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dc.contributor.authorTHORPE, AJen_US
dc.contributor.editorSanderson, Ien_US
dc.date.accessioned2017-01-06T10:47:54Z
dc.date.issued2016-08-22en_US
dc.date.submitted2017-01-05T14:35:50.901Z
dc.identifier.urihttp://qmro.qmul.ac.uk/xmlui/handle/123456789/18407
dc.descriptionThis work was made possible through funding from the Medical Research Council, grant number: MR/J500409/1, and The Barts Charity, grant number: 723/1625.
dc.descriptionThis work was made possible through funding from the Medical Research Council, grant number: MR/J500409/1, and The Barts Charity, grant number: 723/1625.en_US
dc.description.abstractObjectives: Tolerance is a hyporesponsive state caused by repeated exposure to a stimulus. In the intestine, dysregulation of tolerance to luminal stimuli may lead to chronic and deleterious inflammation, such as characterizes Inflammatory Bowel Disease. The role of T-cells in immune tolerance is well known, but that of the epithelium requires investigation. Epithelial tolerance is gene-specific and differentially regulated, but the role of and involvement of epigenetics in tolerance regulation is unknown. We hypothesized that prior stimulation may cause epithelial cells to become hyporesponsive (tolerized) and that modification of histone methylation may alter the response to pro-inflammatory stimulation. The aim of this work was to examine if known inhibitors of histone methylation modifying enzymes affected the expression of CXCL8 in response to IL-1β. Methods: CXCL8 production of intestinal epithelial cells was measured by ELISA after stimulation with the pro-inflammatory stimuli P3CK and IL-1β and small molecule epigenetic inhibitors. The CXCL8 production of cells stimulated with a pro-inflammatory stimulus was compared to pre-stimulated cells after a second stimulus. CXCL8 production of IL-1β-pre-stimulated cells was also compared to CXCL8 production when these cells were incubated with epigenetic inhibitors. The effects of these inhibitors on histone methylation levels were examined by Western blotting for the global effect and by ChIP-qPCR for specific effects at the CXCL8 locus. Results: Intestinal epithelial cells stimulated with pro-inflammatory stimuli produced a large CXCL8 response. Pre-stimulation significantly decreased CXCL8 production after a second stimulus. The time-course of CXCL8 expression was measured to ensure that CXCL8 expression due to pre-stimulation was over before the second IL-1β-stimulation. In the presence of specific epigenetic inhibitors, pre-stimulation by IL-1β did not reduce CXCL8 production after a second IL-1β- stimulation. The specific effect of these inhibitors on the epigenetic signature at the CXCL8 locus was confirmed by ChIP. Thus, histone methylation modification disrupted tolerization of intestinal epithelial cells to a pro-inflammatory stimulus. Conclusion: The inflammatory response of the intestinal epithelium can be tolerized by prior stimulation with pro-inflammatory cytokines. Tolerization is lost after incubation with inhibitors known to modify histone methylation status, indicating for the first time, the involvement of histone methylation in this phenomenon.en_US
dc.description.sponsorshipMedical Research Council, grant number: MR/J500409/1, and The Barts Charity, grant number: 723/1625en_US
dc.language.isoenen_US
dc.subjectimmune toleranceen_US
dc.subjectDigestive diseasesen_US
dc.subjectepigeneticsen_US
dc.titleEpigenetic Regulation of Immune Tolerance in Intestinal Epithelial Cellsen_US
dc.typeThesisen_US
dc.rights.holderThe copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the author.
pubs.notesNo embargoen_US


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    Theses Awarded by Queen Mary University of London

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