Fig. 4

Promotion of ADCP and ADCC by 22B12 mAb. a CFSE-labeled TNBC cell line (MDA-MB231 or IJG1731) was mixed together with THP-1 at an E/T ratio of 1/1 together with isotype control or 22B12 mAb. The anti-EGFR Ab Cetuximab (huIgG1 isotype) was used as positive control. After 2.5 h of cell contact, phagocytosis was evaluated by flow cytometry by detecting the % of THP-1 cells that became CFSE⁺. Results are expressed as the mean ± SD of 3 independent experiments. *p < 0.05; **p < 0.01. b Single spheroids were obtained from IJG1731 cells stably transfected with GFP. After 4 days of growth (arrow), PBMC were added together with a mix of IL2 + IL15 and 22B12 mAb, Cetuximab, or their corresponding isotype-matched Abs. The green fluorescence associated to each spheroid was monitored every 6 h for 4 additional days in a live cell imaging system. Left panels: images of a representative spheroid immediately after addition of PBMC and the indicated Abs (96 h) and at the end of the assay (192 h). Right panels: quantification of the green fluorescence associated to each spheroid over time. Results are expressed as the mean ± SD of triplicates. ***p < 0.001