DISPLAY OF THE NEUTRAL GLYCOLIPID GANGLIO-N-TETRAOSYLCERAMIDE (ASIALO GM1) ON CELLS OF THE NATURAL-KILLER AND T-LINEAGES

Analysis was made of the display of the neutral glycolipid asialo GM1 on cells involved in the differentiation and expression of natural killer (NK) and T cell-mediated cytotoxicity in vitro. Removal of asialo GM1-bearing cells from CBA mouse spleens, by treatment with a specific rabbit antibody in the presence of complement, led not only to the abrogation of NK cell activity but also to the lack of responsiveness of such populations to polyinosinic:polycytidilic acid (poly I:C) and to interferon, indicating that both NK cells and interferon-responsive cells of the NK cell lineage bear asialo GM1. Cytotoxic T lymphocytes (CTL) induced by mixed lymphocyte culture in vitro were unaffected by treatment with antiasialo GM1 serum in the presence of complement, but normal spleen cells subjected to this treatment failed to mount CTL responses to alloantigen, even in the presence of an exogenous source of Interleukin-2 (IL-2). Spleen cell populations depleted of asialo GM1-bearing cells showed a decreased ability to produce IL-2 in response to mitogenic stimulation.