Severe streptococcal infection is associated with M protein-induced platelet activation and thrombus formation.
Författare
Summary, in English
Disturbed haemostasis is a central finding in severe Streptococcus pyogenes infection. In particular, microthrombi are found both at the local site of infection and at distant sites. Platelets are responsible for maintaining vascular function and haemostasis. We report here that M1 protein of S. pyogenes triggers immune-mediated platelet activation and thrombus formation. M1 protein is released from the bacterial surface and forms complexes with plasma fibrinogen. These complexes bind to the fibrinogen receptor on resting platelets. When these complexes also contain immunoglobulin G (IgG) against M1 protein, this will engage the Fc receptor on the platelets and activation will occur. Activation of the platelets leads to platelet aggregation and the generation of platelet-rich thrombi. Neutrophils and monocytes are in turn activated by the platelets. Platelet thrombi are deposited in the microvasculature, and aggregated platelets, IgG and M1 protein colocalize in biopsies from patients diagnosed with S. pyogenes toxic shock syndrome. This chain of events results in a procoagulant and pro-inflammatory state typical of severe S. pyogenes infection.
Avdelning/ar
Publiceringsår
2007
Språk
Engelska
Sidor
1147-1157
Publikation/Tidskrift/Serie
Molecular Microbiology
Volym
65
Issue
5
Fulltext
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Wiley-Blackwell
Ämne
- Microbiology in the medical area
Status
Published
Forskningsgrupp
- epIgG
- SEBRA Sepsis and Bacterial Resistance Alliance
ISBN/ISSN/Övrigt
- ISSN: 1365-2958