The transcription factor FoxP3 is endowed with the ability to repress conventional T cell phenotype while promoting Treg immunoregulatory properties by binding several specific sequences on the genome of T lymphocytes. However, understanding the mechanism by which this myriad of signals is coordinated in Tregs is no easy task, partly due to the fact that the signature genes targeted by FoxP3 represent only a small portion of the sequences actually recognized by this transcription factor on the whole genome; to make things harder, FoxP3 also directly interacts with a huge host of other different transcription factors. The integration of all these signals is behind Treg phenotype and is, to date, still poorly understood.
In this paper, Ho-Keun Kwon et al. addressed this difficult matter by analysing the effect of a panel of specific FoxP3 mutants on DNA binding, interaction with other transcription factors and transcription patterns.