Foxo: in command of T lymphocyte homeostasis and tolerance.

Immunology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
Trends in Immunology (Impact Factor: 12.03). 01/2011; 32(1):26-33. DOI: 10.1016/
Source: PubMed

ABSTRACT The forkhead box O (Foxo) family of transcription factors consists of the mammalian orthologs of the Caenorhabditis elegans longevity protein Daf-16, and has an evolutionarily conserved function in the regulation of nutrient sensing and stress responses. Recent studies have shown that Foxo proteins control expression of immune system-specific genes such as Il7ra in naïve T cells and Foxp3 in regulatory T cells, which are crucial regulators of T cell homeostasis and tolerance. These findings reveal that the ancient Foxo pathway has been co-opted to regulate highly specialized T cell activities. The Foxo pathway probably enables a diverse and self-tolerant population of T cells in the steady state, which is an important prerequisite for the establishment of a functional adaptive immune system.

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