FIG 6.

Peptide 4F-mediated lipid raft depletion from ABCA1-expressing cells inhibits DENV attachment to the cell membrane. (A) RAW 264.7 cells were incubated with NS1 for 24 h, in the presence of different concentrations of peptide 4F. Secreted NO was quantified from culture supernatants by the Griess assay. (B) ABCA1-expressing cells were incubated with 50 μg/ml peptide 4F for 2 h. Cells were fixed and labeled with CTB-FITC, and lipid rafts were analyzed by flow cytometry. The MFI of CTB was quantified relative to control cells incubated with PBS (pH 7.4). (C) ABCA1-expressing cells were incubated with peptide 4F for 2 h and then challenged with DENV2 for 1 h at 4°C for viral attachment. Unbound virus was washed out with PBS, and total RNA was extracted. vRNA was quantified by qRT-PCR. Error bars represent the SDs of at least three independent experiments. Asterisks represent significant differences, compared to control. ***, P < 0.001.