GILZ overexpression protects CTLL-2 cells from interleukin-2 deprivation–mediated apoptosis through down-regulation of Bim expression. (A) Randomly selected control or Myc-GILZ–overexpressing CTLL-2 clones were deprived of IL-2 for the indicated period of time. Cells were then stained with propidium iodide and analyzed for DNA hypodiploidy by flow cytometry. Of 3 representative experiments, 1 is shown. Right hand panel: Western blot analysis of Myc-GILZ–expressing clones. (B-C) Clones overexpressing GILZ (4 and 6) and control clones (1 and 2) were deprived of IL-2 and lysed at the indicated period of time. (B) Western blot was performed using an anti-Bim antibody. After stripping, membranes were reblotted with an anti–β Tubulin antibody as a loading control. Bim expression was quantified by densitometric analysis and normalized to the densitometric value of the β Tubulin (ratio Bim/β Tubulin). (C) Total RNA was extracted and used as a template for RT-PCR using primers specific for Bim or β actin. Bim expression was quantified by densitometric analysis and normalized to the densitometric value of the β actin (ratio Bim/β actin).