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Identification of a multidrug resistance‐like system in Tetrahymena pyriformis : evidence for a new detoxication mechanism in freshwater ciliates
Author(s) -
Bamdad Mahchid,
Brousseau Pauline,
Denizeau Francine
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00978-3
Subject(s) - ciliate , tetrahymena pyriformis , tetrahymena , multiple drug resistance , pyrene , rhodamine 123 , biology , p glycoprotein , benzopyrene , flow cytometry , microbiology and biotechnology , polyclonal antibodies , efflux , benzo(a)pyrene , chemistry , biochemistry , antibody , drug resistance , immunology , ecology , astrobiology
The freshwater ciliate Tetrahymena pyriformis is an ubiquitous organism that is present in all aquatic ecosystems. This protozoan showed a clear resistance against some polycyclic aromatic hydrocarbons which can be attributed to an efflux pump probably of the multidrug resistance (MDR) type. Immunocytochemical detection showed a positive stain of ciliate cells using the monoclonal antibodies 4E3, raised against P‐glycoprotein (P‐gp). The kinetics of P‐gp expression were studied for control cultures and cultures treated with 15 μM benzo(a)pyrene. Western blot analysis using the Ab1, anti‐P‐gp polyclonal antibodies indicates the presence of two bands of 66 and 96 kDa of which the intensity increased with time in benzo(a)pyrene‐treated ciliates. Uptake experiments with target compounds for the MDR pump, namely adriamycin, rhodamine 123 and two polycyclic aromatic hydrocarbons, benzo(a)pyrene and 7,12‐dimethylbenzanthracene, were carried out by flow cytometry, in the presence or absence of cyclosporin (an inhibitor of the multidrug resistant pump). The data indicate that the accumulation of these compounds by ciliate cells is significantly enhanced in the presence of cyclosporin. This suggests that Tetrahymena is provided with a P‐gp‐like system that is functionally active in a way similar to that of the mammalian P‐gp.