Marianne Forkel1, Sophie van Tol1, Charlotte Höög2, Jakob Michaëlsson1, Sven Almer3, Jenny Mjösberg1,4. 1. Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Stockholm, Sweden. 2. Unit for Inflammation, Gastroenterology and Rheumatology, Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden. 3. Department of Medicine, Solna, Karolinska Institutet, and IBD-Center, Gastroenterology, Karolinska University Hospital, Stockholm, Sweden. 4. Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Abstract
BACKGROUND AND AIMS: Innate lymphoid cells [ILC] have been suggested to play a role in inflammatory bowel disease [IBD]. Here, we investigated the ILC compartment in intestinal biopsies and blood from distinct patient groups with Crohn's disease [CD] and ulcerative colitis [UC], either newly diagnosed or with disease established for at least 1 year. This approach allowed us to simultaneously investigate temporal, disease-specific, and tissue-specific changes in ILC composition in IBD. METHODS: ILC subset frequencies, phenotype, and transcription factor profile in blood and intestinal biopsies were investigated by multi-parameter flow cytometry analysis. Endoscopic disease severity was judged using the ulcerative colitis endoscopic index of severity and the simple endoscopic score for Crohn's disease. RESULTS: The frequency of NKp44+ILC3 was decreased in inflamed tissue, both in patients with CD and those with UC, already at the time of diagnosis, and correlated with disease severity. Simultaneously, the frequency of ILC1 was increased in patients with CD, whereas the frequency of ILC2 was increased in patients with UC. However, in patients with established UC or CD, both ILC1 and ILC2 were increased. In contrast to the ILC composition in inflamed tissue, ILC in non-inflamed tissue or blood were unchanged compared with non-IBD controls. Finally, in patients undergoing treatment with an anti-α4β7 antibody the frequencies of ILC in peripheral blood remained unchanged. CONCLUSIONS: We report both shared and distinct changes in ILC composition depending on diagnosis and disease duration. The alterations in ILC composition in IBD occur selectively at inflamed sites in the gut.
BACKGROUND AND AIMS: Innate lymphoid cells [ILC] have been suggested to play a role in inflammatory bowel disease [IBD]. Here, we investigated the ILC compartment in intestinal biopsies and blood from distinct patient groups with Crohn's disease [CD] and ulcerative colitis [UC], either newly diagnosed or with disease established for at least 1 year. This approach allowed us to simultaneously investigate temporal, disease-specific, and tissue-specific changes in ILC composition in IBD. METHODS: ILC subset frequencies, phenotype, and transcription factor profile in blood and intestinal biopsies were investigated by multi-parameter flow cytometry analysis. Endoscopic disease severity was judged using the ulcerative colitis endoscopic index of severity and the simple endoscopic score for Crohn's disease. RESULTS: The frequency of NKp44+ILC3 was decreased in inflamed tissue, both in patients with CD and those with UC, already at the time of diagnosis, and correlated with disease severity. Simultaneously, the frequency of ILC1 was increased in patients with CD, whereas the frequency of ILC2 was increased in patients with UC. However, in patients with established UC or CD, both ILC1 and ILC2 were increased. In contrast to the ILC composition in inflamed tissue, ILC in non-inflamed tissue or blood were unchanged compared with non-IBD controls. Finally, in patients undergoing treatment with an anti-α4β7 antibody the frequencies of ILC in peripheral blood remained unchanged. CONCLUSIONS: We report both shared and distinct changes in ILC composition depending on diagnosis and disease duration. The alterations in ILC composition in IBD occur selectively at inflamed sites in the gut.
Authors: Carlo De Salvo; Kristine-Ann Buela; Brecht Creyns; Daniele Corridoni; Nitish Rana; Hannah L Wargo; Chiara L Cominelli; Peter G Delaney; Alexander Rodriguez-Palacios; Fabio Cominelli; Séverine Vermeire; Theresa T Pizarro Journal: J Clin Invest Date: 2021-03-01 Impact factor: 14.808