Figure 5.

A nonreplicating, minimally UV-inactivated MG1 (MG1-UV^2min) is capable of activating NK cells and attenuates lung metastases. PBS or indicated virus was injected i.v. into B6 mice. Twenty-four hours post–virus injection, spleens were harvested to assess (a) NK cell CD69 expression and (b) ex vivo NK cytotoxicity (^{^}P = 0.05, ^{^^}P = 0.01 comparing treatment to PBS controls; the data are displayed as the mean percent (±SD) of chromium release from triplicate wells for the indicated E:T ratios). (c) PBS or indicated virus was injected i.v. into B6 mice at day 0. At day 1, all mice received B16lacZ tumor cell inoculation. All mice were sacrificed at 3 days post–cell injection and the number of lung tumor metastases was quantified. (d) B6 mice were treated with MG1 i.v. or PBS at day −1. At day 0, all mice received 3 × 10⁵ B16lacZ tumor cell inoculation via tail vein. NK cells were depleted using anti-NK1.1 i.v. or control IgG at days −4, −1 and +1. **P < 0.001; ***P = 0.05.