Figure 5
In vitro carboxypeptidase-M (CPM) expression during monocyte–macrophage (Mo–MA) differentiation and in response to activating cytokines. (a–f) CPM-immunofluorescence (IF) of paraffin-embedded sections obtained from cell cultures during Mo–MA differentiation in the presence or absence of activating cytokines. As demonstrated, monocytes do not express CPM. Differentiating macrophages, however, start expressing CPM, which is culminated at 12th hour (c, red fluorescence) and remains elevated during the culture time (d). Although, interleukin-4 (IL-4) and interferon-γ (INFγ) apparently increases the CPM-protein expression levels (e and f), the corresponding CPM-mRNA (n=3), normalized to cyclophilin, showed no significant upregulation in Mo-derived MAs during the 72-h stimuli (g). In contrast, separate experiments showed that CPM transcripts of macrophages are significantly increased at the 48th hour of culture time in the presence of macrophage-colony-stimulating factor (M-CSF) and IL-4+granulocyte–macrophage-colony-stimulating factor (GM-CSF) (*), the latter representing cells under maturation toward dendritic cells (h). Original magnifications for IF images: × 40; the nuclear counterstain is 4′-6-diamidino-2-phenylindole (DAPI) (blue fluorescence).
