ENDOTOXIN AND TUMOR-NECROSIS-FACTOR INDUCE INTERLEUKIN-1 GENE-EXPRESSION IN ADULT HUMAN VASCULAR ENDOTHELIAL-CELLS

Google Scholar
  • 1 August 1986
    • journal article
    • research article
    • Vol. 124  (2) , 179-185
Abstract
Interleukin 1 (IL-1) can induce potentially pathogenic functions of vascular endothelial cells. This mediator was formerly thought to be produced primarily by activated macrophages. We report here that bacterial endotoxin and recombinant human tumor necrosis factor cause accumulation of IL-1.beta. mRNA in adult human vascular endothelial cells. IL-1.alpha. mRNA was also detected when endothelial cells were exposed to endotoxin under "superinduction" conditions in the presence of cycloheximide. Metabolic labeling of these cells during endotoxin stimulation demonstrated increased synthesis and secretion of immunoprecipitable IL-1 protein that comigrated electrophoretically with the predominant monocyte species. In parallel with increased IL-1 mRNA and protein, endothelial cells exposed to endotoxin also released biologically active IL-1 that was neutralized by anti-IL-1-antibody. Because bloodborne agents must traverse the endothelium before entering tissues, endothelial IL-1 production induced by microbial products or other injurious stimuli could initiate local responses to invasion. Endothelial cells are both a source of and target for IL-1; accordingly, this novel autocrine mechanism might play an early role in the pathogenesis of vasculitis, allograft rejection, and arteriosclerosis.