Relationships between suppressor macrophages and macrophage precursors in the spleens from tumor-bearing mice

Cell Immunol. 1984 Apr 15;85(1):45-57. doi: 10.1016/0008-8749(84)90276-4.


Suppressor macrophages (M phi) which can inhibit mitogen-induced lymphocyte proliferation appeared in the spleens of mice bearing transplanted MC-A fibrosarcoma cells. An analysis of the ontogeny of such M phi revealed additional suppressor activity directed against macrophage stem cells. Treatment of spleen cell suspensions with carbonyl iron followed by centrifugation removed suppressor M phi but did not deplete M phi-colony forming cells (M-CFC) which could be demonstrated in soft agar culture in L-cell conditioned medium (LCM). Untreated spleen cells had normal numbers of M-CFC; phagocyte-depleted mononuclear cells showed a threefold increase in M-CFC 14 days after subcutaneous inoculation of 10(6) MC-A cells per mouse. Further increases in M-CFC were also evident in similar preparations on Days 21 and 28 when the M-CFC concentration reached a maximum of eight times the normal level. The M phi which developed from the M-CFC grown in the presence of LCM were later shown to have indomethacin-sensitive suppressor activity suggesting the mediation of this phenomenon by prostaglandins. These observations suggest that locally produced phagocytic suppressor M phi from the spleens of tumor-bearing mice play important roles not only as inhibitors of lymphocyte proliferation as reported earlier, but also as regulators of monocyte-M phi production.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Dinoprostone
  • Female
  • Fibrosarcoma / immunology*
  • Indomethacin / pharmacology
  • Isoantibodies / pharmacology
  • Lymphocyte Activation / drug effects
  • Macrophages / immunology*
  • Male
  • Mice
  • Mice, Inbred C3H
  • Neoplasm Transplantation
  • Phagocytosis
  • Prostaglandins E / pharmacology
  • Spleen / cytology
  • Stem Cells / immunology*
  • T-Lymphocytes, Regulatory / immunology*


  • Isoantibodies
  • Prostaglandins E
  • anti-Thy antibody
  • Dinoprostone
  • Indomethacin