Barrier defect in the follicle-associated epithelium of SAMP1/YitFc mice demonstrates vulnerability to adherent-invasive Escherichia coli LF82
(English)Manuscript (preprint) (Other academic)
SAMP1/YitFc mice are a unique murine model for Crohn’s disease (CD) as they develop spontaneous intestinal inflammation without chemical or genetic manipulations. Inflammation is primarily located in the distal ileum, which is the hallmark location for CD. It is at the distal ileum of CD where small erosions that develop at the follicle-associated epithelium (FAE) and are one of the earliest observable lesions in recurrent ileitis. In the report, we studied the intestinal permeability defect and examined the role of dendritic cells (DCs) in the SAMP1/YitFc mice ileitis. Segments of FAE and VE from 11 and 27 weeks old SAMP1/YitFc mice and AKR control background stains were mounted on Ussing chambers. Electrical conductivity and permeability to 51Cr-EDTA, horseradish peroxidise (HRP) and E.coli HB101 and LF82 were recorded. There was ileal permeability to 51Cr-EDTA and HRP in the 27 weeks old SAMP1/YitFc mice. Both E.coli HB101 and LF82 increased conductance by two-folds in FAE and VE of SAMP1/YitFc mice. Furthermore, both bacterial strains increased tissue conductance and 51Cr-EDTA passage. There was greater passage of E.coli LF82 in the 27 week old DAMP1/YitFc mice than in controls. Confocal microscopy revealed a high number of CD11c+ DCs in the sub-epithelial dome (SED) area, though there was no difference between the SAMP1/YitFc mice than the AKR controls. Immunofluorescence characterisation also did not reveal any phenotypic difference in DCs between the mice strains. These results show that SAMP1/YitFc mice have a barrier defect, which was more pronounced in the FAE of older mice, and demonstrate a mucosal sensitivity bacteria. It also confirms that this model of chronic ileitis is primarily a defect in permeability defect and not DCs.
52Cr-EDTA, dentric cells, E.coli, HRP, permeability, Ussing chanbers
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-52233OAI: oai:DiVA.org:liu-52233DiVA: diva2:280718