Purified interleukin-1 (IL-1) from human monocytes stimulates acute-phase protein synthesis by rodent hepatocytes in vitro.
A universal component of inflammation is the increased synthesis of a series of plasma proteins (acute-phase proteins) by the liver. The postulated messenger of acute-phase protein induction is released by leucocytes at the site of inflammation and has been shown to co-purify with endogenous pyrogen or lymphocyte-activating factor. Interleukin-1, molecular weight 17,000, pI 6 X 8-7 X 2, was purified to homogeneity from adherent human blood monocytes by a combination of affinity chromatography, gel filtration and isoelectric focusing. We examined the direct effect of pure IL-1 on the induction of acute-phase protein synthesis in vitro using rat and mouse hepatocytes. IL-1 caused significant increased synthesis of alpha 1-acid glycoprotein and smaller increases in the synthesis of other acute-phase proteins, and significant decreased synthesis of albumin. The pattern of induction of acute-phase proteins differs from that seen with a separate 30,000 molecular weight hepatocyte-stimulating factor from human monocytes described previously. We conclude that human IL-1 is one of the mediators responsible for the acute-phase protein response of the liver in inflammation and can directly cause stimulation of specific gene expression in normal hepatocytes.
D000209:Acute-Phase Proteins / Q000096:biosynthesis*; D000818:Animals; D002478:Cells, Cultured; D007375:Interleukin-1 / Q000502:physiology*; D008099:Liver / Q000166:cytology* / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice; D008809:Mice, Inbred C3H; D009000:Monocytes / Q000276:immunology*; D051381:Rats
D000209:Acute-Phase Proteins; D007375:Interleukin-1