INTERLEUKIN-1-DEPENDENT MITOGENIC RESPONSES INDUCED BY PROTOSCOLECES OF ECHINOCOCCUS-MULTILOCULARIS IN MURINE LYMPHOCYTES

Mitogenic effects of protoscoleces (PSCs) of Echinococcus multilocularis on murine lymphocytes were studied. Spleen cell from normal BALB/c mice showed significant proliferative responses when cocultured with PSCs. Proliferative responses were observed in both the T and B cell populations. The PSCs also stimulated cells of the macrophage/monocyte lineage to secrete interleukin-1 (IL-1). Depletion of plastic- and Sephadex G-10-adherent cells from the spleen cell population significantly reduced the proliferative responses to PSCs and the low responsiveness was restored by addition of plastic-adherent cells to these cultures. Furthermore, addition of anti-IL-1 serum to the spleen cell cultures stimulated with PSCs completely suppressed the proliferative responses. These findings demonstrate that the mitogenic effect of PSC on lymphocytes depends on IL-1 secreted by cells of macrophage/monocyte lineage.