Category:IL-17 family

From Ganfyd

Actually a very complex unique family of cytokines well conserved in mammals.

1. IL-17A - T_h17 cells
   • Coded for at 6p12
2. IL-17B (IL-20)
   • Coded for at 5q32-q34
   • Ligand for the cytokine receptor IL17BR
3. LI-17C (IL-21) - high levels in inflammation
   • Coded for at 16q24
4. IL-17D - nervous system and skeletal muscle
   • Coded for at 13q12.11
5. IL-17E (IL-25)
   • Coded for at 14q11.2
   • Two isoforms known
   • Ligand for the cytokine receptor IL17BR
6. IL-17F (ML-1)- T_h17 cells
   • Coded for at 6p12

They have roles in:

• Angiogenesis
• The function of T_h17 cells
  • Enhances T cell priming
  • So stimulates proinflammatory cytokines like IL-1, IL-6, TNF-alpha, IL8, G-CSF as well as prostaglandin E2 and NOS-2.
• Increases fibroblast expression of intracellular adhesion molecule 1 (ICAM-1, CD54)
• Chemotatic to many inflammatory cells such as neutrophils (not eosinophils)

Physiology

• IL-23 mediated activation with STAT3 and NF-κB signalling pathways
• In absence of SOCS3 this causes production of IL-17A and IL-17F
• Some recent evidence for interleukin 23 independent pathways via TGF-β and interleukin 6,

Associations

• IL-17A
  • Rheumatoid arthritis
  • Asthma (airways inflammation)
  • SLE
  • Allograft rejection
  • Anti-tumour immunity
• IL-17B
  • Nasal polyps

They bind at the same receptor complex of interleukin-17 receptor A and interleukin-17 receptor C.