ORGANOTYPIC IN VITRO HUMAN EPITHELIAL MODELS WITH ENGINEERED TOXICOLOGIC REPORTER FUNCTIONS.

3D organotypic in vitro human epithelial models including skin (e.g. EpiDerm, EpiDerm-FT) and airway (e.g. EpiAirway, EpiAirway-FT) are important advances over traditional monolayer cell culture models. For toxicology applications, these models provide more realistic, in vivo-like structure, barrier properties, metabolic functions and dosing capabilities. In the current poster we describe development of organotypic human epithelial models with the added feature of engineered toxicologic reporter functions. Early passage normal human epidermal keratinocytes, dermal fibroblasts, tracheobronchial epithelial cells and airway fibroblasts were tranduced with lentiviral vectors containing NFκB reporters linked to either GFP or luciferase, and puromycin resistance elements. Stably transduced cells were selected by puromycin resistance, expanded several passages and cyropreserved to produce large pools of reporter-expressing cells. Reporter-expressing cells were then utilized to produce organotypic skin and airway epithelial models. Organotypic structure and barrier properties of models produced from reporter-expressing cells were found to be similar to models produced from untransduced cells, as determined by histological assessment of H&E stained paraffin sections, and barrier assessment by transepithelial electrical resistance and/or resistance to TX-100 penetration. NFκB reporters linked to either GFP or luciferace were found to be activated at least 5-fold above background by treatment of the organotypic models with TNFα. GFP was detected in formalin fixed paraffin sections by epifluorescence microscopy. Luciferase activity in tissue extracts was quantified with a microplate luminometer. Production of models containing other reporters of toxicological significance (e.g. for DNA damage, oxidative stress, heavy metal stress, ER stress, etc.) by the same process will provide a suite of human epithelial reporter models that can be utilized to provide mechanistic toxicity screening assays.

AIR-100, EFT-400, Green fluorescent protein (GFP), Histology, Luciferase, Luciferase activity, NFκB reporters, Stably induced

TNFα