Figure 2.

Paneth cells secrete factors, including IL17A, and are impacted by others, such as IL22 or TNFα, which can travel through the blood stream and have local and systemic effects. Paneth cells are induced by TNFα to secrete IL17, which can lead to increased barrier permeability and injury to other organs including kidney and liver. IL22 receptor signaling in Paneth cells promotes their maturation. However, excess IL22 leads to increased expression of genes associated with ER stress. Overt loss of Paneth cells is associated with increased incidence of necrotizing enterocolitis, bacterial infections, and persistent inflammation.