The small intestine epithelium exempts Foxp3+ Tregs from their IL-2 requirement for homeostasis and effector function.

ABSTRACT: Foxp3+ Tregs are potent immunosuppressive CD4+ T cells that are critical to maintain immune quiescence and prevent autoimmunity. Both the generation and maintenance of Foxp3+ Tregs depend on the cytokine IL-2. Hence, the expression of the IL-2 receptor α-chain (CD25) is not only considered a specific marker, but also a nonredundant requirement for Tregs. Here, we report that Foxp3+ Tregs in the small intestine (SI) epithelium, a critical barrier tissue, are exempt from such an IL-2 requirement, since they had dramatically downregulated CD25 expression, showed minimal STAT5 phosphorylation ex vivo, and were unable to respond to IL-2 in vitro. Nonetheless, SI epithelial Tregs survived and were present at the same frequency as in other lymphoid organs, and they retained potent suppressor func

SUBMITTER: Prakhar P 

PROVIDER: S-EPMC8663555 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature