IL-33-induced metabolic reprogramming controls the differentiation of alternatively activated macrophages and the resolution of inflammation (scRNA-seq)
Alternatively activated macrophages (AAMs) contribute to the resolution of inflammation and tissue repair. However, molecular pathways that govern their differentiation upon tissue damage have remained incompletely understood. Here, we show that the transcription factor GATA3 specifically controls the IL-4-independent differentiation of pro-resolving and reparative AAMs in response to injury and the necrotic cell-derived alarmin IL-33. In macrophages, IL-33 sequentially triggered an early expression of pro-inflammatory genes as well as a subsequent differentiation into AAMs.  Global analysis of involved signaling events identified an IL-33-induced GATA-3 transcriptional module that specifically orchestrated AAM differentiation. IL-4-induced AAM differentiation, in contrast, was independent of GATA-3. Conditional deletion of GATA-3 in mononuclear phagocytes accordingly abrogated IL-33-induced differentiation of AAMs in vitro and diminished macrophage-mediated tissue repair in vivo. Our data thus identify an IL-33-GATA3 signaling axis that controls plasticity of macrophages in response to injury and fosters resolution of inflammation. Overall design: Examination of macrophages in the inflammed muscle of 2 mouse strains using single cell RNA sequencing