Fig. 7.

Differential activation of NF-κB by TLR4 ligands. (A) RAW-Blue, (B), THP-1 Dual, (C) mTLR4 HEK-Blue and (D) hTLR4 HEK-Blue cell lines were stimulated with biological and synthetic BECC438 or BECC470, MPL or PHAD over a five-log dilution series. SEAP activity was measured using Quanti-Blue at an optical density of 620 nm. When RAW-Dual cells with TLR4 knocked out were tested as a negative control, no detectable FN-κB activity was seen for any of these lipid A analogues or for E. coli BORT LPS (not shown). Mean results ± SD are graphed with a sigmoidal nonlinear regression of best fit.