The Development of 3D Primary Co-Culture Models of the Human Airway.

Current animal and in vitro cell culture models do not fully recapitulate the physiological and pathophysiological characteristics of the human lung. As a result, the translation of these models to clinical practice is very limited, and clinical trials initiated on the extrapolation of such data fail. Although current models are beneficial in fundamental research, there is a need to constantly improve models to more accurately predict outcomes in clinical trials and personalized medicine. Here, we report important strategies to develop a 3D lung model with human primary lung cells. Starting from the well-established air-liquid interface (ALI) culture system, we describe a gradual increase in the complexity of the system by co-culturing different primary cell types, by testing different coatings, and by adding a three-dimensional matrix. As a result, we have established a reproducible 3D in vitro model of the airway consisting of human primary cells representing a differentiated mucociliary airway epithelium, an underlying submucosa with fibroblasts, and an endothelial interface.