FIG. 7.

During liver disease caused by a hemorrhagic fever virus, PRH decreases and cell division increases. Sections of monkey liver tissue were stained with anti-PRH (top) or an antibody to the proliferation antigen Ki-67 (bottom). The photomicrographs of an LCMV-ARM-infected liver, shown here in the left panels, are identical to pictures of an uninfected liver (not shown) and differ from the diseased liver shown in the right panels. Brown staining indicates the abundant presence of the PRH protein (arrowheads) in the healthy liver and decreased PRH during disease. The Ki-67 nuclear antigen is expressed in cycling cells and was highly expressed in the diseased liver. Ki-67 is seen in hepatocytes and not infiltrating immune cells. In a monkey that recovered from disease, we observed a decrease in Ki-67 staining upon recovery (38). Magnification, ×200 (top panels) and ×400 (bottom panels).