Inhibition of LPS-induced activation of TLR4/MD-2 by LpxL1 LPS. HeLa 57A cells transfected with hTLR4, hMD-2, and hCD14 were stimulated with purified H44/76 LPS, LpxL1 LPS, or mixtures of these LPS preparations at ratios of 1:1 and 1:10 (1 = 10 ng/ml). After 5 h of incubation, NF-κB luciferase activities were measured. Values are expressed in RLU and represent the means ± SEMs for the results of at least three experiments.