Inhibition of tumor cell proliferation by natural suppressor cells present in murine bone marrow.
Natural suppressor (NS) cells, which are Thy-1-, immunoglobulin-, and nonadherent cells with relatively low density (1.063 to 1.075 g/ml), inhibit not only the proliferation of spleen cells which have been stimulated by allogeneic cells or mitogens but also the proliferation of tumor cell lines. Cell-to-cell contact is not necessary for NS cells to exert NS activity. Being radioresistant, DNA synthesis is not necessary for NS cells to suppress proliferation. However, protein synthesis is necessary, since puromycin blocks NS cell activity. In addition, NS cells were found to secrete a factor which inhibits DNA synthesis. Of the various cytokines tested, interleukin 3 and granulocyte-macrophage colony-stimulating factor enhance NS activity. These results suggest that NS cells play an important role in the suppression of not only immune responses but also tumor growth.
Sugiura
K
K
Department of Pediatrics, Children's Hospital, University of South Florida, St. Petersburg 33701.
Inaba
M
M
Ogata
H
H
Yasumuzu
R
R
Sardiña
E E
EE
Inaba
K
K
Kuma
S
S
Good
R A
RA
Ikehara
S
S
D000818:Animals; D001854:Bone Marrow Cells; D002455:Cell Division; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007377:Interleukin-3 / Q000494:pharmacology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D011994:Recombinant Proteins; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*; D014407:Tumor Cells, Cultured / Q000473:pathology*
D003115:Colony-Stimulating Factors; D006133:Growth Substances; D007376:Interleukin-2; D007377:Interleukin-3; D011994:Recombinant Proteins; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor