Lack of association between the -260 C-->T promoter polymorphism of the endotoxin receptor CD14 gene and the CD14 density of unstimulated human monocytes and soluble CD14 plasma levels.
OBJECTIVE
CD14 is a receptor for endotoxin and binds components of Gram-positive and Gram-negative bacteria. CD14-bearing monocytes respond to stimulation with the increased synthesis and release of cytokines. The recently described -260 C-->T promoter polymorphism of the CD14 gene has been found to be related to a risk of myocardial infarction. This study evaluated the role of this polymorphism in the expression of monocyte and soluble CD14. Moreover, the effect of the CD14 -260 genotypes for the ex vivo TNF-alpha response to endotoxin was analyzed in whole blood.


METHODS
Ninety-five healthy blood donors were studied.


RESULTS
CD14 -260 genotyping was performed by means of a real-time PCR with fluorescence labeled hybridization probes. CD14 expression on human monocytes (mCD14) was assessed by fluorescence-activated cell sorting analysis with anti-CD14 monoclonal antibodies. Plasma levels of soluble CD14 (sCD14) were measured by ELISA. The TNF-alpha synthesis was determined by chemiluminescence in whole blood after endotoxin stimulation. There were no differences in mCD14 density, sCD14 levels, or the tumor necrosis factor-alpha concentrations between individuals with the three different CD14 -260 genotypes CC, CT, and TT.


CONCLUSIONS
The CD14 -260 polymorphism does not affect the CD14 expression of unstimulated circulating monocytes or soluble CD14 plasma levels.
Heesen
M
M
Department of Anesthesiology and Intensive Care Medicine, University Hospital of Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany. M.Heesen@amc.uva.nl
Blömeke
B
B
Schlüter
B
B
Heussen
N
N
Rossaint
R
R
Kunz
D
D
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005838:Genotype; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D018950:Lipopolysaccharide Receptors / Q000097:blood* / Q000235:genetics* / Q000276:immunology; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D018709:Statistics, Nonparametric; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D000911:Antibodies, Monoclonal; D018950:Lipopolysaccharide Receptors; D014409:Tumor Necrosis Factor-alpha