Fig. 1

Initial translation and its importance for the HCV life cycle. a Representation of replicons and full-length viruses used in this study (FLUC firefly luciferase, NL nano luciferase). 5′UTR/IRES elements are indicated. The box shows an enlarged schematic of the miR-122-binding sites in the 5′ UTR. b Quantification of mature miR-122 by stem-loop qRT-PCR in naïve Huh7.5 cells, a Huh7.5 miR-122 knock-out cell clone (Huh7.5^ΔmiR), Hep3B cells before (Hep3B), and after (Hep3B^+miR) electroporation of miR-122 mimic. All values were normalized to miR-23b levels, which is homogenously expressed in hepatic cells. c Binding of wild type miR-122 (miR^WT) to a target RNA (HCV^WT) and influence of seed mutations (miR^mut). d Comparison of HCV replication in different cell lines by luciferase assay after co-electroporation of reporter replicons (Luc-SG) and miR^WT or miR^mut into Hep3B cells. Reporter activity was measured at 4 and 48 h. e Luciferase assay of initial translation (left panel) and replication (right panel) of subgenomic HCV. f Luciferase assay to determine the effects of PV IRES-driven polyprotein translation on the viral life cycle (PI-Luc-SG). g, h Confirmation of results from (e) and (f), using full length reporter viruses (Luc-FL, PI-Luc-FL). n.d. not detectable. Mean values (±SD), n = 3, in technical duplicates. RLU relative light units, ΔGDD replication deficient mutant. For translation, statistical significance was determined for miR^WT against miR^mut; for replication HCV + miR^mut was tested against ΔGDD. *P<0.05, **P<0.01, *P<0.001