CRSwNP-derived cells retain native disease-relevant characteristics in vitro

Objective and design : Chronic rhinosinusitis (CRS) is a persistent inflammation of the paranasal sinuses, classified into CRSwNP and CRSsNP. CRSwNP is characterized by a type 2–driven immune response with elevated IL-4 and IL-13, epithelial barrier dysfunction and extracellular matrix deposition. Epithelium and fibroblasts contribute to the Th2 milieu. The aim of this study was to identify differences in immune response-contributing traits between CRSwNP and CRSsNP-derived cells. Methods : ALI cultures of epithelial as well as fibroblast cultures were established from CRSwNP and CRSsNP tissue. Epithelial barrier was assessed in ALI cultures via TEER and inflammatory responsiveness upon TLR stimulation by qRT-PCR. Fibroblast migration and responses to IL-4/IL-13 ± Dupilumab were evaluated through wound healing assays and qRT-PCR. Results : CRSwNP epithelial cultures displayed delayed tight-junction formation. Poly(I:C) induced stronger Th2-related cytokine expression in CRSwNP. CRSwNP fibroblasts showed reduced migration and enhanced induction of Th2 cytokines and extracellular matrix genes upon IL-4/IL-13 stimulation. Conclusion : CRSwNP-derived epithelial cells and fibroblasts retain disease-associated, Th2 properties in vitro, suggesting a stable pathogenic imprint of the polyp microenvironment. CRSsNP-derived cells lack this possible priming or in pathogenic traits, . These findings support CRSwNP as a distinct, self-sustaining disease and highlight the value of patient-derived models for studying CRS mechanisms and targeted therapies.