ADCC Activity

"To identify which mAbs possess ADCC activity, we conducted the ADCC assay using NK - 92 MI FcR cells and target cells, including WT, Delta, or BA.4/5 S protein overexpressing 293T cells as previously described 23 . Among all the mAb s assessed, several mAbs, including 5SB12, 1 - 2SA8, 15SE6, 1 - 2SC5, and 3 - 2SF9, exhibited better ADCC activity toward WT S - 293T cells than the other mAbs ( Fig. 3 d , top), and several of them preserved ADCC activity against Delta or BA.4/5 S protein – expressing cells ( Fig. 3 d , middle and bottom). We are interested in 5SB12 , 1 - 2SA8 and 3 - 2SF9 mAbs as they showed strong and cross - variant ADCC activity. The mAbs with LALA (L234A and L235A) double mutations in the Fc domain, which had defective effector functions du e to their impaired ability to interact with Fc receptor 24,25 , were used to confirm the ADCC activity of 5SB12 , 1 - 2SA8 and 3 - 2SF9 mAbs ( Supplementary Fig. 3c ). In parallel, we characterized the properties of these three mAbs."