Comparison of the mandibular lymph node (LN) of day 12 JUNV and GTOV infected animals.

Blue boxes in rows 1 and 2 represent enlarged areas in rows 3 and 4. Row 1 represents H&E at 4X magnification; note the decreased density of lymphocytes in the cortex (and medullary cords), including follicles and parafollicular areas. The control LN is mildly hyperplastic with follicles containing prominent germinal centers. Row 2 represents ISH at 4X magnification and shows marked labeling of viral RNA (in same area shown in row 1) in the depleted lymph nodes including cortex, medullary cords, and prominent outlining of vessels in the GTOV group. Row 3 represents H&E at 20X magnification; there is depletion of lymphocytes with apoptosis/necrosis, which is more prominent in the GTOV image, increased tingible body macrophages (blue ovals) and vessels with hypertrophied endothelium (blue arrows). Row 4 represents ISH at 20X magnification; there is marked viral RNA labeling in same area shown in row 3, with labeling throughout the cortex including in areas of apoptosis/necrosis and in vessels.