ENHANCEMENT OF C-FOS EXPRESSION IS ASSOCIATED WITH ACTIVATED MACROPHAGES

  • 1 May 1988
    • journal article
    • research article
    • Vol. 2  (5) , 515-521
Abstract
Unique hybrids (HINS and CANS lines) between macrophages and a myeloma cell line, NS1 initially expressed myeloma functions but later expressed active macrophage functions together with constitutive expression of c-fos gene. Enhancement of c-fos transcription was also observed in activated mouse peritoneal macrophages, and a range of macrophage-stimulating substance was found to induced c-fos transcription kinetic unique to each stimulator including immediate, delayed and prolonged responses in aged HINS-B3 cells, which displayed low levels of steady-state c-fos transcription. It was also found that a significant enhancement of c-fos transcription followed restimulation with either interferon .gamma. (IFN-.gamma.) or lipopolysaccharide (LPS) after an initial IFN.gamma. stimulation. Thus it appeared that enhanced c-fos expression was closely connected with macrophage activation. On the other hand, macrophage stimulators suppressed [3H]thymidine incorporation into aged HINS-B3 cells. These results may simply suggest that c-fos expression contributes to macrophase activation but not to cell proliferation. However, it is also possible to speculate that c-fos expression contributes to cell proliferation as a salvage system operating to overcome the suppression during the macrophage activation.