SPP1 and inflammatory response: <i>In vitro</i>, osteopontin stimulation of neutrophils upregulated <i>NDUFA1</i>, a mitochondrial complex I gene.<h4>Conclusions</h4>The present findings indicate that ozone exposure induces osteopontin production primarily from monocyte-derived DCs, which promotes neutrophilic airway inflammation through DC-neutrophil interactions, while having a limited impact on airway hyperresponsiveness.