Control of exogenous proteinases and their inhibitors at the macrophage cell surface.
The actions and availability of human neutrophil elastase and its protein inhibitor, Eglin, when co-incubated with macrophages were investigated. Eglin did not induce radical production by mouse peritoneal macrophages; nor were specific binding sites for Eglin detected on these cells. Mouse peritoneal macrophages could inactivate both elastase and Eglin extensively, when these targets were used at concentrations appropriate to the extravascular fluids. Two methods were used for assessing such inactivation: one, as in previous literature, only took account of molecules remaining in the supernatant after interaction with the cells; the other (lacking from most previous studies) took into account all target molecules, including those associated with the cells. From an analysis of both types of experiment, it was shown that the cell-derived inactivators were stable products, whose quantity was not significantly influenced by the induction of a macrophage oxidative burst and its associated free radicals. They were probably mainly proteinases and proteinase inhibitors. Thus, mouse peritoneal macrophages restrict the activity of proteinases and inhibitors by means of stable molecules, such as proteins. Other mononuclear phagocytes may use free radicals and oxidants more extensively in this respect.
Ciba-Geigy, Basel, Switzerland.
R T
RT
Dean
H P
HP
Schnebli
D000818:Animals; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D005260:Female; D006801:Humans; D008163:Luminescent Measurements; D008264:Macrophages / Q000201:enzymology* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009504:Neutrophils / Q000201:enzymology / Q000378:metabolism; D010101:Oxygen Consumption; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011480:Protease Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism / Q000494:pharmacology; D015843:Serpins
D011480:Protease Inhibitors; D011506:Proteins; D015843:Serpins; C028656:eglin proteinase inhibitors; D010196:Pancreatic Elastase