Expression of TRAIL mRNA in IFNα-stimulated neutrophils and PBMCs. (A) Neutrophils were stimulated for 3 hours with 100 U/mL IFNα, 10 ng/mL GM-CSF, 100 ng/mL LPS, and 10 nM fMLP before total RNA extraction and analysis of TRAIL, IL-1ra, and actin mRNA expression by Northern blotting. (B) Neutrophils and PBMCs, purified from the same donor, were cultured for the times indicated with or without 100 U/mL IFNα and then subjected to Northern blot analysis for TRAIL, FasL, IL-1ra, and actin mRNA expression. Time 0 indicates RNA extraction in freshly isolated leukocytes. Data are representative of at least 2 independent experiments for each panel.