centre for Virology, Burnet Institute, Melbourne, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
- * E-mail:
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