FIG. 8.
Induction of TNF-α or IL-10 in MonoMac 6 cells by S. aureus wild type and the lgt mutant (A through C) or crude extract (D). For time-dependent studies with bacteria, MonoMac 6 cells were infected with a ratio of 40:1. Dose-dependent stimulation was determined after 8 h. Panels A and C show one representative experiment of three, each carried out in duplicate. In panel B, data of three different experiments carried out in duplicate are shown. Panel D illustrates one representative experiment carried out with three separate crude extract preparations. Crude extract was derived from overnight cultures in DMEM-F-12, and the indicated amounts were added to 106 monocytes; 10 μg of the crude extract (wet weight)/ml corresponds to 2.6 × 106 bacteria. Error bars indicate standard deviation. Filled circles, S. aureus SA113 wild type; open circles, the isogenic lgt::erm mutant; gray diamonds, complemented lgt mutant; gray triangles, medium.