Figure 4. Sin/LacZ efficacy is reduced in mice depleted of NK cells, and enhanced in mice augmented with NK cells.

(A) FACS analysis of cells harvested from the peritoneum of Sin/LacZ-treated and mock-treated ES-2 bearing mice that were injected with anti-CD122, or with an isotype control Ab (IgG), shows the depletion NK cells (NKp46+ SSC low) in response to the anti-CD122 treatment; data is representative of 2 independent experiments (n = 5). (B) The effect of NK cell depletion using anti-CD122 on tumor growth in Sin/LacZ and mock-treated mice is shown. The treatment scheme was similar to figure 3, but treatment and imaging started on day 4. Quantification was done as explained in figure 3; data is representative of 3 independent experiments (n = 12). (C) Kaplan-Meier survival plots from 2 independent experiments were combined (n = 7). (D) SCID mice were treated with media, Sin/LacZ or Sin/LacZ +6×10⁵ syngeneic NK cells (one retro-orbital injection 2 h before the first Sin/LacZ treatment), and their survival was plotted. Data is from one experiment (n = 4). Sin/LacZ treatments were administered 4 times a week for 2 weeks, as in previous experiments. Error bars represent SEM.