Human Interleukin 15 (IL15) Protein

Background

Interleukin 15 (IL15) is a pro-inflammatory cytokine that plays a crucial role in regulating innate and adaptive immune responses, particularly by supporting the development, activation, and survival of natural killer (NK) cells and CD8+ T cells. IL-15 is essential for immune surveillance and protection against viral infections and tumors, making it an important cytokine in both immunity and immunotherapy. IL-15 was first identified as a T-cell growth factor similar to IL-2, but it is now recognized as a distinct cytokine with a unique biological role. It is expressed by a wide range of cell types, including monocytes, macrophages, dendritic cells, epithelial cells, and fibroblasts, in response to various inflammatory stimuli. Unlike many cytokines that are secreted and act in an autocrine or paracrine fashion, IL-15 primarily functions through a unique mechanism called trans-presentation, where it binds to its receptor on neighboring cells via cell-cell contact, thus delivering potent activation signals.