title: Entry of human rhinovirus 89 via ICAM-1 into HeLa epithelial cells is inhibited by actin skeleton disruption and by bafilomycin.
abstract: HRV89, a major-group rhinovirus, uses intercellular adhesion molecule 1 (ICAM-1) for cell entry, while minor-group HRV2 uses the LDL receptor for clathrin-mediated endocytosis. Entry of HRV89 into HeLa epithelial cells was found to be inefficient, and infectious virus was still detected on the plasma membrane after 3 h of incubation with the cells. Endocytosis, and consequently infection, of HRV89 but not of HRV2, was almost completely blocked by the actin-polymerization inhibitor cytochalasin D, while the phosphatidylinositol 3-kinase inhibitor LY294002 had no effect on infection with either virus. Cytochalasin D also inhibited major-group HRV infection of rhabdomyosarcoma cells expressing ICAM-1 when the time available for uncoating was limited to 30 min. Although cholesterol depletion strongly inhibited HRV89 infection of HeLa cells, it only slightly affected HRV89 endocytosis, indicating that a lipid raft environment was not essential for virus uptake. The sodium-proton exchange inhibitor 5-(N-ethyl-N-isopropyl) amiloride (EIPA) significantly reduced cell entry and infection by HRV89 only at a concentration that also inhibited HRV2 infection and Alexa 488-transferrin entry. These data rule out classical macropinocytosis as an infectious entry pathway of HRV89 in HeLa cells. Notably, the proton ATPase inhibitor bafilomycin strongly affected cell entry of both viruses, suggesting a role for submembraneous pH in rhinovirus endocytosis.
authors.affiliation: Institute for Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria, beatrix.pfanzagl@meduniwien.ac.at.
authors.forename: Beatrix
authors.initials: B
authors.lastname: Pfanzagl
authors.forename: Daniel
authors.initials: D
authors.lastname: Andergassen
authors.forename: Johanna
authors.initials: J
authors.lastname: Edlmayr
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Niespodziana
authors.forename: Rudolf
authors.initials: R
authors.lastname: Valenta
authors.forename: Dieter
authors.initials: D
authors.lastname: Blaas
mesh_terms: D000199:Actins / Q000378:metabolism*; D015638:Cytochalasin D / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D004847:Epithelial Cells / Q000378:metabolism* / Q000821:virology; D006367:HeLa Cells; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D018942:Macrolides / Q000494:pharmacology*; D010850:Picornaviridae Infections / Q000378:metabolism / Q000821:virology*; D011991:Receptors, Virus / Q000235:genetics / Q000378:metabolism; D012229:Rhinovirus / Q000187:drug effects / Q000502:physiology*; D053586:Virus Internalization
chemical_list: D000199:Actins; D018942:Macrolides; D011991:Receptors, Virus; D018799:Intercellular Adhesion Molecule-1; D015638:Cytochalasin D; C040929:bafilomycin A1