Interleukin-22

Interluekin-22 (IL-22), previously identified as an IL-10 related T cell derived inducible factor, is a member of the IL-10 superfamily, and its receptor is comprised of IL-22R1 and IL-10R2. Under homeostatic conditions, there is a soluble receptor, IL-22 binding protein (IL-22RA2), which prevents binding of IL-22 to the IL-22R1. While IL-22 is produced by mostly lymphocytes, such as T cell helper type 1 (TH1), TH17, TH22 cells, natural killer cells, gamma-delta T cells, and innate lymphoid cell group 3 (ILC3), the functional receptor is expressed on non-hematopoietic cells, mostly epithelial cells. Normal activity of IL-22 is to promote tissue repair and protect the barrier surface. As such, IL-22 plays important roles in several chronic diseases. In autoimmune diseases, such as Crohn?s, psoriasis, and atopic dermatitis high level of IL-22 in circulation is correlated with disease and/or disease severity. For patients with asthma, increased serum IL-22 is associated with disease and disease severity, and maybe a result of the host?s compensatory mechanism to control inflammation. While in cancer, especially for colorectal cancer, IL-22 promotes tumor development and growth, the hypothetical mechanism is most likely by inducing stem cell like characteristics. Circulating IL-22 has been correlated with both protective and pathogenic pathways in several disease states, and an ultrasensitive assay for IL-22 can aid in several phases of clinical research.

Swiss-Prot Accession Number: Q9GZX6