FIG. 6.

IRF-7 is involved in repression of HHV-8 RTA-mediated transactivation upon treatment by IFN-α. (A) TRE×BCBL-1 RTA cells were cultured for 24 h in the presence or absence of IFN-α2b and subsequently induced with 1 μg of tetracycline/ml. At 8 h after induction, the cells were harvested and total protein (10 μg) was analyzed by Western blotting with the anti-His₆, anti-RTA, anti-IRF-7, anti-ORF 57, and anti-β-tubulin antibodies. The TRE×BCBL1 cells were treated with tetracycline and used as negative controls. (B) BJAB or DG75 cells were electroporated with pCMV-Tag50 and various amounts of IRF-7i and subsequently cultured in the presence or absence of 100 U of IFN-α2b/ml. Luciferase activity was measured. The expression levels of IRF-7 and β-tubulin in cell lysate (10 μg of total protein) were analyzed by Western blotting using anti-IRF-7 and anti-β-tubulin antibodies.