Interactions among secretory immunoglobulin A, CD71, and transglutaminase-2 affect permeability of intestinal epithelial cells to gliadin peptides.

Background & Aims: The transferrin receptor (CD71) is up-regulated in duodenal biopsy samples from patients with active celiac disease and promotes retrotransport of secretory immunoglobulin A (SIgA)-gliadin complexes. We studied intestinal epithelial cell lines that overexpress CD71 to determine how interactions between SIgA and CD71 promote transepithelial transport of gliadin peptides.

Methods: We analyzed duodenal biopsy specimens from 8 adults and 1 child with active celiac disease.

Intestinal permeability in coeliac disease: insight into mechanisms and relevance to pathogenesis.

Coeliac disease is a gut disease driven by an abnormal immune response towards dietary gluten in genetically susceptible individuals. Whether and, if so, how abnormal transport of gluten across the gut epithelium may participate in the pathogenesis of coeliac disease remains debatable. This paper summarises the interactions of gluten-derived peptides with the intestinal epithelium and discusses the mechanisms that control their transport across the epithelium.

Effects of essential amino acids or glutamine deprivation on intestinal permeability and protein synthesis in HCT-8 cells: involvement of GCN2 and mTOR pathways.

GCN2 and mTOR pathways are involved in the regulation of protein metabolism in response to amino acid availability in different tissues. However, regulation at intestinal level is poorly documented. The aim of the study was to evaluate the effects of a deprivation of essential amino acids (EAA) or glutamine (Gln) on these pathways in intestinal epithelial cells.