A distal enhancer is required for TNF gene transcription in human macrophages in response to TLR3 stimulation

Macrophages play a critical role in inflammatory responses during infections. Activated macrophages by infections through stimulation of TLRs expressed their cell surface produce pro-inflammatory cytokines, including TNF. However, distal enhancers that regulate TNF gene transcription in human macrophages have not been investigated. In this study, we identified the five putative TNF enhancers using H3K27ac ChIP-seq and ATAC-seq. We showed proximal enhancer (PE), E-16.0, and E-6.5 possessed enhancer activity in a reporter gene assay. Deletion of the distal TNF E-16.0 enhancer resulted in 73% reduction in TNF gene transcription in human macrophage cell line THP-1 in response to ploy(I:C) stimulation. Our study identifies a novel distal enhancer that regulates TNF gene transcription in human macrophages.