M protein from Streptococcus pyogenes induces tissue factor expression and pro-coagulant activity in human monocytes.
Invasive infections caused by the important pathogen Streptococcus pyogenes are often associated with disturbed blood coagulation in the human host, and may in severe cases develop into the life-threatening condition disseminated intravascular coagulation. In this study, the addition of M1 protein to human blood or purified peripheral blood mononuclear cells led to a dose-dependent increase of pro-coagulant activity, which was mediated by an upregulation of tissue factor on monocytes. Analysis of the resulting clots by transmission electron microscopy revealed that the cells were covered with a fibrin network that seemed to originate from the cell surface. Taken together, the results imply an important role for M proteins in the induction of haemostatic disorders in invasive streptococcal infectious diseases.
Påhlman
Lisa I
LI
Department of Clinical Sciences, Lund, Section for Clinical and Experimental Infection Medicine, Lund University, SE-22184 Lund, Sweden.
Malmström
Erik
E
Department of Clinical Sciences, Lund, Section for Clinical and Experimental Infection Medicine, Lund University, SE-22184 Lund, Sweden.
Mörgelin
Matthias
M
Department of Clinical Sciences, Lund, Section for Clinical and Experimental Infection Medicine, Lund University, SE-22184 Lund, Sweden.
Herwald
Heiko
H
Department of Clinical Sciences, Lund, Section for Clinical and Experimental Infection Medicine, Lund University, SE-22184 Lund, Sweden.
D000942:Antigens, Bacterial / Q000502:physiology*; D001425:Bacterial Outer Membrane Proteins / Q000502:physiology*; D001777:Blood Coagulation; D002352:Carrier Proteins / Q000502:physiology*; D006801:Humans; D046529:Microscopy, Electron, Transmission; D009000:Monocytes / Q000276:immunology / Q000382:microbiology* / Q000648:ultrastructure; D013297:Streptococcus pyogenes / Q000502:physiology*; D013925:Thromboplastin / Q000096:biosynthesis*; D015854:Up-Regulation
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein; D013925:Thromboplastin