Comparison of cytotoxic effects and immunotoxin specificity in Tac-receptor expressing cells.

<p>Tac-TGN38 and Tac-furin cells were treated with up to 10 ng/ml of LMB-2. After a 24 hour incubation with immunotoxin, cells were washed and the cells remaining in the well were used for <b>A</b>) Hoechst-based cell count assay or <b>B</b>) LDH assay as described in Methods. Panels A and B show % cytotoxicity plotted against the concentration of LMB-2. The data points represent the cytotoxicity values averaged over several experiments, cell count assay (n = 9), LDH assay (n = 8). The standard error of the mean is shown. <b>C</b>) Tac-TGN38 and Tac-furin cells were seeded and then treated with up to 10 ng/ml of LMB-2 or Erb38 one day after plating. After a 24 hour incubation with immunotoxin, cytotoxicity was assessed by a cell count assay. The number of cells remaining after toxin treatment is shown as a fraction of cells incubated without toxin (n = 5). The standard error of the mean is shown.