Fig. 2.

Effect of surfactant on the surface TLR-4 expression in A549 cells. The cells were preincubated with surfactant lipid preparations Survanta® (250 μg/ml) (A) or DPPC (500 μg/ml) (B) and the surface TLR4 expression determined by flow cytometry with phycoerythrin-conjugated anti-human TLR4. “Cells only” indicates untreated A549 cells stained with anti-TLR4 antibody. Mean fluorescence index (%); cells only 67.02 ± 17.9; DPPC-treated cells 70.08 ± 19.2 and Survanta®-treated cells 72.3 ± 20.4 (NS). Background autofluorescence was produced by A549 cells without antibody. Representative flow cytometry histograms from three independent experiments are shown.