Figure 1.

Impaired IFNγ responsiveness in ICSBP−/− cells. (a) RNA expression of IFNγ-inducible genes was examined by quantitative reverse transcription–PCR in ICSBP+/+ or −/− peritoneal macrophages stimulated with IFNγ for indicated times. iNos, induction of nitric oxide synthase; FcγRI, Fcγ receptor I; hprt, hypoxanthine-guanine phosphoribosyl transferase. (b) NO production in ICSBP+/+ and −/− macrophages after stimulation with IFNγ for 72 h. The values represent the average of measurements from three independent pools of two to three animals ± SD. (c) IFNγ induction of IRF-1 and ICSBP in RAW and CL-2 cells. Immunoblotting was performed with cells treated with IFNγ for 12 h. (d) Impaired GAS reporter activity in ICSBP−/− cells. RAW and CL-2 cells were transiently transfected with luciferase reporters containing WT or mt GAS. Values represent five determinations ±SD. (e) Electrophoretic mobility-shift assay analysis was performed with 10 μg of nuclear extracts from RAW or CL-2 cells treated with IFNγ for 8 h by using ³²P-labeled, single-copy WT-GAS oligonucleotide as a probe. (f) GAS sequences (8, 17); the ICSBP WT and mt sequences were used in this work.