Activation of Epithelial Signal Transducer and Activator of Transcription 1 by Interleukin 28 Controls Mucosal Healing in Mice With Colitis and Is Increased in Mucosa of Patients With Inflammatory Bowel Disease.
We investigated the roles of interleukin 28A (also called IL28A or interferon λ2) in intestinal epithelial cell (IEC) activation, studying its effects in mouse models of inflammatory bowel diseases (IBD) and intestinal mucosal healing.



Colitis was induced in C57BL/6JCrl mice (controls), mice with IEC-specific disruption of Stat1 (Stat1IEC-KO), mice with disruption of the interferon λ receptor 1 gene (Il28ra-/-), and mice with disruption of the interferon regulatory factor 3 gene (Irf3-/-), with or without disruption of Irf7 (Irf7-/-). We used high-resolution mini-endoscopy and in vivo imaging methods to assess colitis progression. We used 3-dimensional small intestine and colon organoids, along with RNA-Seq and gene ontology methods, to characterize the effects of IL28 on primary IECs. We studied the effects of IL28 on the human intestinal cancer cell line Caco-2 in a wound-healing assay, and in mice colon wounds. Colonic biopsies and resected tissue from patients with IBD (n = 62) and patients without colon inflammation (controls, n = 23) were analyzed by quantitative polymerase chain rection to measure expression of IL28A, IL28RA, and other related cytokines; biopsy samples were also analyzed by immunofluorescence to identify sources of IL28 production. IECs were isolated from patient tissues and incubated with IL28; signal transducer and activator of transcription 1 (STAT1) phosphorylation was measured by immunoblots and confocal imaging.



Lamina propria cells in colon tissues of patients with IBD, and mice with colitis, had increased expression of IL28 compared with controls; levels of IL28R were increased in the colonic epithelium of patients with IBD and mice with colitis. Administration of IL28 induced phosphorylation of STAT1 in primary human and mouse IECs, increasing with dose. Il28ra-/-, Irf3-/-, Irf3-/-Irf7-/-, as well as Stat1IEC-KO mice, developed more severe colitis after administration of dextran sulfate sodium than control mice, with reduced epithelial restitution. Il28ra-/-and Stat1IEC-KO mice also developed more severe colitis in response to oxazolone than control mice. We found IL28 to induce phosphorylation (activation) of STAT1 in epithelial cells, leading to their proliferation in organoid culture. Administration of IL28 to mice with induced colonic wounds promoted mucosal healing.



IL28 controls proliferation of IECs in mice with colitis and accelerates mucosal healing by activating STAT1. IL28 might be developed as a therapeutic agent for patients with IBD.
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany. Electronic address: Mircea.Chiriac@uk-erlangen.de.
Mircea T
MT
Chiriac
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Barbara
B
Buchen
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Alexandra
A
Wandersee
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Gheorghe
G
Hundorfean
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Claudia
C
Günther
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Yvonne
Y
Bourjau
ZymoGenetics, Inc, Seattle, Washington.
Sean E
SE
Doyle
Department of Radiation Oncology, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Benjamin
B
Frey
Core Unit Genomics, Institute of Human Genetics, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Arif B
AB
Ekici
Core Unit Genomics, Institute of Human Genetics, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Christian
C
Büttner
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Benno
B
Weigmann
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany; Ludwig Demling Endoscopy Center of Excellence, University of Erlangen-Nuremberg, Erlangen, Germany.
Raja
R
Atreya
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Stefan
S
Wirtz
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Christoph
C
Becker
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany.
Jürgen
J
Siebler
Medical Clinic 1, Department of Medicine, University Hospital Erlangen, University of Erlangen-Nuremberg, Erlangen, Germany; Ludwig Demling Endoscopy Center of Excellence, University of Erlangen-Nuremberg, Erlangen, Germany. Electronic address: Markus.Neurath@uk-erlangen.de.
Markus F
MF
Neurath
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D018938:Caco-2 Cells; D049109:Cell Proliferation; D003092:Colitis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D003713:Dendritic Cells / Q000378:metabolism; D016264:Dextran Sulfate; D004195:Disease Models, Animal; D004847:Epithelial Cells; D005260:Female; D015870:Gene Expression; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics / Q000378:metabolism*; D050838:Interferon Regulatory Factor-3 / Q000235:genetics; D050839:Interferon Regulatory Factor-7 / Q000235:genetics; D007378:Interleukins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008875:Middle Aged; D009940:Organoids; D010766:Phosphorylation; D018121:Receptors, Cytokine / Q000235:genetics / Q000378:metabolism; D017471:Receptors, Interferon / Q000235:genetics; D050794:STAT1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014945:Wound Healing; D055815:Young Adult; D000095022:Interferon Lambda
D016264:Dextran Sulfate; D050838:Interferon Regulatory Factor-3; D050839:Interferon Regulatory Factor-7; D007378:Interleukins; D018121:Receptors, Cytokine; D017471:Receptors, Interferon; D050794:STAT1 Transcription Factor; C000624353:interferon-lambda, human; D000095022:Interferon Lambda; C579640:IFNLR1 protein, human; C000604340:IFNLR1 protein, mouse; C000594666:IL28A protein, mouse; C494233:Irf3 protein, mouse; C494235:Irf7 protein, mouse; C494079:STAT1 protein, human; C494080:Stat1 protein, mouse
Crohn’s Disease; Interferon λ; Ulcerative Colitis; Wound Healing