FIGURE 1.

Cleavage of HCV RNA by RNase L produces small RNAs with PAMP activity. (A) Activation of the IFN-β promoter after 18 h in Huh7 cells in response to transfection with undigested or RNase L-digested HCV RNA segments. (B) RNase L releases svRNA3 from two adjacent stem–loops in the NS5B region of the HCV open reading frame. (C) Detection of RNase L-mediated cleavage product of HCV RNA (svRNA3) in Huh7.5 cells at 96 h after electroporated with full-length HCV genomic RNA or a region of HCV RNA encoding svRNA3 (nt 8703–9416) as determined in a Northern blot (upper) (Materials and Methods). Small RNAs, <200 nt (10 μg), and 100 ng of svRNA3 were stained with gelstar (Cambrex Bio Science) (lower).