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Mollarasouli F, Bahrani S, Amrollahimiyandeh Y, Paimard G. Nanomaterials-based immunosensors for avian influenza virus detection. Talanta 2024; 279:126591. [PMID: 39059066 DOI: 10.1016/j.talanta.2024.126591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 07/01/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024]
Abstract
Avian influenza viruses (AIV) are capable of infecting a considerable proportion of the world's population each year, leading to severe epidemics with high rates of morbidity and mortality. The methods now used to diagnose influenza virus A include the Western blot test (WB), hemagglutination inhibition (HI), and enzyme-linked immunosorbent assays (ELISAs). But because of their labor-intensiveness, lengthy procedures, need for costly equipment, and inexperienced staff, these approaches are considered inappropriate. The present review elucidates the recent advancements in the field of avian influenza detection through the utilization of nanomaterials-based immunosensors between 2014 and 2024. The classification of detection techniques has been taken into account to provide a comprehensive overview of the literature. The review encompasses a detailed illustration of the commonly employed detection mechanisms in immunosensors, namely, colorimetry, fluorescence assay, surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), electrochemical detection, quartz crystal microbalance (QCM) piezoelectric, and field-effect transistor (FET). Furthermore, the challenges and future prospects for the immunosensors have been deliberated upon. The present review aims to enhance the understanding of immunosensors-based sensing platforms for virus detection and to stimulate the development of novel immunosensors by providing novel ideas and inspirations. Therefore, the aim of this paper is to provide an updated information about biosensors, as a recent detection technique of influenza with its details regarding the various types of biosensors, which can be used for this review.
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Affiliation(s)
| | - Sonia Bahrani
- Borjobaru Fars Company, Nanotechnology Department, Fars Science and Technology Park, Shiraz, 7197687811, Iran; Department of Medical Nanotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Yousef Amrollahimiyandeh
- Borjobaru Fars Company, Nanotechnology Department, Fars Science and Technology Park, Shiraz, 7197687811, Iran
| | - Giti Paimard
- Laboratory of Nanoscale Biosensing and Bioimaging (NBAB), School of Ophthalmology and Optometry, School of Biomedical Engineering, State Key Laboratory of Ophthalmology Optometry, and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325027, China
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Khanna M, Sharma K, Saxena SK, Sharma JG, Rajput R, Kumar B. Unravelling the interaction between Influenza virus and the nuclear pore complex: insights into viral replication and host immune response. Virusdisease 2024; 35:231-242. [PMID: 39071870 PMCID: PMC11269558 DOI: 10.1007/s13337-024-00879-6] [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: 06/10/2024] [Accepted: 06/21/2024] [Indexed: 07/30/2024] Open
Abstract
Influenza viruses are known to cause severe respiratory infections in humans, often associated with significant morbidity and mortality rates. Virus replication relies on various host factors and pathways, which also determine the virus's infectious potential. Nonetheless, achieving a comprehensive understanding of how the virus interacts with host cellular components is essential for developing effective therapeutic strategies. One of the key components among host factors, the nuclear pore complex (NPC), profoundly affects both the Influenza virus life cycle and the host's antiviral defenses. Serving as the sole gateway connecting the cytoplasm and nucleoplasm, the NPC plays a vital role as a mediator in nucleocytoplasmic trafficking. Upon infection, the virus hijacks and alters the nuclear pore complex and the nuclear receptors. This enables the virus to infiltrate the nucleus and promotes the movement of viral components between the nucleus and cytoplasm. While the nucleus and cytoplasm play pivotal roles in cellular functions, the nuclear pore complex serves as a crucial component in the host's innate immune system, acting as a defense mechanism against virus infection. This review provides a comprehensive overview of the intricate relationship between the Influenza virus and the nuclear pore complex. Furthermore, we emphasize their mutual influence on viral replication and the host's immune responses.
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Affiliation(s)
- Madhu Khanna
- Department of Virology, V.P Chest Institute, University of Delhi, Delhi, India
| | - Kajal Sharma
- Department of Virology, V.P Chest Institute, University of Delhi, Delhi, India
- Department of Biotechnology, Delhi Technological University, Delhi, India
| | - Shailendra K. Saxena
- Centre for Advanced Research (CFAR), Faculty of Medicine, King George’s Medical University (KGMU), Lucknow, India
| | - Jai Gopal Sharma
- Department of Biotechnology, Delhi Technological University, Delhi, India
| | - Roopali Rajput
- Department of Virology, V.P Chest Institute, University of Delhi, Delhi, India
| | - Binod Kumar
- Department of Antiviral Research, Institute of Advanced Virology, Thiruvananthapuram, Kerala India
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3
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A widespread viral entry mechanism: The C-end Rule motif-neuropilin receptor interaction. Proc Natl Acad Sci U S A 2021; 118:2112457118. [PMID: 34772761 PMCID: PMC8670474 DOI: 10.1073/pnas.2112457118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2021] [Indexed: 01/31/2023] Open
Abstract
Many phylogenetically distant animal viruses, including the new coronavirus severe acute respiratory syndrome coronavirus 2, have surface proteins with polybasic sites that are cleaved by host furin and furin-like proteases. Other than priming certain viral surface proteins for fusion, cleavage generates a carboxy-terminal RXXR sequence. This C-end Rule (CendR) motif is known to bind to neuropilin (NRP) receptors on the cell surface. NRPs are ubiquitously expressed, pleiotropic cell surface receptors with important roles in growth factor signaling, vascular biology, and neurobiology, as well as immune homeostasis and activation. The CendR–NRP receptor interaction promotes endocytic internalization and tissue spreading of different cargo, including viral particles. We propose that the interaction between viral surface proteins and NRPs plays an underappreciated and prevalent role in the transmission and pathogenesis of diverse viruses and represents a promising broad-spectrum antiviral target.
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Prévost J, Medjahed H, Vézina D, Chen HC, Hahn BH, Smith AB, Finzi A. HIV-1 Envelope Glycoproteins Proteolytic Cleavage Protects Infected Cells from ADCC Mediated by Plasma from Infected Individuals. Viruses 2021; 13:2236. [PMID: 34835042 PMCID: PMC8625184 DOI: 10.3390/v13112236] [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: 10/26/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 12/28/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) is synthesized in the endoplasmic reticulum as a trimeric gp160 precursor, which requires proteolytic cleavage by a cellular furin protease to mediate virus-cell fusion. Env is conformationally flexible but controls its transition from the unbound "closed" conformation (State 1) to downstream CD4-bound conformations (States 2/3), which are required for fusion. In particular, HIV-1 has evolved several mechanisms that reduce the premature "opening" of Env which exposes highly conserved epitopes recognized by non-neutralizing antibodies (nnAbs) capable of mediating antibody-dependent cellular cytotoxicity (ADCC). Env cleavage decreases its conformational transitions favoring the adoption of the "closed" conformation. Here we altered the gp160 furin cleavage site to impair Env cleavage and to examine its impact on ADCC responses mediated by plasma from HIV-1-infected individuals. We found that infected primary CD4+ T cells expressing uncleaved, but not wildtype, Env are efficiently recognized by nnAbs and become highly susceptible to ADCC responses mediated by plasma from HIV-1-infected individuals. Thus, HIV-1 limits the exposure of uncleaved Env at the surface of HIV-1-infected cells at least in part to escape ADCC responses.
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Affiliation(s)
- Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Halima Medjahed
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
| | - Dani Vézina
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
| | - Hung-Ching Chen
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (H.-C.C.); (A.B.S.III)
| | - Beatrice H. Hahn
- Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6076, USA;
| | - Amos B. Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (H.-C.C.); (A.B.S.III)
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
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5
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Schön J, Breithaupt A, Höper D, King J, Pohlmann A, Parvin R, Behr KP, Schwarz BA, Beer M, Stech J, Harder T, Grund C. Neuraminidase-associated plasminogen recruitment enables systemic spread of natural avian Influenza viruses H3N1. PLoS Pathog 2021; 17:e1009490. [PMID: 33891662 PMCID: PMC8118554 DOI: 10.1371/journal.ppat.1009490] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 05/13/2021] [Accepted: 03/19/2021] [Indexed: 12/21/2022] Open
Abstract
Repeated outbreaks due to H3N1 low pathogenicity avian influenza viruses (LPAIV) in Belgium were associated with unusually high mortality in chicken in 2019. Those events caused considerable economic losses and prompted restriction measures normally implemented for eradicating high pathogenicity avian influenza viruses (HPAIV). Initial pathology investigations and infection studies suggested this virus to be able to replicate systemically, being very atypical for H3 LPAIV. Here, we investigate the pathogenesis of this H3N1 virus and propose a mechanism explaining its unusual systemic replication capability. By intravenous and intracerebral inoculation in chicken, we demonstrate systemic spread of this virus, extending to the central nervous system. Endoproteolytic viral hemagglutinin (HA) protein activation by either tissue-restricted serine peptidases or ubiquitous subtilisin-like proteases is the functional hallmark distinguishing (H5 or H7) LPAIV from HPAIV. However, luciferase reporter assays show that HA cleavage in case of the H3N1 strain in contrast to the HPAIV is not processed by intracellular proteases. Yet the H3N1 virus replicates efficiently in cell culture without trypsin, unlike LPAIVs. Moreover, this trypsin-independent virus replication is inhibited by 6-aminohexanoic acid, a plasmin inhibitor. Correspondingly, in silico analysis indicates that plasminogen is recruitable by the viral neuraminidase for proteolytic activation due to the loss of a strongly conserved N-glycosylation site at position 130. This mutation was shown responsible for plasminogen recruitment and neurovirulence of the mouse brain-passaged laboratory strain A/WSN/33 (H1N1). In conclusion, our findings provide good evidence in natural chicken strains for N1 neuraminidase-operated recruitment of plasminogen, enabling systemic replication leading to an unusual high pathogenicity phenotype. Such a gain of function in naturally occurring AIVs representing an established human influenza HA-subtype raises concerns over potential zoonotic threats.
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Affiliation(s)
- Jacob Schön
- Institute of Diagnostic Virology, Greifswald–Insel Riems, Germany
| | - Angele Breithaupt
- Department of Experimental Animal Facilities and Biorisk Management, Greifswald–Insel Riems, Germany
| | - Dirk Höper
- Institute of Diagnostic Virology, Greifswald–Insel Riems, Germany
| | - Jacqueline King
- Institute of Diagnostic Virology, Greifswald–Insel Riems, Germany
| | - Anne Pohlmann
- Institute of Diagnostic Virology, Greifswald–Insel Riems, Germany
| | - Rokshana Parvin
- Department of Pathology, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | | | | | - Martin Beer
- Institute of Diagnostic Virology, Greifswald–Insel Riems, Germany
| | - Jürgen Stech
- Institute of Molecular Virology and Cell Biology, Greifswald–Insel Riems, Germany
| | - Timm Harder
- Institute of Diagnostic Virology, Greifswald–Insel Riems, Germany
| | - Christian Grund
- Institute of Diagnostic Virology, Greifswald–Insel Riems, Germany
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Artigas L, Coma M, Matos-Filipe P, Aguirre-Plans J, Farrés J, Valls R, Fernandez-Fuentes N, de la Haba-Rodriguez J, Olvera A, Barbera J, Morales R, Oliva B, Mas JM. In-silico drug repurposing study predicts the combination of pirfenidone and melatonin as a promising candidate therapy to reduce SARS-CoV-2 infection progression and respiratory distress caused by cytokine storm. PLoS One 2020; 15:e0240149. [PMID: 33006999 PMCID: PMC7531795 DOI: 10.1371/journal.pone.0240149] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/22/2020] [Indexed: 02/06/2023] Open
Abstract
From January 2020, COVID-19 is spreading around the world producing serious respiratory symptoms in infected patients that in some cases can be complicated by the severe acute respiratory syndrome, sepsis and septic shock, multiorgan failure, including acute kidney injury and cardiac injury. Cost and time efficient approaches to reduce the burthen of the disease are needed. To find potential COVID-19 treatments among the whole arsenal of existing drugs, we combined system biology and artificial intelligence-based approaches. The drug combination of pirfenidone and melatonin has been identified as a candidate treatment that may contribute to reduce the virus infection. Starting from different drug targets the effect of the drugs converges on human proteins with a known role in SARS-CoV-2 infection cycle. Simultaneously, GUILDify v2.0 web server has been used as an alternative method to corroborate the effect of pirfenidone and melatonin against the infection of SARS-CoV-2. We have also predicted a potential therapeutic effect of the drug combination over the respiratory associated pathology, thus tackling at the same time two important issues in COVID-19. These evidences, together with the fact that from a medical point of view both drugs are considered safe and can be combined with the current standard of care treatments for COVID-19 makes this combination very attractive for treating patients at stage II, non-severe symptomatic patients with the presence of virus and those patients who are at risk of developing severe pulmonary complications.
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Affiliation(s)
| | | | - Pedro Matos-Filipe
- Anaxomics Biotech, Barcelona, Spain
- Structural Bioinformatics Group, Research Programme on Biomedical Informatics, Department of Experimental and Health Science, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain
| | - Joaquim Aguirre-Plans
- Structural Bioinformatics Group, Research Programme on Biomedical Informatics, Department of Experimental and Health Science, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain
| | | | | | - Narcis Fernandez-Fuentes
- Department of Biosciences, U Science Tech, Universitat de Vic—Universitat Central de Catalunya, Vic, Catalonia, Spain
| | - Juan de la Haba-Rodriguez
- Maimonides Biomedical Research Institute, Reina Sofia Hospital, University of Cordoba, Cordoba, Spain
| | - Alex Olvera
- Institut de Recerca de la Sida—IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona (Barcelona), Spain
| | - Jose Barbera
- Servicio de Medicina interna—Unidad de Infecciosas, La Mancha—Centro Hospital, Alcázar de San Juan, Spain
| | - Rafael Morales
- Servicio de Medicina interna—Unidad de Infecciosas, La Mancha—Centro Hospital, Alcázar de San Juan, Spain
| | - Baldo Oliva
- Structural Bioinformatics Group, Research Programme on Biomedical Informatics, Department of Experimental and Health Science, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain
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Venkatesh D, Brouwer A, Goujgoulova G, Ellis R, Seekings J, Brown IH, Lewis NS. Regional Transmission and Reassortment of 2.3.4.4b Highly Pathogenic Avian Influenza (HPAI) Viruses in Bulgarian Poultry 2017/18. Viruses 2020; 12:v12060605. [PMID: 32492965 PMCID: PMC7354578 DOI: 10.3390/v12060605] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 11/20/2022] Open
Abstract
Between 2017 and 2018, several farms across Bulgaria reported outbreaks of H5 highly-pathogenic avian influenza (HPAI) viruses. In this study we used genomic and traditional epidemiological analyses to trace the origin and subsequent spread of these outbreaks within Bulgaria. Both methods indicate two separate incursions, one restricted to the northeastern region of Dobrich, and another largely restricted to Central and Eastern Bulgaria including places such as Plovdiv, Sliven and Stara Zagora, as well as one virus from the Western region of Vidin. Both outbreaks likely originate from different European 2.3.4.4b virus ancestors circulating in 2017. The viruses were likely introduced by wild birds or poultry trade links in 2017 and have continued to circulate, but due to lack of contemporaneous sampling and sequences from wild bird viruses in Bulgaria, the precise route and timing of introduction cannot be determined. Analysis of whole genomes indicates a complete lack of reassortment in all segments but the matrix protein gene (MP), which presents as multiple smaller clusters associated with different European 2.3.4.4b viruses. Ancestral reconstruction of host states of the hemagglutinin (HA) gene of viruses involved in the outbreaks suggests that transmission is driven by domestic ducks into galliform poultry. Thus, according to present evidence, we suggest the surveillance of domestic ducks as they are an epidemiologically relevant species for subclinical infection. Monitoring the spread due to movement between farms within regions and links to poultry production systems in European countries can help to predict and prevent future outbreaks. The 2.3.4.4b lineage which caused the largest recorded poultry epidemic in Europe continues to circulate, and the risk of further transmission by wild birds during migration remains.
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Affiliation(s)
- Divya Venkatesh
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, Hertfordshire AL9 7TA, UK;
- Correspondence:
| | - Adam Brouwer
- OIE/FAO/ International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK; (A.B.); (J.S.); (I.H.B.)
| | - Gabriela Goujgoulova
- National Diagnostic Research Veterinary Medical Institute, 1231 Sofia, Bulgaria;
| | - Richard Ellis
- Surveillance and Laboratory Services Department, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK;
| | - James Seekings
- OIE/FAO/ International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK; (A.B.); (J.S.); (I.H.B.)
- Virology Department, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK
| | - Ian H. Brown
- OIE/FAO/ International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK; (A.B.); (J.S.); (I.H.B.)
| | - Nicola S. Lewis
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, Hertfordshire AL9 7TA, UK;
- OIE/FAO/ International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK; (A.B.); (J.S.); (I.H.B.)
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8
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Limbani B, Bera S, Mondal D. Synthetic Advancement of Neuraminidase Inhibitor “Tamiflu”. ChemistrySelect 2020. [DOI: 10.1002/slct.202000675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Bhagirath Limbani
- School of Chemical Sciences Central University of Gujarat Gandhinagar, Gujarat 382030 India
| | - Smritilekha Bera
- School of Chemical Sciences Central University of Gujarat Gandhinagar, Gujarat 382030 India
| | - Dhananjoy Mondal
- School of Chemical Sciences Central University of Gujarat Gandhinagar, Gujarat 382030 India
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9
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Abstract
In 1918, a strain of influenza A virus caused a human pandemic resulting in the deaths of 50 million people. A century later, with the advent of sequencing technology and corresponding phylogenetic methods, we know much more about the origins, evolution and epidemiology of influenza epidemics. Here we review the history of avian influenza viruses through the lens of their genetic makeup: from their relationship to human pandemic viruses, starting with the 1918 H1N1 strain, through to the highly pathogenic epidemics in birds and zoonoses up to 2018. We describe the genesis of novel influenza A virus strains by reassortment and evolution in wild and domestic bird populations, as well as the role of wild bird migration in their long-range spread. The emergence of highly pathogenic avian influenza viruses, and the zoonotic incursions of avian H5 and H7 viruses into humans over the last couple of decades are also described. The threat of a new avian influenza virus causing a human pandemic is still present today, although control in domestic avian populations can minimize the risk to human health. This article is part of the theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes’. This issue is linked with the subsequent theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control’.
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Affiliation(s)
| | | | - Paul Digard
- The Roslin Institute, University of Edinburgh , Edinburgh , UK
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10
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Benhaim MA, Lee KK. New Biophysical Approaches Reveal the Dynamics and Mechanics of Type I Viral Fusion Machinery and Their Interplay with Membranes. Viruses 2020; 12:E413. [PMID: 32276357 PMCID: PMC7232462 DOI: 10.3390/v12040413] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/04/2020] [Accepted: 04/04/2020] [Indexed: 12/27/2022] Open
Abstract
Protein-mediated membrane fusion is a highly regulated biological process essential for cellular and organismal functions and infection by enveloped viruses. During viral entry the membrane fusion reaction is catalyzed by specialized protein machinery on the viral surface. These viral fusion proteins undergo a series of dramatic structural changes during membrane fusion where they engage, remodel, and ultimately fuse with the host membrane. The structural and dynamic nature of these conformational changes and their impact on the membranes have long-eluded characterization. Recent advances in structural and biophysical methodologies have enabled researchers to directly observe viral fusion proteins as they carry out their functions during membrane fusion. Here we review the structure and function of type I viral fusion proteins and mechanisms of protein-mediated membrane fusion. We highlight how recent technological advances and new biophysical approaches are providing unprecedented new insight into the membrane fusion reaction.
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Affiliation(s)
- Mark A. Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195-7610, USA;
| | - Kelly K. Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195-7610, USA;
- Biological Physics Structure and Design Program, University of Washington, Seattle, WA 98195-7610, USA
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11
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Chen L, Donis RO, Suarez DL, Wentworth DE, Webby R, Engelhardt OG, Swayne DE. Biosafety risk assessment for production of candidate vaccine viruses to protect humans from zoonotic highly pathogenic avian influenza viruses. Influenza Other Respir Viruses 2020; 14:215-225. [PMID: 31659871 PMCID: PMC7040978 DOI: 10.1111/irv.12698] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 10/06/2019] [Accepted: 10/08/2019] [Indexed: 12/01/2022] Open
Abstract
A major lesson learned from the public health response to the 2009 H1N1 pandemic was the need to shorten the vaccine delivery timeline to achieve the best pandemic mitigation results. A gap analysis of previous pre-pandemic vaccine development activities identified possible changes in the Select Agent exclusion process that would maintain safety and shorten the timeline to develop candidate vaccine viruses (CVVs) for use in pandemic vaccine manufacture. Here, we review the biosafety characteristics of CVVs developed in the past 15 years to support a shortened preparedness timeline for A(H5) and A(H7) subtype highly pathogenic avian influenza (HPAI) CVVs. Extensive biosafety experimental evidence supported recent changes in the implementation of Select Agent regulations that eliminated the mandatory chicken pathotype testing requirements and expedited distribution of CVVs to shorten pre-pandemic and pandemic vaccine manufacturing by up to 3 weeks.
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Affiliation(s)
- Li‐Mei Chen
- Virology, Surveillance, and Diagnosis BranchInfluenza DivisionNational Center for Immunization and Respiratory DiseaseCenters for Disease Control and Prevention (CDC)AtlantaGAUSA
- Present address:
IDT‐BiologikaRockvilleMDUSA
| | - Ruben O. Donis
- Virology, Surveillance, and Diagnosis BranchInfluenza DivisionNational Center for Immunization and Respiratory DiseaseCenters for Disease Control and Prevention (CDC)AtlantaGAUSA
- Present address:
Biomedical Advanced Research and Development AuthorityDepartment of Health and Human ServicesWashingtonDCUSA
| | - David L. Suarez
- Exotic and Emerging Avian Viral Diseases Research UnitAgricultural Research ServiceU.S. National Poultry Research CenterU.S. Department of AgricultureAthensGAUSA
| | - David E. Wentworth
- Virology, Surveillance, and Diagnosis BranchInfluenza DivisionNational Center for Immunization and Respiratory DiseaseCenters for Disease Control and Prevention (CDC)AtlantaGAUSA
| | - Richard Webby
- Department of Infectious DiseasesSt Jude Children's Research HospitalMemphisTNUSA
| | - Othmar G. Engelhardt
- Division of VirologyNational Institute for Biological Standards and ControlPotters BarUK
| | - David E. Swayne
- Exotic and Emerging Avian Viral Diseases Research UnitAgricultural Research ServiceU.S. National Poultry Research CenterU.S. Department of AgricultureAthensGAUSA
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12
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Braun E, Sauter D. Furin-mediated protein processing in infectious diseases and cancer. Clin Transl Immunology 2019; 8:e1073. [PMID: 31406574 PMCID: PMC6682551 DOI: 10.1002/cti2.1073] [Citation(s) in RCA: 205] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 07/10/2019] [Accepted: 07/13/2019] [Indexed: 12/17/2022] Open
Abstract
Proteolytic cleavage regulates numerous processes in health and disease. One key player is the ubiquitously expressed serine protease furin, which cleaves a plethora of proteins at polybasic recognition motifs. Mammalian substrates of furin include cytokines, hormones, growth factors and receptors. Thus, it is not surprising that aberrant furin activity is associated with a variety of disorders including cancer. Furthermore, the enzymatic activity of furin is exploited by numerous viral and bacterial pathogens, thereby enhancing their virulence and spread. In this review, we describe the physiological and pathophysiological substrates of furin and discuss how dysregulation of a simple proteolytic cleavage event may promote infectious diseases and cancer. One major focus is the role of furin in viral glycoprotein maturation and pathogenicity. We also outline cellular mechanisms regulating the expression and activation of furin and summarise current approaches that target this protease for therapeutic intervention.
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Affiliation(s)
- Elisabeth Braun
- Institute of Molecular VirologyUlm University Medical CenterUlmGermany
| | - Daniel Sauter
- Institute of Molecular VirologyUlm University Medical CenterUlmGermany
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13
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Laleye A, Joannis T, Shittu I, Meseko C, Zamperin G, Milani A, Zecchin B, Fusaro A, Monne I, Abolnik C. A two-year monitoring period of the genetic properties of clade 2.3.2.1c H5N1 viruses in Nigeria reveals the emergence and co-circulation of distinct genotypes. INFECTION GENETICS AND EVOLUTION 2018; 57:98-105. [DOI: 10.1016/j.meegid.2017.10.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/27/2017] [Accepted: 10/31/2017] [Indexed: 12/11/2022]
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Sid H, Hartmann S, Winter C, Rautenschlein S. Interaction of Influenza A Viruses with Oviduct Explants of Different Avian Species. Front Microbiol 2017; 8:1338. [PMID: 28775714 PMCID: PMC5518544 DOI: 10.3389/fmicb.2017.01338] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/03/2017] [Indexed: 12/12/2022] Open
Abstract
Infection of poultry with low pathogenic avian influenza viruses (LPAIV) is often associated with mild respiratory symptoms but may also lead to loss in egg production in laying birds. In vivo susceptibility of the reproductive tract for LPAIV infection was reported for turkeys and chickens, but virus-interaction with epithelial cells of the oviduct and possible stimulation of the local antiviral immune responses have not been characterized. In this study, we wanted to investigate the suitability of magnum organ cultures (MOC) as an in vitro model to study virus-host interactions. We compared the susceptibility of duck (Du), chicken (Ch), and turkey (Tu) MOC for three different influenza A viruses (IAV). Overall, the course of infection and the antiviral immune response varied between strains as well as host cell origin, but MOC gave reproducible results for all investigated parameters within each species. While pandemic (p) H1N1 and H9N2 efficiently replicated in MOC-Ch and MOC-Tu, MOC-Du were significantly less susceptible to infection as indicated by a reduced replication level for both viruses (p < 0.05). Overall, virus replication levels did not correlate with interferonα (IFNα) mRNA-expression levels in neither species. H9N2-infection led to a significant upregulation of interferonλ (IFNλ) mRNA expression in MOC of all species compared to the non-infected controls (p < 0.05), while a correlation with replication levels was only seen for MOC-Tu. pH1N1-infection induced only significant upregulation of IFNλ mRNA expression in MOC-Tu at 48 hours post infection (p < 0.05), but the expression pattern did not correlate with replication levels. Our results show that MOC are a suitable model to study IAV-interaction with the mucosal surface of the avian reproductive tract. The data suggest that the reproductive tract may play a role in the pathobiology of IAV in poultry.
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Affiliation(s)
- Hicham Sid
- Clinic for Poultry, University of Veterinary Medicine HannoverHannover, Germany
| | - Sandra Hartmann
- Clinic for Poultry, University of Veterinary Medicine HannoverHannover, Germany
| | - Christine Winter
- Institute of Virology, University of Veterinary Medicine HannoverHannover, Germany
| | - Silke Rautenschlein
- Clinic for Poultry, University of Veterinary Medicine HannoverHannover, Germany
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15
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Yun B, Zhang Y, Liu Y, Guan X, Wang Y, Qi X, Cui H, Liu C, Zhang Y, Gao H, Gao L, Li K, Gao Y, Wang X. TMPRSS12 Is an Activating Protease for Subtype B Avian Metapneumovirus. J Virol 2016; 90:11231-11246. [PMID: 27707927 PMCID: PMC5126379 DOI: 10.1128/jvi.01567-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/29/2016] [Indexed: 12/28/2022] Open
Abstract
The entry of avian metapneumovirus (aMPV) into host cells initially requires the fusion of viral and cell membranes, which is exclusively mediated by fusion (F) protein. Proteolysis of aMPV F protein by endogenous proteases of host cells allows F protein to induce membrane fusion; however, these proteases have not been identified. Here, we provide the first evidence that the transmembrane serine protease TMPRSS12 facilitates the cleavage of subtype B aMPV (aMPV/B) F protein. We found that overexpression of TMPRSS12 enhanced aMPV/B F protein cleavage, F protein fusogenicity, and viral replication. Subsequently, knockdown of TMPRSS12 with specific small interfering RNAs (siRNAs) reduced aMPV/B F protein cleavage, F protein fusogenicity, and viral replication. We also found a cleavage motif in the aMPV/B F protein (amino acids 100 and 101) that was recognized by TMPRSS12. The histidine, aspartic acid, and serine residue (HDS) triad of TMPRSS12 was shown to be essential for the proteolysis of aMPV/B F protein via mutation analysis. Notably, we observed TMPRSS12 mRNA expression in target organs of aMPV/B in chickens. Overall, our results indicate that TMPRSS12 is crucial for aMPV/B F protein proteolysis and aMPV/B infectivity and that TMPRSS12 may serve as a target for novel therapeutics and prophylactics for aMPV. IMPORTANCE Proteolysis of the aMPV F protein is a prerequisite for F protein-mediated membrane fusion of virus and cell and for aMPV infection; however, the proteases used in vitro and vivo are not clear. A combination of analyses, including overexpression, knockdown, and mutation methods, demonstrated that the transmembrane serine protease TMPRSS12 facilitated cleavage of subtype B aMPV (aMPV/B) F protein. Importantly, we located the motif in the aMPV/B F protein recognized by TMPRSS12 and the catalytic triad in TMPRSS12 that facilitated proteolysis of the aMPV/B F protein. This is the first report on TMPRSS12 as a protease for proteolysis of viral envelope glycoproteins. Our study will shed light on the mechanism of proteolysis of aMPV F protein and pathogenesis of aMPV.
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Affiliation(s)
- Bingling Yun
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Yao Zhang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Yongzhen Liu
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Xiaolu Guan
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Yongqiang Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Xiaole Qi
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Hongyu Cui
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Changjun Liu
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Yanping Zhang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Honglei Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Li Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Kai Li
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Yulong Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
| | - Xiaomei Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Nan Gang District, Harbin, Heilongjiang Province, People's Republic of China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, People's Republic of China
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16
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Abd El-All AS, Atta SMS, Roaiah HMF, Awad EM, Abdalla MM. New Potent SARS-CoV 3C-Like Protease Inhibitors Derived from Thieno[2,3-d]-pyrimidine Derivatives. Arch Pharm (Weinheim) 2016; 349:202-10. [DOI: 10.1002/ardp.201500407] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 12/22/2015] [Accepted: 01/08/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Amira S. Abd El-All
- Department of Natural and Microbial Products, Research Division of Pharmaceutical and Drug Industries; National Research Centre, Dokki; Giza Egypt
| | - Sanaa M. Sh. Atta
- Department of Natural and Microbial Products, Research Division of Pharmaceutical and Drug Industries; National Research Centre, Dokki; Giza Egypt
| | - Hanaa M. F. Roaiah
- Department of Natural and Microbial Products, Research Division of Pharmaceutical and Drug Industries; National Research Centre, Dokki; Giza Egypt
| | - Enas M. Awad
- Department of Natural and Microbial Products, Research Division of Pharmaceutical and Drug Industries; National Research Centre, Dokki; Giza Egypt
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17
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Maruyama J, Nao N, Miyamoto H, Maeda K, Ogawa H, Yoshida R, Igarashi M, Takada A. Characterization of the glycoproteins of bat-derived influenza viruses. Virology 2016; 488:43-50. [PMID: 26605499 PMCID: PMC7126434 DOI: 10.1016/j.virol.2015.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/30/2015] [Accepted: 11/03/2015] [Indexed: 12/04/2022]
Abstract
Recently found bat-derived influenza viruses (BatIVs) have hemagglutinin (HA) and neuraminidase (NA) gene segments distinct from those of previously known influenza A viruses. However, pathogenicities of these BatIVs remain unknown since infectious virus strains have not been isolated yet. To gain insight into the biological properties of BatIVs, we generated vesicular stomatitis viruses (VSVs) pseudotyped with the BatIV HA and NA. We found that VSVs pseudotyped with BatIV HAs and NAs efficiently infected particular bat cell lines but not those derived from primates, and that proteolytic cleavage with a trypsin-like protease was necessary for HA-mediated virus entry. Treatment of the susceptible bat cells with some enzymes and inhibitors revealed that BatIV HAs might recognize some cellular glycoproteins as receptors rather than the sialic acids used for the other known influenza viruses. These data provide fundamental information on the mechanisms underlying the cellular entry and host restriction of BatIVs.
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Affiliation(s)
- Junki Maruyama
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Naganori Nao
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Hiroko Miyamoto
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Ken Maeda
- Laboratory of Veterinary Microbiology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Hirohito Ogawa
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
| | - Reiko Yoshida
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Manabu Igarashi
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan; Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
| | - Ayato Takada
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan; Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan; School of Veterinary Medicine, the University of Zambia, Lusaka, Zambia.
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18
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Li C, Fang JS, Lian WW, Pang XC, Liu AL, Du GH. In vitro antiviral effects and 3D QSAR study of resveratrol derivatives as potent inhibitors of influenza H1N1 neuraminidase. Chem Biol Drug Des 2014; 85:427-38. [PMID: 25185493 DOI: 10.1111/cbdd.12425] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 07/01/2014] [Accepted: 08/13/2014] [Indexed: 11/28/2022]
Abstract
The anti-influenza virus activities of 50 resveratrol (RV: 3, 5, 4'-trihydroxy-trans-stilbene) derivatives were evaluated using a neuraminidase (NA) activity assay. The results showed that 35 compounds exerted an inhibitory effect on the NA activity of the influenza virus strain A/PR/8/34 (H1N1) with 50% inhibitory concentration (IC50) values ranging from 3.56 to 186.1 μm. Next, the 35 RV derivatives were used to develop 3D quantitative structure-activity relationship (3D QSAR) models for understanding the chemical-biological interactions governing their activities against NA. The comparative molecular field analysis (CoMFA r2=0.973, q2=0.620, qtest2=0.661) and the comparative molecular similarity indices analysis (CoMSIA r2=0.956, q2=0.610, qtest2=0.531) were applied. Afterward, molecular docking was performed to study the molecular interactions between the RV derivatives and NA. Finally, a cytopathic effect (CPE) reduction assay was used to evaluate the antiviral effects of the RV derivatives in vitro. Time-of-addition studies demonstrated that the RV derivatives might have a direct effect on viral particle infectivity. Our results indicate that the RV derivatives are potentially useful antiviral compounds for new drug design and development for influenza treatment.
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Affiliation(s)
- Chao Li
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
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19
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Yamada H, Nagao C, Haredy AM, Mori Y, Mizuguchi K, Yamanishi K, Okamoto S. Dextran sulfate-resistant A/Puerto Rico/8/34 influenza virus is associated with the emergence of specific mutations in the neuraminidase glycoprotein. Antiviral Res 2014; 111:69-77. [PMID: 25234090 DOI: 10.1016/j.antiviral.2014.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 09/02/2014] [Accepted: 09/07/2014] [Indexed: 11/28/2022]
Abstract
Dextran sulfate (DS) is a negatively charged sulfated polysaccharide that suppresses the replication of influenza A viruses. The suppression was thought to be associated with inhibition of the hemagglutinin-dependent fusion activity. However, we previously showed that suppression by DS was observed not only at the initial stage of viral infection, but also later when virus is released from infected cells due to inhibition of neuraminidase (NA) activity. In the present study, we isolated DS-resistant A/Puerto Rico/8/34 (PR8) influenza viruses and analyzed the inhibition by DS. We found six mutations in NA genes of five independent resistant PR8 viruses and each resistant NA gene had two mutations. All mutations were from basic to acidic or neutral amino acids. In addition, R430L, K432E or K435E in the 430-435 region was a common mutation in all resistant NA genes. To determine which amino acid(s) are responsible for this resistance, a panel of recombinant viruses containing a PR8 and A/WSN/33(WSN) chimeric NA gene or an NA gene with different mutation(s) was generated using reverse genetics. Using recombinant viruses containing a PR8/WSN chimeric NA, we showed that one third of the C-terminal region of PR8 NA was responsible for DS-sensitivity. Recombinant viruses with a single mutation in NA replicated better than wild-type PR8 in the presence of DS, but were still DS-sensitive. However, replication of recombinant viruses with double mutations from the resistant viruses was not affected by the presence or absence of DS. In addition, resistant recombinant viruses were found to be sensitive to the NA inhibitor, oseltamivir and the oseltamivir-resistant recombinant virus was sensitive to DS. These results suggested that DS is an NA inhibitor with a different mechanism of action from the currently used NA inhibitors and that DS could be used in combination with these inhibitors to treat influenza virus infections.
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Affiliation(s)
- Hiroshi Yamada
- Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan.
| | - Chioko Nagao
- National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Ahmad M Haredy
- Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Yasuko Mori
- Division of Clinical Virology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kenji Mizuguchi
- National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Koichi Yamanishi
- Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Shigefumi Okamoto
- Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
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20
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Cheng LP, Huang XY, Wang Z, Kai ZP, Wu FH. Combined 3D-QSAR, molecular docking, and molecular dynamics study on potent cyclohexene-based influenza neuraminidase inhibitors. MONATSHEFTE FUR CHEMIE 2014. [DOI: 10.1007/s00706-014-1176-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Zhou J, Xu S, Ma J, Lei W, Liu K, Liu Q, Ren Y, Xue C, Cao Y. Recombinant influenza A H3N2 viruses with mutations of HA transmembrane cysteines exhibited altered virological characteristics. Virus Genes 2013; 48:273-82. [PMID: 24272698 DOI: 10.1007/s11262-013-1011-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 11/06/2013] [Indexed: 01/20/2023]
Abstract
Influenza A H3N2 virus as the cause of 1968 pandemic has since been circulating in human and swine. Our earlier study has shown that mutations of one or two cysteines in the transmembrane domain of H3 hemagglutinin (HA) affected the thermal stability and fusion activity of recombinant HA proteins. Here, we report the successful generation of three recombinant H3N2 mutant viruses (C540S, C544L, and 2C/SL) with mutations of one or two transmembrane cysteines of HA in the background of A/swine/Guangdong/01/98 [H3N2] using reverse genetics, indicating that the mutated cysteines were not essential for virus assembly and growth. Further characterization revealed that recombinant H3N2 mutant viruses exhibited larger plaque sizes, increased growth rate in cells, enhanced fusion activity, reduced thermal and acidic resistances, and increased virulence in embryonated eggs. These results demonstrated that the transmembrane cysteines (C540 and C544) in H3 HA have profound effects on the virological features of H3N2 viruses.
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Affiliation(s)
- Jianqiang Zhou
- State Key Laboratory of Biocontrol, Life Sciences School, Guangzhou Higher Education Mega Center, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China
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22
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Abdelwhab ESM, Veits J, Mettenleiter TC. Genetic changes that accompanied shifts of low pathogenic avian influenza viruses toward higher pathogenicity in poultry. Virulence 2013; 4:441-52. [PMID: 23863606 PMCID: PMC5359749 DOI: 10.4161/viru.25710] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/09/2013] [Accepted: 07/10/2013] [Indexed: 11/19/2022] Open
Abstract
Avian influenza viruses (AIV) of H5 and H7 subtypes exhibit two different pathotypes in poultry: infection with low pathogenic (LP) strains results in minimal, if any, health disturbances, whereas highly pathogenic (HP) strains cause severe morbidity and mortality. LPAIV of H5 and H7 subtypes can spontaneously mutate into HPAIV. Ten outbreaks caused by HPAIV are known to have been preceded by circulation of a predecessor LPAIV in poultry. Three of them were caused by H5N2 subtype and seven involved H7 subtype in combination with N1, N3, or N7. Here, we review those outbreaks and summarize the genetic changes which resulted in the transformation of LPAIV to HPAIV under natural conditions. Mutations that were found directly in those outbreaks are more likely to be linked to virulence, pathogenesis, and early adaptation of AIV.
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Affiliation(s)
- El-Sayed M Abdelwhab
- Friedrich-Loeffler-Institut; Federal Research Institute for Animal Health; Institute of Molecular Biology; Greifswald-Insel Riems, Germany
| | - Jutta Veits
- Friedrich-Loeffler-Institut; Federal Research Institute for Animal Health; Institute of Molecular Biology; Greifswald-Insel Riems, Germany
| | - Thomas C Mettenleiter
- Friedrich-Loeffler-Institut; Federal Research Institute for Animal Health; Institute of Molecular Biology; Greifswald-Insel Riems, Germany
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23
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Böttcher-Friebertshäuser E, Klenk HD, Garten W. Activation of influenza viruses by proteases from host cells and bacteria in the human airway epithelium. Pathog Dis 2013; 69:87-100. [PMID: 23821437 PMCID: PMC7108517 DOI: 10.1111/2049-632x.12053] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 06/03/2013] [Indexed: 11/28/2022] Open
Abstract
Influenza is an acute infection of the respiratory tract, which affects each year millions of people. Influenza virus infection is initiated by the surface glycoprotein hemagglutinin (HA) through receptor binding and fusion of viral and endosomal membranes. HA is synthesized as a precursor protein and requires cleavage by host cell proteases to gain its fusion capacity. Although cleavage of HA is crucial for virus infectivity, little was known about relevant proteases in the human airways for a long time. Recent progress in the identification and characterization of HA‐activating host cell proteases has been considerable however and supports the idea of targeting HA cleavage as a novel approach for influenza treatment. Interestingly, certain bacteria have been demonstrated to support HA activation either by secreting proteases that cleave HA or due to activation of cellular proteases and thereby may contribute to virus spread and enhanced pathogenicity. In this review, we give an overview on activation of influenza viruses by proteases from host cells and bacteria with the main focus on recent progress on HA cleavage by proteases HAT and TMPRSS2 in the human airway epithelium. In addition, we outline investigations of HA‐activating proteases as potential drug targets for influenza treatment. The authors, who are leading experts in this field, present a timely, authoritative review on the proteolytic cleavage of the influenza hemagglutinin (HA), an activation mechanism that is essential for the infectivity of influenza viruses, including the recently emerged H7N9. They also address the potential of host proteases as targets for developing new influenza drugs. This review will be of considerable interest to virologists, microbiologists and pharmaceutical companies alike.
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24
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Maruyama J, Okamatsu M, Soda K, Sakoda Y, Kida H. Factors responsible for pathogenicity in chickens of a low-pathogenic H7N7 avian influenza virus isolated from a feral duck. Arch Virol 2013; 158:2473-8. [PMID: 23779115 DOI: 10.1007/s00705-013-1762-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/04/2013] [Indexed: 11/24/2022]
Abstract
Highly pathogenic avian influenza viruses have poly-basic amino acid sequences at the cleavage site in their hemagglutinin (HA). Although this poly-basic region is a prerequisite factor for pathogenicity in chickens, not much is known about additional factors responsible for the acquisition of pathogenicity of the duck influenza virus in chickens. Here, we introduced multiple basic amino acid residues into the HA cleavage site of the A/duck/Hokkaido/Vac-2/2004 (H7N7) strain of avian influenza virus, which has low pathogenicity in chickens; the resultant Vac2sub-P0 strain was not intravenously pathogenic in chickens. In contrast, the Vac2sub-P3 strain, which was recovered from three consecutive passages of Vac2sub-P0 in chicks, was intravenously pathogenic in chickens. Six amino acid substitutions were identified by comparison of the Vac2sub-P3 and Vac2sub-P0 genomic sequences: Lys123Glu in PB2, Asn16Asp in PB1, Glu227Gly and Ile388Thr in HA, Gly228Arg in M1, and Leu46Pro in M2. The results of intravenous inoculations of chickens with recombinant virus indicated that all six amino acid substitutions were required to varying degrees for Vac2sub-P3 pathogenicity, with Glu227Gly and Ile388Thr in HA being particularly essential. These results reveal the roles of additional viral factors in the acquisition of pathogenicity in addition to the previously characterized role of the poly-basic amino acid sequences at the HA cleavage site.
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Affiliation(s)
- Junki Maruyama
- Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan
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25
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Doyle TM, Jaentschke B, Van Domselaar G, Hashem AM, Farnsworth A, Forbes NE, Li C, Wang J, He R, Brown EG, Li X. The universal epitope of influenza A viral neuraminidase fundamentally contributes to enzyme activity and viral replication. J Biol Chem 2013; 288:18283-9. [PMID: 23645684 DOI: 10.1074/jbc.m113.468884] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The only universally conserved sequence among all influenza A viral neuraminidases is located between amino acids 222 and 230. However, the potential roles of these amino acids remain largely unknown. Through an array of experimental approaches including mutagenesis, reverse genetics, and growth kinetics, we found that this sequence could markedly affect viral replication. Additional experiments revealed that enzymes with mutations in this region demonstrated substantially decreased catalytic activity, substrate binding, and thermostability. Consistent with viral replication analyses and enzymatic studies, protein modeling suggests that these amino acids could either directly bind to the substrate or contribute to the formation of the active site in the enzyme. Collectively, these findings reveal the essential role of this unique region in enzyme function and viral growth, which provides the basis for evaluating the validity of this sequence as a potential target for antiviral intervention and vaccine development.
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Affiliation(s)
- Tracey M Doyle
- Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario K1A 0K9, Canada
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26
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Gupta D, Varghese Gupta S, Dahan A, Tsume Y, Hilfinger J, Lee KD, Amidon GL. Increasing oral absorption of polar neuraminidase inhibitors: a prodrug transporter approach applied to oseltamivir analogue. Mol Pharm 2013; 10:512-22. [PMID: 23244438 DOI: 10.1021/mp300564v] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Poor oral absorption is one of the limiting factors in utilizing the full potential of polar antiviral agents. The neuraminidase target site requires a polar chemical structure for high affinity binding, thus limiting oral efficacy of many high affinity ligands. The aim of this study was to overcome this poor oral absorption barrier, utilizing prodrug to target the apical brush border peptide transporter 1 (PEPT1). Guanidine oseltamivir carboxylate (GOCarb) is a highly active polar antiviral agent with insufficient oral bioavailability (4%) to be an effective therapeutic agent. In this report we utilize a carrier-mediated targeted prodrug approach to improve the oral absorption of GOCarb. Acyloxy(alkyl) ester based amino acid linked prodrugs were synthesized and evaluated as potential substrates of mucosal transporters, e.g., PEPT1. Prodrugs were also evaluated for their chemical and enzymatic stability. PEPT1 transport studies included [(3)H]Gly-Sar uptake inhibition in Caco-2 cells and cellular uptake experiments using HeLa cells overexpressing PEPT1. The intestinal membrane permeabilities of the selected prodrugs and the parent drug were then evaluated for epithelial cell transport across Caco-2 monolayers, and in the in situ rat intestinal jejunal perfusion model. Prodrugs exhibited a pH dependent stability with higher stability at acidic pHs. Significant inhibition of uptake (IC(50) <1 mM) was observed for l-valyl and l-isoleucyl amino acid prodrugs in competition experiments with [(3)H]Gly-Sar, indicating a 3-6 times higher affinity for PEPT1 compared to valacyclovir, a well-known PEPT1 substrate and >30-fold increase in affinity compared to GOCarb. The l-valyl prodrug exhibited significant enhancement of uptake in PEPT1/HeLa cells and compared favorably with the well-absorbed valacyclovir. Transepithelial permeability across Caco-2 monolayers showed that these amino acid prodrugs have a 2-5-fold increase in permeability as compared to the parent drug and showed that the l-valyl prodrug (P(app) = 1.7 × 10(-6) cm/s) has the potential to be rapidly transported across the epithelial cell apical membrane. Significantly, only the parent drug (GOCarb) appeared in the basolateral compartment, indicating complete activation (hydrolysis) during transport. Intestinal rat jejunal permeability studies showed that l-valyl and l-isoleucyl prodrugs are highly permeable compared to the orally well absorbed metoprolol, while the parent drug had essentially zero permeability in the jejunum, consistent with its known poor low absorption. Prodrugs were rapidly converted to parent in cell homogenates, suggesting their ability to be activated endogenously in the epithelial cell, consistent with the transport studies. Additionally, l-valyl prodrug was found to be a substrate for valacyclovirase (K(m) = 2.37 mM), suggesting a potential cell activation mechanism. Finally we determined the oral bioavailability of our most promising candidate, GOC-l-Val, in mice to be 23% under fed conditions and 48% under fasted conditions. In conclusion, GOC-l-Val prodrug was found to be a very promising antiviral agent for oral delivery. These findings indicate that the carrier-mediated prodrug approach is an excellent strategy for improving oral absorption of polar neuraminidase inhibitors. These promising results demonstrate that the oral peptide transporter-mediated prodrug strategy has enormous promise for improving the oral mucosal cell membrane permeability of polar, poorly absorbed antiviral agents and treating influenza via the oral route of administration.
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Affiliation(s)
- Deepak Gupta
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
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Luciani F, Sanders MT, Oveissi S, Pang KC, Chen W. Increasing viral dose causes a reversal in CD8+ T cell immunodominance during primary influenza infection due to differences in antigen presentation, T cell avidity, and precursor numbers. THE JOURNAL OF IMMUNOLOGY 2012; 190:36-47. [PMID: 23233728 DOI: 10.4049/jimmunol.1200089] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
T cell responses are characterized by the phenomenon of immunodominance (ID), whereby peptide-specific T cells are elicited in a reproducible hierarchy of dominant and subdominant responses. However, the mechanisms that give rise to ID are not well understood. We investigated the effect of viral dose on primary CD8(+) T cell (T(CD8+)) ID by injecting mice i.p. with various doses of influenza A virus and assessing the primary T(CD8+) response to five dominant and subdominant peptides. Increasing viral dose enhanced the overall strength of the T(CD8+) response, and it altered the ID hierarchy: specifically, NP(366-374) T(CD8+) were dominant at low viral doses but were supplanted by PA(224-233) T(CD8+) at high doses. To understand the basis for this reversal, we mathematically modeled these T(CD8+) responses and used Bayesian statistics to obtain estimates for Ag presentation, T(CD8+) precursor numbers, and avidity. Interestingly, at low viral doses, Ag presentation most critically shaped ID hierarchy, enabling T(CD8+) specific to the more abundantly presented NP(366-374) to dominate. By comparison, at high viral doses, T(CD8+) avidity and precursor numbers appeared to be the major influences on ID hierarchy, resulting in PA(224-233) T(CD8+) usurping NP(366-374) cells as the result of higher avidity and precursor numbers. These results demonstrate that the nature of primary T(CD8+) responses to influenza A virus is highly influenced by Ag dose, which, in turn, determines the relative importance of Ag presentation, T(CD8+) avidity, and precursor numbers in shaping the ID hierarchy. These findings provide valuable insights for future T(CD8+)-based vaccination strategies.
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Affiliation(s)
- Fabio Luciani
- Infection and Inflammation Research Centre, School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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Affiliation(s)
- H D Klenk
- Institut für Virologie, Philipps-Universität Marburg, Postfach 2360, 35011, Marburg (Lahn), Germany
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Yamada H, Moriishi E, Haredy AM, Takenaka N, Mori Y, Yamanishi K, Okamoto S. Influenza virus neuraminidase contributes to the dextran sulfate-dependent suppressive replication of some influenza A virus strains. Antiviral Res 2012; 96:344-52. [PMID: 23022352 DOI: 10.1016/j.antiviral.2012.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 08/17/2012] [Accepted: 09/15/2012] [Indexed: 11/29/2022]
Abstract
Dextran sulfate (DS), a negatively charged, sulfated polysaccharide, suppresses the replication of an influenza A virus strain, and this suppression is associated with inhibition of the hemagglutinin (HA)-dependent fusion activity. However, it remains unknown whether the replication of all or just some influenza A virus strains is suppressed by DS, or whether HA is the only target for the replication suppression. In the present study, we found that DS inhibited the replication of some, but not all influenza A virus strains. The suppression in the DS-sensitive strains was dose-dependent and neutralized by diethylaminoethyl-dextran (DD), which has a positive charge. The suppression by DS was observed not only at the initial stage of viral infection, which includes viral attachment and entry, but also at the late stage, which includes virus assembly and release from infected cells. Electron microscopy revealed that the DS induced viral aggregation at the cell surface. The neuraminidase (NA) activity of the strains whose viral replication was inhibited at the late stage was also more suppressed by DS than that of the strains whose replication was not inhibited, and this inhibition of NA activity was also neutralized by adding positively charged DD. Furthermore, we found that replacing the NA gene of a strain in which viral replication was inhibited by DS at the late stage with the NA gene from a strain in which viral replication was not inhibited, eliminated the DS-dependent suppression. These results suggest that the influenza virus NA contributes to the DS-suppressible virus release from infected cells at the late stage, and the suppression may involve the inhibition of NA activity by DS's negative charge.
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Affiliation(s)
- Hiroshi Yamada
- Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
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Madani TA, Abuelzein ETME, Abu-Araki H, Azhar EI, Al-Bar HMS. Trypsin-dependent hemagglutination of erythrocytes of a variety of mammalian and avian species by Alkhumra hemorrhagic fever virus. Arch Virol 2012; 158:97-101. [PMID: 22983112 DOI: 10.1007/s00705-012-1469-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 07/30/2012] [Indexed: 11/30/2022]
Abstract
Alkhumra hemorrhagic fever virus (AHFV) is an emerging flavivirus that was discovered in 1994-1995 in Saudi Arabia. Clinical manifestations of AHFV infection include hemorrhagic fever, hepatitis, and encephalitis, with a reported mortality rate as high as 25 %. Biological characteristics of this virus have not been well defined. Agglutination of erythrocytes (hemagglutination) is a laboratory tool for studying the attachment of viruses to cellular receptors. The envelope protein contains sites for attachment to host receptors to initiate the process of infection and is thus an essential component of the virion. In the present study, we examined the ability of AHFV to agglutinate erythrocytes of 13 mammalian and avian species (human group O+, camel, cow, sheep, goat, rabbit, guinea pig, mouse, rat, chicken, duck, goose and turkey) with and without trypsin-treatment. Without trypsin treatment, AHFV failed to agglutinate erythrocytes of all examined species. Following trypsin treatment, AHFV agglutinated erythrocytes of five species, namely, goose, human group O+, rat, guinea pig, and mouse, in descending order of sensitivity. This trypsin-dependent hemagglutination test has potential for use in serological and functional studies of AHFV.
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Affiliation(s)
- Tariq A Madani
- Department of Medicine, Faculty of Medicine, King Abdulaziz University, PO Box 80215, Jeddah 21589, Saudi Arabia.
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Du J, Cross TA, Zhou HX. Recent progress in structure-based anti-influenza drug design. Drug Discov Today 2012; 17:1111-20. [PMID: 22704956 DOI: 10.1016/j.drudis.2012.06.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 05/21/2012] [Accepted: 06/06/2012] [Indexed: 01/22/2023]
Abstract
Seasonal and pandemic influenza have caused high morbidity and mortality worldwide. Recent emergence of influenza A H5N1 and H1N1 strains has heightened concern, especially as a result of their drug resistance. The life cycle of influenza viruses has been well studied and nearly all the viral proteins are becoming potential therapeutic targets. In this review, we present an overview of recent progress in structure-based anti-influenza drug design, paying close attention to the increasing role of computation and strategies for overcoming drug resistance.
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Affiliation(s)
- Juan Du
- Department of Physics, Florida State University, Tallahassee, FL 32306, USA
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Yeom JH, Lee IK, Ki DW, Lee MS, Seok SJ, Yun BS. Neuraminidase Inhibitors from the Culture Broth of Phellinus linteus. MYCOBIOLOGY 2012; 40:142-144. [PMID: 22870059 PMCID: PMC3408306 DOI: 10.5941/myco.2012.40.2.142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 06/01/2012] [Accepted: 06/04/2012] [Indexed: 06/01/2023]
Abstract
During the search for neuraminidase inhibitors from medicinal fungi, we found that the culture broth of Phellinus linteus exhibited potent inhibitory activity. Solvent partition, Sephadex LH-20 column chromatography, and high-performance liquid chromatography (HPLC) were performed for purification of two active substances from the culture broth. According to (1)H NMR measurements and comparison of HPLC retention times with those of authentic compounds, their chemical structures were identified as hispidin and hypholomine B. Compounds (hispidin) 1 and 2 (hypholomine B) inhibited neuraminidase, with IC(50) values of 13.1 and 0.03 µM, respectively.
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Affiliation(s)
- Ji-Hee Yeom
- Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan 570-752, Korea
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Pan HY, Yano M, Kido H. Effects of inhibitors of Toll-like receptors, protease-activated receptor-2 signalings and trypsin on influenza A virus replication and upregulation of cellular factors in cardiomyocytes. THE JOURNAL OF MEDICAL INVESTIGATION 2011; 58:19-28. [PMID: 21372483 DOI: 10.2152/jmi.58.19] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Severe influenza sometimes causes myocarditis. We recently found that influenza A virus (IAV) infection induces various cellular factors, such as proinflammatory cytokines IL-6, IL-1β and TNF-α, matrix metalloproteinases (MMPs) and ectopic trypsin in mice hearts and in H9c2 cardiomyocytes. The induction of these cellular factors in turn promotes viral replication, myocardial inflammation and cellular damage through their intracellular signal transductions in cooperation with the IAV-induced Toll-like receptors (TLRs) and proteinase-activated receptor-2 (PAR-2) signalings, although the precise nature of these interactions remain obscure. By using specific inhibitors of TLRs and PAR-2 signalings and trypsin inhibitor aprotinin, we analyzed the role of TLR signaling and PAR-2 signaling in the IAV-induced pathological changes in cardiomyocytes. Inhibitors of TLR7/8-Myeloid Differentiation factor 88-nuclear factor-κB signaling and aprotinin effectively suppressed IAV-induced upregulation of proinflammatory cytokines, MMPs, trypsinogen and viral replication. Inhibitor of TLR3-Toll/interleukin-1 receptor domain-containing adaptor inducing interferons-dependent signaling predominantly suppressed the upregulation of interferon-β, a key intracellular host immune response factor. In contrast to the suppressive effect of trypsin inhibitor aprotinin on IAV replication, PAR-2 inhibitor FSY-NH(2), induced marginal upregulation of trypsinogen and subsequent stimulation of IAV replication.
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Affiliation(s)
- Hai-Yan Pan
- Division of Enzyme Chemistry, Institute for Enzyme Research, University of Tokushima, Tokushima, Japan
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Liu SL, Zhang Z, Wang C, Dong Y, Pan H, Sun Z, Yang XH, Wang J, Ruan B, Xie L, Deng J, He HX. Evolutionary characterization of human H1N1 influenza virus hemagglutinin genes isolated from 1947 to 2009 in China. Intervirology 2011; 54:233-45. [PMID: 21293099 DOI: 10.1159/000322383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 10/25/2010] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Our aim was to reveal the molecular characteristics of human H1N1 influenza virus hemagglutinin (HA) genes from 1947 to 2009 in China. METHODS 129 HA gene sequences were downloaded from NCBI's GenBank and analyzed by DNASTAR software. Additionally, the three-dimensional structure of HA protein was predicted by the SWISS-MODEL service. RESULTS First, 2009 Chinese HA genes were 99% identical to those of Mexican and American ones; their key sites remained highly conserved. Second, 50 Chinese strains from 1947 to 2009 clustered by the year of isolation, and 2009 strains had only 70% identity to 1947-2008 ones. Third, over the past 60 years, 3 receptor-binding (RB) sites and 2 of the 8 glycosylation sites (amino acids 279 and 290) underwent considerable changes while the cleavage sites remained stable. Fourth, the human HA sequences differed completely from swine and avian isolates. Finally, the mutation of cleavage sites can change the three-dimensional structures, but single mutations cannot. CONCLUSIONS Thus, in the past 60 years, Chinese H1N1 influenza HA genes kept stable with high affinity and low pathogenicity to human except changes in 2 glycosylation and 3 RB sites which were associated with the pandemic strength, range and host specificity of viruses.
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Affiliation(s)
- She-Lan Liu
- Department of Infectious Diseases, Hangzhou Center for Disease Control and Prevention, Hangzhou, China
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Abstract
Although seasonal influenza vaccines play a valuable role in reducing the spread of virus at the population level, ongoing viral evolution to evade immune responses remains problematic. No current vaccines elicit enduring protection in the face of emerging and re-emerging influenza viruses that are rapidly undergoing antigenic drift. Eliciting broadly cross-neutralizing antibody (nAb) responses against influenza virus is a crucial goal for seasonal and pandemic influenza vaccine preparation. Recent three-dimensional structure information obtained from crystallization of influenza antigens in complex with nAbs has provided a framework for interpreting antibody-based viral neutralization that should aid in the design of vaccine immunogens. Here, we will review current knowledge of the structure-based mechanisms contributing to the neutralization and neutralization escape of influenza viruses. We will also explore the potential for this structure-based approach to overcome the obstacles in developing the highly desired "universal" influenza vaccine.
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Affiliation(s)
- Thomas Han
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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Butt AM, Siddique S, Idrees M, Tong Y. Avian influenza A (H9N2): computational molecular analysis and phylogenetic characterization of viral surface proteins isolated between 1997 and 2009 from the human population. Virol J 2010; 7:319. [PMID: 21078137 PMCID: PMC2994543 DOI: 10.1186/1743-422x-7-319] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 11/15/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND H9N2 avian influenza A viruses have become panzootic in Eurasia over the last decade and have caused several human infections in Asia since 1998. To study their evolution and zoonotic potential, we conducted an in silico analysis of H9N2 viruses that have infected humans between 1997 and 2009 and identified potential novel reassortments. RESULTS A total of 22 hemagglutinin (HA) and neuraminidase (NA) nucleotide and deduced amino acid sequences were retrieved from the NCBI flu database. It was identified that mature peptide sequences of HA genes isolated from humans in 2009 had glutamine at position 226 (H3) of the receptor binding site, indicating a preference to bind to the human α (2-6) sialic acid receptors, which is different from previously isolated viruses and studies where the presence of leucine at the same position contributes to preference for human receptors and presence of glutamine towards avian receptors. Similarly, strains isolated in 2009 possessed new motif R-S-N-R in spite of typical R-S-S-R at the cleavage site of HA, which isn't reported before for H9N2 cases in humans. Other changes involved loss, addition, and variations in potential glycosylation sites as well as in predicted epitopes. The results of phylogenetic analysis indicated that HA and NA gene segments of H9N2 including those from current and proposed vaccine strains belong to two different Eurasian phylogenetic lineages confirming possible genetic reassortments. CONCLUSIONS These findings support the continuous evolution of avian H9N2 viruses towards human as host and are in favor of effective surveillance and better characterization studies to address this issue.
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Affiliation(s)
- Azeem M Butt
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, PR China.
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Wang S, Le TQ, Kurihara N, Chida J, Cisse Y, Yano M, Kido H. Influenza virus-cytokine-protease cycle in the pathogenesis of vascular hyperpermeability in severe influenza. J Infect Dis 2010; 202:991-1001. [PMID: 20731583 PMCID: PMC7537608 DOI: 10.1086/656044] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Background. Severe influenza is characterized by cytokine storm and multiorgan failure with edema. The aim of this study was to define the impact of the cytokine storm on the pathogenesis of vascular hyperpermeability in severe influenza. Methods. Weanling mice were infected with influenza A WSN/33(H1N1) virus. The levels of proinflammatory cytokines, tumor necrosis factor (TNF) α, interleukin (IL) 6, IL-1β, and trypsin were analyzed in the lung, brain, heart, and cultured human umbilical vein endothelial cells. The effects of transcriptional inhibitors on cytokine and trypsin expressions and viral replication were determined. Results. Influenza A virus infection resulted in significant increases in TNF-α, IL-6, IL-1β, viral hemagglutininprocessing protease trypsin levels, and viral replication with vascular hyperpermeability in lung and brain in the first 6 days of infection. Trypsin upregulation was suppressed by transcriptional inhibition of cytokines in vivo and by anti-cytokine antibodies in endothelial cells. Calcium mobilization and loss of tight junction constituent, zonula occludens-1, associated with cytokine- and trypsin-induced endothelial hyperpermeability were inhibited by a protease-activated receptor-2 antagonist and a trypsin inhibitor. Conclusions. The influenza virus-cytokine-protease cycle is one of the key mechanisms of vascular hyperpermeability in severe influenza.
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Affiliation(s)
- Siye Wang
- Division of Enzyme Chemistry, Institute for Enzyme Research, The University of Tokushima, Tokushima, Japan
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Abstract
Considerable progress has been made toward understanding the structural basis of the interaction of the two major surface glycoproteins of influenza A virus with their common ligand/substrate: carbohydrate chains terminating in sialic acid. The specificity of virus attachment to target cells is mediated by hemagglutinin, which acquires characteristic changes in its receptor-binding site to switch its host from avian species to humans. Anti-influenza drugs mimic the natural sialic acid substrate of the virus neuraminidase enzyme but utilize the much tighter binding of the drugs for efficacy. Resistance to one of the two main antiviral drugs is differentially acquired by the two distinct subsets of neuraminidase as a consequence of structural differences in the enzyme active site between the two phylogenetic groups.
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Affiliation(s)
- Steven J. Gamblin
- From the Medical Research Council National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
| | - John J. Skehel
- From the Medical Research Council National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
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TMPRSS2 and TMPRSS4 facilitate trypsin-independent spread of influenza virus in Caco-2 cells. J Virol 2010; 84:10016-25. [PMID: 20631123 DOI: 10.1128/jvi.00239-10] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Proteolysis of influenza virus hemagglutinin by host cell proteases is essential for viral infectivity, but the proteases responsible are not well defined. Recently, we showed that engineered expression of the type II transmembrane serine proteases (TTSPs) TMPRSS2 and TMPRSS4 allows hemagglutinin (HA) cleavage. Here we analyzed whether TMPRSS2 and TMPRSS4 are expressed in influenza virus target cells and support viral spread in the absence of exogenously added protease (trypsin). We found that transient expression of TMPRSS2 and TMPRSS4 resulted in HA cleavage and trypsin-independent viral spread. Endogenous expression of TMPRSS2 and TMPRSS4 in cell lines correlated with the ability to support the spread of influenza virus in the absence of trypsin, indicating that these proteases might activate influenza virus in naturally permissive cells. Indeed, RNA interference (RNAi)-mediated knockdown of both TMPRSS2 and TMPRSS4 in Caco-2 cells, which released fully infectious virus without trypsin treatment, markedly reduced the spread of influenza virus, demonstrating that these proteases were responsible for efficient proteolytic activation of HA in this cell line. Finally, TMPRSS2 was found to be coexpressed with the major receptor determinant of human influenza viruses, 2,6-linked sialic acids, in human alveolar epithelium, indicating that viral target cells in the human respiratory tract express TMPRSS2. Collectively, our results point toward an important role for TMPRSS2 and possibly TMPRSS4 in influenza virus replication and highlight the former protease as a potential therapeutic target.
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Kattenbelt JA, Stevens MP, Selleck PW, Gould AR. Analysis of Newcastle disease virus quasispecies and factors affecting the emergence of virulent virus. Arch Virol 2010; 155:1607-15. [PMID: 20602243 PMCID: PMC7086669 DOI: 10.1007/s00705-010-0739-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 06/24/2010] [Indexed: 11/27/2022]
Abstract
Genome sequence analysis of a number of avirulent field isolates of Newcastle disease virus revealed the presence of viruses (within their quasispecies) that contained virulent F0 sequences. Detection of these virulent sequences below the ~1% level, using standard cloning and sequence analysis, proved difficult, and thus a more sensitive reverse-transcription real-time PCR procedure was developed to detect both virulent and avirulent NDV F0 sequences. Reverse-transcription real-time PCR analysis of the quasispecies of a number of Newcastle disease virus field isolates, revealed variable ratios (approximately 1:4–1:4,000) of virulent to avirulent viral F0 sequences. Since the ratios of these sequences generally remained constant in the quasispecies population during replication, factors that could affect the balance of virulent to avirulent sequences during viral infection of birds were investigated. It was shown both in vitro and in vivo that virulent virus present in the quasispecies did not emerge from the “avirulent background” unless a direct selection pressure was placed on the quasispecies, either by growth conditions or by transient immunosuppression. The effect of a prior infection of the host by infectious bronchitis virus or infectious bursal disease virus on the subsequent emergence of virulent Newcastle disease virus was examined.
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Affiliation(s)
- Jacqueline A Kattenbelt
- Australian Animal Health Laboratory, CSIRO Livestock Industries, Private Bag 24, Geelong, VIC, Australia.
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Antiviral properties, metabolism, and pharmacokinetics of a novel azolo-1,2,4-triazine-derived inhibitor of influenza A and B virus replication. Antimicrob Agents Chemother 2010; 54:2017-22. [PMID: 20194696 DOI: 10.1128/aac.01186-09] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Influenza viruses of types A and B cause periodic pandemics in the human population. The antiviral drugs approved to combat influenza virus infections are currently limited. We have investigated an effective novel inhibitor of human influenza A and B viruses, triazavirine [2-methylthio-6-nitro-1,2,4-triazolo[5,1-c]-1,2,4-triazine-7(4I)-one] (TZV). TZV suppressed the replication of influenza virus in cell culture and in chicken chorioallantoic membranes, and it protected mice from death caused by type A and B influenza viruses. TZV was also effective against a rimantadine-resistant influenza virus strain and against avian influenza A virus H5N1 strains. The pharmacokinetic parameters and bioavailability of TZV were calculated after the administration of TZV to rabbits. The TZV metabolite AMTZV [2-methylthio-6-amino-1,2,4-triazolo[5,1-s]-1,2,4-triazin(e)-7(4I)-one] was discovered in IAK 293T and Huh7 cell cultures, a liver homogenate, and rabbit blood after intragastric administration of TZV. AMTZV was nontoxic and inactive as an inhibitor of influenza virus in cell culture. Most likely, this metabolite is a product of TZV elimination.
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Ryu YB, Kim JH, Park SJ, Chang JS, Rho MC, Bae KH, Park KH, Lee WS. Inhibition of neuraminidase activity by polyphenol compounds isolated from the roots of Glycyrrhiza uralensis. Bioorg Med Chem Lett 2010; 20:971-4. [DOI: 10.1016/j.bmcl.2009.12.106] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 12/02/2009] [Accepted: 12/14/2009] [Indexed: 10/20/2022]
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The pH of activation of the hemagglutinin protein regulates H5N1 influenza virus pathogenicity and transmissibility in ducks. J Virol 2009; 84:1527-35. [PMID: 19923184 DOI: 10.1128/jvi.02069-09] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
While the molecular mechanism of membrane fusion by the influenza virus hemagglutinin (HA) protein has been studied extensively in vitro, the role of acid-dependent HA protein activation in virus replication, pathogenesis, and transmission in vivo has not been characterized. To investigate the biological significance of the pH of activation of the HA protein, we compared the properties of four recombinant viruses with altered HA protein acid stability to those of wild-type influenza virus A/chicken/Vietnam/C58/04 (H5N1) in vitro and in mallards. Membrane fusion by wild-type virus was activated at pH 5.9. Wild-type virus had a calculated environmental persistence of 62 days and caused extensive morbidity, mortality, shedding, and transmission in mallards. An N114K mutation that increased the pH of HA activation by 0.5 unit resulted in decreased replication, genetic stability, and environmental stability. Changes of +0.4 and -0.5 unit in the pH of activation by Y23H and K58I mutations, respectively, reduced weight loss, mortality, shedding, and transmission in mallards. An H24Q mutation that decreased the pH of activation by 0.3 unit resulted in weight loss, mortality, clinical symptoms, and shedding similar to those of the wild type. However, the HA-H24(1)Q virus was shed more extensively into drinking water and persisted longer in the environment. The pH of activation of the H5 HA protein plays a key role in the propagation of H5N1 influenza viruses in ducks and may be a novel molecular factor in the ecology of influenza viruses. The data also demonstrate that H5N1 neuraminidase activity increases the pH of activation of the HA protein in vitro.
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Cleavage of the SARS coronavirus spike glycoprotein by airway proteases enhances virus entry into human bronchial epithelial cells in vitro. PLoS One 2009; 4:e7870. [PMID: 19924243 PMCID: PMC2773421 DOI: 10.1371/journal.pone.0007870] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2009] [Accepted: 10/21/2009] [Indexed: 11/22/2022] Open
Abstract
Background Entry of enveloped viruses into host cells requires the activation of viral envelope glycoproteins through cleavage by either intracellular or extracellular proteases. In order to gain insight into the molecular basis of protease cleavage and its impact on the efficiency of viral entry, we investigated the susceptibility of a recombinant native full-length S-protein trimer (triSpike) of the severe acute respiratory syndrome coronavirus (SARS-CoV) to cleavage by various airway proteases. Methodology/Principal Findings Purified triSpike proteins were readily cleaved in vitro by three different airway proteases: trypsin, plasmin and TMPRSS11a. High Performance Liquid Chromatography (HPLC) and amino acid sequencing analyses identified two arginine residues (R667 and R797) as potential protease cleavage site(s). The effect of protease-dependent enhancement of SARS-CoV infection was demonstrated with ACE2 expressing human bronchial epithelial cells 16HBE. Airway proteases regulate the infectivity of SARS-CoV in a fashion dependent on previous receptor binding. The role of arginine residues was further shown with mutant constructs (R667A, R797A or R797AR667A). Mutation of R667 or R797 did not affect the expression of S-protein but resulted in a differential efficacy of pseudotyping into SARS-CoVpp. The R667A SARS-CoVpp mutant exhibited a lack of virus entry enhancement following protease treatment. Conclusions/Significance These results suggest that SARS S-protein is susceptible to airway protease cleavage and, furthermore, that protease mediated enhancement of virus entry depends on specific conformation of SARS S-protein upon ACE2 binding. These data have direct implications for the cell entry mechanism of SARS-CoV along the respiratory system and, furthermore expand the possibility of identifying potential therapeutic agents against SARS-CoV.
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Neumann G, Chen H, Gao GF, Shu Y, Kawaoka Y. H5N1 influenza viruses: outbreaks and biological properties. Cell Res 2009; 20:51-61. [PMID: 19884910 DOI: 10.1038/cr.2009.124] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
All known subtypes of influenza A viruses are maintained in wild waterfowl, the natural reservoir of these viruses. Influenza A viruses are isolated from a variety of animal species with varying morbidity and mortality rates. More importantly, influenza A viruses cause respiratory disease in humans with potentially fatal outcome. Local or global outbreaks in humans are typically characterized by excess hospitalizations and deaths. In 1997, highly pathogenic avian influenza viruses of the H5N1 subtype emerged in Hong Kong that transmitted to humans, resulting in the first documented cases of human death by avian influenza virus infection. A new outbreak started in July 2003 in poultry in Vietnam, Indonesia, and Thailand, and highly pathogenic avian H5N1 influenza viruses have since spread throughout Asia and into Europe and Africa. These viruses continue to infect humans with a high mortality rate and cause worldwide concern of a looming pandemic. Moreover, H5N1 virus outbreaks have had devastating effects on the poultry industries throughout Asia. Since H5N1 virus outbreaks appear to originate from Southern China, we here examine H5N1 influenza viruses in China, with an emphasis on their biological properties.
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Affiliation(s)
- Gabriele Neumann
- Department of Pathological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
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Massin P, Kuntz-Simon G, Barbezange C, Deblanc C, Oger A, Marquet-Blouin E, Bougeard S, van der Werf S, Jestin V. Temperature sensitivity on growth and/or replication of H1N1, H1N2 and H3N2 influenza A viruses isolated from pigs and birds in mammalian cells. Vet Microbiol 2009; 142:232-41. [PMID: 19926410 DOI: 10.1016/j.vetmic.2009.10.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 10/14/2009] [Accepted: 10/16/2009] [Indexed: 11/26/2022]
Abstract
Influenza A viruses have been isolated from a wide range of animal species, aquatic birds being the reservoir for their genetic diversity. Avian influenza viruses can be transmitted to humans, directly or indirectly through an intermediate host like pig. This study aimed to define in vitro conditions that could prove useful to evaluate the potential of influenza viruses to adapt to a different host. Growth of H1N1, H1N2 and H3N2 influenza viruses belonging to different lineages isolated from birds or pigs prior to 2005 was tested on MDCK or NPTr cell lines in the presence or absence of exogenous trypsin. Virus multiplication was compared at 33, 37 and 40 degrees C, the infection site temperatures in human, swine and avian hosts, respectively. Temperature sensitivity of PB2-, NP- and M-RNA replication was also tested by quantitative real-time PCR. Multiplication of avian viruses was cold-sensitive, whatever cell type. By contrast, temperature sensitivity of swine viruses was found to depend on the virus and the host cell: for an H1N1 swine isolate from 1982, multiplication was cold-sensitive on NPTr cells and undetectable at 40 degrees C. From genetic analyses, it appears that temperature sensitivity could involve other residues than PB2 residue 627 and could affect other steps of the replication cycle than replication.
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King MD, Guentzel MN, Arulanandam BP, Lupiani B, Chambers JP. Proteolytic bacteria in the lower digestive tract of poultry may affect avian influenza virus pathogenicity. Poult Sci 2009; 88:1388-93. [PMID: 19531708 DOI: 10.3382/ps.2008-00549] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proteolytic cleavage of hemagglutinin is required for cell entry by receptor-mediated endocytosis and plays a key role in pathogenicity of the influenza virus. Despite several studies describing relationships between bacterial proteases and influenza A viral activation in mammals, very little is known about the role of the normal bacterial flora of birds on hemagglutinin activation. We examined the indigenous intestinal microflora of 100 mixed-sex, 27-d-old Ross chickens from a commercial poultry facility for protease-secreting bacteria. Protease-secreting bacteria were isolated from 82 of 100 chickens with 50 birds exhibiting 2 or more protease-secreting bacterial species. A total of 20 protease-secreting bacterial species were identified: 17 gram-positive cocci, 2 gram-positive rods, and 1 gram-negative rod. Enterococcus faecalis, Enterococcus gallinarum, and Proteus mirabilis were the most frequently observed protease-secreting bacterial species. The presence of proteolytic bacteria in the intestinal tract of poultry in this study suggests the possibility of yet-to-be-described role(s) in cleavage of hemagglutinin that may alter the pathogenicity of avian influenza viruses.
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Affiliation(s)
- M D King
- Department of Civil and Environmental Engineering, College of Engineering, The University of Texas at San Antonio 78249, USA
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Gem-diamine 1-N-iminosugars as versatile glycomimetics: synthesis, biological activity and therapeutic potential. J Antibiot (Tokyo) 2009; 62:407-23. [DOI: 10.1038/ja.2009.53] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Acquisition of a polybasic hemagglutinin cleavage site by a low-pathogenic avian influenza virus is not sufficient for immediate transformation into a highly pathogenic strain. J Virol 2009; 83:5864-8. [PMID: 19297482 DOI: 10.1128/jvi.02649-08] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Highly pathogenic avian influenza viruses (HPAIV) differ from all other strains by a polybasic cleavage site in their hemagglutinin. All these HPAIV share the H5 or H7 subtype. In order to investigate whether the acquisition of a polybasic cleavage site by an avirulent avian influenza virus strain with a hemagglutinin other than H5 or H7 is sufficient for immediate transformation into an HPAIV, we adapted the hemagglutinin cleavage site of A/Duck/Ukraine/1/1963 (H3N8) to that of the HPAIV A/Chicken/Italy/8/98 (H5N2), A/Chicken/HongKong/220/97 (H5N1), or A/Chicken/Germany/R28/03 (H7N7) and generated the recombinant wild-type and cleavage site mutants. In contrast to the wild type, multicycle replication of these mutants in tissue culture was demonstrated by positive plaque assays and viral multiplication in the absence of exogenous trypsin. Therefore, in vitro all cleavage site mutants resemble an HPAIV. However, in chicken they did not exhibit high pathogenicity, although they could be reisolated from cloacal swabs to some extent, indicating enhanced replication in vivo. These results demonstrate that beyond the polybasic hemagglutinin cleavage site, the virulence of HPAIV in chicken is based on additional pathogenicity determinants within the hemagglutinin itself or in the other viral proteins. Taken together, these observations support the notion that acquisition of a polybasic hemagglutinin cleavage site by an avirulent strain with a non-H5/H7 subtype is only one among several alterations necessary for evolution into an HPAIV.
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