Critical Roles of Balanced Innate Lymphoid Cell Subsets in Intestinal Homeostasis, Chronic Inflammation, and Cancer

Figure 3

Potential pro- and antitumorigenic roles of ILCs in intestinal cancer. NK cells express high levels of the activating receptors NKp30 and NKp44 and contribute to the fight against tumor cells. Under the influence of transforming growth factor beta 1 (TGF-β) and granulocyte colony-stimulating factor (G-CSF), NK cells also have a tumor-promoting effect. ILC1s might be involved in antitumor immunity through the release of IFN-γ and TNF-α. ILC2-derived cytokines, IL-5 and IL-13, are associated with a high risk of developing inflammation-driven colorectal cancer. ILC2-derived AREG stimulates regulatory T cells and establishes an immune-suppressive tumor microenvironment. In response to IL-23 stimulation, NCR⁺ ILC3s and NCR⁻ ILC3s mainly produce IL-22 and IL-17, respectively. The IL-23–ILC3–IL-22/IL-17 axis is a critical pathway that promotes tumor growth.