A human respiratory-tissue organ culture incorporating an air interface

The immersion of respiratory tissue in organ cultures is unphysiologic and may influence the interactions of the tissue with experimental agents. We have assessed an organ culture of human nasal turbinate tissue with an air interface by light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), with and without replacement of culture medium. Without replacement of medium, ciliary beat frequency (CBF) was normal (11.3 +/- 0.5 Hz) at 5 d, but fell significantly (p<0.05) to 7.9 +/- 0.8 Hz at 10 d. The degree of ciliation decreased significantly (p<0.05) at 4 and 10 d. Nuclear heterochromatin in all cell types was significantly (p<0.05) reduced at 5 d. Significant (p<0.05) mitochondrial abnormalities occurred in ciliated cells at 5 d and in both ciliated and unciliated cells at 10 d. With daily replacement of medium, CBF fell significantly (p<0.05) from 11.6 +/- 0.2 Hz at Time 0 to 10.6 +/- 0.3 Hz after 20 d. The proportions of ciliated and nonciliated cells did not change after 20 d, but the proportion of mucus cells was higher at 20 d (26.3 +/- 5.4%) than at Time 0 (9.8 +/- 2.7%). No mitochondrial abnormalities, changes in nuclear heterochromatin levels, or reduction in cilial density on ciliated cells were present. The amount of damaged epithelium was less at 20d (7.2 +/- 3.8%) than at Time 0 (19.0 +/- 5.8%). This model more closely reproduces physiologic conditions in vitro than do models involving the immersion of respiratory tissue in media. Its long viability will permit studies of virus and bacterial infections, and of the effects of pharmacologic agents and environmental factors.