Subcellular fractionation of resting and IFN-γ–stimulated eosinophils (5 × 10⁷ per fractionation). These experiments were conducted at different times using purified blood eosinophils from the same donor. Immunoreactivity to RANTES was determined in individual fractions by ELISA and expressed as pg/fraction. Profiles of EPO activity are shown here for comparison. (A) Unstimulated eosinophils, followed by eosinophils stimulated for (B) 10 minutes and (C) 60 minutes with 500 U/mL IFN-γ.