Post-transcriptional control of cytokine production.

The cytokine-encoding messenger RNA (mRNA) molecules transcribed in the nucleus acquire a protein coat that facilitates nuclear export, influences cytoplasmic localization, and determines stability and translational competence. The composition of this coat is determined by sequence elements that recruit proteins that influence the rate of translation and/or mRNA decay. Some of these regulatory proteins direct their associated mRNA molecules to discrete cytoplasmic foci (stress granules and processing bodies) that are essential in 'programming' mRNA 'metabolism'. Studies have begun to identify how these various mechanisms are integrated and regulated to determine the amount of cytokine production in cells involved in immune responses. Understanding of these mechanisms has identified targets for the development of new classes of immunomodulatory drugs.