Peroxisomes support human herpesvirus 8 latency by stabilizing the viral oncogenic protein vFLIP via the MAVS-TRAF complex

PLoS Pathog. 2018 May 10;14(5):e1007058. doi: 10.1371/journal.ppat.1007058. eCollection 2018 May.

Abstract

Human herpesvirus 8 (HHV-8) is causally related to human malignancies. HHV-8 latent viral FLICE-inhibitory protein (vFLIP) is a viral oncoprotein that is linked to pathogenesis, but how its expression is regulated is largely unknown. In an attempt to understand the role of the mitochondrial antiviral signaling (MAVS) adaptor in HHV-8 infection, we discovered that vFLIP expression was post-translationally up-regulated by the MAVS signaling complex on peroxisomes. Furthermore, we demonstrated that vFLIP could be targeted to the peroxisomes, where it was oncogenically active, in a PEX19-dependent manner. Targeted disruption of vFLIP and MAVS interaction resulted in a decrease in vFLIP expression and selectively promoted death of latently HHV-8-infected cells, providing therapeutic potential for treating HHV-8 diseases. Collectively, our experimental results suggest novel involvement of peroxisomes and MAVS in the stabilization of vFLIP and thereby in the establishment or maintenance of HHV-8 latency and associated pathogenesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Autophagy
  • Cell Line
  • Gene Knockout Techniques
  • HEK293 Cells
  • Herpesvirus 8, Human / genetics
  • Herpesvirus 8, Human / immunology
  • Herpesvirus 8, Human / physiology*
  • Humans
  • Immunoblotting
  • Lymphoma, B-Cell / pathology
  • Peroxisomes / metabolism
  • Peroxisomes / physiology*
  • Peroxisomes / virology
  • Real-Time Polymerase Chain Reaction
  • Tumor Cells, Cultured
  • Tumor Necrosis Factor Receptor-Associated Peptides and Proteins / genetics
  • Tumor Necrosis Factor Receptor-Associated Peptides and Proteins / metabolism*
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*
  • Virus Latency* / physiology

Substances

  • Adaptor Proteins, Signal Transducing
  • MAVS protein, human
  • Tumor Necrosis Factor Receptor-Associated Peptides and Proteins
  • Viral Proteins
  • viral FLIP protein, Human herpesvirus 8