FIG. 6.

Mononuclear cell infiltrate of the spleen. Mononuclear infiltrate was noted in the spleens of some ANDV-infected animals. (A) Normal appearance of spleen from an SNV-injected hamster (animal 265, day −7). (B) Mononuclear cell infiltrate in the red pulp that obscures lymphoid follicular architecture in splenic white pulp from an ANDV-infected hamster (animal 206, day 12). (C) Lymphoblasts (arrowhead) and plasma cells (arrows) are the predominant cell types associated with the mononuclear infiltrate, as shown by electron microscopy (animal 206, day 12). (D and E) Immunohistochemistry reveals viral antigen present in endothelial cells randomly scattered throughout the spleens from ANDV-infected hamsters (D) but not control hamsters (E). Size bars = 200 μm (A and B) and 20 μm (D and E). The electron microscopy image in panel C was acquired at a magnification of ×13,500.