title: Role of rsbU and staphyloxanthin in phagocytosis and intracellular growth of Staphylococcus aureus in human macrophages and endothelial cells.
abstract: In Staphylococcus aureus, rsbU down-regulates agr and stimulates production of staphyloxanthin (STX), an antioxidant that may contribute to intracellular survival after phagocytosis. Using isogenic rsbU(-) and rsbU(+) strains, we show that rsbU causes increased internalization and intracellular growth in both THP-1 macrophages and human umbilical vein endothelial cells (more so for the latter) without change in subcellular localization and that inhibition of STX biosynthesis markedly reduces intracellular growth of the rsbU(+) strain (and of clinical isolates, including USA300; tested with macrophages only) without affecting internalization. Thus, rsbU is important for uptake and for STX biosynthesis and is critical for intracellular multiplication of S. aureus.
authors.affiliation: Unité de pharmacologie cellulaire et moléculaire and Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Aurélie C
authors.initials: AC
authors.lastname: Olivier
authors.forename: Sandrine
authors.initials: S
authors.lastname: Lemaire
authors.forename: Françoise
authors.initials: F
authors.lastname: Van Bambeke
authors.forename: Paul M
authors.initials: PM
authors.lastname: Tulkens
authors.forename: Eric
authors.initials: E
authors.lastname: Oldfield
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002460:Cell Line; D042783:Endothelial Cells / Q000382:microbiology*; D006801:Humans; D008264:Macrophages / Q000382:microbiology*; D010587:Phagocytosis; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000254:growth & development* / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology; D024341:Xanthophylls / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D024341:Xanthophylls; C031841:staphyloxanthin; D010744:Phosphoric Monoester Hydrolases; C091162:RsbU protein, Bacillus subtilis