Figure 4.

Induction of apoptosis in liver endothelial cells. KM123L4 IFN^R cells (1x10⁶) were injected into the spleen of nude mice. Seven days later, groups of mice (n=10) received daily s.c. injections of saline (control) or 10,000 U of IFN-α-2a. Mice were euthanized after 7, 14, or 21 days of treatment. The livers were processed for immunohistochemical evaluation. The sections were immunostained for expression of PCNA (to show cell proliferation) and TUNEL (to show cell death). The sections were also stained with immunofluorescent anti-CD-31 antibody and TUNEL A representative sample (x400) of this CD-31/TUNEL (fluorescent double-staining) is shown. Fluorescent red, CD-31-positive endothelial cells; fluorescent green, TUNEL-positive cells; fluorescent yellow, TUNEL-positive endothelial cells.