Tumor necrosis factor

Reviewer: Nat Pernick, M.D. (see Reviewers page)
Revised: 2 November 2015, last major update June 2005
Copyright: (c) 2003-2015,, Inc.
Table of Contents
Definition / General
Definition / General
  • Also called cachectin
  • Initiates similar responses as lymphotoxin alpha
  • Secreted by macrophages and lipopolysaccharides or macrophage activating agents
  • Binds to 55kDa receptor on many cells throughout body
  • Mediators: TRADD, TRAP-1, 55.11
  • Has many biologic activities; initiate signals for cell proliferation and apoptosis; required for normal development and function of immune system; suppresses expression of lipoprotein lipase and anabolic enzymes in fat
  • In large boluses, modifies coagulation properties of endothelial cells, activates neutrophils, induces release of inflammatory cytokines (IL-1), causing cardiovascular collapse
  • In small amounts, causes symptoms of inflammatory response of bone resorption, fever, anemia, wasting
  • Both triggers apoptosis and activates NFKB which blocks apoptosis
  • TNF and IL-1 react with hypothalamic receptors, leading to stimulation of prostaglandin and leukotriene mediated pathways that reset brains thermoregulatory center