A microRNA expression atlas of mouse dendritic cell development.

Dendritic cells (DCs) are sentinel cells of the immune system and are essential for inducing a proper immune response. The mechanisms driving the development of DCs are not fully understood. Although the roles of cytokines and transcription factors have been a major focus, there is now substantial interest in the role of microRNAs (miRNAs). miRNAs are small RNAs that regulate gene expression by targeting messenger RNAs for translational repression and ultimately degradation. By means of deep sequencing, we have assembled a comprehensive and quantitative resource of miRNA expression during DC development. We show that mature DCs and their hematopoietic progenitors can be distinguished based on miRNA expression profiles. On the other hand, we show that functionally distinct conventional and plasmacytoid DC subsets are indistinguishable based on miRNA profile. In addition, we identify differences between ex vivo purified conventional DCs and their in vitro Flt3L-generated counterparts. This miRNA expression atlas will provide a valuable resource for the study of miRNAs in DC development and function.