Canine 563 cells: an established canine salivary gland cell line

Canine mandibular salivary glandular epithelial cells were established in culture and passaged more than 250 times. The cultivated cells show epithelial morphology, and ultrastructurally, show desmosomes, desmosome-like specializations (punctae adhaerens), cytoplasmic tonofilaments, and neoluminae suggestive of glandular epithelium. The cells showed modest PAS reactivity and were negative for alcian blue. Using immunohistochemistry, the 563 cells were shown to express cytokeratins, vimentin and epithelial membrane antigen. Chromosome analysis of the cells revealed a modal number of 76 plus 2 sex chromosomes, and the DNA histogram showed major peaks at 2 C (diploid) and 4 C (tetraploid). Attempts to demonstrate a retrovirus by particle labelling with 3H-uridine or by isolation of 70S RNA gave negative results. A nucleic acid hybridization test for mycoplasma contamination gave negative results. It is anticipated that this established cell line derived from normal canine glandular epithelium will prove useful for canine virologic studies, or as a substrate for the growth of type C retroviruses from heterospecies.