Single-cell and spatial transcriptomics reveal the pathogenesis of chronic granulomatous disease in a natural model

Genetic defects in NOX2 can cause chronic granulomatous disease (CGD), characterized by increased susceptibility to infections and pronounced inflammatory responses that lead to granuloma formation. We developed a CGD model using Ncf2 ^-/- mice through controlled environmental exposure. Unlike in specific pathogen-free environment, these mice spontaneously developed pulmonary granulomas under clean-grade conditions. Employing single-cell RNA sequencing, we observed an expansion of neutrophils and monocyte-derived macrophages (MDMs) within the lung tissue, identifying pro-inflammatory NOS2 ^high -neutrophils and a distinct MDMs subset marked by NOS2 and ARG1. Spatial transcriptomics demonstrated that NOS2 ^high -neutrophils were located at the core area, while the MDMs subset was positioned at the periphery, facilitating extracellular matrix remodeling. Pharmacological targeting of MIF, deletion of the pro-survival gene Morrbid , and elimination of Il1r1 all suppressed granuloma formation by mitigating inflammation. This study underscores how environmental control can establish a natural CGD model, elucidates the mechanisms of granuloma formation, and develops potent therapeutic interventions.