FIGURE 7.

Infection of H441 cells with rRA2 up-regulates iNOS levels. A, upper row, characteristic 10× images of non-inoculated H441 cells immunostained with normal rabbit IgG (IgG), non-inoculated cells (noninoc. iNOS), or cells infected with UV-inactivated rRA2 for 4 days (UV-rRA2 iNOS) and immunostained with a rabbit polyclonal anti-iNOS antibody. Lower row, characteristic 10× images of H441 cells infected with rRA2 for 4 days (rRA2; iNOS, left and middle panels) or incubated with LPS (1 μg/ml) and human IFN-γ (200 ng/ml) for 48 h (LPS+IFN-γ) and immunostained with a rabbit polyclonal anti-iNOS antibody. The middle panel is a merged composite iNOS staining and green filter image showing green fluorescence of GFP(+) cells. The secondary antibody was goat anti-rabbit IgG conjugated to AlexaFluor 594. The scale bar equals to 200 μm. B, characteristic 40× images of non-inoculated cells (non-inoc.) and cells infected with rRA2 for 3 days (rRA2; middle and right panels) immunostained with a rabbit polyclonal antibody to iNOS then labeled by a goat anti-rabbit IgG conjugated to AlexaFluor 594. The middle panel was imaged with a green filter to show GFP(+) cells (arrows). The right panel is a composite merged image obtained with green and red filters to show both GFP(+) cells and iNOS stains. The scale bar equals to 50 μm. C, iNOS fluorescence intensity for the indicated groups. Mean fluorescence intensities of corresponding cell groups were divided by those of the non-inoculated cell groups. Date are the means ± S.E. and are from 3 independent experiments (^*, p < 0.05 as compared with the non-inoculated value; m.o.i. = 1).