Ganglioside GM3 stimulates the uptake and processing of low density lipoproteins by macrophages

Preincubation of low density lipoproteins (LDL) with low concentrations of the ganglioside GM3 (1-2x 10(-5) M/2.5 x 10(-6) M LDL-protein) results in an increase of LDL-uptake, enhances cholesterol accumulation and cholesteryl ester formation by macrophages. At the same time the lysosomal degradation of LDL in macrophages was inhibited under these conditions. These effects depended on the ganglioside structure and concentration. It is suggested that the effects observed could be caused by GM3-induced modification of LDL to a form that becomes recognized by macrophages.