The chromatin landscape and transcription factors in T cell programming

• Multi-tiered action of transcription factors remodels the chromatin landscape.
• Differential chromatin access and partner factors bias binding-site choice.
• Powerful transcription factors can work by modifying effects of other factors.
• Selective transcription factor silencing shapes the regulatory state in early T cells.

T cell development from multipotent progenitors to specialized effector subsets of mature T cells is guided by the iterative action of transcription factors. At each stage, transcription factors interact not only with an existing landscape of histone modifications and nucleosome packing, but also with other bound factors, while they modify the landscape for later-arriving factors in ways that fundamentally affect the control of gene expression. This review covers insights from genome-wide analyses of transcription factor binding and resulting chromatin conformation changes that reveal roles of cytokine signaling in effector T cell programming, the ways in which one factor can completely transform the impacts of previously bound factors, and the ways in which the baseline chromatin landscape is established during early T cell lineage commitment.