Fig. 2

Epitope binding, FcR signaling, internalization and recycling capacity of mAbs. a Epitope competition assay of B100, B106, and A57 against trastuzumab (Trast; left graph) or pertuzumab (Pert; right graph) in dependency of antibody concentration is displayed. b FcR signaling of B100 (left graph) and trastuzumab (right graph) on JIMT-1 (black), SK-BR-3 (yellow), and ZR-75-1 (green) using different antibody concentrations was determined. c Internalization capacity of B100, B106, and A57 in comparison to trastuzumab and pertuzumab on SK-BR-3 cells are displayed: cells were pre-treated with 2 µM Monensin for 2 h to inhibit potential recycling. Amount of HER2 remaining on cell surface were normalized to the amount of HER2 of control cells without treatment, which were set to 100%. Mean ± standard deviation (SD) of three independent experiments are presented. For group wise comparison with Tukey’s multiple comparison post-test was performed (*p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001). d Recycling capacity of B100 in comparison to pertuzumab and trastuzumab was determined on SK-BR-3 cells. Fluorescence signal at each time point was normalized with the 0 min chase time point signal, which was set to 100%, to calculate the fraction of HER2 retained in cells. Mean ± standard deviation (SD) of three independent experiments are presented. For group wise comparison Tukey’s multiple comparison post-test was performed (*p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001)