• Open Access

Semliki Forest virus strongly reduces mosquito host defence signaling

Authors

  • R. Fragkoudis,

    1. The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK;
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    • §

      These authors contributed equally to this manuscript.

  • Y. Chi,

    1. The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK;
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    • Present address: Institute of Biomedical Sciences, Academia Sinica Division of Infectious Diseases No.128, Sec. 2, Academia Rd. Nankang Taipei 11 529 Taiwan, ROC.

    • §

      These authors contributed equally to this manuscript.

  • R. W. C. Siu,

    1. The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK;
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    • §

      These authors contributed equally to this manuscript.

  • G. Barry,

    1. The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK;
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  • G. Attarzadeh-Yazdi,

    1. The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK;
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  • A. Merits,

    1. Institute of Technology, University of Tartu, Nooruse Str. 1, Tartu 50411, Estonia
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  • A. A. Nash,

    1. The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK;
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  • J. K. Fazakerley,

    1. The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK;
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  • A. Kohl

    1. The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK;
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  • Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.

Alain Kohl, The Roslin Institute & Royal (Dick) School of Veterinary Studies, College of Medicine & Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, UK. Fax: +44 (0)131 650 6511; Phone: +44 (0)131 6513907; e-mail: Alain.Kohl@ed.ac.uk.

Abstract

The Alphavirus genus within the Togaviridae family contains several important mosquito-borne arboviruses. Other than the antiviral activity of RNAi, relatively little is known about alphavirus interactions with insect cell defences. Here we show that Semliki Forest virus (SFV) infection of Aedes albopictus-derived U4.4 mosquito cells reduces cellular gene expression. Activation prior to SFV infection of pathways involving STAT/IMD, but not Toll signaling reduced subsequent virus gene expression and RNA levels. These pathways are therefore not only able to mediate protective responses against bacteria but also arboviruses. However, SFV infection of mosquito cells did not result in activation of any of these pathways and suppressed their subsequent activation by other stimuli.

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