Figure 4
Cell survival with a long-term, toxin-induced inhibition of protein synthesis. Vero-d2EGFP cells were incubated for 36 h with (a) 0.05 ng/mL of ricin, (b) 0.01 ng/mL of Stx1, (c) 1.0 ng/mL of EtxA, or (d) 0.05 ng/mL of Dtx. Left column: Representative images were taken at 200 × magnification. Cell viability, as assessed by MTS assay (n = 3, avg. ± std. dev.), is indicated. Center column: Red and blue lines (corresponding to the color-coded toxin concentrations in Supplementary Figure S1) were generated from cytofluorometry analysis of the adherent subpopulation of toxin-treated Vero-d2EGFP cells. Unintoxicated parental Vero cells (black lines) and unintoxicated Vero-d2EGFP cells (green lines) were also processed for each condition. Right column: Cell viability was recorded by cytofluorometry analysis of annexin V and 7-AAD staining (blue), while EGFP fluorescence was recorded by cytofluorometry (grey) or with a plate reader (black). Results are presented as percentages of the values obtained from unintoxicated cells. All measurements in the matched center and right columns were performed on the same population of cells.
