FIG 6.

Specific toxicity of R33ExoA for gD2-expressing cells. Dilutions of immunotoxins were added to Vero cells (A) or z4/6 cells (B), and their cytotoxicity was measured using an MTS assay. While R33ExoA demonstrates cytotoxic activity against gD2-expressing cell lines (IC₅₀ = 0.5 nM) (95% CI, 0.1810 to 1.403), P10ExoA does not. Neither immunotoxin demonstrates activity against Vero cells, which do not express gD2. Dilutions of each protein were added to wells in triplicate, and error bars represent standard deviations.