title: Phosphatidylinositol 3-kinases in carcinoembryonic antigen-related cellular adhesion molecule-mediated internalization of Neisseria gonorrhoeae.
abstract: Neisseria gonorrhoeae can be internalized by mammalian cells through interactions between bacterial opacity-associated (Opa) adhesins and members of the human carcinoembryonic antigen-related cellular adhesion molecule (CEACAM) family. We examined the role of phosphatidylinositol 3-kinases (PI3Ks) in gonococcal invasion of epithelial cell lines expressing either CEACAM1 or CEACAM3. CEACAM3-mediated internalization, but not that mediated by CEACAM1, was accompanied by localized and transient accumulation of the class I PI3K product phosphatidylinositol 3,4,5-trisphosphate at sites of bacterial engulfment. Inhibition of phosphatidylinositol 3-kinases reduced CEACAM3-mediated uptake but, paradoxically, led to an increase in intracellular survival of bacteria internalized via either CEACAM1 or CEACAM3, suggesting additional roles for PI3K products. Consistent with this finding, the class III PI3K product phosphatidylinositol 3-phosphate accumulated and persisted in the membrane of gonococcal phagosomes after internalization. Inhibition of PI3K blocked phagosomal acquisition of the late endosomal marker lysosome-associated membrane protein 2 and reduced phagosomal acidification. Inhibiting phagosomal acidification with concanamycin A also increased survival of intracellular gonococci. These results suggest two modes of action of phosphatidylinositol 3-kinases during internalization of gonococci: synthesis of phosphatidylinositol 3,4,5-trisphosphate is important for CEACAM3-mediated uptake, while phosphatidylinositol 3-phosphate is needed for phagosomal maturation and acidification, which are required for optimal bacterial killing.
authors.affiliation: Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario M5S 1A8, Canada.
authors.forename: James W
authors.initials: JW
authors.lastname: Booth
authors.forename: David
authors.initials: D
authors.lastname: Telio
authors.forename: Edward H
authors.initials: EH
authors.lastname: Liao
authors.forename: Shannon E
authors.initials: SE
authors.lastname: McCaw
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Matsuo
authors.forename: Sergio
authors.initials: S
authors.lastname: Grinstein
authors.forename: Scott D
authors.initials: SD
authors.lastname: Gray-Owen
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015703:Antigens, CD / Q000378:metabolism*; D000943:Antigens, Differentiation / Q000378:metabolism*; D002272:Carcinoembryonic Antigen / Q000378:metabolism*; D015815:Cell Adhesion Molecules; D002455:Cell Division; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D004351:Drug Resistance; D011992:Endosomes / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000378:metabolism / Q000382:microbiology; D005839:Gentamicins / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008247:Lysosomes / Q000378:metabolism; D018942:Macrolides; D018613:Microscopy, Confocal; D009025:Morpholines / Q000494:pharmacology; D009344:Neisseria gonorrhoeae / Q000378:metabolism; D010588:Phagosomes / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism / Q000502:physiology*; D010957:Plasmids / Q000378:metabolism; D013997:Time Factors; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D000900:Anti-Bacterial Agents; D015703:Antigens, CD; D000943:Antigens, Differentiation; D002272:Carcinoembryonic Antigen; D015815:Cell Adhesion Molecules; D002867:Chromones; D004791:Enzyme Inhibitors; D005839:Gentamicins; D018942:Macrolides; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D000077191:Wortmannin; C069847:CD66 antigens; C075729:CEACAM3 protein, human; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C036978:concanamycin A