Fig. 4.

Inflammatory changes of COX1 and COX2 expression in rhesus monkey brain in control, after simian immunodeficiency virus (SIV) infection and antiretroviral treatment with 6-Cl-ddG. Rows demonstrate immunohistochemistry (IHC) against COX1 (A–D) and COX2 (E–H). Columns show representative COX1 and COX2 stainings of subcortical white matter tissue sections of control monkey (Ctrl; A, E), SIV-infected monkey without acquired immunodeficiency syndrome (SIV,-AIDS; B, F), SIV-infected monkey with AIDS (SIV,+AIDS; C, G), and SIV-infected monkey with AIDS and antiretroviral treatment (SIV,+AIDS,+ddG; D, H). (A–C) Parenchymal and juxtavascular ramified COX1-positive microglia (arrows) as seen in Ctrl and SIV,-AIDS become morphologically activated (arrows) and demonstrate typical signs of SIV-induced encephalitis like increased brain monocytic infiltration and formation of microglia/macrophage nodules and multinucleated giant cells (double arrow heads) in SIV,+AIDS. COX1 expression is constitutively found in endothelial cells and is not significantly altered during SIV disease (arrow heads). (E–G) In contrast, COX2 is absent in microglia and endothelial cells in Ctrl and SIV,-AIDS but is induced in some perivascular, nodule and syncytium forming macrophages (double arrow heads) and endothelial cells (arrow heads) in areas of inflammatory infiltrates in SIV,+AIDS. (D, H) Signs of COX1-positive inflammatory reactions as well as induction of COX2 in endothelial cells and macrophages are reversed by antiretroviral treatment with 6-Cl-ddG. But the density of COX1-positive microglia (arrows) is still increased without changes of COX1 expression in endothelial cells (arrow heads) in SIV,+AIDS,+ddG. Note partially overlapped expression of COX1 and COX2 in endothelial cells (arrow heads) and multinucleated giant cells (double arrow heads) in SIV,+AIDS as demonstrated by stainings on adjacent sections (C, G). Asterisks mark the same blood vessel (C, G). Scale bars = (A–H) 100 µm.