FIGURE 8.
Infection of H441 cells with rRA2 increases nitrite (NO-2) concentrations in the medium. Nitrite concentrations in cell culture medium of non-inoculated (solid) cells or cells infected with rRA2 (diagonal lines) or UV-inactivated rRA2 (dense cross-hatching) for 48 h. A fourth group of H441 cells were incubated with LPS (1 μg/ml) and human interferon-γ (IFN, 200 ng/ml) for 48 h (vertical lines). Nitrite concentrations were measured by chemiluminescence and adjusted to protein concentrations as described under “Materials and Methods”; data are normalized by dividing the nitrite concentrations of the various groups by the values of the non-inoculated cell groups. Values are the means ± 1 S.E. (n = 6 from two independent experiments; *, p < 0.05 compared with the non-inoculated mean value).