Figure 4: Treatment of GBM cells with ISCADOR enhances NK cell mediated tumor cell lysis. (a) LNT-229-Luc cells were treated with the appropriated ISCADOR variant (100 μg/mL) for 24 h. The cells were washed and incubated with human PBLs at different E/T cell ratio for 4 h. Cell lysis was measured by quantifying luciferase activity. (b) LNT-229-Luc cells were treated as in (a). PBLs were incubated with neutralizing NKG2D antibody (R&D Systems, Wiesbaden, Germany, 10 μg/mL) or left untreated prior to coincubation with GBM cells at an E/T of 40 : 1. (c). LNT-229-Luc cells were treated as in (a) and coincubated with purified polyclonal NK cells ((a) to (c): one representative out of three independent experiments is shown, bars = SD). (d) CFSE labeled purified NK cells were cocultivated with LNT-229 glioma cells. After extensive washing, NK cells (upper panel) or coculture (lower panels) were microscopically documented ( , one representative experiment is shown). (e) Quantification of NK cell attachment on LNT-229 cells ( , SEM, ).