Anti-Inflammatory Cytokines, Soluble Receptors, and Natural Antagonists

This chapter reviews recent insights in the anti-inflammatory response offered by the impressive amount of research that has been conducted in this field over the last two decades. The focus is on anti-inflammatory cytokines, soluble receptors, and natural antagonists and their regulation. The interleukin (IL)-1 family of cytokines consists of 11 members, including 7 cytokines with agonist activity, 3 receptor antagonists, and an anti-inflammatory cytokine. Most transmembrane receptors for cytokines also exist in a soluble form, which can be generated by either shedding and/or alternative mRNA splicing. The innate immune system can sense danger via a limited number of pattern recognition receptors (PRRs). Soluble decoy toll-like receptors (TLRs) are one of the mechanisms by which the biological activities of TLRs are under control. Neuronal and hormonal mechanisms can also attenuate abundant proinflammatory reactions. The delivery of anti-inflammatory cytokines, soluble receptors, or their natural antagonists holds great potential.