A Commercially Durable Biobank of Genetically Diverse and Differentiation Competent Primary Airway Progenitor Cells Validated for In Vitro Toxicology Screening

Project Abstract While primary human airway epithelial cells (hAECs) have seen increasing use as models for in vitro toxicology screening, there remain severe drawbacks to their broad deployment. The limitations involve: (1) the very limited expansion potential of primary hAECs in culture results in small manufacturing lot sizes and high product costs; (2) the inability of propagated AECs to form fully differentiated, pseudostratified 3D tissue after only 4 to 5 passages in culture, thereby further exacerbating supply and cost issues; and (3) the issues of data variances due to lack of a systematic approach to donor variability and their genetic diversity. Taken together, these drawbacks result in small lot sizes of expanded cells from each donor and very expensive 3D tissue models, making it very challenging to provide or perform cost-effective, standardized in vitro toxicant screening. Propagenix has published on the ability of our EpiX™ cell culture technology to significantly enable the bioproduction of primary human airway epithelial cells possessing genomic stability and differentiative functionality over extended culture propagation. This program seeks to utilize this capability to build a human airway epithelial cell biobank that is intentional about incorporating genetic diversity and is accompanied by a preliminary dataset demonstrating parameters of toxicant response. Of particular importance will be information on toxicant response within specific subsets of airway epithelial cells and the future use of this information to create reporter cell models to decrease commercial barriers for in vitro toxicant screening.Project Narrative on Relevance to Public Health Inhaled toxicants remain a serious health issue in the US and globally (1). Exposure to xenobiotics through the pulmonary system can occur just about everywhere: at home, in the workplace, and the outside environment (2). The ubiquitous nature of airborne toxicants is why it is essential to identify these agents early and to understand what risk they may pose to lung function (3). Thus, having human airway tissue models that accurately mimic toxicant response of the human pulmonary system, that provides reproducible data, and that can represent the inter-individual diversity of the human population for toxicant exposure should significantly help in the fight against pulmonary disease due to toxic agents (4,5). Using the combined technologies and capabilities of the collaborative team described in this proposal, we aim to build a commercially attractive system for the in vitro testing of airborne toxicants, including a dataset to support the validation of this system. This system will offer a cost-effective approach to screening xenobiotics for deleterious effects on the airway epithelium and be adaptable to create multi-tissue organotypic models of airway biology.