Astrogliosis and increased macrophage/microglia density in IL-12p40KO spinal cords.

<p>Paralyzed infected IL-12p40KO mice presented higher immunolabeled area to the astrocytic marker GFAP (A) and increased density of macrophages/microglia (B) in the spinal cord when compared to the matched infected WT group. Pictures in Figure A show astrocytes (arrows) in immunocompetent (left panel) and IL-12p40KO (right panel) spinal cords. No <i>T. cruzi</i>-infected astrocyte was found in WT tissue (left panel inset, arrow points an astrocyte), whereas in IL-12p40KO tissue, only a few astrocytes containing <i>T. cruzi</i> amastigotes were seen (right panel inset, arrow points an astrocyte and arrowheads point parasites). Pictures in Figure B show microglial cell (arrow) with long thin processes in WT tissue (left panel) and round-shaped phagocytes (arrows point macrophages or microglia) in a lesion area of an IL-12p40KO spinal cord section (right panel). While no parasite was found in the WT tissue (right panel inset, arrow shows a microglia), more than a third of all IL-12p40KO macrophages/microglias were infected (right panel upper inset, arrow shows a macrophage/microglia and arrowheads point parasites). M2 cells were visualized in the IL-12p40-KO spinal cord only (right panel lower inset, M2 cells in brown). Sections were immunolabeled to GFAP (A) and CD11b (B, also counterstained with Giemsa), GFAP and <i>T. cruzi</i> (A, inset), CD11b and <i>T. cruzi</i> (B, upper insets) or arginase I (B, right panel lower inset, also counterstained with hematoxylin). Scale bars: A and B, 50 µm; A insets and B upper insets, 20 µm; B right panel lower inset, 50 µm. Data on both graphs are presented as the mean ± SEM. **p<0.01, according to the unpaired <i>t</i>-test.