FIG 1.

Morphology of air-liquid interface (ALI)-grown porcine respiratory epithelial cells (PRECs). (A and B) Relief contrast micrograph of nonadherent PRECs on transwell immediately after seeding (A) and on day 27 completely differentiated PRECs on transwell (B). (C) Paraffin-embedded H&E cross section of ALI-PRECs on transwell on day 27. (D) TEM images of day 27 ALI-PRECs, showing cilium axoneme, tight junctions, and desmosomes in a ciliated cell. Electron-dense secretory granules in some nonciliated cells, potential M cells; basal cells; intermediate cells. (E) Note the presence of mitochondria in ciliated cells, the powerhouse for ciliary movement. (F) Goblet cells were rich in mucin granules showing mucus. Representative images from three biological replicates.