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Khalil AM, Nogales A, Martínez-Sobrido L, Mostafa A. Antiviral responses versus virus-induced cellular shutoff: a game of thrones between influenza A virus NS1 and SARS-CoV-2 Nsp1. Front Cell Infect Microbiol 2024; 14:1357866. [PMID: 38375361 PMCID: PMC10875036 DOI: 10.3389/fcimb.2024.1357866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 01/16/2024] [Indexed: 02/21/2024] Open
Abstract
Following virus recognition of host cell receptors and viral particle/genome internalization, viruses replicate in the host via hijacking essential host cell machinery components to evade the provoked antiviral innate immunity against the invading pathogen. Respiratory viral infections are usually acute with the ability to activate pattern recognition receptors (PRRs) in/on host cells, resulting in the production and release of interferons (IFNs), proinflammatory cytokines, chemokines, and IFN-stimulated genes (ISGs) to reduce virus fitness and mitigate infection. Nevertheless, the game between viruses and the host is a complicated and dynamic process, in which they restrict each other via specific factors to maintain their own advantages and win this game. The primary role of the non-structural protein 1 (NS1 and Nsp1) of influenza A viruses (IAV) and the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respectively, is to control antiviral host-induced innate immune responses. This review provides a comprehensive overview of the genesis, spatial structure, viral and cellular interactors, and the mechanisms underlying the unique biological functions of IAV NS1 and SARS-CoV-2 Nsp1 in infected host cells. We also highlight the role of both non-structural proteins in modulating viral replication and pathogenicity. Eventually, and because of their important role during viral infection, we also describe their promising potential as targets for antiviral therapy and the development of live attenuated vaccines (LAV). Conclusively, both IAV NS1 and SARS-CoV-2 Nsp1 play an important role in virus-host interactions, viral replication, and pathogenesis, and pave the way to develop novel prophylactic and/or therapeutic interventions for the treatment of these important human respiratory viral pathogens.
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Affiliation(s)
- Ahmed Magdy Khalil
- Disease Intervention & Prevention and Host Pathogen Interactions Programs, Texas Biomedical Research Institute, San Antonio, TX, United States
- Department of Zoonotic Diseases, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Aitor Nogales
- Center for Animal Health Research, CISA-INIA-CSIC, Madrid, Spain
| | - Luis Martínez-Sobrido
- Disease Intervention & Prevention and Host Pathogen Interactions Programs, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Ahmed Mostafa
- Disease Intervention & Prevention and Host Pathogen Interactions Programs, Texas Biomedical Research Institute, San Antonio, TX, United States
- Center of Scientific Excellence for Influenza Viruses, National Research Centre, Giza, Egypt
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2
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Li K, McCaw JM, Cao P. Enhanced viral infectivity and reduced interferon production are associated with high pathogenicity for influenza viruses. PLoS Comput Biol 2023; 19:e1010886. [PMID: 36758109 PMCID: PMC9946260 DOI: 10.1371/journal.pcbi.1010886] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 02/22/2023] [Accepted: 01/20/2023] [Indexed: 02/11/2023] Open
Abstract
Epidemiological and clinical evidence indicates that humans infected with the 1918 pandemic H1N1 influenza virus and highly pathogenic avian H5N1 influenza viruses often displayed severe lung pathology. High viral load and extensive infiltration of macrophages are the hallmarks of highly pathogenic (HP) influenza viral infections. However, it remains unclear what biological mechanisms primarily determine the observed difference in the kinetics of viral load and macrophages between HP and low pathogenic (LP) viral infections, and how the mechanistic differences are associated with viral pathogenicity. In this study, we develop a mathematical model of viral dynamics that includes the dynamics of different macrophage populations and interferon. We fit the model to in vivo kinetic data of viral load and macrophage level from BALB/c mice infected with an HP or LP strain of H1N1/H5N1 virus to estimate model parameters using Bayesian inference. Our primary finding is that HP viruses have a higher viral infection rate, a lower interferon production rate and a lower macrophage recruitment rate compared to LP viruses, which are strongly associated with more severe tissue damage (quantified by a higher percentage of epithelial cell loss). We also quantify the relative contribution of macrophages to viral clearance and find that macrophages do not play a dominant role in the direct clearance of free viruses although their role in mediating immune responses such as interferon production is crucial. Our work provides new insight into the mechanisms that convey the observed difference in viral and macrophage kinetics between HP and LP infections and establishes an improved model-fitting framework to enhance the analysis of new data on viral pathogenicity.
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Affiliation(s)
- Ke Li
- School of Mathematics and Statistics, The University of Melbourne, Parkville, VIC, Australia
- * E-mail:
| | - James M. McCaw
- School of Mathematics and Statistics, The University of Melbourne, Parkville, VIC, Australia
- Peter Doherty Institute for Infection and Immunity, The Royal Melbourne Hospital and The University of Melbourne, Parkville, VIC, Australia
- Melbourne School of Population and Global Health, The University of Melbourne, Parkville, VIC, Australia
| | - Pengxing Cao
- School of Mathematics and Statistics, The University of Melbourne, Parkville, VIC, Australia
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3
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Ackerman EE, Weaver JJA, Shoemaker JE. Mathematical Modeling Finds Disparate Interferon Production Rates Drive Strain-Specific Immunodynamics during Deadly Influenza Infection. Viruses 2022; 14:v14050906. [PMID: 35632648 PMCID: PMC9147528 DOI: 10.3390/v14050906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/21/2022] [Accepted: 04/23/2022] [Indexed: 01/13/2023] Open
Abstract
The timing and magnitude of the immune response (i.e., the immunodynamics) associated with the early innate immune response to viral infection display distinct trends across influenza A virus subtypes in vivo. Evidence shows that the timing of the type-I interferon response and the overall magnitude of immune cell infiltration are both correlated with more severe outcomes. However, the mechanisms driving the distinct immunodynamics between infections of different virus strains (strain-specific immunodynamics) remain unclear. Here, computational modeling and strain-specific immunologic data are used to identify the immune interactions that differ in mice infected with low-pathogenic H1N1 or high-pathogenic H5N1 influenza viruses. Computational exploration of free parameters between strains suggests that the production rate of interferon is the major driver of strain-specific immune responses observed in vivo, and points towards the relationship between the viral load and lung epithelial interferon production as the main source of variance between infection outcomes. A greater understanding of the contributors to strain-specific immunodynamics can be utilized in future efforts aimed at treatment development to improve clinical outcomes of high-pathogenic viral strains.
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Affiliation(s)
- Emily E. Ackerman
- Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15260, USA; (E.E.A.); (J.J.A.W.)
| | - Jordan J. A. Weaver
- Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15260, USA; (E.E.A.); (J.J.A.W.)
| | - Jason E. Shoemaker
- Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15260, USA; (E.E.A.); (J.J.A.W.)
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Correspondence:
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4
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Characterization of an intracellular humanized single-chain antibody to matrix protein (M1) of H5N1 virus. PLoS One 2022; 17:e0266220. [PMID: 35358257 PMCID: PMC8970388 DOI: 10.1371/journal.pone.0266220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/16/2022] [Indexed: 11/19/2022] Open
Abstract
We developed a human intracellular antibody based on the M1 protein from avian influenza virus H5N1 (A/meerkat/Shanghai/SH-1/2012) and then characterized the properties of this antibody. The M1 protein sequence was amplified by RT-PCR using the cDNA of the H5N1 virus as a template, expressed in bacterial expression system BL21 (DE3) and purified. A human strain, high affinity, and single chain antibody (HuScFv) against M1 protein was obtained by phage antibody library screening using M1 as an antigen. A recombinant TAT-HuScFv protein was expressed by fusion with the TAT protein transduction domain (PTD) gene of HIV to prepare a human intracellular antibody against avian influenza virus. Further analysis demonstrated that TAT-HuScFv could inhibit the hemagglutination activity of the 300 TCID50 H1N1 virus, thus providing preliminary validation of the universality of the antibody. After two rounds of M1 protein decomposition, the TAT-HuScFv antigen binding site was identified as Alanine (A) at position 239. Collectively, our data describe a recombinant antibody with high binding activity against the conserved sequences of avian influenza viruses. This intracellular recombinant antibody blocked the M1 protein that infected intracellular viruses, thus inhibiting the replication and reproduction of H5N1 viruses.
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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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Moreira EA, Yamauchi Y, Matthias P. How Influenza Virus Uses Host Cell Pathways during Uncoating. Cells 2021; 10:1722. [PMID: 34359892 PMCID: PMC8305448 DOI: 10.3390/cells10071722] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/25/2021] [Accepted: 07/02/2021] [Indexed: 12/15/2022] Open
Abstract
Influenza is a zoonotic respiratory disease of major public health interest due to its pandemic potential, and a threat to animals and the human population. The influenza A virus genome consists of eight single-stranded RNA segments sequestered within a protein capsid and a lipid bilayer envelope. During host cell entry, cellular cues contribute to viral conformational changes that promote critical events such as fusion with late endosomes, capsid uncoating and viral genome release into the cytosol. In this focused review, we concisely describe the virus infection cycle and highlight the recent findings of host cell pathways and cytosolic proteins that assist influenza uncoating during host cell entry.
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Affiliation(s)
| | - Yohei Yamauchi
- Faculty of Life Sciences, School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK;
| | - Patrick Matthias
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland;
- Faculty of Sciences, University of Basel, 4031 Basel, Switzerland
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Wang X, Lin L, Yu Y, Yan Y, Ojha NK, Zhou J. The N-terminal residual arginine 19 of influenza A virus NS1 protein is required for its nuclear localization and RNA binding. Vet Microbiol 2020; 251:108895. [PMID: 33126184 DOI: 10.1016/j.vetmic.2020.108895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 10/11/2020] [Indexed: 11/30/2022]
Abstract
RNA binding ability and cellular distribution are important for nonstructural protein 1 (NS1) of influenza A virus to act as a viral regulatory factor to control virus life cycle. In this study, we identified that the N-terminal residues 19-21 of NS1 are a highly conserved motif depending on all the available NS1 full length sequence of H5N1 influenza A virus from NCBI database. Site-directed mutation analysis demonstrated that the R19 residue of NS1 is critical for its RNA binding and nuclear localization. Furthermore, the residue R19 of NS1 was identified to be critical for regulating M1 mRNA splicing and NS1 nuclear export. Biological analysis of the rescued viruses indicated that the R19A mutation of NS1 did not interfere the replication of H5N1 virus during infection and attenuated the virulence of H5N1 virus in mice.
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Affiliation(s)
- Xingbo Wang
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, 310058, PR China
| | - Lulu Lin
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, 310058, PR China
| | - Yang Yu
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, 310058, PR China
| | - Yan Yan
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, 310058, PR China
| | - Nishant Kumar Ojha
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, 310058, PR China
| | - Jiyong Zhou
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, 310058, PR China; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University, Hangzhou, 310003, PR China.
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8
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Emanuelli G, Nassehzadeh-Tabriz N, Morrell NW, Marciniak SJ. The integrated stress response in pulmonary disease. Eur Respir Rev 2020; 29:29/157/200184. [PMID: 33004527 PMCID: PMC7116220 DOI: 10.1183/16000617.0184-2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 07/15/2020] [Indexed: 02/07/2023] Open
Abstract
The respiratory tract and its resident immune cells face daily exposure
to stress, both from without and from within. Inhaled pathogens, including
severe acute respiratory syndrome coronavirus 2, and toxins from pollution
trigger a cellular defence system that reduces protein synthesis to minimise
viral replication or the accumulation of misfolded proteins. Simultaneously, a
gene expression programme enhances antioxidant and protein folding machineries
in the lung. Four kinases (PERK, PKR, GCN2 and HRI) sense a diverse range of
stresses to trigger this “integrated stress response”. Here we review recent
advances identifying the integrated stress response as a critical pathway in the
pathogenesis of pulmonary diseases, including pneumonias, thoracic malignancy,
pulmonary fibrosis and pulmonary hypertension. Understanding the integrated
stress response provides novel targets for the development of therapies.
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Affiliation(s)
- Giulia Emanuelli
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, UK.,Division of Respiratory Medicine, Dept of Medicine, University of Cambridge, Cambridge, UK.,Equal first authors
| | - Nikou Nassehzadeh-Tabriz
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, UK.,Equal first authors
| | - Nick W Morrell
- Division of Respiratory Medicine, Dept of Medicine, University of Cambridge, Cambridge, UK
| | - Stefan J Marciniak
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, UK .,Division of Respiratory Medicine, Dept of Medicine, University of Cambridge, Cambridge, UK
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9
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Farooq QUA, Shaukat Z, Aiman S, Zhou T, Li C. A systems biology-driven approach to construct a comprehensive protein interaction network of influenza A virus with its host. BMC Infect Dis 2020; 20:480. [PMID: 32631335 PMCID: PMC7339526 DOI: 10.1186/s12879-020-05214-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 06/30/2020] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Influenza A virus (IAV) infection is a serious public health problem not only in South East Asia but also in European and African countries. Scientists are using network biology to dig deep into the essential host factors responsible for regulation of virus infections. Researchers can explore the virus invasion into the host cells by studying the virus-host relationship based on their protein-protein interaction network. METHODS In this study, we present a comprehensive IAV-host protein-protein interaction network that is obtained based on the literature-curated protein interaction datasets and some important interaction databases. The network is constructed in Cytoscape and analyzed with its plugins including CytoHubba, CytoCluster, MCODE, ClusterViz and ClusterOne. In addition, Gene Ontology and KEGG enrichment analyses are performed on the highly IAV-associated human proteins. We also compare the current results with those from our previous study on Hepatitis C Virus (HCV)-host protein-protein interaction network in order to find out valuable information. RESULTS We found out 1027 interactions among 829 proteins of which 14 are viral proteins and 815 belong to human proteins. The viral protein NS1 has the highest number of associations with human proteins followed by NP, PB2 and so on. Among human proteins, LNX2, MEOX2, TFCP2, PRKRA and DVL2 have the most interactions with viral proteins. Based on KEGG pathway enrichment analysis of the highly IAV-associated human proteins, we found out that they are enriched in the KEGG pathway of basal cell carcinoma. Similarly, the result of KEGG analysis of the common host factors involved in IAV and HCV infections shows that these factors are enriched in the infection pathways of Hepatitis B Virus (HBV), Viral Carcinoma, measles and certain other viruses. CONCLUSION It is concluded that the list of proteins we identified might be used as potential drug targets for the drug design against the infectious diseases caused by Influenza A Virus and other viruses.
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Affiliation(s)
- Qurat Ul Ain Farooq
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, 100124, China
| | - Zeeshan Shaukat
- Faculty of Information Technology, Beijing University of Technology, Beijing, 100124, China
| | - Sara Aiman
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, 100124, China
| | - Tong Zhou
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, 100124, China
| | - Chunhua Li
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, 100124, China.
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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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11
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New therapeutic targets for the prevention of infectious acute exacerbations of COPD: role of epithelial adhesion molecules and inflammatory pathways. Clin Sci (Lond) 2019; 133:1663-1703. [PMID: 31346069 DOI: 10.1042/cs20181009] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/27/2019] [Accepted: 06/28/2019] [Indexed: 12/15/2022]
Abstract
Chronic respiratory diseases are among the leading causes of mortality worldwide, with the major contributor, chronic obstructive pulmonary disease (COPD) accounting for approximately 3 million deaths annually. Frequent acute exacerbations (AEs) of COPD (AECOPD) drive clinical and functional decline in COPD and are associated with accelerated loss of lung function, increased mortality, decreased health-related quality of life and significant economic costs. Infections with a small subgroup of pathogens precipitate the majority of AEs and consequently constitute a significant comorbidity in COPD. However, current pharmacological interventions are ineffective in preventing infectious exacerbations and their treatment is compromised by the rapid development of antibiotic resistance. Thus, alternative preventative therapies need to be considered. Pathogen adherence to the pulmonary epithelium through host receptors is the prerequisite step for invasion and subsequent infection of surrounding structures. Thus, disruption of bacterial-host cell interactions with receptor antagonists or modulation of the ensuing inflammatory profile present attractive avenues for therapeutic development. This review explores key mediators of pathogen-host interactions that may offer new therapeutic targets with the potential to prevent viral/bacterial-mediated AECOPD. There are several conceptual and methodological hurdles hampering the development of new therapies that require further research and resolution.
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12
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Vangeti S, Yu M, Smed-Sörensen A. Respiratory Mononuclear Phagocytes in Human Influenza A Virus Infection: Their Role in Immune Protection and As Targets of the Virus. Front Immunol 2018; 9:1521. [PMID: 30018617 PMCID: PMC6037688 DOI: 10.3389/fimmu.2018.01521] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 06/19/2018] [Indexed: 12/12/2022] Open
Abstract
Emerging viruses have become increasingly important with recurrent epidemics. Influenza A virus (IAV), a respiratory virus displaying continuous re-emergence, contributes significantly to global morbidity and mortality, especially in young children, immunocompromised, and elderly people. IAV infection is typically confined to the airways and the virus replicates in respiratory epithelial cells but can also infect resident immune cells. Clearance of infection requires virus-specific adaptive immune responses that depend on early and efficient innate immune responses against IAV. Mononuclear phagocytes (MNPs), comprising monocytes, dendritic cells, and macrophages, have common but also unique features. In addition to being professional antigen-presenting cells, MNPs mediate leukocyte recruitment, sense and phagocytose pathogens, regulate inflammation, and shape immune responses. The immune protection mediated by MNPs can be compromised during IAV infection when the cells are also targeted by the virus, leading to impaired cytokine responses and altered interactions with other immune cells. Furthermore, it is becoming increasingly clear that immune cells differ depending on their anatomical location and that it is important to study them where they are expected to exert their function. Defining tissue-resident MNP distribution, phenotype, and function during acute and convalescent human IAV infection can offer valuable insights into understanding how MNPs maintain the fine balance required to protect against infections that the cells are themselves susceptible to. In this review, we delineate the role of MNPs in the human respiratory tract during IAV infection both in mediating immune protection and as targets of the virus.
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Affiliation(s)
- Sindhu Vangeti
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Meng Yu
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Anna Smed-Sörensen
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
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13
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Combating flu in China. Microbes Infect 2017; 19:567-569. [PMID: 28993229 DOI: 10.1016/j.micinf.2017.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 09/28/2017] [Indexed: 11/24/2022]
Abstract
China is a major source of avian influenza viruses (AIVs) with bird-to-human transmissibility. Thus, understanding these viruses and treating infections at their source should decrease spread of AIVs to other countries in the world. This special issue focuses on the molecular epidemiology and pathogenesis of influenza viruses, and provides results on current efforts to develop vaccines against AIVs.
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