Endotoxaemia modulates Toll-like receptors on leucocytes in humans.
The modulation of Toll-like receptors (TLR) 1, 2 and 4 was studied during experimental human endotoxaemia. Healthy volunteers received 2 ng/kg of lipopolysaccharide (LPS) endotoxin (n = 10). TLR1, 2 and 4 expression occurred on monocytes and neutrophils, with monocytes expressing higher baseline levels of TLR2. LPS infusion downmodulated TLR4 expression on neutrophils, with maximal downregulation occurring at 24 h (-62% from baseline; P < 0.03 versus baseline). Monocyte TLRs were upregulated in vivo (TLR1 and 2), and in vitro (TLR1, 2 and 4) 8 h after LPS bolus (P < 0.05 versus baseline). Therefore, neutrophils and monocytes differentially express surface TLRs, and endotoxaemia differentially regulates TLR expression.
Marsik
Claudia
C
Departments of Clinical Pharmacology, Institute of Medical and Chemical Laboratory Diagnostic, Vienna University, Vienna, Austria.
Mayr
Florian
F
Cardona
Francesco
F
Derhaschnig
Ulla
U
Wagner
Oswald F
OF
Jilma
Bernd
B
D000328:Adult; D001427:Bacterial Toxins / Q000276:immunology; D019446:Endotoxemia / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology; D006801:Humans; D007958:Leukocyte Count; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D009504:Neutrophils / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D051194:Toll-Like Receptor 1; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors
D001427:Bacterial Toxins; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051194:Toll-Like Receptor 1; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors