FIG 2.
Adapted SA13/JFH1orig recombinants show accelerated spread and higher infectivity titers after transfection and infection at different MOIs. (A) Different SA13/JFH1orig mutants were generated; HCV RNA transcripts were transfected into Huh7.5 cell cultures as described in Materials and Methods. From transfection cultures, supernatants were collected at day 3 posttransfection, and infectivity titers were determined. (B and C) Second-passage virus stocks generated from transfection supernatants, polyclonal serially passaged virus stocks described in Fig. 1 and Table 1, and control virus stock J6/JFH1 were used to infect Huh7.5 cell cultures at an MOI of 0.003 (B) or 0.0003 (C). From these, supernatants were collected and infectivity titers were determined. (A, B, and C) Supernatant infectivity titers are shown as means (focus-forming units per milliliter) from three replicates with SEM. The lower limits of detection were determined for each individual experiment and are indicated by a y axis break.