FIG. 3.

SAP prevents the HDL-mediated neutralization of LPS. HDL (30 μg/ml) was preincubated with ReLPS (A) and O111:B4 LPS (B) (1 ng/ml) in the presence of increasing amounts of SAP (0 to 10 μg/ml) for 90 min at 37°C at a volume of 20 μl. Then, 80 μl of undiluted heparinized human blood was added, and the mixture was incubated for 30 min at 37°C. The chemiluminescence response was measured for 10 min after automated injection of fMLP and luminol to 10-fold-diluted blood samples in a luminometer. The background (BG) represents the chemiluminescence response in the absence of LPS and HDL. Data represent the fold increase of the 10-min integral (area under the curve [AUC]) ± SEM of four separate experiments compared to the background.