title: IL-22, cell regeneration and autoimmunity.
abstract: IL-22 as a cytokine is described with opposing pro-inflammatory and anti-inflammatory functions. Cell regeneration, tissue remodelling and balance between commensal bacteria in the gut and host immune system are considered as anti-inflammatory features of IL-22, whereas production of IL-22 from Th17 cells links this cytokine to pro-inflammatory pathways. Th17 cells and group 3 innate lymphoid cells (ILC3) are two major producers of IL-22 and both cell types express ROR-γt and Aryl hydrocarbon receptor (AhR) transcription factors. Typically, the immune system cells are the main producers of IL-22. However, targets of this cytokine are mostly non-hematopoietic cells such as hepatocytes, keratinocytes, and epithelial cells of lung and intestine. Association of IL-22 with other cytokines or transcription factors in different cell types might explain its contrasting role in health and disease. In this review we discuss the regulation of IL-22 production by AhR- and IL-23-driven pathways. A clear understanding of the biology of IL-22 will provide new opportunities for its application to improve human health involving many debilitating conditions.
authors.affiliation: Centre for Human Immunology, Department of Microbiology and Immunology, Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.
authors.forename: Enayat
authors.initials: E
authors.lastname: Nikoopour
authors.affiliation: Centre for Human Immunology, Department of Microbiology and Immunology, Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.
authors.forename: Stacey M
authors.initials: SM
authors.lastname: Bellemore
authors.affiliation: Centre for Human Immunology, Department of Microbiology and Immunology, Robarts Research Institute, University of Western Ontario, London, Ontario, Canada. Electronic address: bsingh@uwo.ca.
authors.forename: Bhagirath
authors.initials: B
authors.lastname: Singh
mesh_terms: D000818:Animals; D015551:Autoimmunity; D002454:Cell Differentiation; D016207:Cytokines / Q000378:metabolism; D004847:Epithelial Cells / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D020381:Interleukin-17 / Q000378:metabolism; D053759:Interleukin-23 / Q000378:metabolism*; D007378:Interleukins / Q000096:biosynthesis / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3 / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D012038:Regeneration; D058504:Th17 Cells / Q000276:immunology; D000097043:Interleukin-22
chemical_list: D016207:Cytokines; D020381:Interleukin-17; D053759:Interleukin-23; D007378:Interleukins; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; D018336:Receptors, Aryl Hydrocarbon; D000097043:Interleukin-22
keywords: Aryl hydrocarbon receptor (AhR); Autoimmune diseases; IL-22; IL-23; Regenerating (Reg) genes