RRC ID 45142
Author Nagashima S, Jirintai S, Takahashi M, Kobayashi T, Tanggis, Nishizawa T, Kouki T, Yashiro T, Okamoto H.
Title Hepatitis E virus egress depends on the exosomal pathway, with secretory exosomes derived from multivesicular bodies.
Journal J Gen Virol
Abstract Our previous studies indicated that hepatitis E virus (HEV) forms membrane-associated particles in the cytoplasm, most likely by budding into intracellular vesicles, and requires the multivesicular body (MVB) pathway to release virus particles, and the released HEV particles with a lipid membrane retain the trans-Golgi network protein 2 on their surface. To examine whether HEV utilizes the exosomal pathway to release the virus particles, we analysed whether the virion release from PLC/PRF/5 cells infected with genotype 3 HEV (strain JE03-1760F) is affected by treatment with bafilomycin A1 or GW4869, or by the introduction of a small interfering RNA (siRNA) against Rab27A or Hrs. The extracellular HEV RNA titre was increased by treatment with bafilomycin A1, but was decreased by treatment with GW4869. The relative levels of virus particles released from cells depleted of Rab27A or Hrs were decreased to 16.1 and 11.5 %, respectively, of that released from cells transfected with negative control siRNA. Electron microscopic observations revealed the presence of membrane-associated virus-like particles with a diameter of approximately 50 nm within the MVB, which possessed internal vesicles in infected cells. Immunoelectron microscopy showed positive immunogold staining for the HEV ORF2 protein on the intraluminal vesicles within the MVB. Additionally, immunofluorescence analysis indicated the triple co-localization of the ORF2, ORF3 and CD63 proteins in the cytoplasm, as specific loculated signals, supporting the presence of membrane-associated HEV particles within the MVB. These findings indicate that membrane-associated HEV particles are released together with internal vesicles through MVBs by the cellular exosomal pathway.
Volume 95(Pt 10)
Pages 2166-2175
Published 2014-10-1
DOI 10.1099/vir.0.066910-0
PMID 24970738
MeSH Cell Line Exosomes / metabolism* Hepatitis E virus / physiology* Hepatocytes / ultrastructure Hepatocytes / virology Humans Microscopy, Electron, Transmission Microscopy, Fluorescence Microscopy, Immunoelectron Multivesicular Bodies / metabolism* Virus Release*
IF 3.376
Times Cited 76
WOS Category BIOTECHNOLOGY & APPLIED MICROBIOLOGY VIROLOGY
Resource
Human and Animal Cells Hep G2(RCB0459) A549(RCB0098)