Production of a multipotential cell (CFU-S) proliferation inhibitor by various populations of mouse and human macrophages.

Abstract

Some bone marrow macrophages from a variety of animal species synthesize a proliferation inhibitor which specifically inhibits the flow of murine CFU-S into DNA-synthesis. Macrophages from other sources have now been assayed for their capacity to produce this inhibitor. Macrophages from mouse blood, marrow, spleen and peritoneum and human blood were cultured and their ability to produce inhibitor assayed against proliferating CFU-S by the tritiated thymidine suicide assay. Inhibitor was observed in all mouse and most human preparations though with varying degrees of activity, showing functional heterogeneity in the development of macrophages in different tissues. Peripheral blood from both mouse and human showed activity approaching that of fresh marrow. This confirms that mouse assay systems can be used to study the human counterpart of the mouse CFU-S proliferation inhibitor and that blood is a convenient source of material for purification and characterization studies.