Figure 7.

Cytotoxic effects of CL4-ipilimumab conjugate on SK-BR-3 tumor cells co-cultured with NK cells. (A) SK-BR-3 cells were co-cultured with NK cells (effector:target cells ratio: 3:1) and treated for 24 h with CL4 aptamer (striped bars), ipilimumab mAb (grey bars), their combination, or CL4-ipilimumab conjugate (black bars), as indicated. SK-BR-3 cells separately treated with the immunoconjugate, the scrambled aptamer, or with hPBMCs were included as controls. The percentage of viable cells is expressed with respect to untreated cells. (B) The release of lactate dehydrogenase was tested for measuring % cell lysis as described in Materials and Methods. (C) The levels of secreted IL-2 and IFN-γ were measured by ELISA on supernatants of cells treated, as indicated. Error bars depict means ± SD. p-values for the indicated treatments are: *** p ≤ 0.001; ** p < 0.01; * p < 0.05.