The transcription factor EHF promotes the maturation and immunosuppression of conventional dendritic cells.

The transcriptional program that regulates immunosuppression in CCR7 conventional dendritic cells (cDCs) is currently unknown. Here, we identify ETS homologous factor (EHF) as a transcription factor that regulates cDC maturation and immunosuppression after TLR7/8/9 stimulation. Mice with conditional deletion of EHF in DCs exhibit increased resistance to autoimmune, infection or tumor challenge. EHF-deficient DCs promotes Th1- and Th17-biased CD4 helper T cell response in vivo and in vitro. EHF-deficient cDC1s and cDC2s exhibit decreased expression of CCR7, CD200 and PD-L1, increased expression of DC-lineage transcriptional factor IRF4, and decreased expression of inhibitory NFκB family member Rel. EHF overexpression in DCs results in the opposite phenotype. CUT&TAG analysis suggests that EHF directly regulate Ccr7, Cd200, Cd274, Irf4 and Rel expression. Additionally, single-cell RNA-sequencing demonstrates that Ehf expression is highly enriched in CCR7 DCs in mice and humans. Our study thus reveals a conserved transcriptional program that regulates cDC maturation and immunosuppression.