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Influenza A virus NS1 protein: molecular mechanisms of host-cell hijack

Applicant Hale Benjamin
Number 159993
Funding scheme Project funding
Research institution Institut für Medizinische Virologie Universität Zürich
Institution of higher education University of Zurich - ZH
Main discipline Medical Microbiology
Start/End 01.09.2015 - 31.08.2018
Approved amount 474'000.00
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All Disciplines (4)

Discipline
Medical Microbiology
Biochemistry
Molecular Biology
Cellular Biology, Cytology

Keywords (9)

NS1; influenza; signaling; virus; PI3K; phosphorylation; proteomics; immunity; virulence

Lay Summary (German)

Lead
Influenzaviren stellen eine Gefährdung der Gesundheit von Mensch und Tier dar. Verschiedene Virusstämme unterscheiden sich in ihrem Krankheitspotential aufgrund viral-kodierter Virulenzfaktoren. Dieses Projekt wird wichtige genomische Sequenzen des Virus identifizieren, die mit Pathogenität assoziiert sind und ihre Wirkweise untersuchen. Erkenntnisse aus diesen Studien können für Therapien genutzt werden.
Lay summary

Inhalt und Ziele des Forschungsprojekts

Unsere Forschung befasst sich mit dem multifunktionellen NS1 Proteins des Influenzavirus, das als Virulenzfaktor die infizierte Wirtszelle umprogrammiert. Eine Funktion von NS1 ist dabei, die Aktivierung eines wichtigen regulatorischen Wirtsproteins (Phosphoinositide 3-kinase (PI3K)), das das überleben der Zelle kontrolliert. Diese Interaktion von NS1 und PI3K ist wichtig für Virusvermehrung und Virulenz. Trotzdem sind die zugrundeliegenden molekularen Mechanismen und biologischen Folgen dieser Interaktion unklar. Dieses Projekt zielt darauf ab, diese Virus-Wirts-Beziehung genau zu verstehen.

In bisherigen Studien haben wir den molekularen „Fussabdruck“ der NS1-PI3K Interaktion definiert, sowie natürlich-vorkommende Varianten von NS1 identifiziert, die sich ihrer PI3K-Bindung unterscheiden. In diesem Projekt werden wir die Folgen der unterschiedlichen PI3K-Bindung analysieren, indem wir Viren generieren, die sich nur in ihrer PI3K-Bindung unterscheiden. Durch das Charakterisieren dieser Viren werden wir die Funktion der Interaktion besser verstehen.

Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts

Das Projekt befasst sich mit Grundlagenforschung. Trotzdem können diese Studien helfen, Virulenzmarker der Influenzaviren zu identifizieren und neue Perspektiven für das Entwickeln von antiviralen Therapien aufzuzeigen.

Direct link to Lay Summary Last update: 29.05.2015

Responsible applicant and co-applicants

Employees

Publications

Publication
Unexpected Functional Divergence of Bat Influenza Virus NS1 Proteins
Turkington Hannah L., Juozapaitis Mindaugas, Tsolakos Nikos, Corrales-Aguilar Eugenia, Schwemmle Martin, Hale Benjamin G. (2018), Unexpected Functional Divergence of Bat Influenza Virus NS1 Proteins, in Journal of Virology, 92(5), e02097-17-e02097-17.
Structure-Guided Functional Annotation of the Influenza A Virus NS1 Protein Reveals Dynamic Evolution of the p85beta-Binding Site during Circulation in Humans
Lopes Antonio M., Domingues Patricia, Zell Roland, Hale Benjamin G. (2017), Structure-Guided Functional Annotation of the Influenza A Virus NS1 Protein Reveals Dynamic Evolution of the p85beta-Binding Site during Circulation in Humans, in JOURNAL OF VIROLOGY, 91(21), e01081-17.
Human Interactome of the Influenza B Virus NS1 Protein
Patzina Corinna, Botting Catherine H., Garcia-Sastre Adolfo, Randall Richard E., Hale Benjamin G. (2017), Human Interactome of the Influenza B Virus NS1 Protein, in JOURNAL OF GENERAL VIROLOGY, 98(9), 2267-2273.
Novel Bat Influenza Virus NS1 Proteins Bind Double-Stranded RNA and Antagonize Host Innate Immunity
Turkington Hannah L., Juozapaitis Mindaugas, Kerry Philip S., Aydillo Teresa, Ayllon Juan, García-Sastre Adolfo, Schwemmle Martin, Hale Benjamin G. (2015), Novel Bat Influenza Virus NS1 Proteins Bind Double-Stranded RNA and Antagonize Host Innate Immunity, in Journal of Virology, 89(20), 10696-10701.

Collaboration

Group / person Country
Types of collaboration
Rick Randall, University of St Andrews Great Britain and Northern Ireland (Europe)
- Publication
Roland Zell, University of Jena Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Martin Schwemmle, Medical Center University Freiburg Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Adolfo Garcia-Sastre, Icahn School of Medicine at Mount Sinai, New York United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Eugenia Corrales-Aguilar, University of Costa Rica Costa Rica (South America)
- Publication
John Burke, University of Victoria Canada (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Microbiology Society Annual Conference 2018 Talk given at a conference Unexpected functional divergence of bat influenza virus NS1 proteins 10.04.2018 Birmingham, Great Britain and Northern Ireland Turkington Hannah Louise;
27th Annual Meeting of the Society for Virology Poster Unexpected Functional Divergence of Bat Influenza Virus NS1 Proteins 22.03.2017 Marburg, Germany Turkington Hannah Louise;
Keystone Symposium: PI3K Pathways in Immunology, Growth Disorders and Cancer Poster Phosphoproteomic Analysis of Influenza A Virus NS1-activated PI3K Signaling 19.01.2017 Santa Fe, New Mexico, United States of America Tsolakos Nikolaos;
74th Swiss Society for Microbiology Annual Meeting Talk given at a conference NOVEL BAT INFLUENZA VIRUS NS1 PROTEINS: USUAL AND UNUSUAL FEATURES 13.06.2016 Bern, Switzerland Hale Benjamin; Turkington Hannah Louise;
7th Orthomyxovirus Research Conference Talk given at a conference Structure-guided mapping of viral polymorphisms at the influenza A virus NS1-host PI3K interface 16.09.2015 Toulouse, France Mil-Homens Luz Lopes Antonio Pedro;


Awards

Title Year
University of Zurich Forschungskredit for Doctoral Students 2016

Abstract

Influenza viruses generate a high human and animal disease burden with significant economic consequences. Zoonotic transmission of influenza viruses from animal reservoirs continually threatens to cause severe human outbreaks, and such spillovers can act as precursors to pandemics. A feature of influenza virus strains is their variability in disease causing potential, of which virus-encoded virulence factors play a major role. Thus, defining key viral genomic sequences associated with pathogenicity is essential for surveillance efforts to identify and eliminate viruses of concern before they infect humans. Understanding the fundamental molecular mechanisms underlying the interaction of viral virulence factors with host-cells may also suggest new targets for therapeutic strategies to limit disease.Our research focuses on the multifunctional influenza virus NS1 virulence factor, which exquisitely re-wires host signaling cascades in the infected cell. A major function of NS1 is to disable host innate immune defenses, a process achieved by multiple well-established mechanisms that vary in efficiency between strains and impact pathogenicity. NS1 also binds and activates the p85ß subunit of human phosphoinositide 3-kinase (PI3K), a host lipid kinase implicated in regulating cell growth, metabolism and survival. This interaction is important for virus replication and virulence, and recent studies have highlighted strain-dependent effects of this event on influenza disease in animal models. Nevertheless, the precise molecular mechanisms and cell biological consequences of NS1 binding p85ß remain to be determined. Furthermore, although broad-spectrum PI3K inhibitors have been proposed as new host-targeted antivirals, there are indications that efficacy may be NS1-genotype dependent. Thus, a thorough understanding of the interplay between NS1 and host p85ß is essential.In preliminary work, we have used a structure-guided alanine-scanning approach to comprehensively identify the ‘molecular footprint’ of the NS1:p85ß interaction. Furthermore, by assessing polymorphisms in NS1 at this site, we have identified several amino-acid substitutions that specifically destabilize or enhance p85ß-binding, suggesting unexplored natural diversity in this NS1 function. Here, we will:Aim A1. Generate influenza viruses expressing NS1 proteins with amino-acid substitutions causing p85ß-binding variation, and characterize the ability of each virus to activate PI3K and replicate efficiently.Aim A2. Determine if phenotypes of the mutant viruses can be compensated by heterologous PI3K, and if so use specific PI3K activating mechanisms to understand those most relevant to influenza viruses.Aim A3. Assess potential roles for NS1-activated PI3K in antagonizing host antiviral stress responses.Aim B. Combine the newly developed viral tools with state-of-the-art quantitative phospho-proteomics to understand the cell signaling consequences of NS1-mediated PI3K activation in an unbiased manner.Our fundamental studies should help elucidate the impact of newly identified strain variation on influenza virus NS1 virulence factor function. By studying these variants with both rational and unbiased approaches, we will reveal the basic molecular mechanisms and biological consequences underlying NS1 hijack of host PI3K. This knowledge will provide a framework for understanding influenza disease markers and virulence determinants, and could provide novel perspectives on basic cell biology systems.
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