Replication-competent recombinant vesicular stomatitis virus (rVSV) expressing foreign envelope glycoproteins has been demonstrated to be a suitable model system to study the role of Effect of S1P Inhibition on LASV Replication www.plosntds.org viral glycoproteins in the context of virus replication [47, 53, 54] . In the present study, we took advantage of a rVSV expressing the LASV glycoprotein GP (designated VSVDG/LASVGP) [48] . In this system biosynthesis and processing of GP was shown to be authentic compared to LASV [48] .