GENERATION AND FUNCTIONAL-CHARACTERIZATION OF CANINE BONE-MARROW-DERIVED MACROPHAGES

A culture of bone marrow cells from the femurs of canine pups at high concentrations of fetal calf serum under non-adherent conditions allow ed the proliferation and differentiation of mononuclear phagocyte line age cells, as evidenced by morphology and CD14 expression. Cells from other lineages progressively diminished in numbers. Cells collected be tween 12 and 19 days of culture expressed an array of macrophage activ ities including ingestion of opsonised erythrocytes, generation of sup eroxide, up-regulation of procoagulant activity and synthesis of tumou r necrosis factor (TNF) upon appropriate stimulation. TNF production w as enhanced when the cultures were simultaneously stimulated with cani ne recombinant, or supernatant-derived, interferon-gamma. in contrast, low levels of inducible nitric oxide (NO) synthase were expressed by only a minority of stimulated macrophages, and nitrite could not be de tected in the medium. Therefore, canine macrophages generated by this novel culture system resemble human macrophages in their inefficient a nd restricted generation of No upon appropriate stimulation.