Fig. 4

SNOC inhibits IL-2 mRNA expression only during the induction phase. EL4-6.1 cells were incubated without (lane 1) or with 1000 U/ml IL-1β (lanes 2–8) for 3 hr. Cells were incubated with IL-1β 30 min prior to addition of 0.5 mM SNOC (lane 2), 1 mM SNOC (lane 3) or 1 mM SNOC_−NO (lane 4). Cells were also treated the other way round. After culture in the absence (lane 5) or presence of 0.5 mM SNOC (lane 6), 1 mM SNOC (lane 7), or 1 mM SNOC_−NO (lane 8) for 30 min, cells were incubated with IL-1β for 3 hr. Results show that NO must be present during the induction phase to inhibit IL-2 mRNA expression. Values are mean ± SD of three independent experiments.