Galectins induce PS exposure in fMLP-activated human neutrophils. (A) fMLP-activated or resting neutrophils were treated with either PBS, 3 μM Gal-4, or 3 μM Gal-4 plus 30 mM TDG for 4 hours, as indicated, followed by analysis of PS exposure using annexin-V. (B) fMLP-activated neutrophils were incubated with either 10 μM Gal-1, 10 μM Gal-2, 3 μM Gal-4, or 100 ng/mL anti-Fas for 8 hours followed by detection for PS exposure. (C) fMLP-activated neutrophils were incubated with either 10 μM Gal-1, 10 μM Gal-2, 3 μM Gal-4, or 100 ng/mL anti-Fas for 8 hours followed by detection for DNA degradation (TUNEL assay). (D) fMLP-activated neutrophils were incubated with either 10 μM Gal-1, 10 μM Gal-2, 3 μM Gal-4, or 100 ng/mL anti-Fas for 8 hours followed by flow cytometric analysis for the percentage of cells exhibiting shrinkage. Results shown are the averages of duplicate analyses and are representative of at least 2 separate experiments. Error bars represent the standard deviation of duplicate samples.