PilT is required for PI(3,4,5)P3-mediated crosstalk between Neisseria gonorrhoeae and epithelial cells.
The retractile type IV pilus participates in a number of fundamental bacterial processes, including motility, DNA transformation, fruiting body formation and attachment to host cells. Retraction of the N. gonorrhoeae type IV pilus requires a functional pilT. Retraction generates substantial force on its substrate (> 100 pN per retraction event), and it has been speculated that epithelial cells sense and respond to these forces during infection. We provide evidence that piliated, Opa non-expressing Neisseria gonorrhoeae activates the stress-responsive PI-3 kinase/Akt (PKB) pathway in human epithelial cells, and activation is enhanced by a functional pilT. PI-3 kinase inhibitors wortmannin and LY294002 reduce cell entry by 81% and 50%, respectively, illustrating the importance of this cascade in bacterial invasion. PI-3 kinase and its direct downstream effectors [PI(3,4,5)P3] and Akt are concentrated in the cell cortex beneath adherent bacteria, particularly at the periphery of the bacterial microcolonies. Furthermore, [PI(3,4,5)P3] is translocated to the outer leaflet of the plasma membrane. Finally, we show that [PI(3,4,5)P3] stimulates microcolony formation and upregulates pilT expression in vitro. We conclude that N. gonorrhoeae activation of PI-3 kinase triggers the host cell to produce a lipid second messenger that influences bacterial behaviour.
Lee
Shaun W
SW
Department of Molecular Microbiology and Immunology, L220, Oregon Health and Science University, Portland, OR 97239-3098, USA.
Higashi
Dustin L
DL
Snyder
Aurelie
A
Merz
Alexey J
AJ
Potter
Laura
L
So
Magdalene
M
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000730:Androstadienes / Q000494:pharmacology; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000378:metabolism* / Q000382:microbiology; D010861:Fimbriae, Bacterial / Q000378:metabolism*; D006801:Humans; D020409:Molecular Motor Proteins / Q000378:metabolism*; D009025:Morpholines / Q000494:pharmacology; D009344:Neisseria gonorrhoeae / Q000378:metabolism / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D011485:Protein Binding; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction; D015854:Up-Regulation; D000077191:Wortmannin
D000251:Adenosine Triphosphatases; D000730:Androstadienes; D001426:Bacterial Proteins; D002867:Chromones; D020409:Molecular Motor Proteins; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D010716:Phosphatidylinositols; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D000077191:Wortmannin; C118303:phosphoinositide-3,4,5-triphosphate; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one