Comparison of the sensitivity of three lung derived cell lines to metals from combustion derived particulate matter

While the effects of inhalation of combustion-derived particulate matter have received extensive study, there remains no reliable means to rapidly quantify inhalation toxicity outside of a laboratory setting. Cell-based biosensors provide a potential solution, but few comparisons have been made of the sensitivity of various cell lines to the wide range of inhalation health hazards that are likely to be encountered. This work compares the response of three immortalized lung cell lines (A549 human epithelia, RLE-6TN rat type II epithelia, and NR8383 rat alveolar macrophages) to metals commonly present in combustion-derived particulate matter. Quantifications of the cell response involved measurement of inhibition of cell culture metabolism (mitochondrial succinate dehydrogenase activity) and cell death (release of lactate dehydrogenase). While these three cell types generally ranked metals in ED ₅₀ values similarly (V < Zn < Cu < Ni < Fe), with one exception, the concentrations of metals leading to a 50% reduction in cell population health differed significantly. Macrophages were most sensitive to metals by nearly an order of magnitude in metal concentration, followed by RLE-6TN rat epithelia, then A549 human cells. This comparison of the sensitivity of three cell types provides a basis for selection of cell types for use in cell-based biosensors.