Effect of ritonavir on the growth and induction of apoptosis of HTLV-I-infected cell lines and freshly isolated ATL cells. (A) Dose-response effect of ritonavir on the growth of HTLV-I-infected cell lines. Cells (105/mL) were cultured for 72 hours in the presence of various concentrations (2.5-40 μM) of ritonavir. Cell growth was assessed by the water-soluble tetrazolium (WST)-8 method and is expressed as a percentage of control (untreated cells) and represents the mean of triplicate cultures. (B) Effect of ritonavir on induction of apoptosis of HTLV-I-infected cell lines. Cells were cultured for 72 hours with ritonavir (40 μM), and apoptosis was measured by Apo2.7 immunostaining. Data represent the mean percentages of apoptotic cells from both untreated (□) and ritonavir-treated (▪) cells. (C) Dose-response effect of ritonavir on induction of apoptosis of MT-4 and HUT-102 cells. (D) Dose-response effect of ritonavir on the cell viability of freshly isolated ATL cells. Cells (106/mL) were cultured for 72 hours in the presence of various concentrations (2.5-40 μM) of ritonavir. (E) Dose-response effect of ritonavir on induction of apoptosis of ATL cells.
