Biology of interleukin-15 Iain B McInnes, Foo Y Liew and J Alastair Gracie

Interleukin-15 (IL-15) is a cytokine with quaternary structural similarities to IL-2.1,2 IL-15 is widely expressed in the immune system, mediating regulatory and effector function in a variety of processes of relevance to both innate and adaptive arms of the immune response. The frequent description of IL-15 expression in inflammatory and autoimmune disorders has increased interest in elucidating its basic biology to properly facilitate targeting in the clinic. This chapter will review the basic biology of IL-15, highlighting particularly those properties and functions of relevance to human pathology.