Format

Send to:

Choose Destination
See comment in PubMed Commons below
Toxins (Basel). 2011 Feb;3(2):120-33. doi: 10.3390/toxins3020120. Epub 2011 Jan 28.

Staphylococcus aureus α-toxin triggers the synthesis of B-cell lymphoma 3 by human platelets.

Author information

  • 1Department of Medicine III, Martin Luther University, Halle, Saale, Germany. schubert-sebastian@gmx.net

Abstract

The frequency and severity of bacteremic infections has increased over the last decade and bacterial endovascular infections (i.e., sepsis or endocarditis) are associated with high morbidity and mortality. Bacteria or secreted bacterial products modulate platelet function and, as a result, affect platelet accumulation at sites of vascular infection and inflammation. However, whether bacterial products regulate synthetic events in platelets is not known. In the present study, we determined if prolonged contact with staphylococcal α-toxin signals platelets to synthesize B-cell lymphoma (Bcl-3), a protein that regulates clot retraction in murine and human platelets. We show that α-toxin induced α(IIb)β(3)-dependent aggregation (EC(50) 2.98 µg/mL ± 0.64 µg/mL) and, over time, significantly altered platelet morphology and stimulated de novo accumulation of Bcl-3 protein in platelets. Adherence to collagen or fibrinogen also increased the expression of Bcl-3 protein by platelets. α-toxin altered Bcl-3 protein expression patterns in platelets adherent to collagen, but not fibrinogen. Pretreatment of platelets with inhibitors of protein synthesis or the mammalian Target of Rapamycin (mTOR) decreased Bcl-3 protein expression in α-toxin stimulated platelets. In conclusion, Staphylococcusaureus-derived α-toxin, a pore forming exotoxin, exerts immediate (i.e., aggregation) and prolonged (i.e., protein synthesis) responses in platelets, which may contribute to increased thrombotic events associated with gram-positive sepsis or endocarditis.

KEYWORDS:

Bcl-3; protein synthesis; α-toxin

PMID:
22069700
[PubMed - indexed for MEDLINE]
PMCID:
PMC3202813
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Multidisciplinary Digital Publishing Institute (MDPI) Icon for PubMed Central
    Loading ...
    Write to the Help Desk