Differential toll-like receptor expression after ex vivo lipopolysaccharide exposure in patients with sepsis and following surgical stress.Clin Immunol. 2006 May; 119(2):180-7.CI
Monocytes from septic patients have a reduced capacity to respond to lipopolysaccharide (LPS). We examined whether the same response occurred after surgical injury, and whether this reduced activity was associated with differential monocyte toll-like receptor (TLR) expression.
MATERIALS AND METHODS
Peripheral blood mononuclear cells (PBMCs) were isolated from septic patients, patients undergoing surgery, and healthy volunteers. Cells were stimulated ex vivo with LPS (1 microg/ml) and stained for CD14, CD16, TLR-2, TLR-4, and HLA-DR surface expression.
TLR-2 and -4 expressions were significantly increased in monocytes from both septic and surgical patients. While ex vivo LPS-stimulation significantly increased TNFalpha and IL-1beta production in PBMCs from surgical patients, LPS-stimulation decreased IL-1beta production from septic patients as compared to surgical and control patients. Ex vivo LPS-stimulation induced TLR-4 upregulation in monocytes from both surgical and control patients, but not from septic patients. HLA-DR expression in CD14+CD16+ monocytes was reduced only in septic patients.
PBMCs from septic patients, but not following surgical injury, have a reduced capacity to respond to a secondary inflammatory signal, but this defect is not associated with reduced TLR-4 or CD14 expression.