Airway and alveolar epithelial cells in culture

Airway and alveolar epithelial cells are daily exposed to large amounts of inhaled air that contains pollutants and pathogens. Local epithelial defence systems are in place to prevent injury, but epithelial cells also play a central role in various lung diseases. The function of these cells in health and disease can be studied in human lung tissue, in animal models and using cell culture. Cell culture offers the important advantage that isolated cells can be exposed under controlled conditions to disease-relevant stimuli, and can be manipulated using a variety of techniques. In this article, we introduce the principles of culturing airway and alveolar epithelial cells, as well as recent new and future developments. Advantages and disadvantages of using cell lines and primary cells isolated from tissue are discussed. In addition, culture of epithelial cells at the physiologically relevant air-liquid interface is described, as well as new culture systems such as lung organoids and the microfluidics lung-on-chip. Finally, genetic editing of cultured cells is discussed. By providing an introduction into epithelial cell culture, we aim to provide a better insight into how these cultures can be used to study the role of epithelial cells in health, disease pathogenesis, drug discovery and evaluation, inhalation toxicology, as well as regenerative medicine.