title: Cells and Culture Systems Used to Model the Small Airway Epithelium.
abstract: The pulmonary epithelium is divided into upper, lower, and alveolar (or small) airway epithelia and acts as the mechanical and immunological barrier between the external environment and the underlying submucosa. Of these, the small airway epithelium is the principal area of gas exchange and has high immunological activity, making it a major area of cell biology, immunology, and pharmaceutical research. As animal models do not faithfully represent the human pulmonary system and ex vivo human lung samples have reliability and availability issues, cell lines, and primary cells are widely used as small airway epithelial models. In vitro, these cells are mostly cultured as monolayers (2-dimensional cultures), either media submerged or at air-liquid interface. However, these 2-dimensional cultures lack a three dimension-a scaffolding extracellular matrix, which establishes the intercellular network in the in vivo airway epithelium. Therefore, 3-dimensional cell culture is currently a major area of development, where cells are cultured in a matrix or are cultured in a manner that they develop ECM-like scaffolds between them, thus mimicking the in vivo phenotype more faithfully. This review focuses on the commonly used small airway epithelial cells, their 2-dimensional and 3-dimensional culture techniques, and their comparative phenotype when cultured under these systems.
authors.affiliation: Department of Chemical Engineering, Oklahoma State University, 420 Engineering North, Stillwater, OK, 74078, USA.
authors.forename: Rudra
authors.initials: R
authors.lastname: Bhowmick
authors.affiliation: Department of Chemical Engineering, Oklahoma State University, 420 Engineering North, Stillwater, OK, 74078, USA. Heather.Fahlenkamp@okstate.edu.
authors.forename: Heather
authors.initials: H
authors.lastname: Gappa-Fahlenkamp
mesh_terms: D001980:Bronchi / Q000166:cytology; D055745:Bronchioles / Q000166:cytology; D002460:Cell Line; D005109:Extracellular Matrix; D006801:Humans; D008954:Models, Biological; D010641:Phenotype; D061251:Primary Cell Culture / Q000379:methods*; D011506:Proteins / Q000378:metabolism; D020545:Respiratory Mucosa / Q000502:physiology*; D018874:Spheroids, Cellular; D054457:Tissue Scaffolds
chemical_list: D011506:Proteins
keywords: 2-Dimensional culture system; 3-Dimensional culture system; Small airway epithelium