Tracheobronchial glands were isolated and cultured from a patient with cystic fibrosis (CF). Cultured epithelial cells were transformed with pSVori-. All transformed cell lines express cytokeratin filaments and at early passages express the junctional complex molecule cell CAM 120/80, indicating their epithelial origin. Several gland cell lines express antigens that localize to secretory cells in vivo. Cl- transport measured by 36Cl efflux shows that CF gland epithelial cells, like CF surface airway and nasal polyp epithelial cells, are unable to respond to increases in intracellular cAMP. However, they do produce an increase in intracellular cAMP after treatment with isoproterenol or forskolin. One CF gland cell line shows increased intracellular calcium in response to a number of agents and increased Cl- efflux comparable to that observed in a non-CF airway surface epithelial cell line after addition of calcium ionophore. All cell lines express CF transmembrane conductance regulator mRNA, as measured by PCR amplification of first-strand cDNA. The CF tracheobronchial gland cell lines described here are compound heterozygotes, having a single copy of the delta F508 mutation.