The p110α and p110β Isoforms of Class I Phosphatidylinositol 3-Kinase Are Involved in Toll-Like Receptor 5 Signaling in Epithelial Cells

Background. Bacterial flagellin triggers inflammation in mammalian cells via Toll-like receptor (TLR) 5. Release of the chemokine IL-8 in response to flagellin involves NF-κB, p38 MAP kinase, and phosphatidylinositol 3-kinase (PI3K). However, PI3K has been reported to be either pro- or anti-inflamma...

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Bibliographic Details
Main Authors: Sabine M. Ivison, Mohammed A. S. Khan, Nicholas R. Graham, Leila A. Shobab, Yu Yao, Arnawaz Kifayet, Laura M. Sly, Theodore S. Steiner
Format: Article
Language:English
Published: Wiley 2010-01-01
Series:Mediators of Inflammation
Online Access:http://dx.doi.org/10.1155/2010/652098
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Summary:Background. Bacterial flagellin triggers inflammation in mammalian cells via Toll-like receptor (TLR) 5. Release of the chemokine IL-8 in response to flagellin involves NF-κB, p38 MAP kinase, and phosphatidylinositol 3-kinase (PI3K). However, PI3K has been reported to be either pro- or anti-inflammatory in different model systems. We hypothesized that this could be due to different activities of the p110α and β isoforms of PI3K. Results. PI3K and Akt were rapidly activated in Caco-2 colon carcinoma cells by flagellin. Using a plasmid-based shRNA delivery system and novel p110 isoform-specific inhibitors, we found that flagellin-induced IL-8 production was dependent on both p110α and p110β. However in the mouse, inhibition of p110β but not p110α reduced the increase of serum IL-6 levels induced by intraperitoneal injection of flagellin. Conclusions. These data demonstrate that the p110α and β isoforms of class IA PI3K are both required for the proinflammatory response to flagellin.
ISSN:0962-9351
1466-1861