Over- And Ectopic-Expression Of FoxN1 At Early Life Adversely Influences Lymphopoiesis

The study investigated the effects of over- and ectopic-expression of FoxN1 at early life stages using R26-STOPflox-FoxN1 mutant mice. Prenatal over-expression of FoxN1 led to a lethal phenotype in newborns with abnormal skin permeability. In infant mice, progressive FoxN1 over-expression influenced thymic epithelial cell development and impaired T- and B-lymphopoiesis. While FoxN1 over-expression in adult mice could delay thymic aging, early induction in infants adversely affected thymocyte and hair follicle development. The findings indicated that FoxN1 expression had stage and tissue-specific sensitivity, with early over-expression negatively impacting thymic, lymphocyte, and skin epithelial development.