Fig. 4: Intestinal ILC2 activation during helminth infection.
Adult hookworm can establish chronic infection in the intestinal tract. Several factors contribute to the activation of intestinal ILC2s. IL-33 released from epithelial cells and from ATP-activated mast cell can directly activate ILC2s. IL-25 and leukotrienes (LTs) produced by tuft cells, and NMU by enteric neurons induce production of IL-13. IL-13 induces hyperplasia of goblet cells and mucus production, and it acts on progenitor intestinal cells to promote goblet cells and tuft cells development. In contrast, IL-33 released from DCs induces expansion of ST2+ TREG that suppress ILC2s activation, reducing type 2 immune responses.
