Effector cell sensitivity to sugar moieties. III. Inhibition by monosaccharides of interleukin-2 enhanced natural killing against viral and nonviral tumor target cells.

Human NK cells recognize multiple target antigens. The ligands (antigens) involved in this interaction have not been clearly identified. Previously, we have shown that some monosaccharides inhibit NK mediated cytolysis in a concentration-dependent fashion and that NK cell activity involves recognition of carbohydrate structures on target cells via receptors on the effector cell surface. Using human IL-2 or recombinant IL-2, we have found that monosaccharides inhibit IL-2 enhanced functional activity in a concentration-dependent fashion; that increased expression of endogenous monosaccharide binding receptors on effector cells occurs after treatment with IL-2; and that greater quantities of monosaccharide were required to obtain equivalent inhibition of IL-2 enhanced NK activity. Our data reinforces the growing belief that effector cells express receptors with different sugar specificities and that quantitative differences in sugar specificities is a likely reason for NK cells having heterogeneous polyclonal activity.