NK cells in latently infected mice protect against a lethal RMA-S lymphoma challenge. (A) Mice were inoculated with medium (mock), MuHV-4, or latency-defective MuHV-4 (O73.stop) 29 days before injection with 103 RMA-S cells intraperitoneally and then followed for survival. These data are pooled from 3 independent experiments with a total of 20 mice per group. *P < .001 (MuHV-4 vs either control). (B) Mice were inoculated with MuHV-4 35 days before injection with anti-NK1.1 or control monoclonal antibody (mAb). One day later, all animals were challenged with RMA-S as in panel A. Antibody injections were continued every 6 to 8 days for the duration of the experiment. These data are pooled from 2 independent experiments with a total of 10 mice per group. *P < .001 (anti-NK1.1 vs control).