Human monocyte production of interleukin-1: parameters of the induction of interleukin-1 secretion by lipopolysaccharides.
The role of lipopolysaccharide (LPS) as an activator of human monocyte interleukin-1 (IL-1) synthesis and secretion has been examined in this study. The results demonstrate that when blood monocytes are prepared under low endotoxin conditions, they do not spontaneously secrete IL-1 activity. When cells are exposed to LPS extracted from different bacterial species, there is variation seen in the potency, with LPS from Salmonella species being the most potent in inducing IL-1 activity from human monocytes. This material is tenfold more potent than LPS obtained from three different strains of Escherichia coli and 10,000-fold more potent than material obtained from two other bacterial species. Detoxified endotoxins are inefficient activators for IL-1 secretion. When monocytes are exposed to LPS, there is a rapid rise in the level of IL-1 activity detected. Activity can be detected in cell lysates after 1 hr with appreciable accumulation seen over the first 6 hr of culture. This is accompanied by IL-1 release into the surrounding medium after 2 hr of culture with subsequent accumulation. Monocyte synthesis of IL-1 activity appears to be sensitive to fg/ml levels of Salmonella minnesota LPS, while appreciable secretion of this activity by monocytes requires pg/ml levels.
D000818:Animals; D002478:Cells, Cultured; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis / Q000378:metabolism*; D008050:Lipid A / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D007375:Interleukin-1; D008050:Lipid A; D008070:Lipopolysaccharides