IMMUNO-SUPPRESSIVE EFFECT OF HUMAN MACROPHAGES .2. INFLUENCE OF MACROPHAGES ON KINETICS OF DNA, RNA AND PROTEIN-SYNTHESIS IN PHA-STIMULATED LYMPHOCYTES

  • 1 January 1978
    • journal article
    • research article
    • Vol. 86  (4) , 187-192
Abstract
Human macrophages obtained by culturing blood monocytes in vitro for 8 days release a soluble factor(s) inhibiting DNA synthesis and cell proliferation in PHA[phytohemagglutinin]-stimulated lymphocytes. Synthesis of RNA and protein was strongly inhibited in PHA-stimulated lymphocytes sedimented on macrophages, and in lymphocytes separated from the macrophages by a membrane, thus demonstrating that inhibition of RNA and protein synthesis was also mediated by a soluble factor(s). The kinetics of the factor-mediated inhibition showed that RNA synthesis was readily inhibited, whereas there was a delay in the inhibition of protein synthesis, thus indicating that the inhibition of protein synthesis and cell proliferation is a result of a blocking effect on the nucleic acid synthesis. The kinetics of DNA and protein synthesis in lymphocytes relieved from macrophage-mediated inhibition indicate a cytostatic effect.