Exosome-mediated transmission of hepatitis C virus between human hepatoma Huh7.5 cells.

Abstract

Recent evidence indicates there is a role for small membrane vesicles, including exosomes, as vehicles for intercellular communication. Exosomes secreted by most cell types can mediate transfer of proteins, mRNAs, and microRNAs, but their role in the transmission of infectious agents is less established. Recent studies have shown that hepatocyte-derived exosomes containing hepatitis C virus (HCV) RNA can activate innate immune cells, but the role of exosomes in the transmission of HCV between hepatocytes remains unknown. In this study, we investigated whether exosomes transfer HCV in the presence of neutralizing antibodies. Purified exosomes isolated from HCV-infected human hepatoma Huh7.5.1 cells were shown to contain full-length viral RNA, viral protein, and particles, as determined by RT-PCR, mass spectrometry, and transmission electron microscopy. Exosomes from HCV-infected cells were capable of transmitting infection to naive human hepatoma Huh7.5.1 cells and establishing a productive infection. Even with subgenomic replicons, lacking structural viral proteins, exosome-mediated transmission of HCV RNA was observed. Treatment with patient-derived IgGs showed a variable degree of neutralization of exosome-mediated infection compared with free virus. In conclusion, this study showed that hepatic exosomes can transmit productive HCV infection in vitro and are partially resistant to antibody neutralization. This discovery sheds light on neutralizing antibodies resistant to HCV transmission by exosomes as a potential immune evasion mechanism.

• Authors: Vedashree Ramakrishnaiah, Christine Thumann, Isabel Fofana, Francois Habersetzer, Qiuwei Pan, Petra E de Ruiter, Rob Willemsen, Jeroen A A Demmers, Victor Stalin Raj, Guido Jenster, Jaap Kwekkeboom, Hugo W Tilanus, Bart L Haagmans, Thomas F Baumert, Luc J W van der Laan
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 110 Issue 32 Pg. 13109-13 (Aug 06 2013) ISSN: 1091-6490 [Electronic] United States
• PMID: 23878230 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Neutralizing
• CD81 protein, human
• Claudin-1
• Immunoglobulin G
• RNA, Viral
• SCARB1 protein, human
• Scavenger Receptors, Class B
• Tetraspanin 28

Topics

• Antibodies, Neutralizing (immunology)
• Carcinoma, Hepatocellular (metabolism, pathology, virology)
• Cell Line, Tumor
• Claudin-1 (immunology, metabolism)
• Exosomes (metabolism, ultrastructure, virology)
• Hepacivirus (genetics, immunology, physiology)
• Hepatitis C (immunology, virology)
• Host-Pathogen Interactions
• Humans
• Immunoglobulin G (immunology)
• Mass Spectrometry
• Microscopy, Confocal
• Microscopy, Electron, Transmission
• RNA, Viral (genetics, metabolism)
• Reverse Transcriptase Polymerase Chain Reaction
• Scavenger Receptors, Class B (immunology, metabolism)
• Tetraspanin 28 (immunology, metabolism)
• Virion (genetics, physiology, ultrastructure)