Intestinal epithelium, intraepithelial lymphocytes and the gut microbiota - Key players in the pathogenesis of celiac disease

Figure 3 Schematic illustration of celiac disease pathogenesis. Microbiota dysbiosis activates innate immunity resulting in pro-inflammatory changes, which leads to IEL infiltration and epithelial barrier disruption. This ultimately results in an increased paracellular and transcellular transfer of immunogenic gluten peptides and activation of adaptive pro-inflammatory Th1/Th17 pathways, leading to villous atrophy and production of autoantibodies against intestinal TTG2. HLA: Human leucocyte antigen; IEL: Intraepithelial lymphocyte; IL: Interleukin; INF: Interferon; NOD: Nucleotide-binding oligomerization domain; Th: T helper; TLR: Toll-like receptor; TTG2: Tissue transglutaminase 2.