Monocyte-derived macrophages aggravate pulmonary vasculitis via cGAS/STING/IFN-mediated nucleic acid sensing
Autoimmune vasculitis is a group of life-threatening diseases, whose underlying pathogenic mechanisms are incompletely understood, hampering development of targeted therapies. Here, we demonstrate that patients suffering from anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) showed increased activity of the DNA sensor cGAS and enhanced IFN-I signature. To identify potential therapeutic targets, we developed a mouse model for pulmonary AAV that mimics severe disease in patients. Immunogenic DNA accumulated during disease onset, triggering cGAS/STING/IRF3-dependent IFN-I release that promoted endothelial damage, pulmonary hemorrhages, and lung dysfunction. Macrophage subsets played dichotomic roles in disease. While recruited monocyte-derived macrophages were major disease drivers by producing most IFN-{beta}, resident alveolar macrophages contributed to tissue homeostasis by clearing red blood cells and limiting infiltration of IFN-{beta}-producing macrophages. Moreover, pharmacological inhibition of STING, IFNAR-I or its downstream JAK/STAT signaling reduced disease severity and accelerated recovery. Our study unveils the importance of STING/IFN-I axis in promoting pulmonary AAV progression and identifies cellular and molecular targets to ameliorate disease outcome. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/493983v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@521964org.highwire.dtl.DTLVardef@13506org.highwire.dtl.DTLVardef@1403dbeorg.highwire.dtl.DTLVardef@958cc4_HPS_FORMAT_FIGEXP M_FIG C_FIG SummaryKessler et al. identify aberrant DNA recognition by cGAS/STING axis and IFN-I production by inflammatory macrophages as a major driver of severe ANCA-associated vasculitis (AAV). Pharmacological interventions blocking this pathway ameliorate disease and accelerate recovery, identifying potential targets for therapeutic intervention in patients.