Isolation of a guinea pig macrophage glycolipid with the properties of the putative migration inhibitory factor receptor.

We have previously established that preincubation of guinea pig macrophages with crude preparations of macrophage glycolipids enhances their response to a mediator of cellular immunity, migration inhibitory factor. This biologically active moiety found in the extracted material was attributed to a single glycolipid component. This component was purified to homogeneity by phase partition, ion exchange, adsorption, and thin layer chromatography. It migrates in the ganglioside region on thin layer plates, contains sialic acid and sphingosine. There is no apparent identity with any of the common gangliosides possessing the gangliotetraose structure. Homogeneity was demonstrated by rechromatography in four additional solvent systems. These results are discussed in the context of their implications for a deeper understanding of the putative receptor function of this glycolipid.