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Superantigens from Staphylococcus aureus induce procoagulant activity and monocyte tissue factor expression in whole blood and mononuclear cells via IL‐1β
Author(s) -
Mattsson E.,
Herwald H.,
Egesten A.
Publication year - 2003
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/j.1538-7836.2003.00498.x
Subject(s) - superantigen , tissue factor , peripheral blood mononuclear cell , staphylococcus aureus , monocyte , microbiology and biotechnology , immunology , sepsis , thromboplastin , enterotoxin , whole blood , toxic shock syndrome , coagulation , biology , medicine , immune system , t cell , bacteria , in vitro , biochemistry , genetics , psychiatry , escherichia coli , gene
Summary. Background : Staphylococcus aureus is one of the most common bacteria in human sepsis, a condition in which the activation of blood coagulation plays a critical pathophysiological role. During severe sepsis and septic shock microthrombi and multiorgan dysfunction are observed as a result of bacterial interference with the host defense and coagulation systems. Objectives : In the present study, staphylococcal superantigens were tested for their ability to induce procoagulant activity and tissue factor (TF) expression in human whole blood and in peripheral blood mononuclear cells. Methods and results : Determination of clotting time showed that enterotoxin A, B and toxic shock syndrome toxin 1 from S. aureus induce procoagulant activity in whole blood and in mononuclear cells. The procoagulant activity was dependent on the expression of TF in monocytes since antibodies to TF inhibited the effect of the toxins and TF was detected on the surface of monocytes by flow cytometry. In the supernatants from staphylococcal toxin‐stimulated mononuclear cells, interleukin (IL)‐1β was detected by ELISA. Furthermore, the increased procoagulant activity and TF expression in monocytes induced by the staphylococcal toxins were inhibited in the presence of IL‐1 receptor antagonist, a natural inhibitor of IL‐1β. Conclusions : The present study shows that superantigens from S. aureus activate the extrinsic coagulation pathway by inducing expression of TF in monocytes, and that the expression is mainly triggered by superantigen‐induced IL‐1β release.