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Interactions Among Secretory Immunoglobulin A, CD71, and Transglutaminase-2 Affect Permeability of Intestinal Epithelial Cells to Gliadin Peptides
- Source :
- Gastroenterology. 143:698-707.e4
- Publication Year :
- 2012
- Publisher :
- Elsevier BV, 2012.
-
Abstract
- BACKGROUND & AIMS: The transferrin receptor (CD71) is up-regulated in duodenal biopsy samples from patients with active celiac disease and promotes retrotransport of secretory immunolglobulin 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. Caco-2 and HT29-19A epithelial cell lines were transfected with fluorescence-labeled small interfering RNAs against CD71. Interactions among IgA, CD71, and transglutaminase 2 (Tgase2) were analyzed by flow cytometry, immunoprecipitation, and confocal microscopy. Transcytosis of SIgACD71 complexes and intestinal permeability to the gliadin 3H-p3149 peptide were analyzed in polarized monolayers of Caco-2 cells. RESULTS: Using fluorescence resonance energy transfer and in situ proximity ligation assays, we observed physical interactions between SIgA and CD71 or CD71 and Tgase2 at the apical surface of enterocytes in biopsy samples and monolayers of Caco-2 cells. CD71 and Tgase2 were co-precipitated with SIgA, bound to the surface of Caco-2 cells. SIgACD71 complexes were internalized and localized in early endosomes and recycling compartments but not in lysosomes. In the presence of celiac IgA or SIgA against p3149, transport of intact 3H-p3149 increased significantly across Caco-2 monolayers; this transport was inhibited by soluble CD71 or Tgase2 inhibitors. CONCLUSIONS: Upon binding to apical CD71, SIgA (with or without gliadin peptides) enters a recycling pathway and avoids lysosomal degradation; this process allows apicalbasal transcytosis of bound peptides. This mechanism is facilitated by Tgase2 and might be involved in the pathogenesis of celiac disease.
- Subjects :
- Immunoglobulin A
Duodenum
Endosome
Tissue transglutaminase
Biopsy
Transfection
digestive system
Gliadin
Permeability
Intestinal absorption
Antigens, CD
GTP-Binding Proteins
Receptors, Transferrin
Fluorescence Resonance Energy Transfer
medicine
Humans
Immunoprecipitation
Protein Glutamine gamma Glutamyltransferase 2
Intestinal Mucosa
Microscopy, Confocal
Transglutaminases
Intestinal permeability
Hepatology
biology
Gastroenterology
Cell Polarity
Flow Cytometry
medicine.disease
Molecular biology
Peptide Fragments
Celiac Disease
Protein Transport
Intestinal Absorption
Transcytosis
Caco-2
Immunoglobulin A, Secretory
biology.protein
RNA Interference
Caco-2 Cells
Lysosomes
HT29 Cells
Subjects
Details
- ISSN :
- 00165085
- Volume :
- 143
- Database :
- OpenAIRE
- Journal :
- Gastroenterology
- Accession number :
- edsair.doi.dedup.....a798861074cc0f5c90c9cbf9812392ea