Fig. 2

Early autoregulation of IL-27 at the infection site and evidence of MRSA-induced secretion of IL-27 by macrophages and osteoblasts but not by osteoclasts. a Female WT and IL-27Rα^−/− mice (n = 3–5) were challenged with a sterile or a MRSA (USA300 LAC::lux)-contaminated transtibial implant, and the infected tibiae were harvested at the indicated times to measure IL-27 protein levels in bone tissue homogenates via ELISA. b Cultured RAW264.7 cells and primary murine bone marrow-derived macrophages differentiated with PBS, IFN-γ (50 ng·mL⁻¹) or IL-4 (20 ng·mL⁻¹) to generate M0, M1 and M2 macrophages, respectively, were exposed to S. aureus USA300 for 24 h (MOI = 1, 10, 50). Subsequently, culture supernatants were collected and assessed for IL-27p28 via ELISA. c Cultured murine calvarial MC3T3-E1 osteoblasts and primary bone marrow-derived osteoblasts were exposed to S. aureus USA300 for 24 h (MOI = 1, 10, 50), and culture supernatants were assessed for IL-27 via ELISA. d Cultured murine primary bone marrow-derived osteoclasts were exposed to S. aureus USA300 (MOI = 1, 10, 50), and supernatants were assessed for IL-27p28 via ELISA. The data from each experiment are presented with the mean ± SD for the group (n = 3–5) (*P < 0.05, **P < 0.01, ***P < 0.001 ****P < 0.000 1, ANOVA)