Sensitive Detection of the Natural Killer Cell-Mediated Cytotoxicity of Anti-CD20 Antibodies and Its Impairment by B-Cell Receptor Pathway Inhibitors

Figure 2

Impairment of ADCC against Raji cells by kinase inhibitors. The antibody-dependent increase in the percentages of maximal LDH release was determined with 5-fold excess of 26.5 effector cells in the absence or presence of 10 μM idelalisib or ibrutinib (a) or the PI3K inhibitors duvelisib and copanlisib (b). Data were derived from nine or eight independent experiments, each of which was performed with triplicate samples, in (a) and (b), respectively. Asterisks above the boxes and whiskers denote the significance of enhanced cytotoxicity compared to the control without addition of antibodies and inhibitors as determined by paired t-tests, while the value ranges for the impairment of ADCC compared to anti-CD20 antibodies as single agents are indicated beneath. Furthermore comparisons by paired t-test were performed among mAb and KI treatments and indicated at the top of the diagrams in black and blue print, respectively. ; ; .

(a)

(b)