Reduced ATL cell growth and induction of apoptosis by abrogation of I-309 signaling.

To block the I-309 receptor (CCR8), ATL (JuanaW) and control (MT-2, HuT-78) cells were incubated with increasing amounts of pertussis toxin for 48 hours. (A) Reduced cell proliferation was calculated from [³H]-thymidine incorporation experiments as described in the legend to Figure 5. In contrast to ATL cells (JuanaW), the proliferation rates of HTLV-1⁺ (MT-2) and HTLV-1⁻ (HuT-78) control cells were not altered. (B) Detection of apoptotic cells by modified propidium iodide staining.53 Columns reflect the means of 3 to 4 independent experiments ± SD. (C) Detection of an early apoptosis marker by annexin V staining (one representative of 3 independent experiments is shown).