The function of interleukin 37 (IL-37; formerly IL-1 family member 7) has remained elusive. Expression of IL-37 in macrophages or epithelial cells almost completely suppressed production of pro-inflammatory cytokines, whereas the abundance of these cytokines increased with silencing of endogenous IL-37 in human blood cells.
IL-37 emerges as a natural suppressor of innate inflammatory and immune responses.
Cytokine receptors (click to enlarge the image).
Overview of the innate immune system (a mind map diagram) (click to enlarge the image).
IL-37 is a fundamental inhibitor of innate immunity. Nature Immunology 11, 1014 - 1022 (2010).