Figure 3.

Dose and time profiles of the cytotoxicity of CD19-NK-92 and CD138-NK-92 cells toward ALL cells expressing both CD19 and CD138 antigens. (a) Flow cytometry gating strategy to specifically detect cell death of PKH67-labeled target (T) cells, i.e., human ALL-derived REH cells, after incubation with effector NK (E) cells, i.e., WT-NK-92 cells, by Annexin V/7-AAD assay. (b) PKH67-labeled REH cells were incubated with WT-NK-92, CD19-NK-92, or CD138-NK-92 cells at the E : T ratio of 1 : 5 or 1 : 1 for 4–24 h, after which they were stained with Annexin V-PE and 7-AAD. Representative dot plots of Annexin V-PE versus 7-AAD in PKH67-labeled REH cells were shown. (c) Percentage of total REH cell death, comprising Annexin V- and/or 7-AAD-positive cells, was plotted. Data are mean ± s.d. (n = 3). ∗p < 0.05 and ∗∗p < 0.01 versus WT-NK-92 cells in the same condition; two-sided Student's t-test.