Rhinovirus-infected nasal polyp epithelial cells: effect on the activation and migration of eosinophils by airborne fungi

Abstract

Rhinovirus and fungi are common environmental factors able to induce airway inflammation. They are associated with the production of chemical mediators by direct activation of epithelial cells. To evaluate the effect of fungal stimulation of rhinovirus-infected nasal polyp epithelial cells (NPECs) on the activation and migration of eosinophils. Rhinovirus-infected NPECs were stimulated with Alternaria and Aspergillus for 48 hours. Then, epithelial cells were co-cultured with freshly isolated eosinophils. An eosinophil migration study was performed with epithelial cell-conditioned media. Interleukin 6, interleukin 8, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor levels were measured to determine the activation of cells. Airborne fungi enhanced the production of cytokines from rhinovirus 16-infected NPECs compared with fungi stimulation or rhinovirus 16 infection alone. Rhinovirus 16-infected NPECs were co-cultured with eosinophils, and cytokine production was not significantly increased except tumor necrosis factor-alpha production by Aspergillus. Epithelial cell-conditioned media, which were stimulated with fungi, enhanced the migration of eosinophils. There was some synergism between rhinovirus 16 infection and airborne fungal exposure, enhancing the inflammatory response of airway epithelial cells.