Macrophages are activated by endocytosis of α2-macroglobulin-protease complexes to produce neutral proteases

  • T. L. Vischer
  • D. Berger
  • E. D. Flory
Part of the Inflammation: Mechanisms and Treatment book series (FTIN, volume 4)


At sites of inflammation, proteases are released by inflammatory and tissue cells. The activation of the complement, the coagulation and the fibrinolytic systems produce additional proteases. Active proteases become inactivated by various inhibitors in the circulation and in tissues. Among the plasma protease inhibitors, alpha1-antitrypsin and alpha2-macroglobulin (α2M) are quantitatively the most important ones. In the circulation, proteases bound to alpharantitrypsin are transferred to α2M1. The α2M-protease complexes are then taken up by the fixed tissue macrophages in liver and spleen1,2. In the experiments summarized in this paper, we have studied the effect of α2M-trypsin complexes on macrophages in vitro.


Plasminogen Activator Synovial Fluid Neutral Protease Fluid Synovial Fluid Human Synovial Fluid 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Ohlsson, K. and Laurell, C. B. (1976). The disappearance of enzyme-inhibitor complexes from the circulation of man. Clin. Sci. Mol. Med., 51, 87PubMedGoogle Scholar
  2. 2.
    Ohlsson, K. (1971). Elimination of 25I-Trypsin-α2-Macroglobulin complexes from blood by reticuloendothelial cells in dog. Acta Physiol. Scand., 81, 269PubMedCrossRefGoogle Scholar
  3. 3.
    Dolovich, J., Debanne, M. T. and Bell, R. (1975). The role of α1-antitrypsin and α2-macro-globulin in the uptake of proteinase by rabbit alveolar macrophages. Am. Rev. Resp. Dis., 112, 521PubMedGoogle Scholar
  4. 4.
    Debanne, M. T., Bell, R. and Dolovich, J. (1975). Uptake of proteinase-α2-macroglobulin complexes by macrophages. Biochim. Biophys. Acta, 411, 295PubMedCrossRefGoogle Scholar
  5. 5.
    Debanne, M. T., Bell, R. and Dolovich, J. (1976). Characteristics of the macrophage uptake of proteinase-a2-macroglobulin complexes. Biochim. Biophys. Acta, 428, 466PubMedCrossRefGoogle Scholar
  6. 6.
    Gordon, S., Unkeless, J. C. and Cohn, Z. A. (1974). Induction of macrophage plasminogen activator by endotoxin stimulation and phagocytosis. J. Exp. Med., 140, 995PubMedCrossRefGoogle Scholar
  7. 7.
    Gordon, S., Newman, W. and Bloom, B. (1978). Macrophage proteases and rheumatic diseases: Regulation of plasminogen activator by thymus-derived lymphocytes. Agents A ctions, 8, 19CrossRefGoogle Scholar
  8. 8.
    Vischer, T. L. and Bertrand, L. (1976). Stimulating effect of neutral proteases on cells in vitro. Agents Actions, 6, 180PubMedCrossRefGoogle Scholar
  9. 9.
    Shtacher, G., Maayan, R. and Feinstein, G. (1973). Proteinase inhibitors in human synovial fluid. Biochim. Biophys. Acta, 303, 138PubMedGoogle Scholar
  10. 10.
    Abe, S. and Nagai, Y. (1973). Evidence for the presence of a complex of collagenase with α2-macroglobulin in human rheumatoid synovial fluid: A possible regulatory mechanism of collagenase activity in vivo. J. Biochem., 73, 897PubMedGoogle Scholar
  11. 11.
    Ohlsson, K. and Skude, C. (1976). Demonstration and semiquantitative determination of complexes between various proteases and human α2-macroglobulin. Clin. Chim. Acta, 66, 1PubMedCrossRefGoogle Scholar
  12. 12.
    Vischer, T. L. and Berger, D. (1980). Activation of macrophages to produce neutral proteinases by endocytosis of α2M-trysin complexes. J. Reticuloendothel. Soc., 28, 427PubMedGoogle Scholar

Copyright information

© MTP Press Limited 1980

Authors and Affiliations

  • T. L. Vischer
    • 1
  • D. Berger
    • 1
  • E. D. Flory
    • 1
  1. 1.Switzerland

Personalised recommendations