The intestinal vascular system exerts a critical barrier function during inflammatory bowel diseases (IBD). IFN-gamma is an important pathogenesis factor in IBD with potent vascular-directed activities. The principal aim of the project is to elucidate the molecular mechanisms by which the activation of vascular endothelial cells by IFN-gamma impairs vascular barrier functions and disturbs the immune – epithelial cell crosstalk in the course of IBD pathogenesis. On the long term, we aim to identify novel molecular mechanisms of IFN-gamma-induced gut-vascular barrier dysfunction, which may be exploited as new targets of therapy in IBD.