FIG. 9.

Cytokine induction in human whole blood by S. aureus cells, supernatants, and synthetic lipopeptides. Fresh blood samples were treated for 5 h with either bacteria (A) or bacterial culture supernatants (B through D). (C and D) Synthetic lipopeptides were added to the bacterial supernatants (diluted 50% with medium) at the indicated concentrations prior to stimulation of the blood samples. Values are means of three (A) or four (B) different experiments, each carried out in duplicate. Panels C and D show one representative experiment of three, carried out in triplicate. Error bars indicate standard deviations. Filled circles, S. aureus SA113 wild type; open circles, the isogenic lgt::ermP mutant; gray diamonds, complemented lgt mutant; gray triangles, medium (control).