Transient NKG2D blockade attenuates GVHD while preserving GVT effects. Irradiated Balb/c mice were transplanted with B6-derived BM alone or with B6-derived BM cells and FACS-sorted CD8⁺ T cells with or without luciferase-expressing A20 cells. The mice were treated 3 times per week with either isotype control antibody (IgG) or anti-NKG2D antibody for 1 week. Mice were monitored for (A) survival, (B) weight changes, and (C) clinical score. (D) The tumor burden measured by bioluminescence is shown as compiled data from 1 representative of 2 independent experiments (n = 4-5 mice/group). (E) Representative bioluminescence images of tumor-bearing mice on days 3, 6, and 18 are shown. CTL represents non–tumor-bearing mice used for measuring background bioluminescence for comparison purposes. (F) The tumor incidence of mice in each group at day 40 post-BMT is shown. The number represents the actual fraction of mice with tumors. The survival graph was generated using all mice from 2 independent experiments (n = 9 mice/group). One representative of 2 independent experiments is shown for weight changes and clinical score (n = 4-5 mice/group). Statistical analysis for survival was performed using the log-rank test.