FIG 3.

Histopathological analysis of tissues of R. australis-infected B6 and ASC^−/− mice. B6 and ASC^−/− mice were inoculated with 0.5 LD₅₀ of R. australis i.v. On day 4 p.i., mice were euthanized, and tissues were collected. (I) As negative controls, uninfected B6 and ASC^−/− mice were monitored and euthanized along with the infected mouse groups. Histopathological analysis of livers and spleens was performed at magnifications of ×10 (scale bar, 200 μm) and ×40 (scale bar, 100 μm). (II) (A and B) Foci of inflammatory cells in liver tissue (arrows). (C to E) Perivascular infiltration (arrows) and polymorphonuclear neutrophils (PMNs) (arrowheads) in livers. (F and G) Coagulative necrotic infarct (arrowheads) only in livers of infected ASC^−/− mice and surrounding inflammation and tissue repair (arrows). (III) (H to K) Spleens of infected B6 and ASC^−/− mice. Clusters of macrophages and normal periarteriolar lymphocyte sheaths, a portion of white pulp, in spleens of both groups of mice are shown. In red pulp, PMNs (arrowheads) were found only in infected B6 mice (H and J), not in infected ASC^−/− mice (I and K).