title: Crimean-Congo hemorrhagic fever virus utilizes a clathrin- and early endosome-dependent entry pathway.
abstract: The early events in Crimean-Congo hemorrhagic fever virus (CCHFV) have not been completely characterized. Earlier work indicated that CCHFV likely enters cells by clathrin-mediated endocytosis (CME). Here we provide confirmatory evidence for CME entry by showing that CCHFV infection is inhibited in cells treated with Pitstop 2, a drug that specifically and reversibly interferes with the dynamics of clathrin-coated pits. Additionally, we show that CCHFV infection is inhibited by siRNA depletion of the clathrin pit associated protein AP-2. Following CME entry, we show that CCHFV has a pH-dependent entry step, with virus inactivation occurring at pH 6.0 and below. To more precisely define the endosomal trafficking of CCHFV, we show for the first time that overexpression of the dominant negative forms of Rab5 protein but not Rab7 protein inhibits CCHFV infection. These results indicate that CCHFV likely enters cells through the early endosomal compartment.
authors.affiliation: United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Maryland, USA.
authors.forename: Aura R
authors.initials: AR
authors.lastname: Garrison
authors.forename: Sheli R
authors.initials: SR
authors.lastname: Radoshitzky
authors.forename: Krishna P
authors.initials: KP
authors.lastname: Kota
authors.forename: Gianluca
authors.initials: G
authors.lastname: Pegoraro
authors.forename: Gordon
authors.initials: G
authors.lastname: Ruthel
authors.forename: Jens H
authors.initials: JH
authors.lastname: Kuhn
authors.forename: Louis A
authors.initials: LA
authors.lastname: Altamura
authors.forename: Steven A
authors.initials: SA
authors.lastname: Kwilas
authors.forename: Sina
authors.initials: S
authors.lastname: Bavari
authors.forename: Volker
authors.initials: V
authors.lastname: Haucke
authors.forename: Connie S
authors.initials: CS
authors.lastname: Schmaljohn
mesh_terms: D033962:Adaptor Protein Complex 2 / Q000378:metabolism; D002966:Clathrin / Q000378:metabolism*; D022163:Clathrin-Coated Vesicles / Q000821:virology*; D004705:Endocytosis; D003225:Hemorrhagic Fever Virus, Crimean-Congo / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053586:Virus Internalization; D020691:rab GTP-Binding Proteins / Q000378:metabolism; D020696:rab5 GTP-Binding Proteins / Q000378:metabolism; D000090802:rab7 GTP-Binding Proteins
chemical_list: D033962:Adaptor Protein Complex 2; D002966:Clathrin; D000090802:rab7 GTP-Binding Proteins; C000716463:rab7 GTP-binding proteins, human; D020691:rab GTP-Binding Proteins; D020696:rab5 GTP-Binding Proteins
keywords: Bunyavirus; CCHF; Crimean–Congo hemorrhagic fever; Nairovirus; Virus entry