Browsing by Subject "IFN-γ"

Equine idiopathic focal eosinophilic enteritis (IFEE) is one form of inflammatory bowel disease. The main clinical signs include colic, weight loss, hypoalbuminemia, acute small intestinal obstruction and pain, occasionally tachycardia and diarrhoea. Macroscopic lesions consist of focal or multifocal erythematous, circumferential bands or circumscribed plaques on the serosal surface of the small intestine. Histological hallmark is a severe focal inflammatory cell infiltration, which is dominated by eosinophils and disrupts the tissue architecture of the small intestine. Neutrophils, haemorrage, necrosis, oedema and activated vascular endothelium represent components of an active inflammatory process, at the same time chronicity is observed as fibroplasia, mononuclear leukocytes and neovascularisation are present in the tissue. Recently it has been suggested that IFEE is a focally exacerbated form of diffuse eosinophilic enteritis (DEE). A wide range of cells in the intestine of horses with IFEE have been shown to express mRNA of eotaxin, which is the major cytokine to recruit eosinophils to the tissue. This study was planned to investigate other significant cytokines in IFEE by examing the expression of interleukin (IL)-4, IL-5, tumor necrosis factor- α (TNF-α), interferon-γ (IFN-γ), transforming growth factor-β (TGF-β) mRNA and vascular endothelial growth factor (VEGF). IL-5 is a major activator of eosinophil differentiation and growth, IL-4 stimulates T cells to differentiate to T helper 2 cells and IFN-γ and TNF-α are known to activate macrophages. TGF-β promotes tissue repair and VEGF induces the proliferation of vascular endothelial cells. IL-5, IFN-γ, TNF-α and TGF-β were successfully amplified by PCR from RNA of a horse with IFEE. IL-4 could not be detected. RNA- in situ hybridisation(ISH) was developed for IFN-γ and TGF-β. 16 IFEE cases, 2 DEE cases and 1 case without any gastrointestinal disorders as a healthy control were included in this study. Mucosal epithelium, lymphocytes, macrophages, fibroblasts, vascular endothelium, eosinophils and neurons of the IFEE cases exhibited positive signals in ISH for IFN-γ and TGF-β mRNA and immunohistochemistry for VEGF. Very similar pattern of positive signals was obtained in ISH of the DEE cases as the IFEE cases. The healthy control case expressed positive signals in epithelium, neurons and vascular endothelium in ISH for IFN-γ mRNA and epithelium and neurons in ISH for TGF-β mRNA.