title: The unusual suspects--innate lymphoid cells as novel therapeutic targets in IBD.
abstract: Innate lymphoid cells (ILCs) are a family of immune cells that selectively accumulate in mucosal tissues serving as sentinels at the vanguard of host protective immunity. However, they are also implicated as cellular mediators of immune-mediated diseases, most notably IBD. ILCs are subdivided into distinct lineages based on the expression of effector cytokines and master transcription factors that programme their differentiation and inflammatory behaviour. Strikingly, these subsets closely resemble CD4(+) T-cell lineages, including T helper (TH)1, TH2 and TH17 cells that are similarly implicated in immune-mediated diseases. However, ILCs that promote the maintenance of intestinal epithelial cells, mostly through production of IL-22, also exist. ILCs rapidly respond to environmental cues, including cytokines, metabolic signals and luminal bacteria. They are potent and immediate producers of key cytokines linked to IBD pathogenesis, including TNF, IL-17, IL-22 and IFN-γ. Some subsets are implicated as mediators of chronic intestinal inflammation, whereas others might provide protective functions. They are present in the gut of patients with IBD and, intriguingly, closer scrutiny of IBD susceptibility loci shows that many of these genes are either expressed by, or are intimately linked to, ILC function. Looking forward, targeting ILCs could represent a new IBD treatment paradigm.
authors.affiliation: Department of Experimental Immunobiology, Division of Transplantation Immunology and Mucosal Biology, London SE1 9RT, UK.
authors.forename: Rimma
authors.initials: R
authors.lastname: Goldberg
authors.affiliation: Department of Medical and Molecular Genetics, King's College London, London SE1 9RT, UK.
authors.forename: Natalie
authors.initials: N
authors.lastname: Prescott
authors.affiliation: Department of Experimental Immunobiology, Division of Transplantation Immunology and Mucosal Biology, London SE1 9RT, UK.
authors.forename: Graham M
authors.initials: GM
authors.lastname: Lord
authors.affiliation: Centre for Immunology and Infectious Disease, Blizard Institute, Barts and the London School of Medicine and Dentistry, London E1 2AT, UK.
authors.forename: Thomas T
authors.initials: TT
authors.lastname: MacDonald
authors.affiliation: Department of Experimental Immunobiology, Division of Transplantation Immunology and Mucosal Biology, London SE1 9RT, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Powell
mesh_terms: D016175:B-Lymphocyte Subsets / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D015212:Inflammatory Bowel Diseases / Q000276:immunology* / Q000628:therapy*; D007422:Intestines / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*