TNFα Impairs Rhabdoviral Clearance by Inhibiting the Host Autophagic Antiviral Response

PLoS Pathog. 2016 Jun 28;12(6):e1005699. doi: 10.1371/journal.ppat.1005699. eCollection 2016 Jun.

Abstract

TNFα is a pleiotropic pro-inflammatory cytokine with a key role in the activation of the immune system to fight viral infections. Despite its antiviral role, a few viruses might utilize the host produced TNFα to their benefit. Some recent reports have shown that anti-TNFα therapies could be utilized to treat certain viral infections. However, the underlying mechanisms by which TNFα can favor virus replication have not been identified. Here, a rhabdoviral infection model in zebrafish allowed us to identify the mechanism of action by which Tnfa has a deleterious role for the host to combat certain viral infections. Our results demonstrate that Tnfa signals through its receptor Tnfr2 to enhance viral replication. Mechanistically, Tnfa does not affect viral adhesion and delivery from endosomes to the cytosol. In addition, the host interferon response was also unaffected by Tnfa levels. However, Tnfa blocks the host autophagic response, which is required for viral clearance. This mechanism of action provides new therapeutic targets for the treatment of SVCV-infected fish, and advances our understanding of the previously enigmatic deleterious role of TNFα in certain viral infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy / physiology
  • Blotting, Western
  • Disease Models, Animal
  • Fluorescent Antibody Technique
  • Host-Parasite Interactions / immunology*
  • Organisms, Genetically Modified
  • Polymerase Chain Reaction
  • Rhabdoviridae / immunology
  • Rhabdoviridae Infections / immunology*
  • Tumor Necrosis Factor-alpha / immunology*
  • Virus Replication / physiology
  • Zebrafish

Substances

  • Tumor Necrosis Factor-alpha

Grants and funding

This study was funded by: MINECO BIO2011-23400 (VM), MINECO CSD2007-00002(VM), MINECO BIO2014-52655-R (VM), MINECO AGL2014-51773-C3-1-R (AE), and Fondos Europeos de Desarrollo Regional (FEDER) (VM AE). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.