Updated publication reference for PubMed record(s): 32690608. Inhalation of the amibient air polution ozone causes lung inflammation and can suppress host defense mechanisms, including impairing macrophage phagocytosis. Ozone reacts with cholesterol in the lung to form oxysterols, like secosterol A and secosterol B, which can form covalent adducts on cellular proteins. How oxysterol-protein adduction modifies the function of lung macrophages is unknown. Herein, we used a preoteomic screen to identify lung macrophage proteins that fomr adducts with ozone-derived oxysterols. Analysis show that the phagocytic receptor CD206 and CD64 formed adducts with secosterol A. Adduction of these receptors with ozone-derived oxysterols impaired ligand binding and corresponded with reduced macrophage phagocytosis. This work suggests a novle mechanism for the suppression of macrophage phagocytosis following ozone exposure through the generation of oxysterols and the formation of oxysterol-protein adducts on phagocytic receptors.