The authors demonstrate that the lipid phosphatidylinositol-5-phosphate (PtdIns5P) is increased upon viral infection and facilitates type I IFN production by binding to IRF3 and its upstream kinase TBK1 and promoting TBK1-mediated IRF3 phosphorylation and activation. Additionally, they determine that PtdIns5P is produced through the kinase PIKfyve, which phosphorylates PtdIns to generate PtdIns5P.
PtdIns5P produced during viral infection is a second messenger that targets the TBK1-IRF3 axis to elicit antiviral immunity.

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Contact:

Shizuo AKIRA
Host Defense
Immunology Frontier Research Center (WPI-IFReC), Osaka University