Bulk RNA-seq analysis of Mycobacterium tuberculosis infected Sp140-sufficient and -deficient mouse lungs with and without pDC depletion
Mycobacterium tuberculosis (Mtb) causes 1.5 million deaths annually. Active tuberculosis correlates with a neutrophil-driven type I interferon (IFN) signature, but the underlying cellular mechanisms remain poorly understood. We found that interstitial macrophages (IMs) and plasmacytoid dendritic cells (pDCs) are dominant producers of type I IFN during Mtb infection in mice and non-human primates, and pDCs localize near human Mtb granulomas. Depletion of pDCs reduces Mtb burdens, implicating pDCs in tuberculosis pathogenesis. During IFN-driven disease, we observe abundant DNA-containing neutrophil extracellular traps (NETs) known to activate pDCs. Single cell RNA-seq indicates that type I IFNs act on IMs to impair their responses to IFNg, a cytokine critical for Mtb control. Cell type-specific disruption of the type I IFN receptor suggests IFNs act on IMs to inhibit Mtb control. We propose pDC-derived type I IFNs, driven by NETs, act on IMs to drive bacterial replication, further neutrophil recruitment, and active tuberculosis disease. Overall design: RNA-Seq