Figure 3.

Preincubation with IRX-2 protects CD8⁺ Jurkat cells from MV-induced DNA fragmentation. (A) Fluorescent microscopy of CD8⁺ Jurkat cells that were either untreated (a), incubated for 24 h with IRX-2 alone (b) or MV alone for 24 h (c) or preincubated with IRX-2 for 24 h and subsequently treated with MV for 24 h (d) and then stained by the TUNEL method to reveal DNA strand breaks (red nuclei) indicative of apoptosis. (B) Percentage of TUNEL-positive CD8⁺ Jurkat cells in the above cocultures. A minimum of 300 CD8⁺ Jurkat cells were counted for each treatment group. Results are expressed as the mean percentages±S.D. of two independent experiments (*P<0.0002 compared to MV-treated sample). (C) Antiapoptotic effects of IRX-2 require a pretreatment of T cells. CD8⁺ Jurkat cells were untreated, treated with IRX-2 (1 : 3 dilution) for 24 h (+ IRX), MV for 3 h (+ MV), preincubated with IRX-2 for 24 h and then treated with MV (10 μg) for 3 h (+ IRX→MV) or first incubated with MV and then treated with IRX-2 (+ MV→IRX-2) or incubated with both agents simultaneously (+ MV and IRX) for 3 h 24 + + or h, respectively. Activation of caspases was analyzed by flow cytometry. Results are mean percentages±S.D. from a representative experiment out of three experiments performed (*P<0.002 compared to MV-treated sample)