Open AccessPhosphatidylinositol‐3‐kinase (PI3K) is activated by influenza virus vRNA via the pathogen pattern receptor Rig‐I to promote efficient type I interferon production
Author(s) -
Hrincius Eike R.,
Dierkes Rüdiger,
Anhlan Darisuren,
Wixler Viktor,
Ludwig Stephan,
Ehrhardt Christina
Publication year - 2011
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/j.1462-5822.2011.01680.x
Subject(s) - rig i , biology , mda5 , virology , interferon , influenza a virus , virus , pi3k/akt/mtor pathway , phosphatidylinositol , kinase , signal transduction , microbiology and biotechnology , receptor , rna , innate immune system , rna interference , gene , genetics
Summary The phosphatidylinositol‐3‐kinase (PI3K) was identified to be activated upon influenza A virus (IAV) infection. An early and transient induction of PI3K signalling is caused by viral attachment to cells and promotes virus entry. In later phases of infection the kinase is activated by the viral NS1 protein to prevent premature apoptosis. Besides these virus supporting functions, it was suggested that PI3K signalling is involved in dsRNA and IAV induced antiviral responses by enhancing the activity of interferon regulatory factor‐3 (IRF‐3). However, molecular mechanisms of activation remained obscure. Here we show that accumulation of vRNA in cells infected with influenza A or B viruses results in PI3K activation. Furthermore, expression of the RNA receptors Rig‐I and MDA5 was increased upon stimulation with virion extracted vRNA or IAV infection. Using siRNA approaches, Rig‐I was identified as pathogen receptor necessary for influenza virus vRNA sensing and subsequent PI3K activation in a TRIM25 and MAVS signalling dependent manner. Rig‐I induced PI3K signalling was further shown to be essential for complete IRF‐3 activation and consequently induction of the type I interferon response. These data identify PI3K as factor that is activated as part of the Rig‐I mediated anti‐pathogen response to enhance expression of type I interferons.