A high-throughput screening method based on stably transformed human cells was used to determine the immunotoxic effects of fluoranthene and other PAHs.

Exogenous substances may compromise the human immune system, but immunotoxic effects of many pollutants have not been sufficiently determined thus far. It is often unknown which parameters should be taken into consideration when the immunotoxicity of a pollutant is analysed. Moreover, certain substances might only affect a primed immune system, but have no effect on healthy individuals. In order to analyse immunological responses caused by exposure to pollutants, a screening method has been established in our laboratory that uses a panel of stably transfected human cell lines containing promoter regions for different cytokines and chemokines. The luciferase sequence present at the 3' end of the promoter allows for the analysis of enzymatic luciferase activity. Four polycyclic aromatic hydrocarbons were used to evaluate this screening assay. Moreover, we compared promoter induction with cytokine production and tested the effect of fluoranthene on primary lung epithelial cells. The results showed that the regulation of different promoter genes is pollutant specific and differs between individual PAHs, and that the regulation is affected by the presence of a pro-inflammatory stimulator. The use of a panel of human cell lines stably transfected with different cytokine promoters is an easy-to-use tool for screening in immunotoxicological studies and might decrease the number of animal tests for such studies.