Fig 6. Simultaneous targeting of HSV-1 with two gRNAs completely impairs virus replication.

a) Vero cells were transduced with the indicated single or double gRNAs and subsequently infected with HSV-1-eGFP at an MOI of 0.5. Cells were analyzed for eGFP-expression by flow cytometry at 1, 2, and 3 dpi to assess the percentage of virus-infected cells. b) Similar experiment as in a) but now performed in human MRC5 cells and at an MOI of 0.005, as MRC5 cells are more susceptible to HSV-1 infection. Cells were analyzed for eGFP-expression by flow cytometry at 1 dpi and 3 dpi to assess the percentage of successfully infected cells. c) Supernatants from b) were subjected to plaque assays to quantify the infectious HSV-1 titer produced by gRNA-expressing MRC5 cells that had been infected with HSV-1-eGFP three days earlier. Plaques were scored if visible by eye. d) Plaques from c) obtained after infection of cells with HSV-1 harvested from control or anti-UL8 gRNA-expressing MRC5-cells were analyzed by light-microscopy. Whereas large plaques (‘P’) are observed in infected cells not carrying any gRNAs, virus harvested from UL8 gRNA- expressing cells induced microplaques. In double gRNA-treated cells, no signs of infection were observed. For all bar diagrams, measurements of triplicate experiments are presented + STD.