Prophylactic treatment with a combination of dexamethasone (2 mg/kg) and an anti-murine IL-17A monoclonal antibody (IL-17mAb) reduced chronic ozone-induced neutrophilia and total inflammatory cells, inhibited BAL protein levels of IL-8, IL-17A, and TNF-α and the mean linear intercept (Lm) as a marker of emphysema. Here, IL17A is linked to pulmonary emphysema.