Fig. 4From: Neurovirulent Simian Immunodeficiency Virus Infection Induces Neuronal, Endothelial, and Glial Apoptosis Astrocytes, endothelial cells, microglia, and neurons are TUNEL positive in the SIV-infected macaque CNS GFAP immunostaining demonstrates TUNEL-positive astrocytes (A, closed arrow). TUNEL-positive cells that are GFAP negative indicate the specificity of the double-labeling procedure (A and B, open arrows). Apoptotic bodies also appear TUNEL positive (B, closed arrow). Cells with distinct morphological characteristics of endothelial cells of the CNS vasculature (C) and neurons (F) demonstrate TUNEL reactivity. Factor VIII immunostaining demonstrates TUNEL-positive (D, closed arrow) and TUNEL-negative (D, open arrow) endothelial cells. RCA-1 immunostaining demonstrates TUNEL-positive cells of the microglia/macrophage lineage (E). Scale bars = 40 µmBack to article page