Remodeling of the Actin Network Associated with the Non-Structural Protein 1 (NS1) of West Nile Virus and Formation of NS1-Containing Tunneling Nanotubes

Wilhelm Furnon (1) , Pascal Fender (2) , Marie-Pierre Confort (1) , Sophie Desloire (1) , Sawitree Nangola (3) , Kuntida Kitidee (4) , Caroline Leroux (1) , Maxime Ratinier (1) , Frederick Arnaud (1) , Sylvie Lecollinet (5) , Pierre Boulanger (1) , Saw-See Hong (1)

1 IVPC - Infections Virales et Pathologie Comparée - UMR 754
2 IBS - UMR 5075 - Institut de biologie structurale
3 Department of Medical Technology, School of Allied Health Sciences
4 Center for Research & Innovation
5 VIRO - Virologie UMR1161

The cellular response to the recombinant NS1 protein of West Nile virus (NS1WNV) was studied using three different cell types: Vero E6 simian epithelial cells, SH-SY5Y human neuroblastoma cells, and U-87MG human astrocytoma cells. Cells were exposed to two different forms of NS1WNV: (i) the exogenous secreted form, sNS1WNV, added to the extracellular milieu; and (ii) the endogenous NS1WNV, the intracellular form expressed in plasmid-transfected cells. The cell attachment and uptake of sNS1WNV varied with the cell type and were only detectable in Vero E6 and SH-SY5Y cells. Addition of sNS1WNV to the cell culture medium resulted in significant remodeling of the actin filament network in Vero E6 cells. This effect was not observed in SH-SY5Y and U-87MG cells, implying that the cellular uptake of sNS1WNV and actin network remodeling were dependent on cell type. In the three cell types, NS1WNV-expressing cells formed filamentous projections reminiscent of tunneling nanotubes (TNTs). These TNT-like projections were found to contain actin and NS1WNV proteins. Interestingly, similar actin-rich, TNT-like filaments containing NS1WNV and the viral envelope glycoprotein EWNV were also observed in WNV-infected Vero E6 cells.

Mots clés: tunneling nanotubes; non-structural protein 1 (NS1); West Nile virus; actin network; cytoskeleton; flavivirus

Domaines: Biologie structurale [q-bio.BM]

Wilhelm Furnon, Pascal Fender, Marie-Pierre Confort, Sophie Desloire, Sawitree Nangola, et al.. Remodeling of the Actin Network Associated with the Non-Structural Protein 1 (NS1) of West Nile Virus and Formation of NS1-Containing Tunneling Nanotubes. Viruses, 2019, 11 (10), pp.901. ⟨10.3390/v11100901⟩. ⟨hal-02361065⟩