Inhibition of E-induced CXCL8 production by an NF-kB inhibitor but not by P38 and ERK1/2 MAP kinase and PKC inhibitors. (A) Inhibition of the E-induced CXCL8 chemokine in the presence of an NF-kB inhibitor. HEK-TLR2 cells were stimulated with the E protein (200 ng/mL) in the presence of the chemical inhibitor of NF-kB, Bay11, used at 1 and 10 µM. Production of CXCL8 in cell supernatants was quantified by ELISA. (B) HEK-TLR2 cells were pretreated with P38 MAP kinase inhibitor SB202190 (0.1–10 µM), ERK1/2 MAP kinase inhibitor PD 98059 (1–100 µM) or PKC inhibitor RO318220 (0.1–10 µM) for 1 h, before stimulation with the E protein (200 ng/mL). Produced CXCL8 in cell supernatants was quantified by ELISA. (C) The cytotoxicity of the used chemical inhibitors: SB202190, PD98059 and RO318220, was tested in a trypan blue exclusion assay at the used concentrations. Statistical significance comparing different groups is denoted with * for p < 0.05, ** for p < 0.01 and *** for p < 0.001, while ns means non-significant.