Effects of PTXL preincubation on the intracellular IL-12 (p40/p70) production of human monocytes. Monocytes were preincubated with medium, LPS (50 ng/mL), or PTXL (10 μmol/L) for 24 hours. Subsequently, cells were stimulated with 300 U/mL IFN-γ and 50 ng/mL LPS for another 24 hours. The percentage of monocytes positive for IL-12 (p40/p70) or IL-6 as detected by flow cytometric measurement are shown. Results are given as mean ± SEM of 5 independent experiments, performed with cells from different donors.