A novel tool for nasal polyp investigation: An Ex vivo Organ Culture System

Background: Nasal polyps are three-dimensional structures arising from the mucosa of the upper airway. Due to their complexity, the reliability of single-layer cell cultures and animal systems as research models is limited. Objectives: To evaluate the feasibility of an ex vivo organ culture of human polyps, preserving tissue structure and function. Methods: Nasal polyps were excised during routine endoscopic sinus surgery for chronic rhinosinusitis and polyposis. Fresh tissue samples were used for pathological evaluation and for the preparation of 250-500 urn sections, which were incubated in culture media. Tissue viability was assessed by visualisation of cilia motility, measurement of glucose uptake, and an infectivity assay. Cytokine secretion was evaluated by enzyme-linked immunosorbent assay and real-time polymerase chain reaction before and after the introduction of steroids. Results: Polyp tissue viability was retained for 2-3 days as demonstrated by cilia motility, glucose uptake and preserved cellular composition. Tissue samples maintained their capacity to respond to infection by herpes simplex virus 1 and adenovirus. Introduction of dexamethasone to cultured tissue samples led to suppression of interferon-g production. Conclusions: The ex vivo nasal polyp organ culture reproduces the physiological, metabolic, and cellular features of nasal polyps. Furthermore, it shows a preserved capacity for viral infection and response to drugs. This system is a useful tool for the investigation nasal-polyps and for the development of novel therapies.