The Glycoproteins of All Filovirus Species Use the Same Host Factors for Entry into Bat and Human Cells but Entry Efficiency Is Species Dependent

Hoffmann, Markus; González Hernández, Mariana; Berger, Elisabeth; Marzi, Andrea; Pöhlmann, Stefan

In comparison to cells treated only with diluent (vehicle control, VC), we found that ammonium chloride, bafilomycin A1, E-64d, MDL28170, tetrandrine and U18666A inhibited entry driven by all filovirus GPs tested, while mannan and camostat mesylate had no appreciable inhibitory effect (Fig 4) . Inhibition of GP-mediated entry into bat cells by ammonium chloride, bafilomycin A1, tetrandrine E-64d and MDL28170 seemed to be slightly less efficient relative to human cells but no clear differences were observed. In comparison, transduction mediated by VSV-G was reduced only by agents interfering with endosomal acidification (Fig 4) , in accordance with published data [70] . Finally, entry of VSVpp harboring NiV-F/G, which were used as an additional control, was not inhibited by any of the compounds tested (Fig 4) . NiV-F needs to undergo proteolytic cleavage by the cysteine proteases cathepsin B or L. However, this step does not take place during the entry process but rather during transport of F protein to the plasma membrane and was not targeted under the experimental conditions chosen here [71] . Collectively, our observations indicate that filovirus GPs use the same cellular factors for entry into human, NHP and bat cell lines.