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Valeri E, Breggion S, Barzaghi F, Abou Alezz M, Crivicich G, Pagani I, Forneris F, Sartirana C, Costantini M, Costi S, Marino A, Chiarotto E, Colavito D, Cimaz R, Merelli I, Vicenzi E, Aiuti A, Kajaste-Rudnitski A. A novel STING variant triggers endothelial toxicity and SAVI disease. J Exp Med 2024; 221:e20232167. [PMID: 38953896 PMCID: PMC11217899 DOI: 10.1084/jem.20232167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 04/18/2024] [Accepted: 06/03/2024] [Indexed: 07/04/2024] Open
Abstract
Gain-of-function mutations in STING cause STING-associated vasculopathy with onset in infancy (SAVI) characterized by early-onset systemic inflammation, skin vasculopathy, and interstitial lung disease. Here, we report and characterize a novel STING variant (F269S) identified in a SAVI patient. Single-cell transcriptomics of patient bone marrow revealed spontaneous activation of interferon (IFN) and inflammatory pathways across cell types and a striking prevalence of circulating naïve T cells was observed. Inducible STING F269S expression conferred enhanced signaling through ligand-independent translocation of the protein to the Golgi, protecting cells from viral infections but preventing their efficient immune priming. Additionally, endothelial cell activation was promoted and further exacerbated by cytokine secretion by SAVI immune cells, resulting in inflammation and endothelial damage. Our findings identify STING F269S mutation as a novel pathogenic variant causing SAVI, highlight the importance of the crosstalk between endothelial and immune cells in the context of lung disease, and contribute to a better understanding of how aberrant STING activation can cause pathology.
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Affiliation(s)
- Erika Valeri
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Sara Breggion
- Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Federica Barzaghi
- Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Pediatric Immunohematology and Bone Marrow Transplantation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Monah Abou Alezz
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, Milan, Italy
| | - Giovanni Crivicich
- Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Isabel Pagani
- Viral Pathogenesis and Biosafety Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Federico Forneris
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
- Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Claudia Sartirana
- Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Matteo Costantini
- Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Stefania Costi
- Unit of Pediatric Rheumatology, ASST Gaetano Pini-CTO, Milan, Italy
| | - Achille Marino
- Unit of Pediatric Rheumatology, ASST Gaetano Pini-CTO, Milan, Italy
| | | | | | - Rolando Cimaz
- Unit of Pediatric Rheumatology, ASST Gaetano Pini-CTO, Milan, Italy
| | - Ivan Merelli
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, Milan, Italy
| | - Elisa Vicenzi
- Viral Pathogenesis and Biosafety Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alessandro Aiuti
- Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Pediatric Immunohematology and Bone Marrow Transplantation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Anna Kajaste-Rudnitski
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, Milan, Italy
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
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2
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Husain M. Influenza Virus Host Restriction Factors: The ISGs and Non-ISGs. Pathogens 2024; 13:127. [PMID: 38392865 PMCID: PMC10893265 DOI: 10.3390/pathogens13020127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/18/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
Influenza virus has been one of the most prevalent and researched viruses globally. Consequently, there is ample information available about influenza virus lifecycle and pathogenesis. However, there is plenty yet to be known about the determinants of influenza virus pathogenesis and disease severity. Influenza virus exploits host factors to promote each step of its lifecycle. In turn, the host deploys antiviral or restriction factors that inhibit or restrict the influenza virus lifecycle at each of those steps. Two broad categories of host restriction factors can exist in virus-infected cells: (1) encoded by the interferon-stimulated genes (ISGs) and (2) encoded by the constitutively expressed genes that are not stimulated by interferons (non-ISGs). There are hundreds of ISGs known, and many, e.g., Mx, IFITMs, and TRIMs, have been characterized to restrict influenza virus infection at different stages of its lifecycle by (1) blocking viral entry or progeny release, (2) sequestering or degrading viral components and interfering with viral synthesis and assembly, or (3) bolstering host innate defenses. Also, many non-ISGs, e.g., cyclophilins, ncRNAs, and HDACs, have been identified and characterized to restrict influenza virus infection at different lifecycle stages by similar mechanisms. This review provides an overview of those ISGs and non-ISGs and how the influenza virus escapes the restriction imposed by them and aims to improve our understanding of the host restriction mechanisms of the influenza virus.
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Affiliation(s)
- Matloob Husain
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
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3
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How Influenza A Virus NS1 Deals with the Ubiquitin System to Evade Innate Immunity. Viruses 2021; 13:v13112309. [PMID: 34835115 PMCID: PMC8619935 DOI: 10.3390/v13112309] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/14/2021] [Accepted: 11/18/2021] [Indexed: 12/11/2022] Open
Abstract
Ubiquitination is a post-translational modification regulating critical cellular processes such as protein degradation, trafficking and signaling pathways, including activation of the innate immune response. Therefore, viruses, and particularly influenza A virus (IAV), have evolved different mechanisms to counteract this system to perform proper infection. Among IAV proteins, the non-structural protein NS1 is shown to be one of the main virulence factors involved in these viral hijackings. NS1 is notably able to inhibit the host's antiviral response through the perturbation of ubiquitination in different ways, as discussed in this review.
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4
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Identification and Characterization of Swine Influenza Virus H1N1 Variants Generated in Vaccinated and Nonvaccinated, Challenged Pigs. Viruses 2021; 13:v13102087. [PMID: 34696517 PMCID: PMC8539973 DOI: 10.3390/v13102087] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/08/2021] [Accepted: 10/13/2021] [Indexed: 01/22/2023] Open
Abstract
Influenza viruses represent a continuous threat to both animal and human health. The 2009 H1N1 A influenza pandemic highlighted the importance of a swine host in the adaptation of influenza viruses to humans. Nowadays, one of the most extended strategies used to control swine influenza viruses (SIVs) is the trivalent vaccine application, whose formulation contains the most frequently circulating SIV subtypes H1N1, H1N2, and H3N2. These vaccines do not provide full protection against the virus, allowing its replication, evolution, and adaptation. To better understand the main mechanisms that shape viral evolution, here, the SIV intra-host diversity was analyzed in samples collected from both vaccinated and nonvaccinated animals challenged with the H1N1 influenza A virus. Twenty-eight whole SIV genomes were obtained by next-generation sequencing, and differences in nucleotide variants between groups were established. Substitutions were allocated along all influenza genetic segments, while the most relevant nonsynonymous substitutions were allocated in the NS1 protein on samples collected from vaccinated animals, suggesting that SIV is continuously evolving despite vaccine application. Moreover, new viral variants were found in both vaccinated and nonvaccinated pigs, showing relevant substitutions in the HA, NA, and NP proteins, which may increase viral fitness under field conditions.
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5
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Charman M, McFarlane S, Wojtus JK, Sloan E, Dewar R, Leeming G, Al-Saadi M, Hunter L, Carroll MW, Stewart JP, Digard P, Hutchinson E, Boutell C. Constitutive TRIM22 Expression in the Respiratory Tract Confers a Pre-Existing Defence Against Influenza A Virus Infection. Front Cell Infect Microbiol 2021; 11:689707. [PMID: 34621686 PMCID: PMC8490869 DOI: 10.3389/fcimb.2021.689707] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 08/26/2021] [Indexed: 12/19/2022] Open
Abstract
The induction of antiviral effector proteins as part of a homeostatically controlled innate immune response to infection plays a critical role in limiting the propagation and transmission of respiratory pathogens. However, the prolonged induction of this immune response can lead to lung hyperinflammation, tissue damage, and respiratory failure. We hypothesized that tissues exposed to the constant threat of infection may constitutively express higher levels of antiviral effector proteins to reduce the need to activate potentially harmful innate immune defences. By analysing transcriptomic data derived from a range of human tissues, we identify lung tissue to express constitutively higher levels of antiviral effector genes relative to that of other mucosal and non-mucosal tissues. By using primary cell lines and the airways of rhesus macaques, we show the interferon-stimulated antiviral effector protein TRIM22 (TRIpartite Motif 22) to be constitutively expressed in the lung independently of viral infection or innate immune stimulation. These findings contrast with previous reports that have shown TRIM22 expression in laboratory-adapted cell lines to require interferon stimulation. We demonstrate that constitutive levels of TRIM22 are sufficient to inhibit the onset of human and avian influenza A virus (IAV) infection by restricting the onset of viral transcription independently of interferon-mediated innate immune defences. Thus, we identify TRIM22 to confer a pre-existing (intrinsic) intracellular defence against IAV infection in cells derived from the respiratory tract. Our data highlight the importance of tissue-specific and cell-type dependent patterns of pre-existing immune gene expression in the intracellular restriction of IAV from the outset of infection.
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Affiliation(s)
- Matthew Charman
- MRC - University of Glasgow Centre for Virus Research, Glasgow, United Kingdom.,Division of Protective Immunity and Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States.,Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Steven McFarlane
- MRC - University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Joanna K Wojtus
- MRC - University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Elizabeth Sloan
- MRC - University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Rebecca Dewar
- The Roslin Institute, University of Edinburgh, Midlothian, United Kingdom
| | - Gail Leeming
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Mohammed Al-Saadi
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom.,Department of Animal Production, University of Al-Qadisiyah, Al-Diwaniyah, Iraq
| | - Laura Hunter
- National Infection Service, Public Health England, Porton Down, Salisbury, United Kingdom
| | - Miles W Carroll
- National Infection Service, Public Health England, Porton Down, Salisbury, United Kingdom
| | - James P Stewart
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Paul Digard
- The Roslin Institute, University of Edinburgh, Midlothian, United Kingdom
| | - Edward Hutchinson
- MRC - University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Chris Boutell
- MRC - University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
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6
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Pagani I, Poli G, Vicenzi E. TRIM22. A Multitasking Antiviral Factor. Cells 2021; 10:cells10081864. [PMID: 34440633 PMCID: PMC8391480 DOI: 10.3390/cells10081864] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/03/2021] [Accepted: 07/16/2021] [Indexed: 02/06/2023] Open
Abstract
Viral invasion of target cells triggers an immediate intracellular host defense system aimed at preventing further propagation of the virus. Viral genomes or early products of viral replication are sensed by a number of pattern recognition receptors, leading to the synthesis and production of type I interferons (IFNs) that, in turn, activate a cascade of IFN-stimulated genes (ISGs) with antiviral functions. Among these, several members of the tripartite motif (TRIM) family are antiviral executors. This article will focus, in particular, on TRIM22 as an example of a multitarget antiviral member of the TRIM family. The antiviral activities of TRIM22 against different DNA and RNA viruses, particularly human immunodeficiency virus type 1 (HIV-1) and influenza A virus (IAV), will be discussed. TRIM22 restriction of virus replication can involve either direct interaction of TRIM22 E3 ubiquitin ligase activity with viral proteins, or indirect protein–protein interactions resulting in control of viral gene transcription, but also epigenetic effects exerted at the chromatin level.
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Affiliation(s)
- Isabel Pagani
- Viral Pathogenesis and Biosafety Unit, IRCCS-Ospedale San Raffaele, 20132 Milan, Italy;
| | - Guido Poli
- Human Immuno-Virology Unit, IRCCS-Ospedale San Raffaele, 20132 Milan, Italy;
- School of Medicine, Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Elisa Vicenzi
- Viral Pathogenesis and Biosafety Unit, IRCCS-Ospedale San Raffaele, 20132 Milan, Italy;
- Correspondence:
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7
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McKellar J, Rebendenne A, Wencker M, Moncorgé O, Goujon C. Mammalian and Avian Host Cell Influenza A Restriction Factors. Viruses 2021; 13:522. [PMID: 33810083 PMCID: PMC8005160 DOI: 10.3390/v13030522] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 12/27/2022] Open
Abstract
The threat of a new influenza pandemic is real. With past pandemics claiming millions of lives, finding new ways to combat this virus is essential. Host cells have developed a multi-modular system to detect incoming pathogens, a phenomenon called sensing. The signaling cascade triggered by sensing subsequently induces protection for themselves and their surrounding neighbors, termed interferon (IFN) response. This response induces the upregulation of hundreds of interferon-stimulated genes (ISGs), including antiviral effectors, establishing an antiviral state. As well as the antiviral proteins induced through the IFN system, cells also possess a so-called intrinsic immunity, constituted of antiviral proteins that are constitutively expressed, creating a first barrier preceding the induction of the interferon system. All these combined antiviral effectors inhibit the virus at various stages of the viral lifecycle, using a wide array of mechanisms. Here, we provide a review of mammalian and avian influenza A restriction factors, detailing their mechanism of action and in vivo relevance, when known. Understanding their mode of action might help pave the way for the development of new influenza treatments, which are absolutely required if we want to be prepared to face a new pandemic.
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Affiliation(s)
- Joe McKellar
- Institut de Recherche en Infectiologie de Montpellier, CNRS, Université de Montpellier, CEDEX 5, 34293 Montpellier, France; (J.M.); (A.R.)
| | - Antoine Rebendenne
- Institut de Recherche en Infectiologie de Montpellier, CNRS, Université de Montpellier, CEDEX 5, 34293 Montpellier, France; (J.M.); (A.R.)
| | - Mélanie Wencker
- Centre International de Recherche en Infectiologie, INSERM/CNRS/UCBL1/ENS de Lyon, 69007 Lyon, France;
| | - Olivier Moncorgé
- Institut de Recherche en Infectiologie de Montpellier, CNRS, Université de Montpellier, CEDEX 5, 34293 Montpellier, France; (J.M.); (A.R.)
| | - Caroline Goujon
- Institut de Recherche en Infectiologie de Montpellier, CNRS, Université de Montpellier, CEDEX 5, 34293 Montpellier, France; (J.M.); (A.R.)
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8
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TRIM Proteins and Their Roles in the Influenza Virus Life Cycle. Microorganisms 2020; 8:microorganisms8091424. [PMID: 32947942 PMCID: PMC7565951 DOI: 10.3390/microorganisms8091424] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/12/2020] [Accepted: 09/15/2020] [Indexed: 12/11/2022] Open
Abstract
The ubiquitin-proteasome system (UPS) has been recognized for regulating fundamental cellular processes, followed by induction of proteasomal degradation of target proteins, and triggers multiple signaling pathways that are crucial for numerous aspects of cellular physiology. Especially tripartite motif (TRIM) proteins, well-known E3 ubiquitin ligases, emerge as having critical roles in several antiviral signaling pathways against varying viral infections. Here we highlight recent advances in the study of antiviral roles of TRIM proteins toward influenza virus infection in terms of the modulation of pathogen recognition receptor (PRR)-mediated innate immune sensing, direct obstruction of influenza viral propagation, and participation in virus-induced autophagy.
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9
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Hage A, Rajsbaum R. To TRIM or not to TRIM: the balance of host-virus interactions mediated by the ubiquitin system. J Gen Virol 2020; 100:1641-1662. [PMID: 31661051 DOI: 10.1099/jgv.0.001341] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The innate immune system responds rapidly to protect against viral infections, but an overactive response can cause harmful damage. To avoid this, the response is tightly regulated by post-translational modifications (PTMs). The ubiquitin system represents a powerful PTM machinery that allows for the reversible linkage of ubiquitin to activate and deactivate a target's function. A precise enzymatic cascade of ubiquitin-activating, conjugating and ligating enzymes facilitates ubiquitination. Viruses have evolved to take advantage of the ubiquitin pathway either by targeting factors to dampen the antiviral response or by hijacking the system to enhance their replication. The tripartite motif (TRIM) family of E3 ubiquitin ligases has garnered attention as a major contributor to innate immunity. Many TRIM family members limit viruses either indirectly as components in innate immune signalling, or directly by targeting viral proteins for degradation. In spite of this, TRIMs and other ubiquitin ligases can be appropriated by viruses and repurposed as valuable tools in viral replication. This duality of function suggests a new frontier of research for TRIMs and raises new challenges for discerning the subtleties of these pro-viral mechanisms. Here, we review current findings regarding the involvement of TRIMs in host-virus interactions. We examine ongoing developments in the field, including novel roles for unanchored ubiquitin in innate immunity, the direct involvement of ubiquitin ligases in promoting viral replication, recent controversies on the role of ubiquitin and TRIM25 in activation of the pattern recognition receptor RIG-I, and we discuss the implications these studies have on future research directions.
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Affiliation(s)
- Adam Hage
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Ricardo Rajsbaum
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA
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10
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Long JS, Mistry B, Haslam SM, Barclay WS. Host and viral determinants of influenza A virus species specificity. Nat Rev Microbiol 2020; 17:67-81. [PMID: 30487536 DOI: 10.1038/s41579-018-0115-z] [Citation(s) in RCA: 318] [Impact Index Per Article: 79.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Influenza A viruses cause pandemics when they cross between species and an antigenically novel virus acquires the ability to infect and transmit between these new hosts. The timing of pandemics is currently unpredictable but depends on ecological and virological factors. The host range of an influenza A virus is determined by species-specific interactions between virus and host cell factors. These include the ability to bind and enter cells, to replicate the viral RNA genome within the host cell nucleus, to evade host restriction factors and innate immune responses and to transmit between individuals. In this Review, we examine the host barriers that influenza A viruses of animals, especially birds, must overcome to initiate a pandemic in humans and describe how, on crossing the species barrier, the virus mutates to establish new interactions with the human host. This knowledge is used to inform risk assessments for future pandemics and to identify virus-host interactions that could be targeted by novel intervention strategies.
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Affiliation(s)
- Jason S Long
- Department of Medicine, Imperial College London, London, UK
| | - Bhakti Mistry
- Department of Medicine, Imperial College London, London, UK
| | - Stuart M Haslam
- Department of Life Sciences, Imperial College London, London, UK
| | - Wendy S Barclay
- Department of Medicine, Imperial College London, London, UK.
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The R251K Substitution in Viral Protein PB2 Increases Viral Replication and Pathogenicity of Eurasian Avian-like H1N1 Swine Influenza Viruses. Viruses 2020; 12:v12010052. [PMID: 31906472 PMCID: PMC7019279 DOI: 10.3390/v12010052] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/29/2019] [Accepted: 12/31/2019] [Indexed: 12/21/2022] Open
Abstract
The Eurasian avian-like swine (EA) H1N1 virus has affected the Chinese swine industry, and human infection cases have been reported occasionally. However, little is known about the pathogenic mechanism of EA H1N1 virus. In this study, we compared the mouse pathogenicity of A/swine/Guangdong/YJ4/2014 (YJ4) and A/swine/Guangdong/MS285/2017 (MS285) viruses, which had similar genotype to A/Hunan/42443/2015 (HuN-like). None of the mice inoculated with 106 TCID50 of YJ4 survived at 7 days post infection, while the survival rate of the MS285 group was 100%. Therefore, a series of single fragment reassortants in MS285 background and two rescued wild-type viruses were generated by using the reverse genetics method, and the pathogenicity analysis revealed that the PB2 gene contributed to the high virulence of YJ4 virus. Furthermore, there were 11 amino acid differences in PB2 between MS285 and YJ4 identified by sequence alignment, and 11 single amino acid mutant viruses were generated in the MS285 background. We found that the R251K mutation significantly increased the virulence of MS285 in mice, contributed to high polymerase activity and enhanced viral genome transcription and replication. These results indicate that PB2-R251K contributes to the virulence of the EA H1N1 virus and provide new insight into future molecular epidemiological surveillance strategies.
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12
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Nuclear localization signal in TRIM22 is essential for inhibition of type 2 porcine reproductive and respiratory syndrome virus replication in MARC-145 cells. Virus Genes 2019; 55:660-672. [PMID: 31375995 PMCID: PMC7089487 DOI: 10.1007/s11262-019-01691-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) infection causes one of the most economically important swine diseases worldwide. Tripartite motif-containing 22 (TRIM22), a TRIM family protein, has been identified as a crucial restriction factor that inhibits a group of human viruses. Currently, the role of cellular TRIM22 in PRRSV infection remains unclear. In the present study, we analyzed the effect of TRIM22 on PRRSV replication in vitro and explored the underlying mechanism. Ectopic expression of TRIM22 impaired the viral replication, while TRIM22-RNAi favored the replication of PRRSV in MARC-145 cells. Additionally, we observed that TRIM22 deletion SPRY domain or Nuclear localization signal (NLS) losses the ability to inhibit PRRSV replication. Finally, Co-IP analysis identified that TRIM22 interacts with PRRSV nucleocapsid (N) protein through the SPRY domain, while the NLS2 motif of N protein is involved in interaction with TRIM22. Although the concentration of PRRSV N protein was not altered in the presence of TRIM22, the abundance of N proteins from simian hemorrhagic fever virus (SHFV), equine arteritis virus (EAV), and murine lactate dehydrogenase-elevating virus (LDV) diminished considerably with increasing TRIM22 expression. Together, our findings uncover a previously unrecognized role for TRIM22 and extend the antiviral effects of TRIM22 to arteriviruses.
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