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Gao L, Zheng S, Wang Y. The Evasion of Antiviral Innate Immunity by Chicken DNA Viruses. Front Microbiol 2021; 12:771292. [PMID: 34777325 PMCID: PMC8581555 DOI: 10.3389/fmicb.2021.771292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 10/11/2021] [Indexed: 11/25/2022] Open
Abstract
The innate immune system constitutes the first line of host defense. Viruses have evolved multiple mechanisms to escape host immune surveillance, which has been explored extensively for human DNA viruses. There is growing evidence showing the interaction between avian DNA viruses and the host innate immune system. In this review, we will survey the present knowledge of chicken DNA viruses, then describe the functions of DNA sensors in avian innate immunity, and finally discuss recent progresses in chicken DNA virus evasion from host innate immune responses.
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Affiliation(s)
- Li Gao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Shijun Zheng
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yongqiang Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing, China
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2
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Lant S, Maluquer de Motes C. Poxvirus Interactions with the Host Ubiquitin System. Pathogens 2021; 10:pathogens10081034. [PMID: 34451498 PMCID: PMC8399815 DOI: 10.3390/pathogens10081034] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 12/16/2022] Open
Abstract
The ubiquitin system has emerged as a master regulator of many, if not all, cellular functions. With its large repertoire of conjugating and ligating enzymes, the ubiquitin system holds a unique mechanism to provide selectivity and specificity in manipulating protein function. As intracellular parasites viruses have evolved to modulate the cellular environment to facilitate replication and subvert antiviral responses. Poxviruses are a large family of dsDNA viruses with large coding capacity that is used to synthetise proteins and enzymes needed for replication and morphogenesis as well as suppression of host responses. This review summarises our current knowledge on how poxvirus functions rely on the cellular ubiquitin system, and how poxviruses exploit this system to their own advantage, either facilitating uncoating and genome release and replication or rewiring ubiquitin ligases to downregulate critical antiviral factors. Whilst much remains to be known about the intricate interactions established between poxviruses and the host ubiquitin system, our knowledge has revealed crucial viral processes and important restriction factors that open novel avenues for antiviral treatment and provide fundamental insights on the biology of poxviruses and other virus families.
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Oliveira M, Rodrigues DR, Guillory V, Kut E, Giotis ES, Skinner MA, Guabiraba R, Bryant CE, Ferguson BJ. Chicken cGAS Senses Fowlpox Virus Infection and Regulates Macrophage Effector Functions. Front Immunol 2021; 11:613079. [PMID: 33633733 PMCID: PMC7901977 DOI: 10.3389/fimmu.2020.613079] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/16/2020] [Indexed: 12/11/2022] Open
Abstract
The anti-viral immune response is dependent on the ability of infected cells to sense foreign nucleic acids. In multiple species, the pattern recognition receptor (PRR) cyclic GMP-AMP synthase (cGAS) senses viral DNA as an essential component of the innate response. cGAS initiates a range of signaling outputs that are dependent on generation of the second messenger cGAMP that binds to the adaptor protein stimulator of interferon genes (STING). Here we show that in chicken macrophages, the cGAS/STING pathway is essential not only for the production of type-I interferons in response to intracellular DNA stimulation, but also for regulation of macrophage effector functions including the expression of MHC-II and co-stimulatory molecules. In the context of fowlpox, an avian DNA virus infection, the cGAS/STING pathway was found to be responsible for type-I interferon production and MHC-II transcription. The sensing of fowlpox virus DNA is therefore essential for mounting an anti-viral response in chicken cells and for regulation of a specific set of macrophage effector functions.
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Affiliation(s)
- Marisa Oliveira
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | | | | | - Emmanuel Kut
- ISP, INRAE, Université de Tours, Nouzilly, France
| | - Efstathios S Giotis
- Department of Infectious Diseases, Imperial College London, London, United Kingdom.,School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Michael A Skinner
- Department of Infectious Diseases, Imperial College London, London, United Kingdom
| | | | - Clare E Bryant
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Brian J Ferguson
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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4
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Giotis ES, Laidlaw SM, Bidgood SR, Albrecht D, Burden JJ, Robey RC, Mercer J, Skinner MA. Modulation of Early Host Innate Immune Response by an Avipox Vaccine Virus' Lateral Body Protein. Biomedicines 2020; 8:E634. [PMID: 33352813 PMCID: PMC7766033 DOI: 10.3390/biomedicines8120634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/14/2022] Open
Abstract
The avian pathogen fowlpox virus (FWPV) has been successfully used as a vaccine vector in poultry and humans, but relatively little is known about its ability to modulate host antiviral immune responses in these hosts, which are replication-permissive and nonpermissive, respectively. FWPV is highly resistant to avian type I interferon (IFN) and able to completely block the host IFN-response. Microarray screening of host IFN-regulated gene expression in cells infected with 59 different, nonessential FWPV gene knockout mutants revealed that FPV184 confers immunomodulatory capacity. We report that the FPV184-knockout virus (FWPVΔ184) induces the cellular IFN response as early as 2 h postinfection. The wild-type, uninduced phenotype can be rescued by transient expression of FPV184 in FWPVΔ184-infected cells. Ectopic expression of FPV184 inhibited polyI:C activation of the chicken IFN-β promoter and IFN-α activation of the chicken Mx1 promoter. Confocal and correlative super-resolution light and electron microscopy demonstrated that FPV184 has a functional nuclear localisation signal domain and is packaged in the lateral bodies of the virions. Taken together, these results provide a paradigm for a late poxvirus structural protein packaged in the lateral bodies, capable of suppressing IFN induction early during the next round of infection.
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Affiliation(s)
- Efstathios S. Giotis
- Section of Virology, School of Medicine, St Mary’s Campus, Imperial College, London W2 1PG, UK; (S.M.L.); (R.C.R.); (M.A.S.)
- School of Life Sciences, University of Essex, Colchester C04 3SQ, UK
| | - Stephen M. Laidlaw
- Section of Virology, School of Medicine, St Mary’s Campus, Imperial College, London W2 1PG, UK; (S.M.L.); (R.C.R.); (M.A.S.)
| | - Susanna R. Bidgood
- Medical Research Council-Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; (S.R.B.); (D.A.); (J.J.B.); (J.M.)
| | - David Albrecht
- Medical Research Council-Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; (S.R.B.); (D.A.); (J.J.B.); (J.M.)
| | - Jemima J. Burden
- Medical Research Council-Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; (S.R.B.); (D.A.); (J.J.B.); (J.M.)
| | - Rebecca C. Robey
- Section of Virology, School of Medicine, St Mary’s Campus, Imperial College, London W2 1PG, UK; (S.M.L.); (R.C.R.); (M.A.S.)
| | - Jason Mercer
- Medical Research Council-Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; (S.R.B.); (D.A.); (J.J.B.); (J.M.)
| | - Michael A. Skinner
- Section of Virology, School of Medicine, St Mary’s Campus, Imperial College, London W2 1PG, UK; (S.M.L.); (R.C.R.); (M.A.S.)
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Chicken Embryonic-Stem Cells Are Permissive to Poxvirus Recombinant Vaccine Vectors. Genes (Basel) 2019; 10:genes10030237. [PMID: 30897824 PMCID: PMC6471371 DOI: 10.3390/genes10030237] [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: 02/18/2019] [Revised: 03/14/2019] [Accepted: 03/15/2019] [Indexed: 12/17/2022] Open
Abstract
The discovery of mammalian pluripotent embryonic stem cells (ESC) has revolutionised cell research and regenerative medicine. More recently discovered chicken ESC (cESC), though less intensively studied, are increasingly popular as vaccine substrates due to a dearth of avian cell lines. Information on the comparative performance of cESC with common vaccine viruses is limited. Using RNA-sequencing, we compared cESC transcriptional programmes elicited by stimulation with chicken type I interferon or infection with vaccine viruses routinely propagated in primary chicken embryo fibroblasts (CEF). We used poxviruses (fowlpox virus (FWPV) FP9, canarypox virus (CNPV), and modified vaccinia virus Ankara (MVA)) and a birnavirus (infectious bursal disease virus (IBDV) PBG98). Interferon-stimulated genes (ISGs) were induced in cESC to levels comparable to those in CEF and immortalised chicken fibroblast DF-1 cells. cESC are permissive (with distinct host transcriptional responses) to MVA, FP9, and CNPV but, surprisingly, not to PBG98. MVA, CNPV, and FP9 suppressed innate immune responses, while PBG98 induced a subset of ISGs. Dysregulation of signalling pathways (i.e., NFκB, TRAF) was observed, which might affect immune responses and viral replication. In conclusion, we show that cESC are an attractive alternative substrate to study and propagate poxvirus recombinant vaccine vectors.
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Evans SM, Rodino KG, Adcox HE, Carlyon JA. Orientia tsutsugamushi uses two Ank effectors to modulate NF-κB p65 nuclear transport and inhibit NF-κB transcriptional activation. PLoS Pathog 2018; 14:e1007023. [PMID: 29734393 PMCID: PMC5957444 DOI: 10.1371/journal.ppat.1007023] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 05/17/2018] [Accepted: 04/11/2018] [Indexed: 01/05/2023] Open
Abstract
Orientia tsutsugamushi causes scrub typhus, a potentially fatal infection that threatens over one billion people. Nuclear translocation of the transcription factor, NF-κB, is the central initiating cellular event in the antimicrobial response. Here, we report that NF-κB p65 nuclear accumulation and NF-κB-dependent transcription are inhibited in O. tsutsugamushi infected HeLa cells and/or primary macrophages, even in the presence of TNFα. The bacterium modulates p65 subcellular localization by neither degrading it nor inhibiting IκBα degradation. Rather, it exploits host exportin 1 to mediate p65 nuclear export, as this phenomenon is leptomycin B-sensitive. O. tsutsugamushi antagonizes NF-κB-activated transcription even when exportin 1 is inhibited and NF-κB consequently remains in the nucleus. Two ankyrin repeat-containing effectors (Anks), Ank1 and Ank6, each of which possess a C-terminal F-box and exhibit 58.5% amino acid identity, are linked to the pathogen's ability to modulate NF-κB. When ectopically expressed, both translocate to the nucleus, abrogate NF-κB-activated transcription in an exportin 1-independent manner, and pronouncedly reduce TNFα-induced p65 nuclear levels by exportin 1-dependent means. Flag-tagged Ank 1 and Ank6 co-immunoprecipitate p65 and exportin 1. Both also bind importin β1, a host protein that is essential for the classical nuclear import pathway. Importazole, which blocks importin β1 activity, abrogates Ank1 and Ank6 nuclear translocation. The Ank1 and Ank6 regions that bind importin β1 also mediate their transport into the nucleus. Yet, these regions are distinct from those that bind p65/exportin 1. The Ank1 and Ank6 F-box and the region that lies between it and the ankyrin repeat domain are essential for blocking p65 nuclear accumulation. These data reveal a novel mechanism by which O. tsutsugamushi modulates the activity and nuclear transport of NF-κB p65 and identify the first microbial proteins that co-opt both importin β1 and exportin 1 to antagonize a critical arm of the antimicrobial response.
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Affiliation(s)
- Sean M. Evans
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, United States of America
| | - Kyle G. Rodino
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, United States of America
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, United States of America
| | - Jason A. Carlyon
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, United States of America
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Rohde F, Schusser B, Hron T, Farkašová H, Plachý J, Härtle S, Hejnar J, Elleder D, Kaspers B. Characterization of Chicken Tumor Necrosis Factor-α, a Long Missed Cytokine in Birds. Front Immunol 2018; 9:605. [PMID: 29719531 PMCID: PMC5913325 DOI: 10.3389/fimmu.2018.00605] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/09/2018] [Indexed: 11/13/2022] Open
Abstract
Tumor necrosis factor-α (TNF-α) is a pleiotropic cytokine playing critical roles in host defense and acute and chronic inflammation. It has been described in fish, amphibians, and mammals but was considered to be absent in the avian genomes. Here, we report on the identification and functional characterization of the avian ortholog. The chicken TNF-α (chTNF-α) is encoded by a highly GC-rich gene, whose product shares with its mammalian counterpart 45% homology in the extracellular part displaying the characteristic TNF homology domain. Orthologs of chTNF-α were identified in the genomes of 12 additional avian species including Palaeognathae and Neognathae, and the synteny of the closely adjacent loci with mammalian TNF-α orthologs was demonstrated in the crow (Corvus cornix) genome. In addition to chTNF-α, we obtained full sequences for homologs of TNF-α receptors 1 and 2 (TNFR1, TNFR2). chTNF-α mRNA is strongly induced by lipopolysaccharide (LPS) stimulation of monocyte derived, splenic and bone marrow macrophages, and significantly upregulated in splenic tissue in response to i.v. LPS treatment. Activation of T-lymphocytes by TCR crosslinking induces chTNF-α expression in CD4+ but not in CD8+ cells. To gain insights into its biological activity, we generated recombinant chTNF-α in eukaryotic and prokaryotic expression systems. Both, the full-length cytokine and the extracellular domain rapidly induced an NFκB-luciferase reporter in stably transfected CEC-32 reporter cells. Collectively, these data provide strong evidence for the existence of a fully functional TNF-α/TNF-α receptor system in birds thus filling a gap in our understanding of the evolution of cytokine systems.
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Affiliation(s)
- Franziska Rohde
- Department of Veterinary Science, Ludwig-Maximilians-Universität, Munich, Germany
| | - Benjamin Schusser
- Reproductive Biotechnology, Department of Animal Sciences, Technical University Munich, Munich, Germany
| | - Tomáš Hron
- Laboratory of Viral and Cellular Genetics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Helena Farkašová
- Laboratory of Viral and Cellular Genetics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Jiří Plachý
- Laboratory of Viral and Cellular Genetics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Sonja Härtle
- Department of Veterinary Science, Ludwig-Maximilians-Universität, Munich, Germany
| | - Jiří Hejnar
- Laboratory of Viral and Cellular Genetics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Daniel Elleder
- Laboratory of Viral and Cellular Genetics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Bernd Kaspers
- Department of Veterinary Science, Ludwig-Maximilians-Universität, Munich, Germany
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8
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Giotis ES, Ross CS, Robey RC, Nohturfft A, Goodbourn S, Skinner MA. Constitutively elevated levels of SOCS1 suppress innate responses in DF-1 immortalised chicken fibroblast cells. Sci Rep 2017; 7:17485. [PMID: 29235573 PMCID: PMC5727488 DOI: 10.1038/s41598-017-17730-2] [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: 08/22/2016] [Accepted: 11/29/2017] [Indexed: 01/08/2023] Open
Abstract
The spontaneously immortalised DF-1 cell line is rapidly replacing its progenitor primary chicken embryo fibroblasts (CEFs) for studies on avian viruses such as avian influenza but no comprehensive study has as yet been reported comparing their innate immunity phenotypes. We conducted microarray analyses of DF-1 and CEFs, under both normal and stimulated conditions using chicken interferon-α (chIFN-α) and the attenuated infectious bursal disease virus vaccine strain PBG98. We found that DF-1 have an attenuated innate response compared to CEFs. Basal expression levels of Suppressor of Cytokine Signalling 1 (chSOCS1), a negative regulator of cytokine signalling in mammals, are 16-fold higher in DF-1 than in CEFs. The chSOCS1 “SOCS box” domain (which in mammals, interacts with an E3 ubiquitin ligase complex) is not essential for the inhibition of cytokine-induced JAK/STAT signalling activation in DF-1. Overexpression of SOCS1 in chIFN-α-stimulated DF-1 led to a relative decrease in expression of interferon-stimulated genes (ISGs; MX1 and IFIT5) and increased viral yield in response to PBG98 infection. Conversely, knockdown of SOCS1 enhanced induction of ISGs and reduced viral yield in chIFN-α-stimulated DF-1. Consequently, SOCS1 reduces induction of the IFN signalling pathway in chicken cells and can potentiate virus replication.
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Affiliation(s)
- E S Giotis
- Section of Virology, School of Medicine, St Mary's Campus, Imperial College London, London, W2 1PG, UK
| | - C S Ross
- Institute for Infection and Immunity, St George's, University of London, London, SW17 0RE, UK
| | - R C Robey
- Section of Virology, School of Medicine, St Mary's Campus, Imperial College London, London, W2 1PG, UK
| | - A Nohturfft
- Institute for Infection and Immunity, St George's, University of London, London, SW17 0RE, UK
| | - S Goodbourn
- Institute for Infection and Immunity, St George's, University of London, London, SW17 0RE, UK
| | - M A Skinner
- Section of Virology, School of Medicine, St Mary's Campus, Imperial College London, London, W2 1PG, UK.
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Townsend DG, Trivedi S, Jackson RJ, Ranasinghe C. Recombinant fowlpox virus vector-based vaccines: expression kinetics, dissemination and safety profile following intranasal delivery. J Gen Virol 2017; 98:496-505. [PMID: 28056224 PMCID: PMC5797952 DOI: 10.1099/jgv.0.000702] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/03/2017] [Indexed: 12/23/2022] Open
Abstract
We have previously established that mucosal uptake of recombinant fowlpox virus (rFPV) vaccines is far superior to other vector-based vaccines. Specifically, intranasal priming with rFPV vaccines can recruit unique antigen-presenting cells, which induce excellent mucosal and systemic HIV-specific CD8+ T-cell immunity. In this study, we have for the first time investigated the in vivo dissemination, safety and expression kinetics of rFPV post intranasal delivery using recombinant viruses expressing green fluorescent protein or mCherry. Both confocal microscopy of tissue sections using green fluorescent protein and in vivo Imaging System (IVIS) spectrum live animal and whole organ imaging studies using mCherry revealed that (i) the peak antigen expression occurs 12 to 24 h post vaccination and no active viral gene expression is detected 96 h post vaccination. (ii) The virus only infects the initial vaccination site (lung and nasal cavity) and does not disseminate to distal sites such as the spleen or gut. (iii) More importantly, rFPV does not cross the olfactory receptor neuron pathway. Collectively, our findings indicate that rFPV vector-based vaccines have all the hallmarks of a safe and effective mucosal delivery vector, suitable for clinical evaluation.
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Affiliation(s)
- David G Townsend
- Molecular Mucosal Vaccine Immunology Group, Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra ACT 2601, Australia
| | - Shubhanshi Trivedi
- Molecular Mucosal Vaccine Immunology Group, Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra ACT 2601, Australia
- Present address: Division of Infectious Diseases, Department of Internal Medicine, The University of Utah, Salt Lake City, UT, USA
| | - Ronald J Jackson
- Molecular Mucosal Vaccine Immunology Group, Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra ACT 2601, Australia
| | - Charani Ranasinghe
- Molecular Mucosal Vaccine Immunology Group, Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra ACT 2601, Australia
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Giotis ES, Robey RC, Skinner NG, Tomlinson CD, Goodbourn S, Skinner MA. Chicken interferome: avian interferon-stimulated genes identified by microarray and RNA-seq of primary chick embryo fibroblasts treated with a chicken type I interferon (IFN-α). Vet Res 2016; 47:75. [PMID: 27494935 PMCID: PMC4974698 DOI: 10.1186/s13567-016-0363-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/18/2016] [Indexed: 12/24/2022] Open
Abstract
Viruses that infect birds pose major threats-to the global supply of chicken, the major, universally-acceptable meat, and as zoonotic agents (e.g. avian influenza viruses H5N1 and H7N9). Controlling these viruses in birds as well as understanding their emergence into, and transmission amongst, humans will require considerable ingenuity and understanding of how different species defend themselves. The type I interferon-coordinated response constitutes the major antiviral innate defence. Although interferon was discovered in chicken cells, details of the response, particularly the identity of hundreds of stimulated genes, are far better described in mammals. Viruses induce interferon-stimulated genes but they also regulate the expression of many hundreds of cellular metabolic and structural genes to facilitate their replication. This study focusses on the potentially anti-viral genes by identifying those induced just by interferon in primary chick embryo fibroblasts. Three transcriptomic technologies were exploited: RNA-seq, a classical 3'-biased chicken microarray and a high density, "sense target", whole transcriptome chicken microarray, with each recognising 120-150 regulated genes (curated for duplication and incorrect assignment of some microarray probesets). Overall, the results are considered robust because 128 of the compiled, curated list of 193 regulated genes were detected by two, or more, of the technologies.
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Affiliation(s)
- Efstathios S. Giotis
- Section of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, Norfolk Place, London, W2 1PG UK
| | - Rebecca C. Robey
- Section of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, Norfolk Place, London, W2 1PG UK
| | | | - Christopher D. Tomlinson
- Bioinformatics Support Service, Imperial College London, Sir Alexander Fleming Bldg, London, SW7 2AZ UK
| | - Stephen Goodbourn
- Institute for Infection and Immunity, St. George’s, University of London, London, SW17 0RE UK
| | - Michael A. Skinner
- Section of Virology, Faculty of Medicine, Imperial College London, St. Mary’s Campus, Norfolk Place, London, W2 1PG UK
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11
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Herbert MH, Squire CJ, Mercer AA. Poxviral ankyrin proteins. Viruses 2015; 7:709-38. [PMID: 25690795 PMCID: PMC4353913 DOI: 10.3390/v7020709] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/05/2015] [Accepted: 02/09/2015] [Indexed: 02/08/2023] Open
Abstract
Multiple repeats of the ankyrin motif (ANK) are ubiquitous throughout the kingdoms of life but are absent from most viruses. The main exception to this is the poxvirus family, and specifically the chordopoxviruses, with ANK repeat proteins present in all but three species from separate genera. The poxviral ANK repeat proteins belong to distinct orthologue groups spread over different species, and align well with the phylogeny of their genera. This distribution throughout the chordopoxviruses indicates these proteins were present in an ancestral vertebrate poxvirus, and have since undergone numerous duplication events. Most poxviral ANK repeat proteins contain an unusual topology of multiple ANK motifs starting at the N-terminus with a C-terminal poxviral homologue of the cellular F-box enabling interaction with the cellular SCF ubiquitin ligase complex. The subtle variations between ANK repeat proteins of individual poxviruses suggest an array of different substrates may be bound by these protein-protein interaction domains and, via the F-box, potentially directed to cellular ubiquitination pathways and possible degradation. Known interaction partners of several of these proteins indicate that the NF-κB coordinated anti-viral response is a key target, whilst some poxviral ANK repeat domains also have an F-box independent affect on viral host-range.
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Affiliation(s)
- Michael H Herbert
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Christopher J Squire
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Andrew A Mercer
- Virus Research Unit, Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand.
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12
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Brady G, Bowie AG. Innate immune activation of NFκB and its antagonism by poxviruses. Cytokine Growth Factor Rev 2014; 25:611-20. [PMID: 25081317 DOI: 10.1016/j.cytogfr.2014.07.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 07/03/2014] [Indexed: 12/18/2022]
Abstract
In recent years there has been an acceleration of discovery in the field of innate anti-viral immunity to the point that many of the key events in early virus sensing and the discrete anti-viral responses they trigger have been elucidated in detail. In particular, pattern recognition receptors (PRRs) that detect viruses at the plasma membrane, in endosomes, and within the cytosol have been characterized. Upon stimulation by viruses, most of these PRRs trigger signal transduction pathways culminating in NFκB activation. NFκB contributes both to type I interferon induction, and to production of pro-inflammatory cytokines from infected cells. Our understanding of host anti-viral innate immunity has been greatly aided by an appreciation of the ways in which poxviruses have evolved strategies to inhibit both innate sensing and effector responses. A recurring feature of poxviral immunomodulation is the apparent necessity for poxviruses to evolve multiple, non-redundant inhibitors of NFκB activation which often appear to act on the same innate signalling pathway. The reason for such apparent over-targeting of one transcription factor is not clear. Here we describe the current understanding of how host cells sense poxvirus infection to trigger signalling pathways leading to NFκB activation and pro-inflammatory cytokine induction, and the ways in which poxviruses have evolved to concisely antagonize these systems.
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Affiliation(s)
- Gareth Brady
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
| | - Andrew G Bowie
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
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13
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Laidlaw SM, Skinner MA. Construction of Deletion-knockout Mutant Fowlpox Virus (FWPV). Bio Protoc 2014; 4:e1126. [PMID: 27257612 DOI: 10.21769/bioprotoc.1126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The construction of deletion-knockout poxviruses is a useful approach to determining the function of specific virus genes. This protocol is an adaptation of the transient dominant knockout selection protocol published by Falkner and Moss (1990) for use with vaccinia virus. The protocol makes use of the dominant selectable marker Escherichia coli guanine phosphoribosyltransferase (gpt) gene (Mulligan and Berg, 1981), under the control of an early/late poxvirus promoter. The deletion viruses that are produced no longer contain a selectable marker, which may be preferable for the production of vaccines.
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Affiliation(s)
- Stephen M Laidlaw
- Section of Virology, Faculty of Medicine, Imperial College London, London, UK
| | - Michael A Skinner
- Section of Virology, Faculty of Medicine, Imperial College London, London, UK
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Abstract
Subclinical immunosuppression in chickens is an important but often underestimated factor in the subsequent development of clinical disease. Immunosuppression can be caused by pathogens such as chicken infectious anemia virus, infectious bursal disease virus, reovirus, and some retroviruses (e.g., reticuloendotheliosis virus). Mycotoxins and stress, often caused by poor management practices, can also cause immunosuppression. The effects on the innate and acquired immune responses and the mechanisms by which mycotoxins, stress and infectious agents cause immunosuppression are discussed. Immunoevasion is a common ploy by which viruses neutralize or evade immune responses. DNA viruses such as herpesvirus and poxvirus have multiple genes, some of them host-derived, which interfere with effective innate or acquired immune responses. RNA viruses may escape acquired humoral and cellular immune responses by mutations in protective antigenic epitopes (e.g., avian influenza viruses), while accessory non-structural proteins or multi-functional structural proteins interfere with the interferon system (e.g., Newcastle disease virus).
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15
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Genetic screen of a library of chimeric poxviruses identifies an ankyrin repeat protein involved in resistance to the avian type I interferon response. J Virol 2013; 87:5028-40. [PMID: 23427151 DOI: 10.1128/jvi.02738-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Viruses must be able to resist host innate responses, especially the type I interferon (IFN) response. They do so by preventing the induction or activity of IFN and/or by resisting the antiviral effectors that it induces. Poxviruses are no exception, with many mechanisms identified whereby mammalian poxviruses, notably, vaccinia virus (VACV), but also cowpox and myxoma viruses, are able to evade host IFN responses. Similar mechanisms have not been described for avian poxviruses (avipoxviruses). Restricted for permissive replication to avian hosts, they have received less attention; moreover, the avian host responses are less well characterized. We show that the prototypic avipoxvirus, fowlpox virus (FWPV), is highly resistant to the antiviral effects of avian IFN. A gain-of-function genetic screen identified fpv014 to contribute to increased resistance to exogenous recombinant chicken alpha IFN (ChIFN1). fpv014 is a member of the large family of poxvirus (especially avipoxvirus) genes that encode proteins containing N-terminal ankyrin repeats (ANKs) and C-terminal F-box-like motifs. By binding the Skp1/cullin-1 complex, the F box in such proteins appears to target ligands bound by the ANKs for ubiquitination. Mass spectrometry and immunoblotting demonstrated that tandem affinity-purified, tagged fpv014 was complexed with chicken cullin-1 and Skp1. Prior infection with an fpv014-knockout mutant of FWPV still blocked transfected poly(I·C)-mediated induction of the beta IFN (ChIFN2) promoter as effectively as parental FWPV, but the mutant was more sensitive to exogenous ChIFN1. Therefore, unlike the related protein fpv012, fpv014 does not contribute to the FWPV block to induction of ChIFN2 but does confer resistance to an established antiviral state.
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