Indirect and selective down-regulation of serum tumor necrosis factor-alpha release by interleukin-1 beta.
A selective inhibition of LPS-induced tumor necrosis factor-alpha (TNF) response in mice was caused by an injection of recombinant human interleukin-1 (IL-1). The decrease in serum TNF level reached 70 to 80 percent of the controls receiving LPS alone when IL-1 was given simultaneously or prior to the challenge. At the same time serum IL-6 release was more elevated. Ex vivo assays have shown that macrophages from IL-1 treated animals did not respond to LPS when stimulated immediately after harvesting but recovered their normal responsiveness after being cultured for 2 hours and then washed. In vitro with or without addition of IL-1, mouse elicited macrophages responded equally to LPS in releasing TNF. In the absence of a direct and lasting effect on TNF-producing cells, the host reaction responsible for the inhibitory effect of IL-1 could be related to the overproduction of corticosterone that occurred after IL-1 injection, since it was not observed in adrenalectomized animals. Indeed the blockade of corticoid secretion by indomethacin prevented the inhibition of TNF production induced by IL-1 administration before LPS challenge. TNF administration did not result in elevation of corticosterone level and in contrast to IL-1 enhanced the TNF response to LPS injection. In vitro and ex vivo assays have shown this enhanced response to LPS was linked to a direct and prolonged effect of TNF on TNF-producing cells. Muramyl dipeptide (MDP) which was used as a known priming agent for enhanced cytokine release had a similar effect on TNF-producing cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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Laboratoire d'Immunopharmacologie Expérimentale, CNRS UPR 405, Paris, France.
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D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000494:pharmacology; D000311:Adrenal Glands / Q000378:metabolism; D000315:Adrenalectomy; D000818:Animals; D003345:Corticosterone / Q000097:blood; D003907:Dexamethasone / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects*; D005260:Female; D005856:Germ-Free Life; D007213:Indomethacin / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology*; D015850:Interleukin-6 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D011994:Recombinant Proteins / Q000494:pharmacology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000494:pharmacology
D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D000119:Acetylmuramyl-Alanyl-Isoglutamine; D003907:Dexamethasone; D003345:Corticosterone; D007213:Indomethacin