IFN-α inhibits PPIX-induced Δψ_m loss in the clonal Th2 cells.

CD3⁻CD4⁺ cells from hypereosinophilic patient 1 were cultured for 24 hours in presence of PPIX (30 μmol/L). IFN-α (10⁴ IU/mL) was added at the beginning of the culture. At the end of the culture, cells were stained for 15 minutes at 37°C with DiOC₆ followed by flow cytometry analysis using gating on live cells. The histograms represent DiOC₆ staining of Th2 cells obtained from patient 1 at time 0 (black histogram), after 24 hours of culture in the absence (solid lines) or presence (broken lines) of IFN-α.