Serum lipoproteins inhibitors of granulocyte-macrophage (GM) colony formation.

Normal and chloroform-extracted human sera, fractionated by Sephadex column chromatography, were tested for inhibitory activity on granulocyte-macrophage (GM) colony formation. This activity was found to be connected with lipoproteins with a molecular weight of about 200,000. Serum native fractions of lipoproteins were isolated and mainly high density lipoproteins (HDL) and very low density lipoproteins (VLDL) were shown to have an unspecific inhibitory activity directed on colony stimulating factor (CSF) action.