Figure 4.

Th17-associated cytokines regulate the IFN-γ production and inducible nitric oxide synthase enzyme (iNOS) expression during the experiment of virulent yeast strain 18 of Paracoccidioides brasiliensis (Pb18) infection. (A,B) C57BL/6, IL-6^−/−, IL-23^−/−, and IL-17 receptor A (IL-17RA)^−/− mice were infected (intravenously) with 1 × 10⁶ Pb18 yeast cells. (A) IFN-γ levels were measured by enzyme-linked immunosorbent assay in the lung homogenate at 15 and 30 days postinfection (dpi). (B) Immunohistochemistry was performed in lung tissue to analyze the iNOS expression at 30 dpi. (C) The percentage of the pulmonary area containing iNOS⁺ cells is indicated. Lung sections were stained for iNOS at 30 dpi using immunohistochemistry. Scale bar: 50 µm. Similar results were obtained in three independent experiments. Data represent the mean ± SEM of five mice. Uninfected mice are represented by the dashed line. *p < 0.05 compared to uninfected mice. ^#p < 0.05 compared to Pb18-infected C57BL/6 mice at the same time point.