FIG. 3.

Expression of mCD14, mTLR4, or mMD-2 alone does not impart responsiveness to Salmonella lipid A. THP-1 cells were transiently transfected with either a control vector (mock) or a plasmid for mCD14, mTLR4, or mMD-2 (all 0.1 μg) together with the pELAM-L luciferase reporter plasmid. After 24 h, the cells were stimulated for 6 h without (none) or with 10 ng of E. coli lipid A/ml (ELA) or 100 ng of Salmonella lipid A/ml (SLA) in the presence of 10% (vol/vol) FCS, and the luciferase activities were measured. The values are means ± standard errors of the means from seven independent experiments. ∗, P < 0.05 compared with the respective responses in mock-transfected cells by two-tailed Student's t test.