FIG. 10.

SR-BI mediates HCVcc uptake into DCs. (A) For analysis of HCVcc entry, DCs were incubated with PBS (left panel) or iodixanol gradient-purified JFH1 HCVcc (right panels) at 37°C as described in Materials and Methods. Internalized HCVcc were detected by immunofluorescence using a monoclonal anti-HCV E2 antibody (red fluorescence). For costaining of cytoplasmic structures, cells were coincubated with an antiactin antibody (green fluorescence). The nucleus is stained with DAPI (4′,6′-diamidino-2-phenylindole) (blue fluorescence). Arrows indicate HCVcc E2 protein. To study whether HCVcc uptake is mediated by SR-BI, DCs were preincubated with purified anti-SR-BI IgG or control IgG as described in Materials and Methods. (B) HCVcc uptake was quantified by counting the average number of cells with positive staining for HCVcc E2 protein per total cells (n = 300) in the presence or absence of purified anti-SR-BI IgG or control IgG. Results shown are the means and standard deviations of the results of three independent experiments (from three different DC preparations and two donors) performed in duplicate (number of HCV E2-positive cells for DCs incubated with HCVcc in the absence of purified antibody, 100%). Statistical significance of differences between the number of E2-positive DCs following preincubation with purified anti-SR-BI IgG compared to DCs preincubated with purified control IgG was determined by the two-tailed t test.