Soluble receptor-mediated targeting of mouse hepatitis coronavirus to the human epidermal growth factor receptor

J Virol. 2005 Dec;79(24):15314-22. doi: 10.1128/JVI.79.24.15314-15322.2005.

Abstract

The mouse hepatitis coronavirus (MHV) infects murine cells by binding of its spike (S) protein to murine CEACAM1a. The N-terminal part of this cellular receptor (soR) is sufficient for S binding and for subsequent induction of the conformational changes required for virus-cell membrane fusion. Here we analyzed whether these characteristics can be used to redirect MHV to human cancer cells. To this end, the soR domain was coupled to single-chain monoclonal antibody 425, which is directed against the human epidermal growth factor receptor (EGFR), resulting in a bispecific adapter protein (soR-425). The soR and soR-425 proteins, both produced with the vaccinia virus system, were able to neutralize MHV infection of murine LR7 cells. However, only soR-425 was able to target MHV to human EGFR-expressing cancer cells. Interestingly, the targeted infections induced syncytium formation. Furthermore, the soR-425-mediated infections were blocked by heptad repeat-mimicking peptides, indicating that virus entry requires the regular S protein fusion process. We conclude that the specific spike-binding property of the CEACAM1a N-terminal fragment can be exploited to direct the virus to selected cells by linking it to a moiety able to bind a receptor on those cells. This approach might be useful in the development of tumor-targeted coronaviruses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Coronavirus Infections / immunology
  • Coronavirus Infections / metabolism*
  • ErbB Receptors / metabolism*
  • Humans
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / physiology*
  • Mice
  • Murine hepatitis virus / physiology*
  • Spike Glycoprotein, Coronavirus
  • Viral Envelope Proteins / chemistry
  • Viral Envelope Proteins / physiology*

Substances

  • Membrane Glycoproteins
  • Spike Glycoprotein, Coronavirus
  • Viral Envelope Proteins
  • spike glycoprotein, SARS-CoV
  • spike protein, mouse hepatitis virus
  • ErbB Receptors