TJ alterations correlated with monocyte infiltration in brain tissue with HIVE. Microvessels from control brain showed intact and continuous TJs (claudin-5, brown) and rare perivascular macrophages (CD163, purple [A,F]). Decreased staining for claudin-5 (arrows) was seen in microvessels in areas of intensive monocyte migration (arrowheads) in severe (B-C) and moderate (D) HIVE. Brain tissue with mild HIVE demonstrated little changes in claudin-5 staining (brown) and perivascular macrophages (CD163, purple [E]). Original magnification (A-B) × 100; (C-F) × 200. Images were visualized using a 10 ×/0.3 NA (A-B) or a 20 ×/0.5 NA (C-F) objective and were acquired using a Color View II digital CCD camera.