Figure 3
Cetuximab significantly enhances cytolytic activity and ADCC is negatively affected by inhibition of activating receptor-ligand interactions. Ex-vivo expanded cells from cancer patient 1 were evaluated for their ability to mediate ADCC against autologous (patient 1) and allogeneic (TU-167 and H-358) EGFR expressing lung cancer cells. (A) Cytolytic activity of ex-vivo expanded cells was enhanced in the presence of Cetuximab (10 μg/ml, black bar) but not in the presence of control human IgG1 (10 μg/ml; dotted bar) or media alone (white bar). The mean percentage cytotoxicity is shown from triplicate wells from one representative experiment. Error bars represent the SD. Experiment shown represents one of two individual experiments. (B) The addition of blocking antibodies (10 μg/ml) against DNAM-1, NKp46, NKp44 and NKp30 (= all) significantly reduced (P = 0.0176) Cetuximab-mediated ADCC. Statistical analysis is based on three experiments performed. Error bars represent the SD. * P < 0.05. HuIgG1 indicates human IgG1, Ctx; Cetuximab and moIgG1; mouse IgG1.