FIG. 3.

Expression of the influenza virus NS1 or Ebola virus VP35 proteins prevents plasmid transfection-induced inhibition of NDV-GFP replication. (A) GFP expression in NDV-GFP-infected cells transfected 24 h prior to infection with various plasmids. Cells were mock transfected, transfected with empty pCAGGS or pcDNA3 expression plasmids, or transfected with expression plasmids for the influenza A virus NS1 protein or the Ebola virus VP35 protein as indicated. (B) Mean relative green fluorescence intensity of CEFs transfected with the indicated plasmids (pCAGGS, pCAGGS-NS1, or pcDNA3-VP35) and subsequently infected with NDV-GFP. The graph shows the mean relative intensity of green fluorescence for 10⁴ cells from each culture as determined by FACS. The results from panel A and panel B are from the same experiment and are representative of typical results with the indicated plasmids. (C) Expression of NS1 in green fluorescent cells. CEFs were transfected with NS1 expression plasmid and infected with NDV-GFP 24 h posttransfection. At 24 h postinfection, the cells were fixed, permeabilized, and stained with rabbit antiserum against the influenza A virus NS1 protein. FACS analysis was then performed to detect both NS1 (y axis) and GFP (x axis).