Exosomes from hepatitis C infected patients transmit HCV infection and contain replication competent viral RNA in complex with Ago2-miR122-HSP90

PLoS Pathog. 2014 Oct 2;10(10):e1004424. doi: 10.1371/journal.ppat.1004424. eCollection 2014 Oct.

Abstract

Antibodies targeting receptor-mediated entry of HCV into hepatocytes confer limited therapeutic benefits. Evidence suggests that exosomes can transfer genetic materials between cells; however, their role in HCV infection remains obscure. Here, we show that exosomes isolated from sera of chronic HCV infected patients or supernatants of J6/JFH1-HCV-infected Huh7.5 cells contained HCV RNA. These exosomes could mediate viral receptor-independent transmission of HCV to hepatocytes. Negative sense HCV RNA, indicative of replication competent viral RNA, was present in exosomes of all HCV infected treatment non-responders and some treatment-naïve individuals. Remarkably, HCV RNA was associated with Ago2, HSP90 and miR-122 in exosomes isolated from HCV-infected individuals or HCV-infected Huh7.5 cell supernatants. Exosome-loading with a miR-122 inhibitor, or inhibition of HSP90, vacuolar H+-ATPases, and proton pumps, significantly suppressed exosome-mediated HCV transmission to naïve cells. Our findings provide mechanistic evidence for HCV transmission by blood-derived exosomes and highlight potential therapeutic strategies.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Argonaute Proteins / metabolism
  • Cells, Cultured
  • Exosomes / metabolism*
  • HSP90 Heat-Shock Proteins / metabolism
  • Hepacivirus / physiology*
  • Hepatocytes / virology*
  • Humans
  • MicroRNAs / metabolism
  • Protein Binding
  • RNA, Viral / genetics*
  • Receptors, Virus / isolation & purification
  • Virus Replication / physiology

Substances

  • AGO2 protein, human
  • Argonaute Proteins
  • HSP90 Heat-Shock Proteins
  • MIRN122 microRNA, human
  • MicroRNAs
  • RNA, Viral
  • Receptors, Virus