Analysis of the infectious entry pathway of human papillomavirus type 33 pseudovirions.
Human papillomavirus type 33 (HPV-33) pseudovirus infection is a slow process dependent on the initial interaction with cell-surface heparan sulfate (T. Giroglou, L. Florin, F. Schafer, R. E. Streeck, and M. Sapp, 2001a, J. Virol. 75, 1565-1570). We have now further dissected the initial steps of pseudovirus uptake using removal of cell-surface proteoglycans and selective inhibition of entry pathways. Treatment of cells with heparinase I, but not with phosphoinositol-specific phospholipase C (PIPLC), prevented binding of papillomavirus-like particles and infection with HPV-33 pseudovirions, indicating that GPI-linked proteoglycans (glypicans) are not required for productive infection. The slow entry of pseudovirions was inhibited by cytochalasin D and nocodazole in a concentration-dependent manner, suggesting actin polymerization and intact microtubuli be required. Inhibitors of the caveolae-mediated uptake did not significantly affect pseudoinfection. Interestingly, pseudoinfection was blocked by selective inhibitors of endosomal acidification up to 12 h postinfection. Together, our results suggest that binding of HPV pseudovirions to heparan sulfate proteoglycans, most likely syndecans, is followed by delayed internalization via the endosomal pathway.
Selinka
Hans-Christoph
HC
Institute for Medical Microbiology and Hygiene, Johannes Guterberg University of Mainz, Hochhaus am Augustusplatz, D-55101 Mainz, Germany. selinka@mail.uni-mainz.de
Giroglou
Tzenan
T
Sapp
Martin
M
D000199:Actins / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D019556:COS Cells; D006367:HeLa Cells; D019812:Heparan Sulfate Proteoglycans / Q000502:physiology; D006801:Humans; D018942:Macrolides; D008870:Microtubules / Q000502:physiology; D009761:Nystatin / Q000494:pharmacology; D027383:Papillomaviridae / Q000502:physiology*; D014771:Virion / Q000502:physiology*
D000199:Actins; D000900:Anti-Bacterial Agents; D019812:Heparan Sulfate Proteoglycans; D018942:Macrolides; D009761:Nystatin; C040929:bafilomycin A1