Mitogen stimulation of splenocytes from mice infected with scrapie agent

Spleen weights and mitogen responsiveness of splenocyte cultures from scrapie agent-infected and control-inoculated mice were compared over two-month periods fol-lowing inoculation. Splenocytes from Swiss, C57BI, and BALBjc mice were stimu-lated with the T (thymus-derived) cell mitogens phytohemagglutinin or concanava-lin A, the B (bone marrow-derived) cell mitogen bacterial lipopolysaccharide, or pokeweed mitogen, a stimulator of both T and B cells. Although significant splen-omegaly was associated with scrapie infection, we failed to observe any significant differences in the activation of experimental and control cells. Studies with BALB j c mice suggested the possibility, however, that with both phytohemagglutinin and lipopolysaccharide, specific decreases in lymphocyte activation might occur with more optimal culture conditions. The data are consistent with the idea that the scrapie agent stimulates only subtle immunological changes within the host as it destroys the cells of the central nervous system. Scrapie infection causes extensive spongiform changes within the central nervous system of th