FIG 4.

Determinants within domain 2 of core critically affect the induction of IFN-α responses by pDC. (A) Lunet N cells were transfected with Jc1, JFH1, or JFH1 chimeras encoding different portions of the J6CF isolate, as indicated. In the schematic overview of the constructs used, J6CF-derived genome segments are depicted in white, whereas JFH1-derived genes are shown in gray. (B) After 24 h of incubation, cells transfected with the construct depicted in panel A were cocultured with pDC for 18 h, and IFN-α was assessed in the cell culture supernatant by an ELISA method (pDC, n ≥ 5). **, P = 0.0078; *, P = 0.0156 (Wilcoxon test). (C) Immunofluorescence analysis of Lunet N cells transfected with JFH1, Jc1, or the different core chimeras stained for NS3, as shown in panel A. (D) Lunet N cells were transfected with chimeras containing one of the three domains of the J6-derived core protein. Then, the transfectants were cocultured with pDC for 18 h, and IFN-α was assessed in the supernatant by an ELISA method (pDC, n = 9). ***, P = 0.001; **, P ≤ 0.0039 (Wilcoxon test). The error bars indicate SEM.