Different effect of (L)-fucose binding lectin on macrophage migration inhibition caused by guinea pig migration inhibitory factor and synthetic muramyl dipeptide.

(L)-Fucose binding lectin of Ulex europeus (UEA-I) was applied for the study of receptors for macrophage migration inhibitory factor (MIF) and synthetic muramyl dipeptide (MDP). The lectin was found to reduce the responsiveness of macrophages towards MIF when the cells were pretreated with the lectin. The suppressive effect of the lectin on MIF was reversed by (L)-fucose, but not by (D)-galactose, indicating that the effect of lectin is a sugar-specific phenomenon. By immunofluorescence technique the lectin appeared to be on the cell surface of the macrophages. These results suggest that the receptor for MIF and UEA-I lectin was identical or at least partially common. The lectin, however, did not prevent the responsiveness of cells toward MDP, which is known to inhibit macrophage migration just as MIF. These findings suggest that the mechanisms of the inhibitory effect on macrophage migration caused by the two substances (MIF and MDP) may be different, at least at the level of the receptors.