IL-10 is an immune regulatory cytokine and its genetic defect leads to gastrointestinal inflammation in humans and mice. Moreover, the IL-23/Th17 axis is known to be involved in these inflammatory disorders. IL-17A, a representative cytokine produced by Th17 cells, has an important role for the pathological process of inflammatory diseases. However, the precise function of IL-17A in inflammatory bowel disease (IBD) remains controversial. In this study, we evaluated the effect of IL-17A on colitis in IL-10-deficient (Il10-/-) mice. Mice lacking both IL-10 and IL-17A (Il10-/-Il17a-/-) suffered from fatal wasting and manifested more severe colitis compared with Il10-/-Il17a+/- mice. Moreover, we found that CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) accumulated in the bone marrow, spleen and peripheral blood of Il10-/-Il17a-/- mice. These MDSCs highly expressed inducible nitric oxide synthase (iNOS) (Nos2) and suppressed the T-cell response in vitro in a NOS-dependent manner. In correlation with these effects, the concentration of nitric oxide was elevated in the serum of Il10-/-Il17a-/- mice. Surprisingly, the severe colitis observed in Il10-/-Il17a-/- mice was ameliorated in Il10-/-Il17a-/-Nos2-/- mice. Our findings suggest that IL-17A plays suppressive roles against spontaneous colitis in Il10-/- mice in an iNOS-dependent manner and inhibits MDSC differentiation and/or proliferation.
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http://dx.doi.org/10.1093/intimm/dxz076 | DOI Listing |
Dig Dis Sci
January 2025
Department of Gastroenterology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-Ku, Chiba, 260-8670, Japan.
Purpose: The performance of endoscopic evaluation of ulcerative colitis (UC) using conventional scoring, including Mayo endoscopic subscore (MES) and ulcerative colitis endoscopic index of severity (UCEIS), is not satisfactory. Recently, the usefulness of novel image-enhanced endoscopy (IEE) such as texture and color enhancement imaging (TXI) and red dichromatic imaging (RDI) has been reported in the endoscopic evaluation of UC. We evaluated the performance of IEEs in UC, particularly focusing on the correlation with MES and UCEIS, and prediction of relapse.
View Article and Find Full Text PDFExpert Rev Gastroenterol Hepatol
January 2025
Department of Gastroenterology and Hepatology, Concord Repatriation General Hospital, Sydney, Australia.
Introduction: Ulcerative colitis is a chronic inflammatory condition of the colon driven by aberrant immune activation. Although advanced medical therapies form the cornerstone of ulcerative colitis management, unmet needs include failure to induce and sustain remission in a substantial proportion of patients and in managing acute severe ulcerative colitis. We review new treatment strategies that might improve patient outcomes in the management of moderate-to-severe ulcerative colitis.
View Article and Find Full Text PDFExp Anim
January 2025
Division of Medical Sciences, Institute of Medicine, University of Tsukuba.
Unbalanced redox homeostasis leads to the production of reactive oxygen species and exacerbates inflammatory bowel disease. To investigate the role of the transcription factor Nrf2, a major antioxidative stress sensor, in intestinal epithelial cells (IECs), we generated IEC-specific Nrf2 gene knock-in mice (Nrf2-vRes), which express Nrf2 only in IECs, using the cre/loxp system. Colitis was induced in wild-type (WT) mice, whole-body Nrf2-knockout (Nrf2-KO) mice, and Nrf2-vRes mice by administering dextran sulfate sodium (DSS) for 1 week (acute model) or intermittently for 5 weeks (chronic model).
View Article and Find Full Text PDFMol Immunol
January 2025
Department of Gastroenterology and Hepatology, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu Province 226006, China. Electronic address:
Background: The intestinal mucosa of ulcerative colitis patients expresses high levels of interleukin 34, and mice lacking IL-34 have more severe DSS-induced experimental colitis. There are no studies on the effects of directly upregulating intestinal IL-34 on experimental colitis in mice.
Methods: The bacteria EcN/CSF-1 and EcN/IL-34, which express CSF-1 and IL-34, respectively, were genetically engineered from Escherichia coli Nissle 1917 (EcN).
Methods Cell Biol
January 2025
Laboratory of Translational Oncology, Program in Solid Tumors, Cima Universidad de Navarra, Cancer Center Clínica Universidad de Navarra (CCUN), Pamplona, Spain; Department of Biochemistry and Genetics, School of Sciences, Universidad de Navarra, Pamplona, Spain; Navarra's Health Research Institute (IDISNA), Pamplona, Spain; Centro de Investigación Biomédica en Red Cáncer (CIBERONC), Madrid, Spain. Electronic address:
Combined blockade of the immune checkpoints PD-1 and CTLA-4 has shown remarkable efficacy in patients with melanoma, renal cell carcinoma, non-small-cell lung cancer and mesothelioma, among other tumor types. However, a proportion of patients suffer from serious immune-related adverse events (irAEs). In severe cases, a reduction of the doses or the complete cessation of the treatment is required, limiting the antitumor efficacy of these treatments.
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