A Novel System for the Quantification of the ADCC Activity of Therapeutic Antibodies

Figure 6

Quantification of the ADCC activity of rituximab. Individual vials of frozen iLite effector cells (1.2 × 10⁵ cells/well) and vials of frozen CD20⁺ target cells from 3 different production lots (1 to 3) were thawed, mixed at E:T ratio of 3 : 1, and incubated for 4 hours at 37°C in the presence of increasing concentrations of rituximab in a 384-well microtiter plate prior to the addition of Nano-Glo Dual-luciferase reagent (Promega, Madison, WI) and the sequential determination of FL and NL activity (a). RTU frozen iLite effector cells and CD20⁺ target cells frozen separately or together at E:T ratio of 3 : 1 and incubated for 4 hours or thaw-and-use NFAT effector cells and CD20⁺target cells at an E:T ratio of 6 : 1 and incubated for 6 hours at 37°C in the presence of increasing concentrations of rituximab (b). Results are expressed as fold induction relative to the control sample consisting of effector cells and target cells without rituximab.

(a)

(b)