Molekulare Physiologie und Pathobiochemie ausgewählter Magen ...

ZIEL
Molekulare Physiologie - Pathobiochemie
Depiction of the intestinal mucosa with emphasis on the factors that take part in the development and control of coeliac disease. a | The parts of gluten that are
resistant to processing p gby y luminal and brush-border enzymes y will survive digestion, g , and can be transported p across the mucosal epithelium p as polypeptides.
p yp p
Gluten peptides are deamidated by tissue transglutaminase (TG2), which, in the intestinal mucosa, is located mainly extracellularly in the subepithelial region,
but is also found in the brush border. CD4+ T cells in the lamina propria recognize deamidated gluten peptides predominantly, presented by HLA-DQ2 or -DQ8
molecules on the cell surface of antigen-presenting cells (APCs). b | Immunofluorescence staining of TG2 (pink), HLA-DQ (green) and T cells (CD3; purple) in
the small-intestine mucosa of an untreated coeliac-disease patient. Note that there is a close spatial relationship between TG2, APCs that express HLA-DQ and
T cells just beneath the epithelium.