PURIFIED INTERLEUKIN-1 (IL-1) FROM HUMAN-MONOCYTES STIMULATES ACUTE-PHASE PROTEIN-SYNTHESIS BY RODENT HEPATOCYTES INVITRO

  • 1 February 1987
    • journal article
    • research article
    • Vol. 60  (2) , 203-207
Abstract
A universal component of inflammation is the increased synthesis of a series of plasma proteins (acute-phase proteins) by the liver. The postulated messenger of acute-phase protein induction is released by leukocytes at the site of inflammation and has been shown to co-purify with endogenous pyrogen or lymphocyte-activating factor. Interleukin-1, molecular weight 17,000, pI 6.8-7.2, was purified to homogeneity from adherent human blood monocytes by a combination of affinity chromatography, gel filtration and isoelectric focusing. We examined the direct effect of pure IL-1 on the induction of acute-phase protein synthesis in vitro using rat and mouse hepatocytes. IL-1 caused significant increased synthesis of .alpha.1-acid glycoprotein and smaller increases in the synthesis of other acute-phase proteins, and significant decreased synthesis of albumin. The pattern of induction of acute-phase proteins differs from that seen with a separate 30,000 molecular weight hepatocyte-stimulating factor from human monocytes described previously. We conclude that human IL-1 is one of the mediators responsible for the acute-phase protein response of the liver in inflammation and can directly cause stimulation of specific gene expression in normal hepatocytes.