Pneumolysin Mediates Platelet Activation In Vitro.
Lung
; 194(4): 589-93, 2016 08.
Article
em En
| MEDLINE
| ID: mdl-27192991
ABSTRACT
This study has explored the role of the pneumococcal toxin, pneumolysin (Ply), in activating human platelets. Following exposure to Ply (10-80 ng/ml), platelet activation and cytosolic Ca(2+) concentrations were measured flow cytometrically according to the level of expression of CD62P (P-selectin) and spectrofluorimetrically, respectively. Exposure to Ply resulted in marked upregulation of expression of platelet CD62P, achieving statistical significance at concentrations of 40 ng/ml and higher (P < 0.05), in the setting of increased influx of Ca(2+). These potentially pro-thrombotic actions of Ply were attenuated by depletion of Ca(2+) from the extracellular medium or by exposure of the cells to a pneumolysoid devoid of pore-forming activity. These findings are consistent with a mechanism of Ply-mediated platelet activation involving sub-lytic pore formation, Ca(2+) influx, and mobilization of CD62P-expressing α-granules, which, if operative in vivo, may contribute to the pathogenesis of associated acute lung and myocardial injury during invasive pneumococcal disease.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estreptolisinas
/
Plaquetas
/
Ativação Plaquetária
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Cálcio
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Selectina-P
/
Citosol
Limite:
Humans
Idioma:
En
Revista:
Lung
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
África do Sul