Studies on the responsiveness of spleen cells to various polyclonal T and B cell activators during Trichinella spiralis infection

Summary Spleen cells from mice infected with Trichinella spiralis 1, 2, 3 and 8 weeks before the assay, were stimulated with various polyclonal T and B cell activators. It was observed that T. spiralis infection was accompanied by increased spontaneous DNA synthesis which probably reflects lymphocyte activation in vivo . The infection also caused a depressed T cell reactivity during the intestinal stage (1 week after infection) and enhanced DxS response during the late muscular stage (8 weeks after infection). The depression of T cell reactivity seems to reflect qualitative rather than quantitive changes, presumably associated with the regulation of the host's specific immune response to the parasitic antigen. The increased response to DxS may partially be associated with increased macrophage activity. Attempts to evaluate the effects of infection on the reactivity of the cells to PHA and Con A during the migration stage and onwards, to PPD and LPS during the whole observation period and to DxS before the late muscular stage gave conflicting results.