iNOS−/− mice show a better disease outcome than WT mice.

<p>Positive DTH reactions and well-organized lesions appear to compensate the increased fungal burdens, and are associated with increased survival times of iNOS^−/− mice. (A) iNOS ^−/− and WT mice were i.t. infected with 1×10⁶<i>P.brasiliensis</i> yeasts and DTH reactions measured 2 and 10 weeks later. Uninfected mice were used as control. DTH reactions were evaluated in control and infected mice by the footpad swelling 48 h after the s.c. injection of 25 µl of a soluble <i>P. brasiliensis</i> antigen. The bars depict means ± SE of footpad swelling. (n = 6–8). (B) Photomicrographs of pulmonary lesions of WT (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002325#pntd-0002325-g004" target="_blank">Fig. 4B</a>, upper panel), and iNOS^−/− (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002325#pntd-0002325-g004" target="_blank">Fig. 4B</a>, lower panel) at weeks 10 of infection with 1×10⁶<i>P. brasiliensis</i> yeasts. Both mouse strains developed extensive lesions, but organized lesions were only observed in NO-deficient mice (HE, 100×). (C) Survival times of iNOS^−/− and WT control mice (n = 6–8) after i.t. infection with 1×10⁶<i>P. brasiliensis</i> yeast cells was determined in a period of 300 days. The data are representative of three independent experiments with equivalent results. * (<i>P</i><0.05), and *** (<i>P</i><0.001) compared with WT controls.