title: Regulation of interferon lambda-1 (IFNL1/IFN-λ1/IL-29) expression in human colon epithelial cells.
abstract: The efficient regulation of intestinal immune responses is critical to colon health. Viruses, for example noraviruses, are key pathogens of the intestine. The lambda interferons (comprising three ligands: IFNL1, L2 and L3 - the so-called "Type III" interferons) constitute the most recently discovered IFN family and are known to be important in intestinal anti-viral defense. A fourth family member, IFNL4, was recently described. Expression of the IFN-lambda receptor is restricted to epithelial and immune cells; together, these ligands and their receptor represent an important anti-viral and immunoregulatory component of the immune/epithelial inteface. We investigated control of IFNL1 expression in human colon epithelial cells. We used the TLR3 agonist poly I:C to drive expression of IFNL1 in SW480 cells, and small interfering RNA (siRNA) to knockdown target transcription factors. We identified ZEB1 and BLIMP-1 as transcription factors that strongly inhibited IFNL1 expression in SW480 cells. Interestingly, while BLIMP-1 inhibited both type-III and type-I interferons (IFN-β), the inhibitory action of ZEB1 was specific for IFNL1. We also defined the NF-κB family member, p65 as a key activator of IFNL1 and NF-κB p50 as a key inhibitor. Finally, we demonstrated that siRNA targeting of ZEB1 or NF-κB p50 resulted in a significant elevation of secreted IFN-λ1 protein and expression of the anti-viral gene OAS1, while knockdown of p65 inhibited these events. Our data provide insight to the regulation of IFNL1 expression in the human colon and suggest novel therapeutic approaches to elevate IFNλ-1 protein where required.
authors.affiliation: Genetic Immunology Laboratory, HUMIGEN LLC, 2439 Kuser Road, Hamilton, NJ 08690, United States(1).
authors.forename: Adam
authors.initials: A
authors.lastname: Swider
authors.forename: Rachael
authors.initials: R
authors.lastname: Siegel
authors.forename: Joyce
authors.initials: J
authors.lastname: Eskdale
authors.forename: Grant
authors.initials: G
authors.lastname: Gallagher
mesh_terms: D015088:2',5'-Oligoadenylate Synthetase / Q000096:biosynthesis; D045744:Cell Line, Tumor; D003106:Colon / Q000166:cytology / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D019073:HT29 Cells; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D007372:Interferons; D007378:Interleukins / Q000096:biosynthesis*; D052002:NF-kappa B p50 Subunit / Q000235:genetics / Q000378:metabolism; D011070:Poly I-C / Q000494:pharmacology; D000074462:Positive Regulatory Domain I-Binding Factor 1; D034622:RNA Interference; D034741:RNA, Small Interfering; D012097:Repressor Proteins / Q000235:genetics; D051196:Toll-Like Receptor 3 / Q000819:agonists; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics; D000071799:Zinc Finger E-box-Binding Homeobox 1; D000095022:Interferon Lambda
chemical_list: D015088:2',5'-Oligoadenylate Synthetase; D018398:Homeodomain Proteins; D007372:Interferons; D007378:Interleukins; D052002:NF-kappa B p50 Subunit; D011070:Poly I-C; D000074462:Positive Regulatory Domain I-Binding Factor 1; D034741:RNA, Small Interfering; D012097:Repressor Proteins; D051196:Toll-Like Receptor 3; D051996:Transcription Factor RelA; D014157:Transcription Factors; D000071799:Zinc Finger E-box-Binding Homeobox 1; C000624353:interferon-lambda, human; D000095022:Interferon Lambda; C495344:TLR3 protein, human; C486307:ZEB1 protein, human; C087042:PRDM1 protein, human; C475085:OAS1 protein, human
keywords: BLIMP-1; IFN-λ1; IFNL1; IL-29; ZEB1