Jean Pierre, M. | bioRxiv Science

bioRxiv2025

Spatial organization of pulmonary type 2 inflammation by a macrophage-derived cholesterol metabolite

Effective pulmonary immunity requires the precise spatial organization of immune cells, yet the mechanisms guiding their intratissue positioning during inflammation remain unclear. Here, we identify a cholesterol-derived chemotactic axis that spatially organizes T helper 2 (TH2) cells during fungal-induced pulmonary type 2 inflammation. Inflammation-expanded macrophages expressing cholesterol-25-hydroxylase (CH25H) produce 25-hydroxycholesterol, which is converted into the oxysterol 7,25-dihydroxycholesterol to attract GPR183-expressing TH2 cells into infectious lesions. This TH2 positioning suppresses interferon-{gamma} responsiveness in inflammatory Ly6C macrophages, promoting fungal persistence. Disruption of this axis via TH2-specific GPR183 deletion restores type 1 macrophage activation and enhances fungal clearance. Our findings reveal a macrophage-driven, metabolite-based mechanism of immunosuppressive cell positioning in inflamed lung tissue.

immunology↗

bioRxiv2025

Alternatively activated monocyte-derived myeloid cells promote extracellular pathogen persistence within pulmonary fungal granulomas.

Inhaled fungal pathogens often generate granuloma-contained latent infections that can reactivate to cause invasive disease. However, the mechanisms underlying the inability to generate sterilizing immunity against latent infection remains poorly understood. Here, we leveraged spatial transcriptomics and flow cytometry to characterize the immune dynamics and cellular architecture of cryptococcal granulomas. Using fate mapping and murine genetic tools, we demonstrate that alternative activation of monocyte-derived myeloid cells by CD4+ T helper 2 cells antagonizes pulmonary fungal clearance during latent infection. In contrast to the prevailing view in the field, we find that alternatively activated myeloid cells are not an intrinsic replication niche for the fungus and more broadly, Cryptococcus predominantly resides in the extracellular environment. We propose a T helper 2 cell-myeloid circuit establishes a local immunosuppressive environment to drive extracellular fungal persistence, which could be leveraged as a new target for host-directed therapy to treat latent fungal infections.

immunology↗