Human IL-15

Interleukin-15 (IL-15), encoded by the IL15 gene, is an inflammatory cytokine that shares structural similarities with interleukin-2 (IL-2). It plays a crucial role in the development of immune responses against microbial invaders and parasites by stimulating the proliferation of natural killer cells, T-cells, and B-cells, while promoting the secretion of various cytokines. IL-15 is unique in that it is expressed on the surface of IL-15-producing cells in association with its high-affinity receptor (IL15RA), facilitating direct signaling to target cells that express IL2RB and IL2RG. This binding triggers the phosphorylation of JAK1 and JAK3, activating signaling pathways involving STAT3 and STAT5, and plays a significant role in mast cell survival and cytokine release.