Precision cut lung slices for testing of gaseous compounds

Determination of immunotoxicological effects induced by exposure to inhalable chemicals displays a critical point in vitro. Insolubility of respirable chemicals and difficulties to design adequate cell culture test systems play a decisive role. Precision cut lung slices (PCLS), including all cell types of the respiratory tract, represent an ex vivo method which might be exposed to gaseous or particulate mixtures and can be analysed. Mouse PCLS were prepared and exposed to a range of different flow rates of clean air. LPS treated PCLS were used as a positive control. Analysis of viability was performed by measuring WST-1 and live/dead staining for confocal microscopy. Extrinsic and intrinsic cytokine profiles were analysed by ELISA. Exposure of PCLS to volume flows from 3 to 30 ml/min resulted in no loss of viability. WST-1 showed no decrease in enzyme activity. Vitality staining revealed no (serious) changes of cell structure in dependency of increasing stress. Treatment with clean air resulted in no up regulation of cytokines IL-1? and MIP-1?. In contrast positive control LPS induced 2.5 to 15 fold up regulation between for both cytokines. These experiments showed that PCLS can be exposed to gaseous test atmospheres like clean air without significant loss of vitality. This offers the opportunity to perform ex vivo immunotoxicological analysis of airborne substances using a complex biological test system in an air/lifted situation. Next steps will be to use this method for investigation of toxic gaseous compounds to characterize sensitivity and reproducibility of the test system.