Transformation induced by Echinococcus granulosus protoscoleces in unprimed murine spleen cells: identity and MHC restriction of participating cell types.

Transformation induced by Echinococcus granulosus in unprimed murine spleen cells in vitro was not prevented by rigorous T- or B-cell depletion. When naïve T- or B-cell populations were further depleted of macrophages, B-cell transformation was relatively unaffected whereas T-cell transformation was totally inhibited. Peritoneal macrophages from infected mice could present a mitogenic stimulus to purified, naïve T-cells, provided that the T-cells had identity in the I region of the H2 complex. K/D identity was neither necessary nor sufficient. It is concluded that transformation can be induced by E. granulosus in both T- and B-cells and that, at least in naïve T-cells, the stimulus can be an I region-restricted, macrophage-presented signal.