IRF3-CL inhibits IKKε-mediated and SeV-triggered nuclear translocation of IRF3. (a) HEK293 cells were transfected with pEGFP-IRF3-CL with or without pRK-HA-IKKε. The expression of IKKε was confirmed by immunofluorescence of the same cells with anti-HA antibody. (b) HEK293 cells were transfected with pEGFP-IRF3-CL. After 24 h, cells were infected with SeV or left uninfected for 8 h. (c) HEK293 cells were transfected with pDsRed-IRF3 with or without pRK-HA-IKKε. After 24 h, cells were infected with SeV or left uninfected for 8 h. (d) HEK293 cells were cotransfected with pDsRed-IRF3 and pEGFP-IRF3-CL. (e) HEK293 cells were transfected with pDsRed-IRF3, pEGFP-IRF3-CL and pRK-HA-IKKε. (f) HEK293 cells were cotransfected with pDsRed-IRF3 and pEGFP-IRF3-CL. After 24 h, cells were infected with SeV or left uninfected for 8 h. Images represent 70–100% of the cells in the cultures. HA, hemagglutinin; IKKε, inhibitor of NF-κB kinase-ε IRF3, interferon regulatory factor-3; Sev, Sendai virus.