In Vitro and In Vivo Attenuation of Vesicular Stomatitis Virus (VSV) by Phosphoprotein Deletion

PLoS One. 2016 Jun 17;11(6):e0157287. doi: 10.1371/journal.pone.0157287. eCollection 2016.

Abstract

Vesicular stomatitis virus (VSV) is highly immunogenic and able to stimulate both innate and adaptive immune responses. However, its ability to induce adverse effects has held back the use of VSV as a potential vaccine vector. In this study we developed VSV-ΔP, a safe yet potent replication-defective recombinant VSV in which the phosphoprotein (P) gene was deleted. VSV-ΔP replicated only in supporting cells expressing P (BHK-P cells) and at levels more than 2 logs lower than VSV. In vivo studies indicated that the moderate replication of VSV-ΔP in vitro was associated with the attenuation of this virus in the mouse model, whereas mice intracranially injected with VSV succumbed to neurotoxicity. Furthermore, we constructed VSV and VSV-ΔP expressing a variety of antigens including hemagglutinin-neuraminidase (HN) from Newcastle disease virus (NDV), hemagglutinin (HA) from either a 2009 H1N1 pandemic influenza virus (pdm/09) or the avian H7N9. VSV and VSV-ΔP incorporated the foreign antigens on their surface resulting in induction of robust neutralizing antibody, serum IgG, and hemagglutination inhibition (HAI) titers against their corresponding viruses. These results indicated that VSV with P gene deletion was attenuated in vitro and in vivo, and possibly expressed the foreign antigen on its surface. Therefore, the P gene-deletion strategy may offer a potentially useful and safer approach for attenuating negative-sense RNA viruses which use phosphoprotein as a cofactor for viral replication.

MeSH terms

  • Animals
  • Gene Expression Regulation, Viral / genetics
  • Genetic Vectors / adverse effects
  • Genetic Vectors / genetics*
  • Genetic Vectors / therapeutic use
  • Hemagglutinins / genetics
  • Humans
  • Influenza A Virus, H7N9 Subtype / genetics
  • Mice
  • Newcastle disease virus / genetics
  • Phosphoproteins / genetics
  • Sequence Deletion / genetics
  • Vesiculovirus / genetics*
  • Vesiculovirus / pathogenicity
  • Viral Vaccines / genetics
  • Viral Vaccines / therapeutic use*
  • Virus Replication / genetics*

Substances

  • Hemagglutinins
  • Phosphoproteins
  • Viral Vaccines

Grants and funding

This work was funded in part by grant P-14-51228 from the Cluster Program Management Office, National Science and Technology Development Agency, Thailand.