Morphologic characteristics and expression of the macrophage-specific marker F4/80 in macrophages from wild-type (WT) and C/EBPε−/− (KO) mice.

Cytocentrifugation preparations from cultured bone marrow macrophages stained with (A) Wright-Giemsa stain (original magnification, ×200), (B) nonspecific esterase (unstimulated cells, original magnification, ×400), and (C) nonspecific esterase (after stimulation of the cells for 24 hours with LPS). Arrows indicate large multinucleated macrophages (after culturing C/EBPε−/− cells in the presence of rIL-3 and rGM-CSF for 11 to 14 days. These photomicrographs are representative of the results obtained from 3 independent experiments. (D) Histograms of total fluorescence binding of phycoerythrin-conjugated F4/80 (right peak) versus isotype-matched control antibody samples (left peak). Mean fluorescence intensity ratios (total fluorescence divided by control) are shown in the upper right-hand corner of each histogram.