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Funk M, Spronken MI, Bestebroer TM, de Bruin AC, Gultyaev AP, Fouchier RA, te Velthuis AJ, Richard M. Transient RNA structures underlie highly pathogenic avian influenza virus genesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.11.574333. [PMID: 38370829 PMCID: PMC10871305 DOI: 10.1101/2024.01.11.574333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Highly pathogenic avian influenza viruses (HPAIVs) cause severe disease and high fatality in poultry1. They emerge exclusively from H5 and H7 low pathogenic avian influenza viruses (LPAIVs)2. Although insertion of a furin-cleavable multibasic cleavage site (MBCS) in the hemagglutinin gene was identified decades ago as the genetic basis for LPAIV-to-HPAIV transition3,4, the exact mechanisms underlying said insertion have remained unknown. Here we used an innovative combination of bioinformatic models to predict RNA structures forming around the influenza virus RNA polymerase during replication, and circular sequencing5 to reliably detect nucleotide insertions. We show that transient H5 hemagglutinin RNA structures predicted to trap the polymerase on purine-rich sequences drive nucleotide insertions characteristic of MBCSs, providing the first strong empirical evidence of RNA structure involvement in MBCS acquisition. Insertion frequencies at the H5 cleavage site were strongly affected by substitutions in flanking genomic regions altering predicted transient RNA structures. Introduction of H5-like cleavage site sequences and structures into an H6 hemagglutinin resulted in MBCS-yielding insertions never observed before in H6 viruses. Our results demonstrate that nucleotide insertions that underlie H5 HPAIV emergence result from a previously unknown RNA-structure-driven diversity-generating mechanism, which could be shared with other RNA viruses.
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Affiliation(s)
- Mathis Funk
- Department of Viroscience; Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands
| | - Monique I. Spronken
- Department of Viroscience; Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands
| | - Theo M. Bestebroer
- Department of Viroscience; Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands
| | - Anja C.M. de Bruin
- Department of Viroscience; Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands
| | - Alexander P. Gultyaev
- Department of Viroscience; Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands
- Group Imaging and Bioinformatics, Leiden Institute of Advanced Computer Science (LIACS); Leiden University, 2300 RA Leiden, The Netherlands
| | - Ron A.M. Fouchier
- Department of Viroscience; Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands
| | - Aartjan J.W. te Velthuis
- Lewis Thomas Laboratory, Department of Molecular Biology; Princeton University, 08544 New Jersey, United States
| | - Mathilde Richard
- Department of Viroscience; Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands
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2
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SUSCEPTIBILITY OF LAUGHING GULLS (LEUCOPHAEUS ATRICILLA) AND MALLARDS (ANAS PLATYRHYNCHOS) TO RUDDY TURNSTONE (ARENARIA INTERPRES MORINELLA) ORIGIN TYPE A INFLUENZA VIRUSES. J Wildl Dis 2020. [DOI: 10.7589/2019-03-065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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3
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Bahnson CS, Poulson RL, Hollander LP, Bradley JAC, Stallknecht DE. SUSCEPTIBILITY OF LAUGHING GULLS ( LEUCOPHAEUS ATRICILLA) AND MALLARDS ( ANAS PLATYRHYNCHOS) TO RUDDY TURNSTONE ( ARENARIA INTERPRES MORINELLA) ORIGIN TYPE A INFLUENZA VIRUSES. J Wildl Dis 2020; 56:167-174. [PMID: 31532732 PMCID: PMC9202238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Delaware Bay, US is the only documented location where influenza A virus (IAV) is consistently detected in a shorebird species, the Ruddy Turnstone (RUTU; Arenaria interpres morinella). Although IAV in shorebirds has been well studied at this site for decades, the importance of other species in the avian community as potential sources for the IAVs that infect RUTUs each spring remains unclear. We determined the susceptibility of Mallards (Anas platyrhynchos) and Laughing Gulls (Leucophaeus atricilla), to IAVs isolated from RUTUs in order to gain insight into the potential host range of these viruses. Captive-reared gulls were challenged with RUTU-origin H6N1, H10N7, H11N9, H12N4, and H13N6 IAV, as well as Mallard-origin H6N1 and H11N9. We challenged captive-reared Mallards with the same viruses, except for H13N6. At a biologically plausible challenge dose (104 50% embryo infective doses/0.1 mL), one of five gulls challenged with both H6N1 IAVs shed virus. The remaining gulls were resistant to infection with all viruses. In contrast, all Mallards were infected and shed virus. The H12N4 Mallard challenge group was an exception with no birds infected. These results indicated that Mallards are permissive to infection with viruses originating from a shorebird host and that interspecies transmission could occur. In contrast, host adaptation of IAVs to RUTUs may compromise their ability to be transmitted back to gulls.
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Affiliation(s)
- Charlie S. Bahnson
- Southeastern Cooperative Wildlife Disease Study, 589 D. W. Brooks Drive, College of Veterinary Medicine, Department of Population Health, The University of Georgia, Athens, Georgia 30602, USA
| | - Rebecca L. Poulson
- Southeastern Cooperative Wildlife Disease Study, 589 D. W. Brooks Drive, College of Veterinary Medicine, Department of Population Health, The University of Georgia, Athens, Georgia 30602, USA
| | - Laura P. Hollander
- Southeastern Cooperative Wildlife Disease Study, 589 D. W. Brooks Drive, College of Veterinary Medicine, Department of Population Health, The University of Georgia, Athens, Georgia 30602, USA
| | - Jo A. Crum Bradley
- Southeastern Cooperative Wildlife Disease Study, 589 D. W. Brooks Drive, College of Veterinary Medicine, Department of Population Health, The University of Georgia, Athens, Georgia 30602, USA
| | - David E. Stallknecht
- Southeastern Cooperative Wildlife Disease Study, 589 D. W. Brooks Drive, College of Veterinary Medicine, Department of Population Health, The University of Georgia, Athens, Georgia 30602, USA
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4
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van Eijk M, Hillaire MLB, Rimmelzwaan GF, Rynkiewicz MJ, White MR, Hartshorn KL, Hessing M, Koolmees PA, Tersteeg MH, van Es MH, Meijerhof T, Huckriede A, Haagsman HP. Enhanced Antiviral Activity of Human Surfactant Protein D by Site-Specific Engineering of the Carbohydrate Recognition Domain. Front Immunol 2019; 10:2476. [PMID: 31749796 PMCID: PMC6842947 DOI: 10.3389/fimmu.2019.02476] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/03/2019] [Indexed: 12/11/2022] Open
Abstract
Innate immunity is critical in the early containment of influenza A virus (IAV) infection and surfactant protein D (SP-D) plays a crucial role in innate defense against IAV in the lungs. Multivalent lectin-mediated interactions of SP-D with IAVs result in viral aggregation, reduced epithelial infection, and enhanced IAV clearance by phagocytic cells. Previous studies showed that porcine SP-D (pSP-D) exhibits distinct antiviral activity against IAV as compared to human SP-D (hSP-D), mainly due to key residues in the lectin domain of pSP-D that contribute to its profound neutralizing activity. These observations provided the basis for the design of a full-length recombinant mutant form of hSP-D, designated as “improved SP-D” (iSP-D). Inspired by pSP-D, the lectin domain of iSP-D has 5 amino acids replaced (Asp324Asn, Asp330Asn, Val251Glu, Lys287Gln, Glu289Lys) and 3 amino acids inserted (326Gly-Ser-Ser). Characterization of iSP-D revealed no major differences in protein assembly and saccharide binding selectivity as compared to hSP-D. However, hemagglutination inhibition measurements showed that iSP-D expressed strongly enhanced activity compared to hSP-D against 31 different IAV strains tested, including (pandemic) IAVs that were resistant for neutralization by hSP-D. Furthermore, iSP-D showed increased viral aggregation and enhanced protection of MDCK cells against infection by IAV. Importantly, prophylactic or therapeutic application of iSP-D decreased weight loss and reduced viral lung titers in a murine model of IAV infection using a clinical isolate of H1N1pdm09 virus. These studies demonstrate the potential of iSP-D as a novel human-based antiviral inhalation drug that may provide immediate protection against or recovery from respiratory (pandemic) IAV infections in humans.
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Affiliation(s)
- Martin van Eijk
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | | | - Guus F Rimmelzwaan
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine, Hanover, Germany
| | - Michael J Rynkiewicz
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, United States
| | - Mitchell R White
- Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Kevan L Hartshorn
- Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Martin Hessing
- U-Protein Express B.V., Life Science Incubator, Utrecht, Netherlands
| | - Peter A Koolmees
- Division of Veterinary Public Health, Faculty of Veterinary Medicine, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, Netherlands
| | - Monique H Tersteeg
- Division of Veterinary Public Health, Faculty of Veterinary Medicine, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, Netherlands
| | | | - Tjarko Meijerhof
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Anke Huckriede
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Henk P Haagsman
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
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5
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Spronken MI, Short KR, Herfst S, Bestebroer TM, Vaes VP, van der Hoeven B, Koster AJ, Kremers GJ, Scott DP, Gultyaev AP, Sorell EM, de Graaf M, Bárcena M, Rimmelzwaan GF, Fouchier RA. Optimisations and Challenges Involved in the Creation of Various Bioluminescent and Fluorescent Influenza A Virus Strains for In Vitro and In Vivo Applications. PLoS One 2015; 10:e0133888. [PMID: 26241861 PMCID: PMC4524686 DOI: 10.1371/journal.pone.0133888] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/03/2015] [Indexed: 01/15/2023] Open
Abstract
Bioluminescent and fluorescent influenza A viruses offer new opportunities to study influenza virus replication, tropism and pathogenesis. To date, several influenza A reporter viruses have been described. These strategies typically focused on a single reporter gene (either bioluminescent or fluorescent) in a single virus backbone. However, whilst bioluminescence is suited to in vivo imaging, fluorescent viruses are more appropriate for microscopy. Therefore, the idea l reporter virus varies depending on the experiment in question, and it is important that any reporter virus strategy can be adapted accordingly. Herein, a strategy was developed to create five different reporter viruses in a single virus backbone. Specifically, enhanced green fluorescent protein (eGFP), far-red fluorescent protein (fRFP), near-infrared fluorescent protein (iRFP), Gaussia luciferase (gLUC) and firefly luciferase (fLUC) were inserted into the PA gene segment of A/PR/8/34 (H1N1). This study provides a comprehensive characterisation of the effects of different reporter genes on influenza virus replication and reporter activity. In vivo reporter gene expression, in lung tissues, was only detected for eGFP, fRFP and gLUC expressing viruses. In vitro, the eGFP-expressing virus displayed the best reporter stability and could be used for correlative light electron microscopy (CLEM). This strategy was then used to create eGFP-expressing viruses consisting entirely of pandemic H1N1, highly pathogenic avian influenza (HPAI) H5N1 and H7N9. The HPAI H5N1 eGFP-expressing virus infected mice and reporter gene expression was detected, in lung tissues, in vivo. Thus, this study provides new tools and insights for the creation of bioluminescent and fluorescent influenza A reporter viruses.
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Affiliation(s)
- Monique I. Spronken
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Kirsty R. Short
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Sander Herfst
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Theo M. Bestebroer
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Vincent P. Vaes
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Barbara van der Hoeven
- Department of Molecular Cell Biology, Section Electron Microscopy, Leiden University Medical Centre, Leiden, the Netherlands
| | - Abraham J. Koster
- Department of Molecular Cell Biology, Section Electron Microscopy, Leiden University Medical Centre, Leiden, the Netherlands
| | - Gert-Jan Kremers
- Erasmus Optical Imaging Centre, Department of Pathology, Erasmus University Medical Centre, Rotterdam, the Netherlands
| | - Dana P. Scott
- Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States of America
| | - Alexander P. Gultyaev
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
- Leiden Institute of Advanced Computer Science, Leiden University, Leiden, the Netherlands
| | - Erin M. Sorell
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
- Milken Institute School of Public Health, Department of Health Policy and Management, George Washington University, Washington, DC, United States of America
| | - Miranda de Graaf
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Montserrat Bárcena
- Department of Molecular Cell Biology, Section Electron Microscopy, Leiden University Medical Centre, Leiden, the Netherlands
| | - Guus F. Rimmelzwaan
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Ron A. Fouchier
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
- * E-mail:
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6
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Vachieri SG, Xiong X, Collins PJ, Walker PA, Martin SR, Haire LF, Zhang Y, McCauley JW, Gamblin SJ, Skehel JJ. Receptor binding by H10 influenza viruses. Nature 2014; 511:475-7. [PMID: 24870229 DOI: 10.1038/nature13443] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 05/07/2014] [Indexed: 01/18/2023]
Abstract
H10N8 follows H7N9 and H5N1 as the latest in a line of avian influenza viruses that cause serious disease in humans and have become a threat to public health. Since December 2013, three human cases of H10N8 infection have been reported, two of whom are known to have died. To gather evidence relating to the epidemic potential of H10 we have determined the structure of the haemagglutinin of a previously isolated avian H10 virus and we present here results relating especially to its receptor-binding properties, as these are likely to be major determinants of virus transmissibility. Our results show, first, that the H10 virus possesses high avidity for human receptors and second, from the crystal structure of the complex formed by avian H10 haemagglutinin with human receptor, it is clear that the conformation of the bound receptor has characteristics of both the 1918 H1N1 pandemic virus and the human H7 viruses isolated from patients in 2013 (ref. 3). We conclude that avian H10N8 virus has sufficient avidity for human receptors to account for its infection of humans but that its preference for avian receptors should make avian-receptor-rich human airway mucins an effective block to widespread infection. In terms of surveillance, particular attention will be paid to the detection of mutations in the receptor-binding site of the H10 haemagglutinin that decrease its avidity for avian receptor, and could enable it to be more readily transmitted between humans.
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Affiliation(s)
- Sebastien G Vachieri
- 1] MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK [2]
| | - Xiaoli Xiong
- 1] MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK [2]
| | - Patrick J Collins
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Philip A Walker
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Stephen R Martin
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Lesley F Haire
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Ying Zhang
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - John W McCauley
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Steven J Gamblin
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - John J Skehel
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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7
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Kreijtz JHCM, Wiersma LCM, De Gruyter HLM, Vogelzang-van Trierum SE, van Amerongen G, Stittelaar KJ, Fouchier RAM, Osterhaus ADME, Sutter G, Rimmelzwaan GF. A single immunization with modified vaccinia virus Ankara-based influenza virus H7 vaccine affords protection in the influenza A(H7N9) pneumonia ferret model. J Infect Dis 2014; 211:791-800. [PMID: 25246535 DOI: 10.1093/infdis/jiu528] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Since the first reports in early 2013, >440 human cases of infection with avian influenza A(H7N9) have been reported including 122 fatalities. After the isolation of the first A(H7N9) viruses, the nucleotide sequences became publically available. Based on the coding sequence of the influenza virus A/Shanghai/2/2013 hemagglutinin gene, a codon-optimized gene was synthesized and cloned into a recombinant modified vaccinia virus Ankara (MVA). This MVA-H7-Sh2 viral vector was used to immunize ferrets and proved to be immunogenic, even after a single immunization. Subsequently, ferrets were challenged with influenza virus A/Anhui/1/2013 via the intratracheal route. Unprotected animals that were mock vaccinated or received empty vector developed interstitial pneumonia characterized by a marked alveolitis, accompanied by loss of appetite, weight loss, and heavy breathing. In contrast, animals vaccinated with MVA-H7-Sh2 were protected from severe disease.
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Affiliation(s)
| | | | | | | | | | | | - Ron A M Fouchier
- Department of Viroscience, Erasmus Medical Center Viroclinics Biosciences, Rotterdam, the Netherlands Institute for Infectious Diseases and Zoonoses, LMU University of Munich German Center for Infection Research, Braunschweig, Germany
| | | | - Gerd Sutter
- Institute for Infectious Diseases and Zoonoses, LMU University of Munich German Center for Infection Research, Braunschweig, Germany
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8
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Kandeil A, Bagato O, Zaraket H, Debeauchamp J, Krauss S, El-Shesheny R, Webby RJ, Ali MA, Kayali G. Proteolytic enzymes in embryonated chicken eggs sustain the replication of egg-grown low-pathogenicity avian influenza viruses in cells in the absence of exogenous proteases. J Virol Methods 2014; 202:28-33. [PMID: 24626064 DOI: 10.1016/j.jviromet.2014.02.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 02/25/2014] [Accepted: 02/27/2014] [Indexed: 11/26/2022]
Abstract
Low pathogenic influenza viruses grow readily in embryonated chicken eggs but require the addition of exogenous proteases to grow in MDCK cell culture. In this study, we found that the influenza viruses propagated previously in eggs, can grow for up to two passages in cell culture without the addition of exogenous proteolytic enzymes. These results indicate that the reason for virus propagation in cells during the first two passages may be due to proteases from egg allantoic fluid carried over from egg culture. The ability of influenza viruses to grow in cells in the absence of trypsin is currently considered as a hallmark of highly pathogenic influenza viruses. Our data indicate that differentiating between high and low pathogenicity using cell culture only is not appropriate and other indicators such as sequence analysis and in vitro pathogenicity index should be performed.
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Affiliation(s)
- Ahmed Kandeil
- Environmental Research Division, National Research Centre, Dokki 12311, Giza, Egypt
| | - Ola Bagato
- Environmental Research Division, National Research Centre, Dokki 12311, Giza, Egypt
| | - Hassan Zaraket
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, United States
| | - Jennifer Debeauchamp
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, United States
| | - Scott Krauss
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, United States
| | - Rabeh El-Shesheny
- Environmental Research Division, National Research Centre, Dokki 12311, Giza, Egypt
| | - Richard J Webby
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, United States
| | - Mohamed A Ali
- Environmental Research Division, National Research Centre, Dokki 12311, Giza, Egypt
| | - Ghazi Kayali
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, United States.
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9
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Tønnessen R, Hauge AG, Hansen EF, Rimstad E, Jonassen CM. Host restrictions of avian influenza viruses: in silico analysis of H13 and H16 specific signatures in the internal proteins. PLoS One 2013; 8:e63270. [PMID: 23646204 PMCID: PMC3639990 DOI: 10.1371/journal.pone.0063270] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Accepted: 04/02/2013] [Indexed: 12/01/2022] Open
Abstract
Gulls are the primary hosts of H13 and H16 avian influenza viruses (AIVs). The molecular basis for this host restriction is only partially understood. In this study, amino acid sequences from Eurasian gull H13 and H16 AIVs and Eurasian AIVs (non H13 and H16) were compared to determine if specific signatures are present only in the internal proteins of H13 and H16 AIVs, using a bioinformatics approach. Amino acids identified in an initial analysis performed on 15 selected sequences were checked against a comprehensive set of AIV sequences retrieved from Genbank to verify them as H13 and H16 specific signatures. Analysis of protein similarities and prediction of subcellular localization signals were performed to search for possible functions associated with the confirmed signatures. H13 and H16 AIV specific signatures were found in all the internal proteins examined, but most were found in the non-structural protein 1 (NS1) and in the nucleoprotein. A putative functional signature was predicted to be present in the nuclear export protein. Moreover, it was predicted that the NS1 of H13 and H16 AIVs lack one of the nuclear localization signals present in NS1 of other AIV subtypes. These findings suggest that the signatures found in the internal proteins of H13 and H16 viruses are possibly related to host restriction.
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Affiliation(s)
- Ragnhild Tønnessen
- Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Oslo, Norway.
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10
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Galloway SE, Reed ML, Russell CJ, Steinhauer DA. Influenza HA subtypes demonstrate divergent phenotypes for cleavage activation and pH of fusion: implications for host range and adaptation. PLoS Pathog 2013; 9:e1003151. [PMID: 23459660 PMCID: PMC3573126 DOI: 10.1371/journal.ppat.1003151] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 12/07/2012] [Indexed: 12/17/2022] Open
Abstract
The influenza A virus (IAV) HA protein must be activated by host cells proteases in order to prime the molecule for fusion. Consequently, the availability of activating proteases and the susceptibility of HA to protease activity represents key factors in facilitating virus infection. As such, understanding the intricacies of HA cleavage by various proteases is necessary to derive insights into the emergence of pandemic viruses. To examine these properties, we generated a panel of HAs that are representative of the 16 HA subtypes that circulate in aquatic birds, as well as HAs representative of the subtypes that have infected the human population over the last century. We examined the susceptibility of the panel of HA proteins to trypsin, as well as human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2). Additionally, we examined the pH at which these HAs mediated membrane fusion, as this property is related to the stability of the HA molecule and influences the capacity of influenza viruses to remain infectious in natural environments. Our results show that cleavage efficiency can vary significantly for individual HAs, depending on the protease, and that some HA subtypes display stringent selectivity for specific proteases as activators of fusion function. Additionally, we found that the pH of fusion varies by 0.7 pH units among the subtypes, and notably, we observed that the pH of fusion for most HAs from human isolates was lower than that observed from avian isolates of the same subtype. Overall, these data provide the first broad-spectrum analysis of cleavage-activation and membrane fusion characteristics for all of the IAV HA subtypes, and also show that there are substantial differences between the subtypes that may influence transmission among hosts and establishment in new species. IAV is associated with significant morbidity and mortality, and represents a challenging public health threat that affects social and economic welfare each year, particularly during IAV pandemics. Although we know that all human strains derive, either directly or via intermediate hosts, from avian viral sources, we know very little about the phenotypic characteristics of the 16 HA subtypes that circulate in aquatic birds and have potential to infect mammals. HA membrane fusion properties, in conjunction with the characteristics for protease activation of HA, a requirement for fusion, are critical factors involved in the ecology and transmission of IAVs, and need to be understood if we are to derive explanations for how pandemic viruses emerge in humans. We examined the cleavage-activation and membrane fusion characteristics for the 16 HA subtypes by transiently expressing HA proteins in cells. Our findings show that the cleavability of the HAs vary considerably between subtypes and depending on the protease. Additionally, analysis of the pH of fusion for each subtype showed that HA stability varied significantly among the subtypes, as well as within subtypes from viruses isolated from different species. Overall, these data have implications for host range, potential for adaptation, and persistence in natural environments.
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Affiliation(s)
- Summer E. Galloway
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail: (SEG); (DAS)
| | - Mark L. Reed
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Charles J. Russell
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - David A. Steinhauer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail: (SEG); (DAS)
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11
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Hillaire MLB, van Eijk M, Nieuwkoop NJ, Vogelzang-van Trierum SE, Fouchier RAM, Osterhaus ADME, Haagsman HP, Rimmelzwaan GF. The number and position of N-linked glycosylation sites in the hemagglutinin determine differential recognition of seasonal and 2009 pandemic H1N1 influenza virus by porcine surfactant protein D. Virus Res 2012; 169:301-5. [PMID: 22921759 DOI: 10.1016/j.virusres.2012.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 07/31/2012] [Accepted: 08/07/2012] [Indexed: 11/25/2022]
Abstract
C-type lectins are important molecules of the innate immune system. These molecules, like surfactant protein D (SP-D) can recognize glycans on pathogens and neutralize these. Also influenza viruses are recognized by SP-D and their susceptibility to neutralization by SP-D is dependent on the number of N-linked glycosylation sites in the hemagglutinin in particular. Porcine SP-D displayed stronger neutralizing activity to human influenza A viruses than to swine influenza A viruses. Although viruses from these species differ with regard to the number of glycosylation sites in the hemagglutinin, the mechanism underlying the differential recognition by porcine SP-D is poorly understood. Here we investigated the molecular basis for the differential recognition of a seasonal H1N1 and a 2009 pandemic H1N1 virus by porcine SP-D. We demonstrated that the number and position of glycosylation sites determine viral susceptibility to the neutralizing activity of porcine SP-D. However, predicting the effect remains difficult as it was shown to be dependent on the strain and the position of the glycosylation sites.
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Osterhaus A, Fouchier R, Rimmelzwaan G. Towards universal influenza vaccines? Philos Trans R Soc Lond B Biol Sci 2011; 366:2766-73. [PMID: 21893539 PMCID: PMC3146782 DOI: 10.1098/rstb.2011.0102] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Vaccination is the most cost-effective way to reduce the considerable disease burden of seasonal influenza. Although seasonal influenza vaccines are effective, their performance in the elderly and immunocompromised individuals would benefit from improvement. Major problems related to the development and production of pandemic influenza vaccines are response time and production capacity as well as vaccine efficacy and safety. Several improvements can be envisaged. Vaccine production technologies based on embryonated chicken eggs may be replaced by cell culture techniques. Reverse genetics techniques can speed up the generation of seed viruses and new mathematical modelling methods improve vaccine strain selection. Better understanding of the correlates of immune-mediated protection may lead to new vaccine targets besides the viral haemagglutinin, like the neuraminidase and M2 proteins. In addition, the role of cell-mediated immunity could be better exploited. New adjuvants have recently been shown to increase the breadth and the duration of influenza vaccine-induced protection. Other studies have shown that influenza vaccines based on different viral vector systems may also induce broad protection. It is to be expected that these developments may lead to more universal influenza vaccines that elicit broader and longer protection, and can be produced more efficiently.
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Affiliation(s)
- Ab Osterhaus
- Department of Virology, Erasmus MC, Rotterdam, The Netherlands.
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Hillaire MLB, van Eijk M, van Trierum SE, van Riel D, Saelens X, Romijn RA, Hemrika W, Fouchier RAM, Kuiken T, Osterhaus ADME, Haagsman HP, Rimmelzwaan GF. Assessment of the antiviral properties of recombinant porcine SP-D against various influenza A viruses in vitro. PLoS One 2011; 6:e25005. [PMID: 21935489 PMCID: PMC3173486 DOI: 10.1371/journal.pone.0025005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 08/25/2011] [Indexed: 11/19/2022] Open
Abstract
The emergence of influenza viruses resistant to existing classes of antiviral drugs raises concern and there is a need for novel antiviral agents that could be used therapeutically or prophylacticaly. Surfactant protein D (SP-D) belongs to the family of C-type lectins which are important effector molecules of the innate immune system with activity against bacteria and viruses, including influenza viruses. In the present study we evaluated the potential of recombinant porcine SP-D as an antiviral agent against influenza A viruses (IAVs) in vitro. To determine the range of antiviral activity, thirty IAVs of the subtypes H1N1, H3N2 and H5N1 that originated from birds, pigs and humans were selected and tested for their sensitivity to recombinant SP-D. Using these viruses it was shown by hemagglutination inhibition assay, that recombinant porcine SP-D was more potent than recombinant human SP-D and that especially higher order oligomeric forms of SP-D had the strongest antiviral activity. Porcine SP-D was active against a broad range of IAV strains and neutralized a variety of H1N1 and H3N2 IAVs, including 2009 pandemic H1N1 viruses. Using tissue sections of ferret and human trachea, we demonstrated that recombinant porcine SP-D prevented attachment of human seasonal H1N1 and H3N2 virus to receptors on epithelial cells of the upper respiratory tract. It was concluded that recombinant porcine SP-D holds promise as a novel antiviral agent against influenza and further development and evaluation in vivo seems warranted.
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Affiliation(s)
| | - Martin van Eijk
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | | | | | - Xavier Saelens
- Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Roland A. Romijn
- U-Protein Express B.V., Science Park Utrecht, Utrecht, The Netherlands
| | - Wieger Hemrika
- U-Protein Express B.V., Science Park Utrecht, Utrecht, The Netherlands
| | | | - Thijs Kuiken
- Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Albert D. M. E. Osterhaus
- Erasmus Medical Centre, Rotterdam, The Netherlands
- Viroclinics Biosciences BV, Rotterdam, The Netherlands
| | - Henk P. Haagsman
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- * E-mail: (GFR); (HPH)
| | - Guus F. Rimmelzwaan
- Erasmus Medical Centre, Rotterdam, The Netherlands
- Viroclinics Biosciences BV, Rotterdam, The Netherlands
- * E-mail: (GFR); (HPH)
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