NCIt definition : A recombinant agent that is chemically identical or similar to the endogenous form
of the human cytokine interleukin-15 (IL-15) with immunomodulating activity. IL-15,
secreted by mononuclear phagocytes (and some other cell types) following viral infection,
regulates T and natural killer cell activation and proliferation. This cytokine induces
activation of transcription activators STAT3, STAT5, and STAT6 via JAK kinase signal
transduction pathways in mast cells, T cells, and dendritic epidermal T cells. IL-15
and interleukin-2 (IL-2) are structurally similar and share many biological activities;
both may bind to common hematopoietin receptor subunits, negatively regulating each
other's activity. CD8 memory T cell number has been shown to be regulated by a balance
between IL-15 and IL-2.;