FIG 3.

Adaptive mutations result in increased HCV assembly. CD81-deficient S29 cells (32) were transfected with the HCV RNA transcripts indicated, as described in Materials and Methods. (A and B) Intracellular Core titers were determined at 4, 12, 24, 36, and 48 h posttransfection (A), and extracellular Core titers were determined at 12, 24, 36 and 48 h posttransfection (B) as described in Materials and Methods. Intra- and extracellular Core titers are shown as percent Core at the indicated time point, relative to intracellular Core measured 4 h posttransfection. Measurements were performed in duplicate and are shown with SEM. (C and D) Intracellular (C), and extracellular (D) HCV infectivity titers were determined at 12, 24, 36, and 48 h posttransfection. Intracellular infectivity titers are shown as the means (focus-forming units per well) from three replicates with SEM. Extracellular infectivity titers are shown as means (focus-forming units per milliliter) from three replicates with SEM. For infectivity titers, the lower limits of detection were determined for each individual experiment and are indicated by a y axis break. For Core titers, the asterisks indicate values below cutoff.