Opposing effects of tumor necrosis factor alpha and leukemia inhibitory factor in lipopolysaccharide-stimulated myelopoiesis.
Three myelopoietically active, lipopolysaccharide (LPS)-stimulated monokines, interleukin-1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF-alpha), and leukemia inhibitory factor (LIF), were tested for effect in an in vitro model for LPS-induced inflammatory murine monocytopoiesis. Neither cytokine stimulated clonal proliferation of marrow-derived progenitors; however, both IL-1 alpha and TNF-alpha enhanced macrophage colony-stimulating factor (M-CSF)-dependent colony formation. The additional progenitors stimulated by IL-1 alpha and TNF-alpha to form colonies in response to M-CSF were equivalent to the precommitment, transitional progenitors stimulated by M-CSF and bacterial LPS. In addition, the additional colonies elicited by IL-1 alpha and TNF-alpha were not additive in cultures containing both M-CSF and LPS, indicating these colonies arose from the same LPS-responsive, two-signal-dependent transitional progenitors. Leukemia inhibitory factor did not influence M-CSF-stimulated colony formation; however, LIF effected a dose-dependent inhibition of colony formation by transitional progenitors responding to combinations of M-CSF and LPS, IL-1 alpha, TNF-alpha, or an additional transitional cell costimulant, substance P. Neutralizing anti-murine TNF-alpha antibodies abrogated transitional cell colony formation stimulated by combinations of M-CSF and TNF-alpha, IL-1 alpha, LPS, or substance P but had no effect on colony formation stimulated solely by M-CSF. The results indicate that TNF-alpha may be an important positive stimulus for commitment of progenitors to the mononuclear phagocyte lineage and that TNF-alpha may be the endogenous regulator of the costimulatory effects of LPS, IL-1, and substance P. In addition, the results indicate that LIF may play an opposing negative regulatory role acting to inhibit LPS and TNF-alpha stimulation of the transitional progenitors.
Kreisberg
R
R
Department of Microbiology, University of Tennessee, Knoxville 37996-0845.
Detrick
M S
MS
Moore
R N
RN
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D006131:Growth Inhibitors / Q000494:pharmacology*; D006410:Hematopoiesis / Q000187:drug effects*; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008222:Lymphokines / Q000494:pharmacology*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D009000:Monocytes / Q000187:drug effects* / Q000502:physiology; D013373:Substance P / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000494:pharmacology*
D000911:Antibodies, Monoclonal; D006131:Growth Inhibitors; D007375:Interleukin-1; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse; D008070:Lipopolysaccharides; D008222:Lymphokines; D014409:Tumor Necrosis Factor-alpha; D013373:Substance P; D016173:Macrophage Colony-Stimulating Factor