Analysis of HCV-LP binding to cell lines stably expressing TLR2 and 4. (A) Cell surface expression of TLR2 and TLR4 in CHO-CD14, CHO-CD14/TLR2, and CHO-CD14/TLR4 cells. CHO cell lines⁵⁵  were incubated with anti-TLR2, anti-TLR4, or isotype-matched control mAbs and analyzed for cell surface expression of TLR2 and TLR4 by flow cytometry. Open curves represent TLR-specific staining; gray shaded curves show staining with isotype-matched control Abs. (B) HCV-LP binding to the human hepatoma cell line Huh-7³¹  and TLR-transfected CHO cell lines. Cells were incubated with HCV-LPs for 1 hour at 4°C and HCV-LP binding was quantified by flow cytometry. Data are shown as Δ MFI (mean ± SD) of a representative experiment performed in triplicate. (C) Binding of HCV-LPs to imDCs in the presence of anti-TLR antibodies. ImDCs were preincubated with anti-TLR2, anti-TLR4, or control mAb (50 μg/mL) prior to the addition of HCV-LPs and cellular HCV-LP binding was analyzed as described in Figure 3A. Data are shown as percentage binding relative to the binding of HCV-LPs without antibody preincubation (100%). Mean ± SD of 3 experiments is shown (HCV-LP binding in the absence of antibody = 100%).