: Li, H.; Pohler, U.; Strehlow, I.; Hertig, S.; Baccarini, M.; Emmendörffer, A.; Tschopp, J.; Lohmann-Matthes, M.-L.

Abstract
Macrophage precursor cells, derived from mouse bone marrow culture with granulocyte-macrophage colony-stimulating factor or colony-stimulating factor 1 (CSF- 1) as growth factor and interleukin-2 (IL-2) as stimulating factor, were activated by IL-2 to exert strong cytolytic activity against Yac-1 cells. In response to IL-2 stimulation these bone marrow macrophage precursor cells produced perforin as lytic molecules. The purity of the precursor cells for the study was proved as homogeneous positivity for Mac-1, NK-1.1 and negativity for Lyt 1 and 2. The cells express CSF-1 receptors on their surface, are able to proliferate and differentiate into typical macrophages when stimulated with CSF-1, and are therefore members of the macrophage lineage.