Interleukin

Function

Interleukin (IL) is a cytokine which functions in the immune system. IL families are denoted by numbers^[1].

• IL-1 is a group of 11 cytokines which regulate immune and inflammatory response. See Interleukin-1 beta.
  
• IL-2 is a cytokine made by leukocytes. It is used in cancer therapy to boost the immune system.
  
• IL-3 improves the body's natural response to disease by stimulating the differentiation of multipotent hematopoietic stem cells into myeloid or lymphoid progenitor cells.
  
• IL-4 induces the differentiation of naive helper T cells (Th0) to Th2 cells.
  
• IL-5 stimulates B cell growth and increases immunoglobulin secretion.
  
• IL-6 is both a pro-inflammatory cytokine and anti-inflammatory myokine. Several studies have outlined the importance of autocrine IL-6 signaling in lung and breast cancers. For example, one group found a positive correlation between persistently activated tyrosine-phosphorylated STAT3 (pSTAT3), found in 50% of lung adenocarcinomas, and IL-6. Further investigation revealed that mutant EGFR could activate the oncogenic STAT3 pathway via upregulated IL-6 autocrine signaling.
• IL-7 is a cytokine important for B and T cells development.
  
• IL-8 induces chemotaxis and phagocytosis.
  
• IL-10 see Interleukin-10 and Inflammation & Rheumatoid Arthritis.
  
• IL-11 involved in the stimulation of megakaryocyte maturation.
  
• IL-12 induces the differentiation of naive helper T cells (Th0) to Th1 cells. See Interleukin-12.
  
• IL-13 induces the differentiation of naive helper T cells (Th0) to Th2 cells.
  
• IL-15 see Interleukin-15.
  
• IL-16 acts as chemoattractant, modulator of T cell activity and inhibitor of HIV replication.
  
• IL-17 recruits monocytes and neutrophils to the site of inflammation.
  
• IL-18 induces cell-mediated immunity following infection by microbial lipopolysaccharides.
  
• IL-19 induces activation of the signal transducer and activator of STAT3.
  
• IL-21 has potent effect on natural killer cells.
  
• IL-22 stimulates inflammatory responses like S100 and defensin.
  
• IL-23 induces activation of the signal transducer and activator of STAT4.
  
• IL-24 induces activation of the signal transducer and activator of STAT1 and STAT3.
  
• IL-28 has a role in the immune defense against viruses.
  
• IL-29 similar to IL-28.
  
• IL-33 induces helper T cells, mast cells, eosinophils and basophils to produce type 2 cytokines.
  
• IL-34 increases growth or survival of monocytes.
  
• IL-36 acts on naïve CD4+ T cells.
  
• IL-37 has a role in inhibiting both innate and adaptive immune responses.
  

See also Growth factors

Relevance

Uncontrolled activation of IL-1 is a component of of some inflammatory diseases including gout^[2].
IL-8 is implicated in inflammatory lung diseases^[3].
IL-10 is implicated in inflammatory bowel disease^[4].
IL-10 is a potent anti-inflammatory agent^[5].
IL-23 is implicated in Crohn's disease^[6].

Disease

IL deficiency results in autoimmune disease^[7].

3D structures of interleukin

Interleukin 3D structures