Previous Article | Next Article ![]()
Infect. Immun., Jan 1995, 248-252, Vol 63, No. 1
G Qing, K Rajaraman and R Bortolussi
Previous research in our laboratory has shown that polymorphonuclear
leukocytes (PMN) from neonates are not primed effectively in vitro with
lipopolysaccharide (LPS) (from Escherichia coli 0111:B4) compared with
priming of adult PMN. This finding led us to speculate that differences
between neonatal and adult LPS receptors may account for the lower response
by neonatal PMN to LPS. In these experiments, we investigated if CD14 or
other LPS receptors contribute to the priming activity of PMN by LPS. We
found that unprimed neonatal and adult PMN expressed similar numbers of
CD14 (11.6 +/- 9.2 versus 18.6 +/- 2.7 fluorescence units [FlU]; P >
0.05) and LPS-binding sites (2.94 +/- 1.4 versus 4.94 +/- 0.79 FlU; P >
0.05). Monoclonal antibody against CD14 (MY4) did not significantly change
the binding of LPS to adult unprimed PMN, suggesting that LPS receptors
other than CD14 receptors are predominant on PMN. However, when PMN were
pretreated with LPS (10 ng/ml) for 45 min at 37 degrees C, expression of
CD14 on adult PMN increased to 33.8 +/- 4.9 FlU (P < 0.05 versus
unprimed adult PMN) while that on neonatal PMN showed little change,
increasing to 17.2 +/- 10.3 FlU (P > 0.05 versus unprimed neonatal PMN;
P < 0.05 versus primed adult PMN). Furthermore, MY4 specifically blocked
oxidative-radical production from PMN primed with LPS (10 ng/ml) compared
with that from control PMN (P < 0.01). These studies suggest that LPS
primes PMN by activating CD14 expression. We conclude that lower expression
of CD14 or failure to up- regulate CD14 after LPS pretreatment contributes
to the inability of neonatal PMN to be primed by LPS.
Copyright © 1995, American Society for Microbiology
Diminished priming of neonatal polymorphonuclear leukocytes by lipopolysaccharide is associated with reduced CD14 expression
Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|