Toscana virus (TOSV) productively infects iPSC-derived human neurons.

(A) Induced human pluripotent stem cell (iPSC)-derived neurons were infected with TOSV at the indicated multiplicities of infection (MOIs). Intracellular expression of viral proteins was detected by immunostaining and flow cytometry analysis 48 h later. (B) TOSV infection was monitored in iPSC-derived neurons over 48 h assay as described in A. (C) A549 cells were infected with TOSV for 24 h, and the expression of viral proteins was analyzed by immunostaining and flow cytometry. (D) The titer of TOSV stocks produced on BHK-21 cells was assessed on A549 cells and BHK-21 cells by a plaque-forming unit (pfu) assay. Examples are shown for 10−8 dilutions of virus productions. (E) TOSV infection was monitored in A549 cells over 24 h and analyzed as described in C and S1 Fig. (F) Supernatants from A549 cells challenged with TOSV at an MOI 2 were assessed for the production of infectious viral progeny over 48 h by the pfu assay described in D.