RESUMO
PURPOSE: Data on the effects of direct particulate matter (PM) exposure on the eyes and the nose are limited. Here, an interleukin (IL)-17/neutrophil-dominant ovalbumin (OVA)/polyinosinic-polycytidylic acid (Poly(I:C)) mouse model was used to evaluate the effect of different-sized titanium dioxide (TiO2) particles on the eyes and the nose. We also examined whether IL-17-neutralizing antibody (IL-17Ab) treatment could reverse TiO2 effects. METHODS: The nasal cavities and conjunctival sacs of each mouse were challenged with OVA and Poly(I:C) to induce neutrophil-dominant inflammation and then exposed to micro- and nano-TiO2. Subsequently, IL-17Ab was administered to investigate the role of IL-17 and inflammatory parameters. RESULTS: Micro- and nano-TiO2 resulted in significant decreases in tear-break-up time and increases in corneal damage. Airborne micro-TiO2 also increased nasal rubbing and sneezing counts compared with the OVA/Poly(I:C). Micro-TiO2 exposure increased infiltration of neutrophils and IL-17A+ cells in the conjunctival tissues and the nasal mucosae. In addition, these increased symptoms and inflammation in the eyes and the nose by micro-TiO2 exposure were inhibited by the IL-17Ab, suggesting IL-17 dependency. CONCLUSIONS: TiO2 aggravated IL-17-induced eye and nose inflammation and the IL-17Ab alleviated inflammation in the OVA/Poly(I:C) mouse model. These results may help develop a therapeutic modality for PM exposure and provide evidence for PM-associated diseases.
