Assessment of a panel of interleukin-8 reporter lung epithelial cell lines to monitor the pro-inflammatory response following zinc oxide nanoparticle exposure under different cell culture conditions

Background: stably transfected lung epithelial reporter cell lines pose an advantageous alternative to replace complex experimental techniques to monitor the pro-inflammatory response following nanoparticle (np) exposure. previously,reporter cell lines have been used under submerged culture conditions,however,their potential usefulness in combination with air-liquid interface (ali) exposures is currently unknown. therefore,the aim of the present study was to compare a panel of interleukin-8 promoter (pil8)-reporter cell lines (i.e. green or red fluorescent protein (gfp,rfp),and luciferase (luc)),originating from a549 lung epithelial type ii-like cells cells,following nps exposure under both submerged and ali conditions. methods: all cell lines were exposed to zinc oxide (zno) nps at 0.6 and 6.2 μg/cm2 for 3 and 16 hours under both submerged and ali conditions. following physicochemical characterization,the cytotoxic profile of the zno-nps was determined for each exposure scenario. expression of il-8 from all cell types was analyzed at the promoter level and compared to the mrna (qrt-pcr) and protein level (elisa). results: in summary,each reporter cell line detected acute pro-inflammatory effects following zno exposure under each condition tested. the pil8-luc cell line was the most sensitive in terms of reporter signal strength and onset velocity following tnf-aα treatment. both pil8-gfp and pil8-rfp also showed a marked signal induction in response to tnf-aα,although only after 16 hrs. in terms of zno-np-induced cytotoxicity pil8-rfp cells were the most affected,whilst the pil8-luc were found the least responsive. conclusions: in conclusion,the use of fluorescence-based reporter cell lines can provide a useful tool in screening the pro-inflammatory response following np exposure in both submerged and ali cell cultures. © 2015 stoehr et al.