Interleukin-31 (IL-31) is a protein that in humans is encoded by the IL31 gene that resides on chromosome 12.
IL-31 is an inflammatory cytokine that helps trigger cell-mediated immunity against pathogens.
Has a role in a number of chronic inflammatory diseases, including atopic dermatitis.
It is produced by a variety of cells, namely type 2 helper (TH2) T-cells.
IL-31 sends signals through the receptor complex: IL-31RA and oncostatin M receptor β (OSMRβ) expressed in immune and epithelial cells.
These signals activate three pathways: ERK1/2 MAP kinase, PI3K/AKT, and JAK1/2 signaling pathways.
IL-31 is a cytokine in the /IL-6 cytokine family.
This family includes IL-6, IL-11, IL-27.
The cytokines in the IL-6 family signal through type I cytokine receptors.
IL-31 signals via a receptor complex that is composed of IL-31 receptor A (IL31RA) and oncostatin M receptor (OSMR) subunits.
These receptor subunits are expressed in activated monocytes and in unstimulated epithelial cells.
When IL-31 binds to the receptor complex, JAK kinases are activated which phosphorylate and activate STAT1, STAT3, and STAT5.
When IL-31 binds to the IL-31RA/OSMR complex, the JAK, PI3K/AKT, and ERK signaling pathways are activated.
Interleukin 31 is an inflammatory cytokine produced by activated CD4+ T lymphocytes, activated TH2 helper cells, mast cells, macrophages, and dendritic cells.
Interleukin 31’s major sites of action are the skin, lung, intestine and the nervous system.
It facilitates cell-mediated immunity against pathogens.
IL-31 and its receptors are also involved in regulating hematopoietic progenitor cell homeostasis.
IL-31 has a role in chronic inflammation diseases: atopic dermatitis, or eczema.
Levels of IL-31 are elevated in biopsies of patients with atopic dermatitis, inducing chemokine genes CCL1, CCL17, and CCL22.
These chemokines transcribed from these genes recruit T-cells to the irritated skin where they secrete more IL-31.
Along with atopic dermatitis, IL-31 is believed to play a role in inflammatory bowel disease, airway hypersensitivity,
pruritic forms of inflammatory skin diseases, have been found to have elevated levels of IL-31 mRNA in patient biopsies.
IL-31 receptor complex found that IL-31RA is abundant in dorsal root ganglia where the cell bodies of primary sensory neurons reside.
Dorsal root ganglia are also believed to be where the itch sensation originates.