The transcriptional repressor Polycomb group factor 6 (PCGF6) negatively regulates dendritic cell activation and promotes quiescence

We identified that DC activation and immunogenicity are regulated by the transcriptional repressor polycomb group factor 6 (PCGF6). Pcgf6 is rapidly downregulated upon stimulation and this downregulation is necessary to permit full DC activation. Silencing PCGF6 expression enhanced both spontaneous and stimulated DC activation. We show that PCGF6 associates with the H3K4me3 demethylase JARID1c, and together they negatively regulate H3K4me3 levels in DCs. Our results identify two key regulators – PCGF6 and JARID1c – that temper DC activation, and implicate active transcriptional silencing via histone demethylation as a previously unappreciated mechanism for regulating DC activation and quiescence Overall design: ATAC-seq analysis of BMDCs transduced with either control vectors, cDNA to over-express, or hpRNA to knockdown Pcgf6.Â