Interleukin 15

Overview
Interleukin 15 (IL-15) is a cytokine with structural similarity to IL-2 that is secreted by mononuclear phagocytes (and some other cells) following infection by virus(es). This cytokine induces cell proliferation of natural killer cells; cells of the innate immune system whose principal role is to kill virally infected cells.

Maintenance of memory cells does not appear to require persistence of the original antigen; instead, survival signals for memory lymphocytes are provided by cytokines such as IL-15.

In transgenic mice that have the IL-15 receptor alpha (IL-15Ralpha) gene knocked out, natural killer cells cells do not develop.

In people with history of acute infectious mononucleosis (the syndrome associated with primary Epstein-Barr virus infection), IL-15R expressing lymphocytes are not detected--even 14 years after infection.

Interleukina 15