IMMUNOHISTOCHEMICAL STUDIES OF LYMPHOID-TISSUES OF RABBITS INFECTED WITH RINDERPEST VIRUS

The pathogenesis of infection with the L-strain of rinderpest virus (R PV) in rabbits was investigated. Of several lymphoid tissues examined, those associated with the gut showed the most marked virus growth. Th e virus titres were maximal 4 days after inoculation but had declined at day 6. The distribution of viral antigen was examined immunohistoch emically with the recently established anti-rabbit CD5 monoclonal anti body (MoAb), which is a pan-T-cell marker, and the anti-RPV-nucleoprot ein MoAb. The virus antigen was localized in the CD5(+) area at the in itial stage of infection but spread to all areas of the lymphoid tissu es at the later stages. By flow cytometric analysis with both rabbit C D5 and CD4 MoAbs, a decrease of the CD4(+) and CD5(+) subpopulations w as observed in the spleen and mesenteric lymph nodes.