Flood, Peter; Fanning, Aine; Woznicki, Jerzy A.; Crowley, Tadhg; Christopher, Andrea; Vaccaro, Alessandra; Houston, Aileen; McSweeney, Sheila; Ross, Sarah; Hogan, Aileen; Brint, Aileen; Skowyra, Agnieszka; Bustamante, Milan; Ambrose, Monica; Moloney, Gerard M.; MacSharry, John; Hammarström, Marie-Louise; Hurley, Margot; Fitzgibbons, Christine; Quigley, Eamonn M. M.; Shanahan, Fergus; Zulquernain, Syed A.; McCarthy, Jane; Dodson, G. Steven; Dabbagh, Karim; McRae, Bradford L.; Melgar, Silvia; Nally, Ken

2022

September

American Journal of Physiology - Gastrointestinal and Liver Physiology

DNA sensor associated type I Interferon signalling is increased in ulcerative colitis and induces JAK-dependent inflammatory cell death in colonic organoids.

Validated

()

Ulcerative colitis Epithelium Interferon Inflammasome JAK inhibitor

DNA sensor pathways can initiate inflammasome, cell death and type I interferon (IFN) signalling in immune-mediated inflammatory diseases (IMIDs); including type I interferonopathies. We investigated the involvement of these pathways in the pathogenesis of ulcerative colitis (UC); by analysing expression of DNA sensor, inflammasome, and type I IFN biomarker genes in colonic mucosal biopsy tissue from control (n=31), inactive UC (n=31), active UC (n=33) and a UC single cell RNA-Seq dataset. The effects of type I IFN (IFN-ß), IFN-¿ and TNF-a on gene expression, cytokine production and cell death were investigated in human colonic organoids. In organoids treated with cytokines alone, or in combination with NLRP3, caspase or JAK inhibitors, cell death was measured, and supernatants were assayed for IL-1ß/IL-18/CXCL10. The expression of DNA sensor pathway genes - PYHIN family members (AIM2, IFI16, MNDA, PYHIN1), as well as ZBP1, cGAS and DDX41 were increased in active UC and expressed in a cell type restricted pattern. Inflammasome genes (CASP1, IL1B, IL18), type I IFN inducers (STING, TBK1, IRF3), IFNB1 and type I IFN biomarker genes (OAS2, IFIT2, MX2) were also increased in active UC. Co-treatment of organoids with IFN-ß or IFN-¿ and TNFa increased expression of IFI16, ZBP1, CASP1, cGAS and STING, induced cell death and IL-1ß/IL-18 secretion. This inflammatory cell death was blocked by the JAK inhibitor tofacitinib but not by inflammasome or caspase inhibitors. Increased type I IFN activity may drive elevated expression of DNA sensor genes and JAK-dependent but inflammasome-independent inflammatory cell death of colonic epithelial cells in UC.

1522-1547

10.1152/ajpgi.00104.2022