Volume 9 Supplement 2
Differential regulation of IL-22BP in Crohn’s disease versus ulcerative colitis
© Martin et al; licensee BioMed Central Ltd. 2011
Published: 23 November 2011
IL-22 is a newly described IL-10 cytokine family member. It mainly acts on epithelial cells and hepatocytes by interacting with a membrane receptor. IL-22 has been shown to have protective or deleterious effects on its targets cells depending on the context. IL-22 has been implicated in inflammatory bowel diseases (IBD) but its role still remains unclear. IL-22 is increased in Crohn’s disease (CD) but not in ulcerative colitis (UC). Furthermore IL-22 appears to have beneficial effects in several murine models of IBD. IL-22BP is a soluble inhibitory receptor specific for IL-22 whose physiological role and regulation are mainly unknown during inflammatory conditions.
To assess the regulation of IL-22BP during IBD.
Colonic biopsies were obtained from patients with active CD or UC. Biopsies were made in inflammatory and non-inflammatory mucosa for both conditions. Patients with polyps were used as healthy controls. IL-22BP mRNA expression was assessed by q-PCR and confirmed at the protein level by immunohistology, using a monoclonal Ab to IL-22BP. Informed consent was obtained from all the patients.
No difference could be observed in the IL-22BP mRNA expression between the non inflammatory mucosa of CD or UC patients compared with healthy controls. In UC patients, IL-22BP was expressed at the same level in inflammatory or non inflammatory samples. In contrast, important up-regulation of IL-22BP mRNA expression was detected in the inflammatory mucosa of CD patients as compared to non inflammatory samples. This upregulation was confirmed at the protein level by immunostaining experiments. IL-22BP was mostly detected in the lamina propria of the colon. In UC patients, IL-22BP protein exhibited actually a diminished expression as compared to controls.
Taken together these results highlight a different profile of IL-22BP production during CD and UC. Up-regulation of IL-22BP during CD is probably concomitant to IL-22 up-regulation already described, suggesting an immunomodulatory function of IL-22BP specific to CD.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.