Regulation of lymphoid homeostasis by interleukin-15.

Interleukin (IL)-15 is a member of the common gamma chain family of cytokines, and is closely related to IL-2. While these two cytokines share several important biological functions in vitro, recent mouse models have demonstrated unique roles for these two cytokines in supporting lymphoid homeostasis in vivo. IL-15 has been shown to regulate the homeostasis of both innate and adaptive immune cells, and this review will discuss several ways in which this pleiotropic cytokine may support lymphoid homeostasis.