Fig 2.

Role of TLR4 and NF-κB in NhhA-induced cytokine release. (A) RAW 264.7 macrophages were preincubated with or without (control) 1 μM CLI-095 (TLR4 inhibitor), 5 μM Celastrol (NF-κB inhibitor), or 1 μM polymyxin B (PMB) for 1 h. Thereafter, cells were stimulated with NhhA (400 nM, 20 h), and the release of IL-6 and TNF was determined by ELISA. *, P < 0.05 versus NhhA-treated control. (B) RAW 264.7 macrophages were preincubated with or without (control) 1 μM CLI-095 or 1 μM polymyxin B for 1 h. Thereafter, cells were stimulated with 500 ng/ml E. coli LPS for 20 h, and the release of IL-6 and TNF was determined by ELISA. Values indicate means ± SD from three independent experiments. *, P < 0.05 versus LPS-treated control.