Cytokines: molecular and biological characteristics.

Cytokines are soluble molecules with many cells as the source of their origin and as targets for their actions. They are pleiotropic in their biological functions. Some cytokines are distinct with respect to their molecular structure yet they have overlapping biological properties (Interleukin 1 and tumor necrosis factors). Others are structurally distinct and often have contrasting biological activities (e.g. tumor necrosis factors and transforming growth factor-beta). In this article I have briefly reviewed the molecular and biological properties of four cytokines that appears to play an important role in the pathogenesis of certain immunoinflammatory disorders. It is also to be stressed that there are additional cytokines (e.g. granulocyte-monocyte colony stimulating factors, interleukin 2, interferons etc.) that could also play a role in the pathogenesis of immunoinflammatory disorders.