RECONSTRUCTED, DIFFERENTIATED AIRWAY EPITHELIAL CULTURES TO MODEL RESPIRATORY INFECTION.

Normal human tracheal-bronchial epithelial cells (NHBE) have been cultured using serum free medium to form a three dimensional tissue-like structure, EpiAirway, that closely resembles the epithelial tissue of the respiratory tract. Histological cross-sections of both the in vitro tissue and a normal human bronchiole reveal a four layer, bipartite structure. Transmission electron microscopy revealed numerous cilia on the apical surface of the cultures and verified the presence of tight junctions between cells; dot blot analysis was used to quantify mucin secretion from the cultures. Scientists at MedImmune Inc. and MatTek Corp. utilized the EpiAirway in vivo-like tissue model system to study Streptococcus pneumoniae adherence to NHBE cultures. Pneumococci adhered to these stratified NHBE cells in a dose-dependent and saturable manner. In addition, the level of pneumococcal adherence was lower on NHBE cultures secreting mucin on the cell surface. Full pneumococcal adherence was restored when mucin was washed from the surface of mucin-secreting cells, suggesting that mucin inhibits attachment to the bronchial epithelium. These results indicate that the EpiAirway differentiated airway epithelial culture system may be used to study the interaction of pneumococci with human bronchial epithelium, and that these cultures could aid in the development of novel intervention strategies to combat pneumococcal infections in vivo.

Airway epithelial cultures, Barrier properties, Bronchial epithelium, Cytotoxicity, Electron microscopy, transmission (TEM), EpiAirway, Mucin, NHBE, Pneumococcal adherence, Pneumococcal infections, Respiratory infections, Streptococcus pneumoniae adherence, Surfactants, TEM, Tracheal-bronchial epithelial cells, normal human (NHBE)