RECONSTRUCTED, DIFFERENTIATED AIRWAY EPITHELIAL CULTURES TO DETECT OCCUPATIONAL ASTHMA CAUSING AGENTS.

Normal human tracheal-bronchial epithelial cells (NHBE) have been cultured using serum free medium to form a three dimensional tissue-like structure 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 dot blot analysis was used to quantify mucin secretion. These cultures were exposed to a saturated atmosphere of some common respiratory asthma inducing agents including toluene diisocyanate (TDI), phthalic anhydride, and formaldehyde. The culture medium beneath the cultures was analyzed for cytokine release using enzyme linked immunosorbent assay (ELISA) kits. Compared with air-exposed controls, the level of prostaglandin E-2 and 15-hydroxy eicosatetraenoic acid (15-HETE) increased by 2-fold or greater after a 45 minute exposure; interleukin (IL)-8 increased by 2-fold following a 4 hour exposure to TDI. No increases above basal levels of IL-6 or tumor necrosis factor (TNF-a) were observed following exposure to any of the materials tested. These data indicate that the newly developed NHBE culture model may be a useful in vitro means to detect chemicals that are likely to cause non-immunological occupational asthma.

15-HETE, 15-Hydroxy eicosatetraenoic acid (15-HETE), Airway epithelial cultures, Asthma, Cilia, EpiAirway, IL-6, IL-8, Interleukin (IL), Occupational asthma, PGE-2, Prostaglandin E-2, Respiratory asthma, Respiratory tract, TNF-a, Tracheal bronchial epithelial (TBE), Tumor necrosis factor alpha