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, ).