Statistical analyses were performed using Welch’s two-sample t test, Kolmogorov-Smirnoff’s test, and, alternatively, Wilcoxon’s test (for more than five biological replicates). P values <0.1 were considered marginal significant, <0.05

was considered statistically Ridaforolimus purchase significant, whereas <0.01 was considered highly significant. HCV viral load, HCV genotype, and liver biopsies from patients with chronic hepatitis C (CHC; n = 24) were obtained in the context of routine diagnostic workup. Grading and staging of CHC was performed according to the Metavir classification. All patients gave written informed consent in accord with local ethical committees. RNA was extracted with TRIzol reagent (Invitrogen, Carlsbad, CA), according to the manufacturer's instructions. Additional methods can be found in the Supporting Materials. Recently, we reported that the human hepatoblastoma

cell line, HuH6, supports efficient HCV RNA replication and production of infectious virus particles.[8] However, these cells were refractory to infection with the GT2a/2a chimeric virus, Jc1. The poor permissiveness of HuH6 cells to GT2a infection was linked to low endogenous CLDN1 expression in these cells, because CD81, SCARB-1, and OCLN were highly expressed and because ectopic expression of CLDN1 rendered the cells susceptible to Jc1.8 To analyze whether the resistance of HuH6 cells was limited to HCV GT2a viruses, we challenged click here these cells with HCVpp bearing the glycoproteins of different HCV GTs on their surface and transducing a luciferase-expressing lentiviral vector (Fig. 1A). Huh-7.5 cells, highly permissive to HCV infection of multiple HCV isolates, were used as control. As expected, Huh-7.5 cells were infected by all tested HCVpp, as evidenced by high expression of luciferase 72 hours postinoculation (Fig. 1A). Moreover, we confirmed that HuH6 cells were resistant to GT2a pseudoparticles (J6 and JFH1). Surprisingly, however, these cells were readily infected

with GT1a- Phosphoglycerate kinase (H77 isolate) and GT1b-derived (Con1 isolate) HCVpp (Fig. 1A). To extend this finding, we challenged both cell lines with HCVcc of different JFH1-based infectious chimeras representing HCV genotypes 1 through 710 (Fig. 1B). Despite low CLDN1 expression in HuH6 cells (Fig. 1C),[8] these cells were permissive to infection by H77c (GT1a), Con1 (GT1b) and J4 (GT1b), J8 (GT2b), S52 (GT3a), ED43 (GT4a), and HK6a (GT6a) particles (Fig. 1B). In contrast, Jc1 carrying J6-derived glycoproteins (GT2a), JFH1 (GT2a), SA13 (GT5a), and QC69 (GT7a) viruses did not infect these cells, suggesting that absence of CLDN1 expression in HuH6 cells limits infection by these strains. To quantify strain-specific differences between susceptibility of Huh-7.5 and HuH6 cells, we calculated the fold difference of the infectious titer for each virus chimera toward these two cell lines (Supporting Fig. 1).