Human autoinflammatory disease reveals ELF4 as a transcriptional regulator of inflammation

Transcription factors specialized to limit the destructive potential of inflammatory immune cells remain ill-defined. We discovered loss-of-function variants in the X-linked ETS transcription factor gene ELF4 in multiple unrelated male patients with early-onset mucosal autoinflammation and inflammatory bowel disease (IBD) characteristics including fevers and ulcers that responded to IL-1, TNF, or IL-12p40 blockade. Using cells from patients and two newly generated mouse models, we uncovered hyperinflammatory responses of ELF4-mutant macrophages to a range of innate stimuli. Mechanistically, Elf4 in macrophages both sustained expression of anti-inflammatory genes such as Il1rn and limited upregulation of inflammation amplifiers, including S100A8, Lcn2, Trem1, and neutrophil chemoattractants. Indeed, therapeutic Trem1 blockade reversed inflammation and intestine pathology in Elf4-mutant mice challenged with lipopolysaccharide in vivo. Thus, the ELF4 transcription factor restrains inflammation and protects against mucosal disease, a discovery with broad translational relevance for human inflammatory diseases such as IBD. Examination of transcriptional and chromatin organization differences between WT and Elf4-/- mice. 49 samples total, experiments were performed with minimum 3 samples per genotype.