The effect of IL-3, IL-5 and GM-CSF neutralization on the antiapoptotic effect of TNF-α in human eosinophils.

Eosinophils were incubated with the IgG1 isotype control or the indicated neutralizing antibody to IL-3, IL-5 or GM-CSF (each at 10 µg/ml) and various concentrations of TNF-α for 40 hours. Apoptosis was assessed by measuring the relative DNA content of propidium iodide-stained cells by flow cytometry and is expressed as percentage of control, where the corresponding value obtained in the absence of TNF-α is set as 100%. Results are means ± SEM of 5–6 independent determinations using eosinophils from different donors.