Lack of TLR5-dependent NF-κB activation by flagellin-deficient <i>B</i>. <i>pseudomallei</i>.

HEK293 cells were transiently transfected with empty vector pEF6 (EV) or TLR5, NF-κB-dependent firefly ELAM luciferase, and control Renilla luciferase. Cells were unstimulated or stimulated with IL-1β 20 ng/ml, Salmonella Typhimurium flagellin 500 ng/ml (Flg), wildtype B. pseudomallei 1026b (BP) or B. pseudomallei 1026b lacking fliC, the gene that encodes flagellin (ΔfliC) at a range of bacteria:cell ratios for 24 hours. NF-κB activation was measured by luciferase assay (ratio of ELAM/Renilla luciferase signal expressed as relative light units). Mean values ± standard deviations of triplicate conditions are displayed. *, P≤0.05; **, P≤0.01 comparing TLR5-transfected to empty vector-transfected cells using the t test. One representative example of two independent experiments is shown.