Fig. 6. HCV dsRNAs need to have a minimal length of ~80-100 bp to activate TLR3 signaling.
(A) Gel electrophoresis of in vitro synthesized HCV dsRNAs with various length. The 50-, 100- and 250-bp long dsRNAs were all derived from E2/p7-coding region, while the 1860-bp dsRNA was synthesized from the entire E1-p7 coding sequence. (B) 7.5-TLR3 cells were mock-treated, incubated in culture medium or transfected with the indicated HCV dsRNA for 6 h. Induction of RANTES mRNA was determined by qPCR. (C) qPCR analysis of RANTES mRNA induction in 7.5-TLR3 cells transfected with individual HCV dsRNAs of the specified lengths. “*” and “**” denote statistical differences exist when compared with mock-treated cells with a p-value of <0.05 and <0.01, respectively. The lower panel shows gel electrophoresis of the individual HCV dsRNAs used.