Human papillomavirus types 16, 31, and 58 use different endocytosis pathways to enter cells

Abstract

The early steps of the intracellular trafficking of human papillomavirus type 16 (HPV-16), -31, and -58 pseudovirions were studied by investigating the effects of drugs acting at defined points of endocytosis pathways on virus-like particle-mediated pseudoinfection by overexpression of a dominant-negative form of the Eps15 protein to inhibit clathrin-mediated endocytosis and by electron microscopy. The results obtained suggested the involvement of clathrin-mediated endocytosis in HPV-16 and HPV-58 entry and caveola-mediated endocytosis in HPV-31 entry.

FIG. 1.

Gene transfer of HPV-16 and -31 L1 pseudovirions and HPV-31 and -58 L1-plus-L2 pseudovirions in COS-7 cells (results obtained using 5 μg of VLPs per well).

FIG. 2.

HPV-16 and HPV-31 cell internalization. HPV-16 VLPs (A to E) and HPV-31 VLPs (F to J) are shown. The electron micrographs show cells after incubation with VLPs at 4°C (A and G) and at 37°C for 10 min (B, F, and H), 20 min (C and I), and 1 h (D, E, and J). Bars, 150 nm. Cav, caveolae; Cla, clathrin-coated vesicles.