Elastase of U-937 monocytelike cells. Comparisons with elastases derived from human monocytes and neutrophils and murine macrophagelike cells

J Clin Invest. 1982 Feb;69(2):384-93. doi: 10.1172/jci110462.


As an approach to facilitating the understanding of proteinases associated with monocytes we have studied U-937 monocytelike cells. Elastase activity was identified in U-937 cell extracts and compared to monocyte elastase activity, neutrophil elastase, and the elastase activity from a continuous line of murine macrophagelike cells (P388D1). Serine proteinase activity which solubilized (14)C-labeled elastin accounted for >90% of the neutral proteinase activity of both U-937 cells and monocyte extracts. U-937 cell and monocyte elastase activities were similar catalytically, resembling neutrophil elastase. U-937 cells and monocytes showed other similarities: (a) both had activities reacting with [(3)H]diisopropylfluorophosphate that migrated in sodium dodecyl sulfate (SDS) polyacrylamide gels at approximately 30,000 and 60,000 daltons and (b) both contained material that cross-reacted with antiserum raised to neutrophil elastase. Preliminary characterization of U-937 cell elastase activity by affinity chromatography and ion-exchange chromatography suggested the presence of at least two distinct elastases. Minimal elastase activity was found in U-937 cell-conditioned medium, indicating that the activity is not spontaneously released by the cells. In contrast to the elastase activity associated with U-937 cells and monocytes, the elastase activity associated with P388D1 cells was a metalloproteinase and was found principally in the culture medium. These results indicate (a) U-937 cells will be useful for further investigation of proteinases associated with normal monocytes; (b) monocytes and U-937 cells contain material with catalytic and immunologic similarities to neutrophil elastase; (c) monocyte elastase activity differs from elastase activity secreted by murine macrophages and murine macrophagelike cells of the P388D1 line.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Chloromethyl Ketones / pharmacology
  • Animals
  • Cells, Cultured
  • Chromatography, Affinity
  • Electrophoresis, Polyacrylamide Gel
  • Histocytochemistry
  • Humans
  • Isoflurophate / metabolism
  • Macrophages / enzymology*
  • Macrophages / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Monocytes / enzymology*
  • Monocytes / metabolism
  • Monocytes / ultrastructure
  • Neutrophils / enzymology*
  • Pancreatic Elastase / metabolism*
  • Phenylmethylsulfonyl Fluoride / pharmacology


  • Amino Acid Chloromethyl Ketones
  • Isoflurophate
  • Phenylmethylsulfonyl Fluoride
  • methoxysuccinyl-alanyl-alanyl-prolyl-valine chloromethyl ketone
  • Pancreatic Elastase