Single Cell RNA-Seq Analysis Reveals Fate Decision of Human Pre-cDC Determined by Transcription Factor Competition

Classic dendritic cells (cDCs) play a central role in the immune system and consist of two major subsets: CD141+ cDC (cDC1) and CD1c+ cDC (cDC2). The pre-cDCs is the immediate precursors to both cDC subsets. Previous studies showed that there were two pre-committed pre-cDC subpopulations. However, the key molecular drivers of pre-commitment in human pre-cDCs were not investigated. To address this question, we performed both single cell and bulk RNA sequencing (RNA-seq) of two cDC subsets and pre-cDCs. We inferred a list of sixteen candidate master regulator transcriptional factors (TFs) that can indeed separate pre-cDCs into two sub-populations, with one close to cDC1 and the other close to cDC2. More importantly, these two pre-cDC sub-populations are correlated with ratio of IRF8 to IRF4 expression level more than their individual expression level. Our results suggest the concept that the ratio of antagonistic TFs and their competition determine cDC subset differentiation fate.