11.03 Cytokines

Cytokines are a diverse class of small cell signalling molecules secreted by immune cells. They include interleukins (ILs), which broadly target leukocytes (e.g. IL-1), and interferons (IFN), which are anti-viral and anti-tumour agents (e.g. IFNα, IFNβ. IFNγ). Colony stimulating factors, which stimulate the formation of leukocytes and tumour necrosis factors (TNF), which affect growth and development of cells (e.g. TNFa).

The cytokines can be broadly sub-classified into pro-inflammatory and anti-inflammatory by the way they affect the inflammatory cascade. In most cases cytokines can amplify responses of other cytokines or alter expression of other cytokine receptors. The signalling is complex, given the variety of mediators and targets involved.