IL-27 Robert A. Kastelein* and Stefan Pflanz DNAX Research Institute, 901 California Ave, Palo Alto, CA 94304, USA * corresponding author tel: (650) 496-1271, fax: (650) 496-1200, e-mail:
[email protected] DOI: 10.1006/rwcy.2002.0331.
SUMMARY Interleukin 27 (IL-27) is a heterodimeric cytokine that consists of a four helix bundle cytokine-like subunit, termed p28, and a soluble cytokine receptor-like subunit, EBI3 (Epstein±Barr virus-induced gene 3). The p28 subunit has homology with other singlechain cytokines, whereas EBI3 is related to the extracellular domain of the hematopoietic cytokine receptor family. As such, IL-27 is a member of a small family of heterodimeric cytokines that includes IL-12 and IL-23. Efficient expression and secretion of the IL-27