Innate Lymphoid Cells: Regulators of Gut Barrier Function and Immune Homeostasis

Figure 2

Illustration of interactions of ILCs and DCs in the intestinal tract. At the initial site of viral infection, virus DNA activates DCs, further activating ILC1 (mainly NK cells) by the TLR9/MyD88 pathway. After damage caused by helminths, epithelial cells produce TSLP, IL-33, and IL-25. These cytokines stimulate ILC2s producing type 2 cytokines including IL-4, IL-5, IL-9, and IL-13 which participate in repair of epithelial cells and mucus layer. In addition, ILC2-derived Th2 and IL-13 stimulate DCs, inducing the release of CCL17 and CCL22 and recruitment of CCR4-expressing memory TH2 cells. IL: interleukin; TSLP: thymic stromal lymphopoietin; DC: dendritic cell; ILC: innate lymphoid cell; CCL: chemokine (C-C motif) ligand; Th: helper T cell.