Figure 6. Relative contribution of shaving and modulation for loss of CD20 from CLL cells with type I and II anti-CD20 mAbs.
(A) Confocal microscopy of Rituximab-pHrodo opsonised Hoescht33342 labelled B-CLL cells seen ingested by celltracker green labelled MDM. (B-D) Primary CLL samples were opsonised with RTX-AF488, (E-G) Obinutuzmab-AF488 or (H-J) BHH2-AF488 at 10µg/ml for 30 minutes on ice before being cultured alone or co-cultured with MDMs pre-loaded with different concentrations of beads for 16-18 hours at 37°C. Cells were cultured in 96-well plates at an effector:target ratio of 1:5. Proportion of surface accessible mAb:CD20, percentage of total mAb:CD20 and percentage of mAb:CD20 modulated from the surface of CLL cells normalised to that of the 4°C and 37°C controls is shown. Data composite of 3-5 independent experiments, error bars mean± SD, analysed by ANOVA, ns: not significant.