Monocyte toll-like receptor 4 expression and LPS-induced cytokine production increase during gestational aging.
Pediatr Res
; 58(1): 121-4, 2005 Jul.
Article
en En
| MEDLINE
| ID: mdl-15879290
ABSTRACT
Premature newborns are highly susceptible to severe bacterial infections. This is partially due to their immature innate immune system, characterized by decreased neutrophil and monocyte activity as well as by reduced concentrations of complement factors. However, additional mechanisms might be important for innate immunity and are still the subject of considerable debate. The importance of pattern recognition domains such as Toll-like receptors (TLR) has been fully acknowledged within the last few years. Therefore, we investigated age-related monocyte TLR4 expression and lipopolysaccharide-induced cytokine secretion from very low birth weight infants (VLBWI) and from newborns after wk 30 of gestation in comparison to healthy adults. In VLBWI, expression of TLR4 surface protein, detected by flow cytometry, and TLR4-specific mRNA, quantified by real time-PCR, were significantly reduced in comparison to mature infants and to adults. Reduced TLR4 expression was paralleled by significantly diminished ex vivo LPS stimulated IL-1beta, IL-6, and tumor necrosis factor-alpha secretion into whole blood. We conclude that, in VLBWI, the minimized expression of TLR4 contributes to the susceptibility of VLBWI to infections with Gram-negative bacteria due to the lack of cytokines to boost initial immune response.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Glicoproteínas de Membrana
/
Monocitos
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Lipopolisacáridos
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Receptores de Superficie Celular
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Regulación del Desarrollo de la Expresión Génica
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Sangre Fetal
Límite:
Humans
/
Newborn
Idioma:
En
Revista:
Pediatr Res
Año:
2005
Tipo del documento:
Article
País de afiliación:
Austria