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

Chronic rhinosinusitis (CRS) is a heterogeneous inflammatory disease of the paranasal sinuses, which is divided into CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP is typically caused by type 2 inflammation, which is characterized by elevated IL-4 and IL-13 levels, impairment of the epithelial barrier, and tissue remodeling. While the involvement of immune cells is well known, it remains unclear to what extent structural cells intrinsically maintain disease-specific functional programs. The aim of this study was to determine whether epithelial cells and fibroblasts derived from CRSwNP and CRSsNP differ in their barrier properties, inflammatory reactivity, and type 2-associated functional characteristics. Air–liquid interface (ALI) epithelial cultures and primary fibroblast cultures were generated from CRSwNP and CRSsNP tissue. Epithelial barrier integrity was assessed by transepithelial electrical resistance (TEER), and inflammatory responses to TLR stimulation were analyzed by qRT-PCR. Fibroblast migration was evaluated using scratch assays. Cellular responses to IL-4/IL-13 with or without Dupilumab were quantified by qRT-PCR. CRSwNP-derived epithelial cells exhibited delayed tight junction formation and impaired differentiation compared to CRSsNP cells. Poly(I:C) stimulation induced stronger expression of Th2-associated cytokines in CRSwNP cultures. CRSwNP fibroblasts showed reduced migratory capacity and a heightened induction of Th2 cytokines and extracellular matrix genes following IL-4/IL-13 stimulation relative to CRSsNP fibroblasts. Epithelial cells and fibroblasts derived from CRSwNP retain disease-associated type 2 characteristics in vitro, indicating persistent disease-aligned programmed functional alterations of the polyp microenvironment. In contrast, CRSsNP-derived cells lacked comparable enhanced type 2 responsiveness. These findings support CRSwNP as a distinct, self-sustaining inflammatory endotype and underscore the value of patient-derived models for investigating disease mechanisms and targeted therapies.