IL-15 is secreted by immune (dendritic) and non-immune (epithelial) cells located at the interface with the environment, following interactions with microbes, food antigens and allergens. IL-15 orchestrates the fate of innate (NK cells, eosinophils) and adaptive (T and B cells) immune cells, notably that of tissue resident memory T cells. Uncontrolled IL-15 secretion mediates tissue inflammation and destruction through the activation of those cellular mediators, including Th1, Th2 and/or Th17 responses.
Illustrated by 3DforScience-Visuals for Bio&Health
Tissue-resident memory cells and other cells types controlled by IL-15 play an important role in the onset and maintenance of a large number of auto-immune, inflammatory and immune-metabolic diseases, some of them which are shown in the figure below.