see also:

• autacoids
• fever - the febrile response to infections

• cytokines are small proteins released by cells which act through binding to cell wall receptors and affect the behaviour of other cells and perhaps the same cell which are particularly important in the immune response but generally excludes growth factors, hormones, adipokines and adipose-derived hormones (produced by adipose tissue) and autacoids
• many cytokines appear to share similar functions
• cytokines include:
  • chemokines - mediate chemotaxis
  • interferons
  • interleukins - mainly produced by T-helper cells
    • those with genetically low IL-1 activity have increased LDL, 15% higher risk IHD, and incr. risk AAA
  • lymphokines - produced by lymphocytes
  • monokines - produced by monocytes
  • colony stimulating factors
  • TNF
• the body produces a wide array of pyrogenic cytokines such as interleukins (IL-1beta, IL-6), interferon, and tumour necrosis factor alpha and perhaps complement factor 5a and platelet-activating factor, are carried to the blood-brain-barrier (BBB) in the blood
• excessive cytokine release may produce a cytokine storm with possible multi-organ failure and death as may occur in some people with infections such as influenza
  • Suppressors of Cytokine Signalling (SOCS) molecules control the flow of chemical messages inside cells and suppress the activity of the cytokines to prevent unwanted inflammation and tissue damage.
    • the protein SOCS4 plays a crucial role in moderating the immune system's response to influenza ¹⁾
• it is thought that viruses may stimulate cells to produce virokines that modulate the actions of cytokines, perhaps by blocking their action at cytokine receptors
• the major anti-inflammatory cytokines include:
  • interleukin (IL)-1 receptor antagonist
  • IL-4, IL-6, IL-10, IL-11, and IL-13
  • specific cytokine receptors for IL-1, tumor necrosis factor-alpha, and IL-18 also function as proinflammatory cytokine inhibitors