Figure 2: Dose-response of the TLR4 antagonist B. quintana LPS.

Human PBMCs were isolated from healthy subjects, using a standard protocol. PBMCs were pre-incubated with a dose-range of B. quintana LPS (10–1000 ng/ml) for 2 h. Thereafter, 10 ng/ml E. coli LPS was added and the PBMCs were cultured for another 24 h. IL-6 was determined by using ELISA (A). (B) Percentage inhibition was calculated using the IL-6 concentration of E. coli LPS exposure as 100%. PBMCs of 6 subjects were used in this experiment. IC50 was 37.04 ng/ml. *P < 0.001, two-sided Mann-Whitney U test.