Development of an in vitro human nasal epithelial (HNE) cell model.

The upper respiratory tract is mainly involved in reactions to airborne substances. So the primary culture of human nasal tissue may provide an application model for assessment of toxic or inflammatory processes caused by environmental pollutants. HNE cells were isolated from nasal tissue biopsies by protease digestion and cultured in serum-free hormone-supplemented medium. When grown on porous membranes at the air-liquid interface, a higher portion of ciliated cells developed within 2 weeks compared with cells maintained submerged. Submerged grown cultures on collagen gel matrix maintained a cuboidal epithelial-like morphology and stained positive for cytokeratin. The primary cultures of nasal cells exhibited a marked activity for acid phosphatase. Second passage HNE cells exhibited marked enzymatic reactivity upon treatment with particulate matter. Induction of the lysosomal marker enzyme acid phosphatase was stronger in cells treated with toluene-extracted diesel exhaust particles compared with cells treated with native diesel exhaust particles. Non-specific esterase activity was increased more than 7-fold by native diesel particles, whereas the induction of esterase activity by extracted particles was relatively low compared with the control group.