Figure 9.

Inhibition of lipopolysaccharide (LPS)-induced IRF3 activation by caffeic acid phenethyl ester (CAPE) is dependent on Cys133 in MD2. (A) 293T cells were transfected with the expression plasmids of TLR4, TRIF and IFN-β PRDIII-I-luc with MD2 wild-type (WT) or MD2 (C133S). (B) 293T cells were transfected with the expression plasmids for TLR4 and NFκB-luc with MD2 (WT) or MD2 (C133S). (A, B) Cells were pre-treated with CAPE for 1 h and then stimulated with LPS (10 ng mL⁻¹) for an additional 8 h. Cell lysates were analysed for luciferase and β-galactosidase activities to determine relative luciferase activity. *Significantly different from LPS alone with MD2 (WT). +, significantly different from LPS alone with MD2 (C133S), P < 0.05. N.S., not significant.