Diminished phagocytosis-induced cell death (PICD) in neonatal monocytes upon infection with Escherichia coli.
Pediatr Res
; 63(1): 33-8, 2008 Jan.
Article
em En
| MEDLINE
| ID: mdl-18043500
ABSTRACT
An imbalance in apoptosis or survival of immune cells plays an essential role in the pathophysiology of sepsis. Phagocytosis-induced cell death (PICD) is a common result of the pathogen-host cell interaction mediated by reactive oxygen species (ROS). Neonatal sepsis is frequently characterized by hyperinflammation. Cord blood monocytes (CBMO) are equivalent to monocytes of adults [peripheral blood monocytes (PBMO)], both in terms of phagocytosis and killing of Escherichia coli. We investigated whether CBMO are less sensitive toward PICD compared with PBMO. Monocytes were infected with green fluorescent protein (GFP)-labeled E. coli. Phagocytic activity, cell-count, Annexin V staining, hypoploid DNA content, CD95 and CD95L expression, and caspase-8 and -9 activities were analyzed by flow cytometry, ROS production by chemiluminescence, and CD95L mRNA expression by reverse-transcriptase polymerase chain reaction. With equal phagocytic activity and ROS production, PBMO cell count was decreased by 82 +/- 6% versus 28 +/- 8% for CBMO after infection. Annexin V binding was enhanced fivefold on PBMO; 56 +/- 15% of PBMO showed a hypodiploid DNA content compared with 9 +/- 6% of CBMO. Caspases CD95L and CD95L mRNA were up-regulated in PBMO. Our results indicate that CBMO are less sensitive toward E. coli-mediated PICD than PBMO. Modifying monocyte apoptosis may be a target for future interventions in sepsis.
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Base de dados:
MEDLINE
Assunto principal:
Fagocitose
/
Monócitos
/
Apoptose
/
Escherichia coli
/
Infecções por Escherichia coli
Limite:
Adult
/
Humans
/
Newborn
Idioma:
En
Revista:
Pediatr Res
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Alemanha