P. Henneke, I. Osmers, K. Bauer, N. Lamping, H. T. Versmold, R. R. Schumann
Impaired CD14-dependent and independent response of polymorphonuclear
leukocytes in preterm infants
Preterm newborn infants are especially susceptible to
Gram-negative sepsis that is associated with a lethality
of up to 40%.
Aims: We tested whether polymorphonuclear leukocytes
(PMN) from preterm infants exhibit an impaired antibacterial
response upon stimulation with lipopolysaccharide
(LPS) from Escherichia coli when compared to full term
newborns or adults.
Methods: We studied the effect of LPS on the expression
of the surface proteins CD11b and CD14 and the secretion
of elastase by PMN from preterm infants, term infants
and adults ex vivo.
Results: We found a significantly reduced antibacterial
activity of PMN from preterm infants upon stimulation
with LPS as indicated by low surface expression of the
adhesion molecule CD11b and the reduced secretion of
PMN elastase. LPS-induced CD11b expression was dependent
on binding of LPS to the surface protein CD14
as CD14 antibodies inhibited LPS dependent CD11b
upregulation. Furthermore CD14 expression was lower
on PMN from preterm infants than from adults. In addition,
CD14 independent upregulation of CD11b in response
to tumor necrosis factor (TNF-?), N-formyl peptides
(FMLP) and phorbol ester (PMA) was impaired.
Conclusion: PMN from preterm infants are distinctly hyporesponsive
to LPS, which may explain the predisposition
of these children to invasive disease due to gramnegative
bacteria.
Journal of Perinatal Medicine, Walter de Gruyter
Print ISSN: 1619-3997
Volume: 31, 03/2003
Pages: 176 - 183
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