Fig. 3

Ras overexpression and Rb deletion induce resistance to NK cell-mediated cytotoxicity in in vitro transformed astrocytes. NK cells were purified from C57 mice spleens and co-cultured with in vitro transformed astrocytes (GFP expressing cells) to an effector target ratio of 10:1. After 4 h of incubation at 37 °C, cells were stained with 7-AAD and the percentage of dead cells in the GFP+ population (target cells) was calculated, and referred to as the % of NK cell-mediated cytotoxicity. Results show the media +/− S.D. of four independent experiments. In all cases the % of NK cell-mediated cytotoxicity was lower in transformed cells than in the parental (cRb ^loxP/loxP) cells (p < 0.001)