The regulation of thymic stromal lymphopoietin in gut immune homeostasis.

Thymic stromal lymphopoietin is a novel IL-7-like cytokine that exerts immunomodulatory effects and is constitutively expressed by intestinal epithelial cells in response to commensal bacteria colonization. Thymic stromal lymphopoietin can directly or indirectly promote Th2 and Treg responses, and is believed to inhibit Th1 and Th17 responses and limit the expression of proinflammatory cytokines such as IL-17 and IFN-γ. In response to infection by enteric pathogens, intestinal epithelial cells upregulate thymic stromal lymphopoietin expression in order to generate balance between inflammation and immune clearance. Recently, however, aberrant expression of thymic stromal lymphopoietin has been associated with inflammatory bowel disease. Thus, we sought to examine the relationship between the TLSP-TSLPR pathway and inflammation in hopes of contributing to the search for a novel therapeutic target to treat a variety of inflammatory diseases, including inflammatory bowel disease.