FIG. 2.

SeV-induced IFN production activates Jak/STAT signaling and ISG induction. (A) U937 cells were infected with SeV (150 HA U/mL) for 4, 8, 16, and 24 h. Nuclear and cytoplasmic protein extracts were prepared and western blots probing for pIRF-3(S386), IRF-3, IRF-7, and IRF-9 were performed. RNA pol II and β-tubulin were the nuclear and cytoplasmic loading controls, respectively. N, nuclear, C, cytoplasmic. (B) U937 cells were infected with SeV (150 HA U/mL) for 4, 8, 16, and 24 h and whole cell protein lysates were prepared. Western blots probing for pSTAT1(Y701), STAT1(total), pSTAT2(Y689), STAT2(total), ISG15, and IFIT3, and tubulin as the loading control were performed. (C) A549 cells were infected with SeV (150 HA U/mL) for 4, 8, 16, and 24 h and whole protein lysates were prepared. Western blots probing for pSTAT1(Y701), STAT1(total), pSTAT2(Y689), STAT2(total), IRF-9, IRF-7, and Mx1, and tubulin as the loading control were performed. (D) ISG15 and IFIT3 mRNA expression in U937 cells infected with SeV (150 HA U/mL) for 4, 8, 16, and 24 h. (E) IRF-7 and Mx1 mRNA expression in A549 cells infected with SeV (150 HA U/mL) for 4, 8, 16, and 24 h. IRF-7 and Mx1 mRNA induction in (F) primary monocytes and (G) Namalwa cells infected with SeV (150 HA U/mL) for 24 h. All gene induction data are expressed as the % of relative HPRT expression. All data are representative of 3 independent biological replicates. UI, uninfected, untreated. IRF, IFN regulatory factor; ISG, interferon-stimulated gene; HPRT, hypoxanthine-guanine phosphoribosyltransferase.