Epigenetic repression of IL-1β by C1QBP restricts Dectin-1-mediated host defense against invasive candidiasis

Dendritic cell-derived interleukin-1β, orchestrated via Dectin-1-mediated β-glucan recognition, is central to antifungal defense. While the Dectin-1/Syk/CARD9 axis governing Il1b transcription is defined, the epigenetic regulatory mechanisms remain elusive.

Here we identify Complement C1q binding protein (C1QBP) as a critical negative regulator of Dectin-1-mediated interleukin-1β production. C1QBP sequesters phosphorylated protein kinase C δ in the cytoplasm, preventing its nuclear transport. Nuclear phosphorylated-PKCδ activates the RNF20/RNF40 ubiquitin ligase complex, which recruits the methyltransferase DOT1L to catalyze histone H3 lysine 79 trimethylation at the Il1b locus to promote its transcription.