Some but not All Tetrahymena Species Destroy Monolayer Cultures of Cells from a Wide Range of Tissues and Species.
The activities of Tetrahymena corlissi, Tetrahymena thermophila, and Tetrahymena canadensis were studied in coculture with cell lines of insects, fish, amphibians, and mammals. These ciliates remained viable regardless of the animal cell line partner. All three species could engulf animal cells in suspension. However, if the animal cells were monolayer cultures, the monolayers were obliterated by T. corlissi and T. thermophila. Both fibroblast and epithelial monolayers were destroyed but the destruction of human cell monolayers was done more effectively by T. thermophila. By contrast, T. canadensis was unable to destroy any monolayer. At 4 °C T. thermophila and T. corlissi did not carryout phagocytosis and did not destroy monolayers, whereas T. canadensis was able to carryout phagocytosis but still could not destroy monolayers. Therefore, monolayer destruction appeared to require phagocytosis, but by itself this was insufficient. In addition, the ciliates expressed a unique swimming behavior. Tetrahymena corlissi and T. thermophila swam vigorously and repeatedly into the monolayer, which seemed to loosen or dislodge cells, whereas T. canadensis swam above the monolayer. Therefore, differences in swimming behavior might explain why T. corlissi has been reported to be a pathogen but T. canadensis has not.
Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
Marcel D O
MD
Pinheiro
Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
Niels C
NC
Bols
D000663:Amphibians / Q000469:parasitology; D000818:Animals; D061245:Axenic Culture; D018929:Cell Culture Techniques; D002460:Cell Line; D005399:Fishes / Q000469:parasitology; D006367:HeLa Cells; D006801:Humans; D007313:Insecta / Q000166:cytology / Q000469:parasitology; D008322:Mammals / Q000469:parasitology; D010587:Phagocytosis; D013550:Swimming; D013696:Temperature; D013768:Tetrahymena / Q000145:classification / Q000472:pathogenicity* / Q000502:physiology*; D016808:Tetrahymena thermophila / Q000472:pathogenicity / Q000502:physiology / Q000648:ultrastructure
Cell culture; ciliate; coculture; fish; monolayer destruction; parasitology