Figure 2.

Potential pro- and anti-inflammatory roles of ILCs in intestinal chronic inflammation. NK cells and ILC1s are increased in the colonic lamina propria tissue of inflammatory bowel disease (IBD) patients. NK cells produce IFN-γ, whereas ILC1s produce IFN-γ and TNF-α. ILC2s play a pathogenic role by promoting IL-13- and IL-5-driven inflammation in a mouse model of colitis, which is ameliorated by blocking IL-25. IL22⁺ NCR⁺ ILC3s are decreased dramatically and NCR⁻ ILC3s are increased under chronic inflammation conditions. The NCR⁻ ILC3 subset can contribute to intestinal chronic inflammation through the production of IL-17A and IFN-γ.