FIG 4.

MEV NS1-induced apoptosis. (A and B) F81 (A) and HEK293T cells (B) were transfected with NS1-, VP1-, and VP2-expressing plasmids, as indicated, and subjected to cell cycle analysis by cytometry at 24, 48, and 72 h posttransfection. Empty-vector- and mock-transfected cells were used as negative controls. The histograms show representative cell cycle analyses of NS1-, VP1-, VP2-, empty-vector-, and mock-transfected cells, and the bar charts show percentages of averages and standard error of the mean of the cells in each phase of the cell cycle. (C and D) Apoptosis analysis using annexin V/PI staining. Cells were transfected with the NS1, VP1, VP2, or empty vectors or mock transfected. F81 (C) and HEK293T cells (D) at 24, 48, and 72 h posttransfection were analyzed. The annexin V-positive cells were regarded as apoptotic cells. For all assays, data are representative of results from three independent experiments. *, P < 0.05, and **, P < 0.01, compared with control groups.