B. pseudomallei activates TLR2 and TLR4. HEK293 cells were transiently transfected with (A) murine or (B) human TLR2, TLR2/1, TLR2/6, or TLR4; co-receptors CD14 and MD-2; and NF-κB-dependent firefly ELAM luciferase and control β-actin-dependent Renilla luciferase. In (C) HEK293 cells were transiently transfected with human TLR4 and co-receptor CD14 with or without MD-2; and firefly ELAM and Renilla luciferases. Cells were stimulated with media alone, (B) IL-1β 20 ng/mL, (A & B) Pam3CSK4 100 ng/mL, E. coli 0111:B4 LPS 10 ng/mL, or heat-killed BP-1 at various concentrations in CFU/mL. NF-κB activation was measured by light emission (relative light units). In (A&B) data plotted are means ± standard deviations of triplicate conditions. In (C) the means ± standard deviations of triplicate human TLR4-mediated relative light units (normalized to mean empty vector values) are plotted from parallel experiments with or without co-transfection of MD-2. For (A & B) * indicates p < 0.05 and § indicates p = 0.001 compared with empty vector stimulated with the same ligand, and † indicates p < 0.05 compared with TLR2 stimulated with the same ligand using analysis of variance followed by the Bonferroni post-test. Other comparisons are not shown for clarity. The data in (A) represent one of two independently performed experiments. The data in (B) represent one of three independently performed experiments, but the data displayed, in contrast to the two other experiments, show the response to a hyper-responding variant TLR1 plasmid. The data in (C) represent one of three independently performed experiments.
West et al. BMC Immunology 2008 9:46 doi:10.1186/1471-2172-9-46