Inhibition of expression of monocyte interleukin-1 by inhibitors of Hageman factor (factor XII)

O D Ratnoff1, J A Voytus, Z Toossi

  • 1Department of Medicine, Case Western Reserve University, University Hospitals of Cleveland, OH 44106.

In an earlier study, activated species of Hageman factor (factor XII) induced elaboration of interleukin-1 by human monocytes. These observations did not address whether Hageman factor participated in endotoxin-induced release of interleukin-1. To examine this question, the release of interleukin-1 by endotoxin-stimulated human mononuclear cells was measured in the presence of popcorn inhibitor, a specific inhibitor of Hageman factor. In the experiments herein described, popcorn inhibitor sharply decreased the release of interleukin-1 by human mononuclear cells that were incubated with endotoxin. This observation suggests that Hageman factor may play a role in the elaboration of interleukin-1 by human mononuclear cells. Conforming with this view, the addition of antiserum directed against Hageman factor inhibited the release of interleukin-1 from endotoxin-stimulated mononuclear cells.

Related Concept Videos

Anticoagulant Drugs: Low-Molecular-Weight Heparins01:30

Anticoagulant Drugs: Low-Molecular-Weight Heparins

Hemostasis is a crucial process that prevents excessive blood loss from damaged blood vessels. It involves various mechanisms such as vasoconstriction, platelet adhesion and activation, and fibrin formation. The importance of each mechanism depends on the type of vessel injury. In contrast, thrombosis is the abnormal formation of a blood clot within the blood vessels, leading to potential complications if the clot obstructs blood flow. Thrombosis can be caused by increased coagulability of the...
Inhibitors of Viral Protein Synthesis01:30

Inhibitors of Viral Protein Synthesis

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...
Inhibitors of Virion Maturation and Assembly01:19

Inhibitors of Virion Maturation and Assembly

As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an...