Figure 1:

ADCC synapse formation in mice treated by the Chi-Tn mAb. BALB/c mice were grafted i.p. with TA3Ha-GFP cells (10⁶/mouse) on day 0. PBS or CTX (50 mg/kg) was given on day 1, and Chi-Tn mAb (n = 3) or trastuzumab (n = 3) were injected at 20 mg/kg on day 2. Peritoneal cells were harvested 4 h after mAbs injection. (A) Peritoneal cells from wild-type (WT) mice or from FcR-γ chain-deficient (FcR-γ^−/−) mice treated with the indicated combination were labeled with phalloidin (yellow) and DAPI (blue). Green, TA3Ha-GFP cells. Synapses were observed in all experimental conditions where the Chi-Tn mAb was injected. Tumor rejection occurred in WT mice only when CTX was associated to Chi-Tn mAb treatment. FcR-γ^−/− mice treated with CTX+Chi-Tn did not display tumor rejection. (B) Peritoneal cells were labeled using the indicated primary antibody against FcR-γ chain or FcγRIII (1st Ab, red), and phalloidin (yellow). TA3Ha-GFP cells are in green, and nuclei labeled with DAPI are in blue. Merge images represent close contacts between TA3Ha-GFP+ and immune cells. One representative analysis of several conjugates is shown. Synapses between FcγRIII+ cells and TA3Ha-GFP+ cells were studied by three-dimensional analysis of the interface in the z, x plane. Yellow, phalloidin; red, FcγRIII. One representative experiment is shown.