Effects of CeO2 on DEP induced pro- and anti-inflammatory cytokine production by AM with or without ex vivo LPS challenge. AMs were isolated at 1 day after exposure by bron-choalveolar lavage. The productions of IL-12, IL-6 and IL-10 by AM obtained are presented in panels A, B and C, respectively. Panel D shows the production of the fibrotic cytokine, TGF-β1, by AM, isolated at 3 and 10 days post-exposure. *Significantly different from AM control; p < 0.05. +CeO2 is significantly different from DEP; p < 0.05. #CeO2 is significantly different from DEP + CeO2, p < 0.05.