Human endothelial cell responses to endotoxin are dramatically enhanced by human blood
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Vascular endothelia activated by endotoxin (lipopolysaccharide, LPS) or cytokines actively participate in local and systemic inflammation such as those observed during Gram-negative sepsis, by secreting cytokines and chemokines, and upregulating adhesions molecules for blood leukocytes. LPS can directly activate endothelial cells via its interaction, with soluble CD14, but may also activate endothelial cell indirectly through LPS-induced, monocyte-derived cytokines. Here we show that the addition of blood cells to plasma rendered the endothelial cells sensitive to LPS concentrations 1000 times lower than when only plasma was present. We demonstrated that this effect was carried by monocytes and more precisely by soluble factors produced by monocytes, and they were further identified as tumor necrosis factor (TNF) and interleukin-1 (IL-1).
KeywordsEndothelial Cell Blood Cell Tumor Necrosis Tumor Necrosis Factor Adhesion Molecule
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