SARS-CoV-2 virions enter the host cells by docking their spike glycoproteins to the membrane-bound Angiotensin Converting Enzyme 2. After intracellular assembly, the newly formed virions are released from the infected cells to propagate the infection, using the extra-cytoplasmic ACE2 docking mechanism. However, the molecular events underpinning SARS-CoV-2 transmission between host cells are not fully understood. Here, we report the findings of a scanning Helium-ion microscopy study performed on Vero E6 cells infected with mNeonGreen-expressing SARS-CoV-2. Our data reveal, with unprecedented resolution, the presence of: (1) long tunneling nanotubes that connect two or more host cells over submillimeter distances; (2) large scale multiple cell fusion events (syncytia); and (3) abundant extracellular vesicles of various sizes. Taken together, these ultrastructural features describe a novel intra-cytoplasmic connection among SARS-CoV-2 infected cells that may act as an alternative route of viral transmission, disengaged from the well-known extra-cytoplasmic ACE2 docking mechanism. Such route may explain the elusiveness of SARS-CoV-2 to survive from the immune surveillance of the infected host.
【저자키워드】 SARS-CoV-2, Cell signalling, 【초록키워드】 ACE2, spike glycoprotein, Infection, docking, immune, SARS-CoV-2 transmission, Surveillance, Microscopy, Viral transmission, extracellular vesicle, molecular, Vero E6 cell, angiotensin, host cell, connection, virion, infected cell, membrane-bound, Host, feature, Cell, event, alternative route, performed, released, explain, docking mechanism, intracellular assembly, SARS-CoV-2 infected cell, SARS-CoV-2 virion, 【제목키워드】 SARS-CoV-2 transmission, Microscopy,