First Author | Arman M | Year | 2014 |
Journal | Blood | Volume | 123 |
Issue | 20 | Pages | 3166-74 |
PubMed ID | 24642751 | Mgi Jnum | J:211684 |
Mgi Id | MGI:5575846 | Doi | 10.1182/blood-2013-11-540526 |
Citation | Arman M, et al. (2014) Amplification of bacteria-induced platelet activation is triggered by FcgammaRIIA, integrin alphaIIbbeta3, and platelet factor 4. Blood 123(20):3166-74 |
abstractText | Bacterial adhesion to platelets is mediated via a range of strain-specific bacterial surface proteins that bind to a variety of platelet receptors. It is unclear how these interactions lead to platelet activation. We demonstrate a critical role for the immune receptor FcgammaRIIA, alphaIIbbeta3, and Src and Syk tyrosine kinases in platelet activation by Staphylococcus aureus, Streptococcus sanguinis, Streptococcus gordonii, Streptococcus oralis, and Streptococcus pneumoniae. FcgammaRIIA activation is dependent on immunoglobulin G (IgG) and alphaIIbbeta3 engagement. Moreover, feedback agonists adenosine 5'-diphosphate and thromboxane A2 are mandatory for platelet aggregation. Additionally, platelet factor 4 (PF4) binds to bacteria and reduces the lag time for aggregation, and gray platelet syndrome alpha-granule-deficient platelets do not aggregate to 4 of 5 bacterial strains. We propose that FcgammaRIIA-mediated activation is a common response mechanism used against a wide range of bacteria, and that release of secondary mediators and PF4 serve as a positive feedback mechanism for activation through an IgG-dependent pathway. |