Suppression splenic T lymphocytes in human hepatosplenic Schistosomiasis mansoni

Splenic suppressor cell activity was evaluated in 10 patients with advanced hepatosplenic Schistosomiasis mansoni undergoing elective splenectomy. We used cell mixing experiments to assess the effect of mitomycin-C-treated spleen cells on antigen and mitogen-induced 3H-thymidine incorporation of responder cells. The suppressor to responder ratio was 1.0. Spleen cells from 7 of 10 patients caused at least 20% suppression of phytohemagglutinin-induced 3H-thymidine incorporation of one or more populations of responder cells (spleen cells, autologous and allogeneic peripheral blood mononuclear cells)Responses of peripheral blood mononuclear cells to streptokinase-streptodornase and schistosome soluble egg and worm antigen preparations also were inhibited by co-cultured spleen cells. An inverse correlation was apparent between the spleen cell response to PHA and the suppressor activity of that spleen cell population (r = -0.74, p less than 0.05). Cell purification procedures showed that the active suppressor splenic cell was non-adherent and rosetted neuraminidase-treated sheep erythrocytes. This splenic suppressor T lymphocyte may modulate splenic and peripheral blood lymphocyte responses in patients with hepatosplenic schistosomiasis.