Time Courses of the augmentation of IL-6 mRNA expression and protein production induced by coactivation of TLR4 and TLR2/6. A. Kinetics of IL-6 mRNA expression and protein production in response to LPS (a and b), pam2CSK4 (d and d) or LPS plus pam2CSK4 (e and f). U937 cells were treated with 100 ng/ml of LPS, 100 ng/ml of pam2CSK4 or both for 2, 4, 8, 12, 24, or 36 h. At each time point, RNA was isolated from cells for quantification of IL-6 mRNA using real-time PCR; culture medium was collected for quantification of IL-6 protein production using ELISA. The data presented are the representative of 3 independent experiments with similar results. B. Augmentation of IL-6 mRNA expression (a), IL-6 protein production (b), MMP-1 mRNA expression (c) and MMP-1 protein production (d) by activation of TLR4, TLR2/6, or TLR4 and TLR2/6. U937 cells were treated with 100 ng/ml of LPS, 100 ng/ml of pam2CSK4 or LPS plus pam2CSK4 for 2, 4, 12 or 24 h. Culture medium and cells were collected at each time point. IL-6 and MMP-1 mRNA was quantified using real-time PCR and IL-6 and MMP-1 protein in culture medium was quantified using ELISA. The data presented are the representative of 3 independent experiments with similar results.