Comparison of Cell Fusions Induced by Influenza Virus and SARS-CoV-2

Abstract

Virus–cell fusion is the key step for viral infection in host cells. Studies on virus binding and fusion with host cells are important for understanding the virus–host interaction and viral pathogenesis for the discovery of antiviral drugs. In this review, we focus on the virus–cell fusions induced by the two major pandemic viruses, including the influenza virus and SARS-CoV-2. We further compare the cell fusions induced by the influenza virus and SARS-CoV-2, especially the pH-dependent fusion of the influenza virus and the fusion of SARS-CoV-2 in the type-II transmembrane serine protease 2 negative (TMPRSS2-) cells with syncytia formation. Finally, we present the development of drugs used against SARA-CoV-2 and the influenza virus through the discovery of anti-fusion drugs and the prevention of pandemic respiratory viruses.

Interplay between RNA viruses and cGAS/STING axis in innate immunity

“…Two distinct mechanisms seem to contribute to the activation of STING signalling pathway after IAV infection ( Holm et al., 2016 ; Moriyama et al., 2019 ) ( Figure 3 ). On one hand, cell-cell fusion observed during IAV infection may stimulate STING activation and IFN-I production through a cGAS-independent pathway ( Holm et al., 2012 ; Holm et al., 2016 ; Zhang et al., 2022a ). On the other hand, IAV M2 viroporin ion channel triggers the translocation of mtDNA into the cytosol in a MAVS-dependent manner, leading to the recognition of mtDNA by cGAS and subsequent activation of STING by cGAMP ( Moriyama et al., 2019 ).…”