Role of Th17 Cells in the Pathogenesis of Human IBD

Figure 5

The intestine microbiota plays a key role in the pathogenesis of human IBD. Changes in the microbiota composition have been reported to be responsible for switching the tolerogenic response that normally occurs in healthy individuals to an activated, potentially pathogenic, immune response in IBD patients, characterized by the expansion of Th17 cells. Bacteria-infected apoptotic epithelial cells provide both TLR ligands and phosphatidylserine, which induce the production of IL-6 and TGF𝛽 from DCs, thus promoting Th17 differentiation.