A glycolipid on the surface of mouse natural killer cells

Abstract

Cytotoxic treatment with rabbit antiserum raised against purified glycosphingolipid “asialo GM1” was capable of eliminating natural killer (NK) activity of spleen cells from different inbred mouse strains including CBA/J, C57BL/6, BALB/c, AKR, and athymic nude mice. The anti‐asialo GM 1 antiserum showed little cross‐reactivity with structurally related glycolipids, e.g. GM 1, GD 1 b and asialo GM 2 in the microflocculation test. The specific reactivity of this antiserum with NK cells was confirmed by the quantitative absorption of anti‐NK activity with graded amounts of asialo GM 1 but not with other glycosphingolipids. The absorption of anti‐brain‐associated T cell antigen (anti‐BAT) with asialo GM 1 also effectively diminished its anti‐NK activity, leaving the ability to kill T cells intact. This suggests that the antibody to asialo GM 1 is responsible for the anti‐NK activity contained in the anti‐BAT antiserum. In contrast to the extreme sensitivity of NK cells to anti‐asialo GM 1, alloreactive cytotoxic T killer cells generated in the mixed lymphocyte culture were not killed by anti‐asialo GM 1 and complement. These results indicate that asialo GM 1 is expressed on mouse NK cells in a high concentration.