2. Academic Validation
  3. Syncytia formation by SARS-CoV-2-infected cells

Syncytia formation by SARS-CoV-2-infected cells

  • EMBO J. 2020 Dec 1;39(23):e106267. doi: 10.15252/embj.2020106267.
Julian Buchrieser 1 2,  Jérémy Dufloo 1 2 3,  Mathieu Hubert 1 2,  Blandine Monel 1 2,  Delphine Planas 1 2 4,  Maaran Michael Rajah 1 2 3,  Cyril Planchais 5,  Françoise Porrot 1 2,  Florence Guivel-Benhassine 1 2,  Sylvie Van der Werf 6 7,  Nicoletta Casartelli 1 2,  Hugo Mouquet 5,  Timothée Bruel 1 2,  Olivier Schwartz 1 2 4
Affiliations

Affiliations

  • 1 Virus and Immunity Unit, Department of Virology, Institut Pasteur, Paris, France.
  • 2 CNRS-UMR3569, Paris, France.
  • 3 Bio Sorbonne Paris Cité (BioSPC), Université de Paris, Paris, France.
  • 4 Vaccine Research Institute, Créteil, France.
  • 5 Laboratory of Humoral Immunology, Department of Immunology, Institut Pasteur, INSERM U1222, Paris, France.
  • 6 Molecular Genetics of RNA Viruses, Department of Virology, Institut Pasteur, CNRS UMR 3569, Université de Paris, Paris, France.
  • 7 National Reference Center for Respiratory Viruses, Institut Pasteur, Paris, France.
PMID: 33051876 DOI: 10.15252/embj.2020106267
Abstract

Severe cases of COVID-19 are associated with extensive lung damage and the presence of infected multinucleated syncytial pneumocytes. The viral and cellular mechanisms regulating the formation of these syncytia are not well understood. Here, we show that SARS-CoV-2-infected cells express the Spike protein (S) at their surface and fuse with ACE2-positive neighboring cells. Expression of S without any other Viral Proteins triggers syncytia formation. Interferon-induced transmembrane proteins (IFITMs), a family of restriction factors that block the entry of many viruses, inhibit S-mediated fusion, with IFITM1 being more active than IFITM2 and IFITM3. On the contrary, the TMPRSS2 serine protease, which is known to enhance infectivity of cell-free virions, processes both S and ACE2 and increases syncytia formation by accelerating the fusion process. TMPRSS2 thwarts the Antiviral effect of IFITMs. Our results show that SARS-CoV-2 pathological effects are modulated by cellular proteins that either inhibit or facilitate syncytia formation.

Keywords

SARS-CoV-2; fusion; interferon; syncytia.

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