IL-2–induced Stat5-dependent transcription is inhibited by JAB/SOCS1/SSI-I^WT.

YT cells were transfected using the DEAE dextran method according to standard protocols with 2 μg β-casein luciferase reporter, 20 ng pRL-TK control reporter, and with or without 5 μg JAB/SOCS1/SSI-1^WT cDNA. Twenty-four hours later the cells were either left untreated or stimulated with 10 nM IL-2 for 24 hours. The data are the mean ± SD of normalized luciferase values of 4 experiments. The normalized luciferase values (average ± SD) of cells transfected with control plasmid were 2.3 ± 0.7 and 12.6 ± 4.3, and the values of JAB/SOCS1/SSI-1^WT–transfected cells were 1.8 ± 0.1 and 2.2 ± 0.4.