TLR-specific activation of whole blood by Gram-positive bacteria. Dose-dependent induction of IL-6 secretion by heat-inactivated Gram-positive bacteria (L monocytogenes, B subtilis, S aureus) in human whole blood (A). Error bars show ± SEM. Inhibitory effects of anti-TLR4, anti–MD-2, anti-TLR2, and anti-CD14 mAbs on the activation of cells by 106/mL L monocytogenes and B subtilis, and 107/mL S aureus (B). The different points per condition represent experiments performed with 3 different healthy blood donors. Because the magnitude of IL-6 production was variable among different donors, results are given as the percentage of inhibition of IL-6 release compared with the condition with the isotype control antibody (corresponding to 100% activation). Horizontal bars represent the mean.
