CILIOGENESIS AND MUCUS SYNTHESIS IN CULTURED HUMAN RESPIRATORY EPITHELIAL-CELLS

The mechanisms for the regulation of ciliogenesis and for the synthesis of mucus are not well understood. We sought to develop a culture system for differentiating ciliated and secretory types of human respiratory epithelial (HRE) cells. Dissociated HRE cells obtained from nasal polyps and maxillary sinus mucosa were cultured on type I collagen gel. Cells grown to confluence on collagen gel lost their cilia and exhibited a flat, squamouslike appearance. After reaching confluence, the cultured cells with a collagen gel substrate were removed from plastic dishes and floated in the culture medium After 7 days in the floating culture, some cells exhibited several centrioles or basal bodies, while others showed secretory granules. The secretory phenotype predominated after 7 days. After 14 days in the floating culture, nearly all cells were ciliated. The results demonstrate that the differentiation of HRE cells can be induced by floating cultured cells with a collagen gel substrate in a defined culture medium.