Extracellular superoxide dismutase in macrophages augments bacterial killing by promoting phagocytosis.
Am J Pathol
; 178(6): 2752-9, 2011 Jun.
Article
em En
| MEDLINE
| ID: mdl-21641397
ABSTRACT
Extracellular superoxide dismutase (EC-SOD) is abundant in the lung and limits inflammation and injury in response to many pulmonary insults. To test the hypothesis that EC-SOD has an important role in bacterial infections, wild-type and EC-SOD knockout (KO) mice were infected with Escherichia coli to induce pneumonia. Although mice in the EC-SOD KO group demonstrated greater pulmonary inflammation than did wild-type mice, there was less clearance of bacteria from their lungs after infection. Macrophages and neutrophils express EC-SOD; however, its function and subcellular localization in these inflammatory cells is unclear. In the present study, immunogold electron microscopy revealed EC-SOD in membrane-bound vesicles of phagocytes. These findings suggest that inflammatory cell EC-SOD may have a role in antibacterial defense. To test this hypothesis, phagocytes from wild-type and EC-SOD KO mice were evaluated. Although macrophages lacking EC-SOD produced more reactive oxygen species than did cells expressing EC-SOD after stimulation, they demonstrated significantly impaired phagocytosis and killing of bacteria. Overall, this suggests that EC-SOD facilitates clearance of bacteria and limits inflammation in response to infection by promoting bacterial phagocytosis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fagocitose
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Superóxido Dismutase
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Escherichia coli
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Viabilidade Microbiana
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Espaço Extracelular
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Macrófagos
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Am J Pathol
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos