Gene Regulatory Circuits in Innate and Adaptive Immune Cells.

Cell identity and function largely rely on the programming of transcriptomes during development and differentiation. Signature gene expression programs are orchestrated by regulatory circuits consisting of cis-acting promoters and enhancers, which respond to a plethora of cues via the action of transcription factors. In turn, transcription factors direct epigenetic modifications to revise chromatin landscapes, and drive contacts between distal promoter-enhancer combinations. In immune cells, regulatory circuits for effector genes are especially complex and flexible, utilizing distinct sets of transcription factors and enhancers, depending on the cues each cell type receives during an infection, after sensing cellular damage, or upon encountering a tumor. Here, we review major players in the coordination of gene regulatory programs within innate and adaptive immune cells, as well as integrative omics approaches that can be leveraged to decipher their underlying circuitry.