The CoA-IT inhibitor, SK&F 98625, induced eosinophil apoptosis in vitro. (A) Human eosinophils were cultured for 7 to 24 hours alone, or with SK&F 98625 at 0, 1, or 10 μM (as marked). DNA was harvested and apoptosis was indicated by the banding pattern of the resulting DNA ladder (3 μg total DNA per lane, one example shown). (B) Human eosinophils were cultured for 0 to 72 hours alone (control, solid bars), or with SK&F 98625 at 20 μM (hatched bars) or 40 μM (open bars). Apoptosis was measured as the percent of eosinophils expressing surface phosphatidylserine (annexin V binding). Samples were taken at 0, 24, 48, or 72 hours. *P < 0.05 between control and SK&F 98625 at each time point. (C) The experiment was repeated by adding IL-5 alone (50 pg/ml, solid bars) to human eosinophils in culture for 0 to 72 hours or in combination with SK&F 98625 at 20 μM (hatched bars) or 40 μM (open bars). Apoptosis was again measured as the percent of eosinophils expressing surface phosphatidylserine. *Significant differences of P < 0.05 between IL-5 alone and SK&F 98625 + IL-5 at each time point (n = 3–4 separate cell preparations).