Innate immune-induced depletion of bone marrow neutrophils aggravates systemic bacterial infections.
Proc Natl Acad Sci U S A
; 106(17): 7107-12, 2009 Apr 28.
Article
em En
| MEDLINE
| ID: mdl-19351895
ABSTRACT
Neutrophils are the most abundant leukocytes in circulation and provide a primary innate immune defense function against bacterial pathogens before development of a specific immune response. These specialized phagocytes are short lived (12-24 hours) and continuously replenished from bone marrow. We found that if the host is overwhelmed by a high inoculum of Listeria monocytogenes, neutrophils are depleted despite high granulocyte-colony stimulating factor induction. In contrast to a low-dose innocuous L. monocytogenes infection, high-dose Listeria challenge blocks neutrophil recruitment to infectious abscesses and bacterial proliferation is not controlled, resulting in lethal outcomes. Administering synthetic TLR2-ligand or heat-killed bacteria during the innocuous L. monocytogenes infection reproduced these effects, once again leading to overwhelming bacterial propagation. The same stimuli also severely aggravated Salmonella typhimurium, Staphylococcus aureus, and Streptococcus pyogenes systemic infection. These data implicate systemic innate immune stimulation as a mechanism of bone marrow neutrophil exhaustion which negatively influences the outcome of bacterial infections.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Salmonelose Animal
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Medula Óssea
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Infecções por Bactérias Gram-Positivas
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Apoptose
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Imunidade Inata
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Neutrófilos
Limite:
Animals
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
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