Interleukin-15 as a potential regulator of the innate immune response.
Interleukin-15 (IL-15) is a newly-discovered cytokine that is produced by activated monocytes early in the course of the innate immune response. IL-15 is able to bind to components of the interleukin-2 receptor (IL-2R) despite the fact that it has no sequence homology with IL-2. IL-15 stimulates human natural killer cell proliferation, cytotoxicity, and cytokine production and can substitute for IL-2 under most conditions. In vitro studies indicate that monocyte-derived IL-15 may be an important determinant of IFN-gamma production by NK cells. In addition, IL-15 is able to promote the survival of natural killer cells under serum-free conditions. The IL-15 receptor is a heterotrimeric complex which is composed of the IL-2R beta and gamma chains in combination with a unique alpha chain (IL-15 alpha). The IL-15R alpha chain has strong sequence homology to the IL-2R alpha chain and confers high affinity binding to the IL-15R. In contrast to IL-2, transcript for IL-15 and IL-15 alpha is expressed in a number of tissues and indicates that IL-15 may be an important ligand for cells that express components of the IL-2R.
Carson
W
W
Division of Surgery, Roswell Park Cancer Institute, Buffalo, NY, USA.
Caligiuri
M A
MA
D001402:B-Lymphocytes; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology*; D007371:Interferon-gamma; D018664:Interleukin-12; D019409:Interleukin-15 / Q000276:immunology*; D007694:Killer Cells, Natural; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes
D019409:Interleukin-15; D015375:Receptors, Interleukin-2; D018664:Interleukin-12; D007371:Interferon-gamma