Upregulation of a single transcription factor FOXN1 can reverse age-related thymic involution in mice
Thymic involution occurs in adults and is accompanied by decline in immune function. Consequently, regenerating of thymus would be likely to improve the immune system of adults and elderly people. British researchers demonstrated that diminished expression of the thymic epithelial cell (TEC)-specific transcription factor Forkhead box N1 (FOXN1) has been implicated as a component of the mechanism regulating age-related involution. They also showed that forced, TEC-specific upregulation of FOXN1 in the fully involuted thymus of aged mice results in robust thymus regeneration characterized by increased thymopoiesis and increased naive T cell output. Regenerated thymus was actually identical with thymus of juvenile mice in terms of gene expression and structure. It’s significant that mutation in this gene has been correlated with T-cell immunodeficiency.