Fig. 2
Purified SitC-SC induced ten times higher TLR2 signaling than SitC-SA. (a) The Coomassie blue-stained SDS page of purified SitC from S. carnosus (SitC-SC), S. carnosus pCX-lnt (SitC-SClnt), and S. aureus SA113 (SitC-SA); M, size standard. (b) IL-8 production (pg/ml) after 18-h stimulation of permanent TLR2-transfected HEK cells with purified SitC from S. carnosus (SitC-SC), S. carnosus pCX-lnt (SitC-SClnt), and S. aureus SA113 (SitC-SA) with different concentrations (50, 100, and 250 ng/ml). For positive controls, synthetic Lpp Pam2CSK4 (P2C) and Pam3CSK4 (P3C) were applied in the same concentration (500 ng/ml). The experiments in triplicate were conducted at least three times. Error bars indicate standard error. Statistical significances were calculated by using Student’s t tests or analysis of variance (ANOVA): not significant P > 0.05, *P < 0.05, **P < 0.01, ***P < 0.001. (c) Monocyte-derived dendritic cells (MoDC) were left unstimulated (Ø) or stimulated with 0.1 µg/ml SitC-SC or SitC-SA and 0.1 μg/ml P2C, P3C, or nonstimulatory P1C, respectively; cytokines in the cell-free supernatants were measured after 16 h by ELISA. Levels of IL-6, TNF, and IL-12p40 are displayed as the mean of n = 8 independent donors ± SEM. Statistical significance was calculated using the Wilcoxon matched-pairs signed rank test. *P < 0.05, **P < 0.01. (d) TNF production (pg/ml) after 4-h stimulation of MonoMac6 (MM6) with purified SitC from S. carnosus (SitC-SC), S.carnosus pCX-lnt (SitC-SClnt), and S. aureus SA113 (SitC-SA) with different concentrations (50, 100, and 250 ng/ml). For positive controls, P2C and P3C were applied in the same concentration (200 ng/ml). The experiments in triplicate were conducted at least three times. Error bars indicate standard error. Statistical significances were calculated by using Student’s t tests or analysis of variance (ANOVA): not significant P > 0.05, *P < 0.05, **P < 0.01, ***P < 0.001
