Luo H, Urbonaviciute V, Saei AA, Lyu H, Gaetani M, Végvári Á, Li Y, Zubarev RA, Holmdahl R
JCI Insight - (-) - [2023-02-28; online 2023-02-28]
Low capacity to produce reactive oxygen species (ROS) due to mutations in neutrophil cytosolic factor 1 (NCF1/p47phox), a component of NADPH oxidase 2 (NOX2) complex, is strongly associated with systemic lupus erythematosus in both humans and mouse models. Here, we aim to identify the key immune cell type(s) and cellular mechanisms driving lupus pathogenesis under the condition of NCF1-dependent ROS deficiency. Using a set of cell-specific Cre-deleter, the human NCF1-339 variant knock-in, and transgenic mouse strains, we show that low ROS production in plasmacytoid dendritic cells (pDCs) exacerbates both pristane-induced lupus and a newly established Yaa-related spontaneous model by promoting pDC accumulation in multiple organs during lupus development, accompanied by elevated IFNα levels and expression of IFN-stimulated genes. Mechanistic studies reveal that ROS deficiency enhances pDC generation through the AKT/mTOR pathway and CCR2-mediated migration to tissues, which together with hyperactivation of the redox-sensitive STING/IFNα/JAK1/STAT1 cascade further augments type I IFN responses. More importantly, by suppressing these pathways, restoration of NOX2-derived ROS specifically in pDCs protects against lupus. These discoveries explain the causative effect of dysfunctional NCF1 in lupus and demonstrate the protective role of pDC-derived ROS in disease development driven by NCF1-dependent ROS deficiency.