Human In Vitro Models for Respiratory Toxicology: Evaluation of Goblet Cell Hyperplasia, Mucus Production, and Ciliary Beating Assays
Presented at SOT 2018
* This author is not affiliated with PMI.
Robust non-animal models and assays for pulmonary toxicology are required to make competent product development and risk assessments for new materials requiring toxicity testing. Three in vitro assays (goblet cell hyperplasia [GCH], ciliary beat frequency [CBF], and MUC5AC quantitation) were evaluated for performance and reproducibility. To assess these assays, 6 laboratories contributed data using a common protocol utilizing IL-13 as an inducer of adverse mucociliary-relevant tissue changes. MatTek EpiAirway™ and Epithelix MucilAir™ 3D tissue models were used to evaluate endpoints using histology for GCH, software-based applications, Cilia FA and SAVA, for CBF, and ELISA assay for MUC5AC. Continuous 10 ng/mL IL-13 (GCH, MUC5AC) exposures or one hour 10 μM procaterol (CBF) exposures prior to day 7 and 14 time-points were included as positive controls. Quality control endpoints (e.g. adenylate kinase tissue content and trans-epithelial electrical resistance) were also evaluated. Multi-fold increases (ranging from 2.6 to 33-fold, and 1.5 to 238-fold) in MUC5AC-stained goblet cells were measured in both tissue models after exposure with IL-13 after 7 and 14 days induction, respectively. For CBF, procaterol caused a significant increase, and IL-13 elicited a significant decrease as expected. However, the MUC5AC ELISA did not yield consistent results when frozen apical rinse samples were thawed and assayed. These results suggest these non-animal test systems may provide consistent, human-relevant data corresponding to key events involved in respiratory disease. A streamlined protocol using these controls will be applied toward additional testing. These assays, utilized in a pragmatic manner with other in vitro assays have the potential to be included in a Reduced Risk Product assessment framework.