Characteristics of oncolytic vesicular stomatitis virus displaying tumor-targeting ligands

J Virol. 2013 Dec;87(24):13543-55. doi: 10.1128/JVI.02240-13. Epub 2013 Oct 2.

Abstract

We sought proof of principle that tumor-targeting ligands can be displayed on the surface of vesicular stomatitis virus (VSV) by engineering its glycoprotein. Here, we successfully rescued VSVs displaying tumor vasculature-targeting ligands. By using a rational approach, we investigated various feasible insertion sites on the G protein of VSV (VSV-G) for display of tumor vasculature-targeting ligands, cyclic RGD (cRGD) and echistatin. We found seven sites on VSV-G that tolerated insertion of the 9-residue cRGD peptide, two of which could tolerate insertion of the 49-amino acid echistatin domain. All of the ligand-displaying viruses replicated as well as the parental virus. In vitro studies demonstrated that the VSV-echistatin viruses specifically bound to targeted integrins. Since the low-density lipoprotein receptor (LDLR) was recently identified as a major receptor for VSV, we investigated the entry of ligand-displaying viruses after masking LDLR. The experiment showed that the modified viruses can enter the cell independently of LDLR, whereas entry of unmodified virus is significantly blocked by a specific monoclonal antibody against LDLR. Both parental and ligand-displaying viruses displayed equal oncolytic efficacies in a syngeneic mouse myeloma model. We further demonstrated that single-chain antibody fragments against tumor-specific antigens can be inserted at the N terminus of the G protein and that corresponding replication-competent VSVs can be rescued efficiently. Overall, we demonstrated that functional tumor-targeting ligands can be displayed on replication-competent VSVs without perturbing viral growth and oncolytic efficacy. This study provides a rational foundation for the future development of fully retargeted oncolytic VSVs.

Publication types

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

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Female
  • Humans
  • Intercellular Signaling Peptides and Proteins
  • Ligands
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Neoplasms / therapy*
  • Neoplasms / virology
  • Oncolytic Virotherapy*
  • Oncolytic Viruses / genetics*
  • Oncolytic Viruses / physiology
  • Peptides / genetics*
  • Peptides / metabolism
  • Peptides, Cyclic / genetics*
  • Peptides, Cyclic / metabolism
  • Protein Engineering
  • Vesicular stomatitis Indiana virus / genetics*
  • Vesicular stomatitis Indiana virus / physiology
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / metabolism
  • Virus Internalization

Substances

  • G protein, vesicular stomatitis virus
  • Intercellular Signaling Peptides and Proteins
  • Ligands
  • Membrane Glycoproteins
  • Peptides
  • Peptides, Cyclic
  • Viral Envelope Proteins
  • cyclic arginine-glycine-aspartic acid peptide
  • echistatin