Microplastic Exposure in COPD Alters the Immune Microenvironment: Implications for Tumor-Promoting Inflammation

COPD is a major risk factor for lung cancer, with chronic inflammation, immune dysregulation, and tissue remodeling contributing to tumor initiation. Microplastics (MPs), as environmental pollutants, may exacerbate these processes, but their impact on tumor-promoting microenvironments in COPD remains unclear. scRNA-seq was performed on lung tissues from Normal, COPD, Normal+MPs, and COPD+MPs groups to analyze cellular dynamics and pathway activity. Functional experiments included flow cytometry, cytokine profiling, vascular permeability assays, and organoid-based epithelial repair studies. MP exposure exacerbated COPD-associated inflammation and tissue remodeling, creating a tumor-permissive microenvironment. scRNA-seq revealed increased alveolar and interstitial macrophages, alongside elevated CD4+ T cell recruitment and CD8+ T cell exhaustion. Flow cytometry confirmed significant increases in BALF, suggesting immune suppression and chronic inflammation. AT2 cell populations critical for lung repair were significantly reduced in COPD+MPs. Organoid experiments demonstrated impaired epithelial regeneration under MP exposure, with reduced organoid size and differentiation efficiency . Microplastic exposure intensifies chronic inflammation, immune dysregulation, and tissue remodeling in COPD, fostering a tumor-promoting environment. erj;66/suppl_69/PA1590/F1F1F1