HTLV-1– and HTLV-2–transformed cell lines as well as HTLV-1 cells from patients are sensitive to As₂O₃.

(A) HTLV-1– or HTLV-2–transformed cells (C8166, HUT-102, C19), (B) HTLV-1 IL-2–dependent cells lines from TSP/HAM or ATL patients (Boul, Bes), (C) ATL cells from patients (PH868 and PH878), and (D) non-HTLV control cell lines (CEM, MOLT-4, T2) were treated with buffer control, IFN-α, As₂O₃ or IFN-α + As₂O₃ for 60 hours and then processed using the XTT assay kit. Panels A, B, and D represent the mean of 3 independent experiments performed in duplicate. Panel C represents the mean of 2 independent experiments.