Journalartikel

Jahr der Veröffentlichung: 1990

Seiten: 14377-14381

Zeitschrift: Journal of Biological Chemistry

Bandnummer: 265

Heftnummer: 24

eISSN: 1083-351X

Verlag: Elsevier

Abstract: 
.alpha.-Toxin, the major cytolysin of Staphylococcus aureus, promotes blood coagulation by its attack on human platelets (Bhakdi S., Muhly, M., Mannhardt, U., Hugo, F., Klapettek, K., Mueller-Eckhardt, C., and Roka, L. (1988) J. Exp. Med. 168, 527-542). In the present study we demonstrate that toxin attack on gel-filtered human platelets initiates the assembly of prothrombinase complexes at rates up to 10-fold of controls. Treatment of platelets with 0.1 .mu.g/ml .alpha.-toxin resulted in generation of 1.4 units of thrombin/108 platelets. A similar rate of thrombin generation was noted when platelets were subjected to three cycles of freezing and thawing. However, the .alpha.-toxin-induced prothrombinase activity was not due to platelet lysis, since >1% of total cellular lactate dehydrogenase was released by this .alpha.-toxin concentration. Two distinct and dissociable processes contributed to enhanced prothrombinase assembly. First, .alpha.-toxin promoted the exocytotic release of factor V from .alpha.-granules, which was accompanied by co-secretion of platelet factor 4. This process was calcium-dependent. Second, toxin-treated platelets exhibited an enhanced capacity to bind external factor V(a), a phenomenon that was not linked to Ca2+-dependent factor V secretion. Assembly of prothrombinase complexes via these two mechanisms together accounts for the procoagulant action of S. aureus .alpha.-toxin.

Harvard-Zitierstil: ARVAND, M., BHAKDI, S., DAHLBACK, B. and PREISSNER, K. (1990) STAPHYLOCOCCUS-AUREUS ALPHA-TOXIN ATTACK ON HUMAN PLATELETS PROMOTES ASSEMBLY OF THE PROTHROMBINASE COMPLEX, Journal of Biological Chemistry, 265(24), pp. 14377-14381

APA-Zitierstil: ARVAND, M., BHAKDI, S., DAHLBACK, B., & PREISSNER, K. (1990). STAPHYLOCOCCUS-AUREUS ALPHA-TOXIN ATTACK ON HUMAN PLATELETS PROMOTES ASSEMBLY OF THE PROTHROMBINASE COMPLEX. Journal of Biological Chemistry. 265(24), 14377-14381.