Healthy Human 3D Lung Organoids Respond Differentially to Environmental Exposures

Airborne biohazards are risk factors in the development of airway inflammatory diseases including asthma. Mechanisms underlying repair and regeneration following exposures remain unclear and newer experimental models to investigate processes could lead to novel strategies. Donor-matched primary human bronchial epithelial cells and lung fibroblasts from 3 transplant-rejected healthy subjects were used to generate 3D organoids in the presence or absence of agricultural organic dust extract (ODE), lipopolysaccharide, peptidoglycan, and intracellular Toll-like receptor (TLR) agonists, Poly I:C, R837, and R848 for 14 days. Host immune response panel and key protein mediators were analyzed by NanoString and Luminex/ELISA, respectively. Unsupervised hierarchy by nSolverTM clustered males separate from female and control from ODE. Transcript levels of Th2/Th17 cytokines (IL-5,-13,-17F,-22,-24), chemokines/receptors (CCL21, CCL14, CXCR3), NOX1 and complement (C5) were increased with ODE exposure. ODE induced 57 genes in female nonsmoker (4 shared with male former smoker and 17 with male nonsmoker). Interestingly, only 14 genes were upregulated in male former smoker (3 shared with the nonsmoker male). Nonsmoker male had 96 genes that were upregulated with ODE. Genes were differentially regulated by respective TLR agonists. Protein levels of FGF13, FGF23, C5a, IL-10, IL-25, S100A8, sRAGE and IL-33 were increased, whereas FGF1 was decreased in male nonsmoker with ODE. Organoids derived from healthy lungs respond to external stimuli differently based on sex and smoking history. Inflammatory cascade with Th2/Th17 (as opposed to Th1) polarization was observed with organic dust exposures. These studies support expanding lung organoid models to understand host-environmental, epithelial-fibroblast interactions.