FIG 4.

EGFR and Abl2 regulate pit induction and dilation/maturation, respectively. (A to C) HeLa ATCC cells were treated with 25 μM Iressa (B) or 25 μM imatinib (C) for 30 min or were left untreated (A) and subsequently infected with HPV16 PsVs. Cells were fixed at 6 h p.i., and endocytic pits were analyzed by ultrathin section TEM. (D) Virus-containing plasma membrane invaginations were counted and normalized to untreated control cells. At least 10 cells were counted per experiment in several independent experiments, excluding nilotinib where only one experiment was done. (E) The amount of virus-filled atypical pits per cell (e.g., in panel C) was determined and normalized to the amount of atypical pits in control cells.