Stimulation of monocyte tissue factor expression in an in vitro model of bacterial endocarditis.
The coagulation system plays a major role in the formation of the infected endocardial vegetation in bacterial endocarditis. Since monocytes can express tissue factor (TF) on their surfaces, they are thought to be responsible for the extrinsic activation of the coagulation cascade during this disease. The present study used an in vitro model in which fibrin plates, isolated adherent monocytes, and Streptococcus sanguis were used as an analog for endocardial vegetations. Adherence to fibrin by itself was found to stimulate TF expression on the monocytes, but stimulation by S. sanguis significantly increased TF expression, which was found to be maximal at a bacterium-to-monocyte ratio of 9 or more.
Department of Infectious Diseases, Leiden State University Hospital, The Netherlands.
M J
MJ
Bancsi
J
J
Thompson
R M
RM
Bertina
D001777:Blood Coagulation / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D004697:Endocarditis, Bacterial; D005337:Fibrin / Q000502:physiology; D006801:Humans; D008954:Models, Biological; D009000:Monocytes / Q000378:metabolism*; D013298:Streptococcus sanguis / Q000502:physiology*; D013925:Thromboplastin / Q000096:biosynthesis*
D005337:Fibrin; D013925:Thromboplastin