FIG. 1.
CpG ODN “prime” host cells to produce NO when exposed to heat-killed L. monocytogenes (HKLM). C57BL/6 mice were injected i.p. with 50 μg of control or CpG ODN. Peritoneal cells isolated 3 (A) or 0 to 7 (B) days later were cultured with 2 × 105 CFU/ml of HKL for 48 h. NO production was measured using the Griess reagent. Data represent the means ± standard deviations (SD) of values for more than seven independently studied mice in two independent experiments. **, P < 0.01; ***, P < 0.001 (two-tailed Student's t test).