Epigenetic program and transcription factor circuitry of dendritic cell development

Area of Science:

• Immunology
• Cell Biology
• Epigenetics

Background:

• Dendritic cells (DCs) are crucial antigen-presenting cells originating from hematopoietic stem cells.
• DC development involves distinct progenitor stages: Multipotent Progenitors (MPP) commit to Common DC Progenitors (CDP), differentiating into classical DCs (cDC) and plasmacytoid DCs (pDC).

Purpose of the Study:

• To elucidate the epigenetic states and regulatory transcription factor networks governing DC differentiation.
• To map genome-wide gene expression, histone modifications, and transcription factor occupancy during MPP-CDP-cDC/pDC development.

Main Methods:

• Analysis of genome-wide gene expression and histone modifications across DC progenitor stages.
• Mapping transcription factor occupancy, particularly PU.1, and integrating it with gene expression data.

Main Results:

• Common DC Progenitors (CDP) exhibit a DC-primed epigenetic signature that strengthens during differentiation.
• Coincidence of epigenetic marks and PU.1 occupancy increases with DC differentiation.
• A transcription factor regulatory circuitry, including key factors like Irf4, Irf8, Tcf4, Spib, and Stat, was defined for DC commitment and subset specification.

Conclusions:

• The study describes the fundamental transcription factor regulatory circuitry orchestrating DC development.
• This circuitry involves hierarchical factors and feedback loops that stabilize distinct DC developmental stages and subsets.