Specificity of NK-92-scFv(FRP5)-ζ cells.

(A) Competition of ErbB2 binding. ErbB2-expressing MDA-MB453 cells were incubated with NK-92-scFv(FRP5)-ζ cells at an E/T ratio of 10:1 for 2 hours in the absence of competitor (filled bar) or in the presence of 30 μg/mL ErbB2-specific mAb FRP5 or an isotype-matched control antibody as indicated (hatched bars). Parental NK-92 cells were included as a control (open bar). Specific lysis was determined in europium-release assays as described in the legend of Figure 2. (B-C) Cytotoxic activity of NK-92-scFv(FRP5)-ζ against transfected murine cell lines. Renca-lacZ murine renal cell carcinoma cells expressing theEscherichia coli β-galactosidase gene (B) and Renca-lacZ/ErbB2 cells further transfected with a human c-erbB2 cDNA construct (C) were incubated with NK-92-scFv(FRP5)-ζ (○) or parental NK-92 cells (●) at different E/T ratios for 2 hours. Specific lysis was determined in europium-release assays as described in the legend of Figure 2.