Novel precision-cut lung slice immune co-culture models to study macrophage and fibroblast interactions in pulmonary fibrosis 3481

Abstract Description Precision-cut lung slices (PCLS) are widely used ex vivo models for studying lung fibrosis but traditionally lack immune cell infiltration, which is critical for understanding inflammation and fibrosis. To address this limitation, we developed autologous PCLS-immune co-culture models that replicate inflammation, repair, and immune cell recruitment. Mouse PCLS were exposed to several fibrosis inducers, including nicotine, cigarette smoke extract (CSE), and a fibrosis-inducing cocktail (FCK), to evaluate fibrotic responses. Two co-culture systems were established: a direct co-culture simulating the repair phase and an indirect co-culture mimicking immune cell recruitment via blood vessels. Fibrosis-inducing stimuli upregulated α-SMA expression in fibroblasts, as confirmed by immunofluorescence and Western blotting, while Sirius Red staining demonstrated increased collagen deposition. Chemotactic assays revealed enhanced migration of bone marrow-derived macrophages (BMDMs) toward CSE-injured PCLS. Direct co-culture with autologous BMDMs significantly increased collagen deposition, underscoring the role of macrophage-fibroblast interactions in fibrosis progression. These findings validate our novel PCLS co-culture models as tools to study macrophage-driven fibrosis and provide insights into potential macrophage-targeted therapies for pulmonary fibrosis. Funding Sources This work was supported by the NIH grant R01HL146802, the UCOP TRDRP grant T32IR5347, and the DoD PRMRP grant W81XWH2110086 (#PR202411). Topic Categories Technological Innovations in Immunology (TECH)