IL27: its roles in the induction and inhibition of inflammation.

IL27 is the newest member of the IL6/IL12 family. It consists of Epstein-Barr virus-induced gene 3 (EBI3) and p28 subunits and signals through the IL27 receptor complex formed by WSX-1 and gp130 subunits. IL27-IL27 receptor interaction was initially shown to induce an early signal for the induction of Th1 responses. Recently other studies indicate that IL27 inhibits inflammatory Th17 lineage development. Despite the overall effects observed, the role of individual IL27 subunits remains controversial and is largely unclear. EBI3, while predominately found with p28 to form IL27, has different expression kinetics than p28. P28 has also been shown to signal independently of EBI3. Moreover, EBI3 has other potential binding partners such as the p35 subunit of IL12 and theoretically may regulate the inflammatory response through yet undiscovered mechanisms. Understanding the inflammatory and anti-inflammatory roles of IL27 and its subunits are essential before the immunological regulatory therapies can be developed.