Caveola-dependence for DENV-3 entry.

<p>(A) Cells were pretreated with nystatin or methyl-β-cyclodextrin. Then monolayers were washed and infected with DENV-3. After 1h of internalization, cells were treated with proteinase K and the cell pellets were plated onto Vero cells to determine internalized virus by an infectious centre assay. (B) Cells transiently transfected with GFP-cav-1 wt, GFP-cav-1 DN or GFP-cav-1 Y14F were infected with DENV-3. After 24 h, cells were fixed and viral antigen expression was visualized by immunofluorescence staining using mouse anti-E glycoprotein antibody and TRITC-labelled anti-mouse IgG. (C) For quantification of samples shown in B, 250 transfected cells with similar levels of GFP expression were screened and cells positive for viral antigen were scored. In (A) and (C) results are expressed as the mean of three independent experiments ± SD. Asterisks indicate statistical significance (* <i>p</i> < 0.05, ** <i>p</i> < 0.01).