Cyst Formation from Virulent RH Strain of Toxoplasma gondii Tachyzoite: In Vitro Cultivation
Abstract
Background: This study was performed to induce conversion of RH strain tachyzoites of Toxoplasma gondii to bradyzoites by pH changing of the culture medium.
Methods: HeLa cell monolayers were infected at a 1:1 tachyzoite to cell ratio. Four hours after infection, the culture medium was removed and replaced with culture medium and 5% FCS, adjusted to pH 8 with NaOH. The culture was maintained at 37 °C without CO2 until the end of the experiment. Cyst-like structures were collected and stained with periodic acid schiff (PAS) staining method. The soluble antigens of cyst-like structures of RH strain, in addition to RH tachyzoite, bradyzoites of avirulent Tehran strain and uninfected HeLa cells were electrophoresed on 12.5% polyacrylamide gel. The gel was stained by coomassie brilliant blue R-250.
Results: Four days after infection of HeLa cells with tachyzoites of T. gondii, RH strain, cyst- like structures were noticed and stained with PAS. In the SDS-PAGE, protein bands of these structures had some differences with tachyzoites of RH strain, but there was quite similarity between protein bands of these structures and tissue cysts (bradyzoites) of Tehran strains. P34 and P36 (bradyzoite-specific proteins) were observed only in T. gondii bradyzoites of RH (cyst like structures) and bradyzoites of Tehran strains.
Conclusion: Alkalization of culture medium to pH 8 induced expression of bradyzoite- specific proteins and production of RH cysts in cell culture.
Dubey JP. Toxoplasmosis. J Am Vet Med Assoc. 1994; 205: 1593-1598.
Frenkel KK. Pathophysiology of toxoplasmo¬sis. Parasitol. 1988; 4: 273- 278.
Weiss LM, Kim K. The develop¬ment and biology of bradyzoites of Toxoplasma gondii. Front Biosci. 2000; 5:D391–D405.
Navia BD, Petito CK, Gold JW, Cho ES, Jor¬dan BD, Price RW. Cerebral toxoplasmosis complicating the ac-quired immune deficiency syndrome: Clinical and neuropathological find¬ings in 27 patients. Ann Neurol. 1986; 19:224- 238.
Gross U, Bohne W, Soête M, Du-bremetz J F. Development differentia-tion between tachyzoites and bradyzo-ites of Toxoplasma gondii. Parasitol To¬day. 1996; 12: 30- 33.
Darde ML, Bouteille B, Leboutet MJ, Loubet A, Pestre-Alexander M. Toxo-plasma gondii: étude ultrastructurale des formations kystiques observées en cul-ture de fibroblastes humains. Ann Par-asitol Hum Comp.1989; 64: 403- 411.
Soete M, Fortier B, Camus D, Dubremetz J F. Toxoplasma gondii: kinetics of bradyzoite- tachyzoite interconversion in vitro. Exp Para¬sitol. 1993; 76: 259-264.
Soête M, Fortier B, Camus D, Du-bremetz J F. Toxoplasma gondii: Patterns of bradyzoite-tachyzoite interconversion in vitro. NATO ASI Ser Ser A Life Sci. 1993; 78: 93- 98.
Bohne W, Heesemann J, Gross U. Induction of bradyzoite-specific Toxoplasma gondii anti¬gens in gam¬ma interferon treated mouse mac¬rophages. Infect immun. 1993; 61: 1141- 1145.
Hammouda NA, Brahim IR, Elkerdany ED, Negm AY, Allam SR. Experimental conver¬sion of virulent RH Toxoplasma gondii tachyzo¬ites in vitro. East Mediterr Health J. 2001; 7: 181-188.
Weiss LM, Laplace D, Takvorian PM, Tan¬owitz HB, Calli A, Wittner M. A cell culture system for study of the development of Toxo¬plasma gondii bradyzoites. J Eukaryot Microbiol. 1995; 42: 150-157.
Weiss LM, Laplace D, Takvorian PM, Tan¬owitz HB, Wittner M. The association of the stress response and Toxoplasma gondii bradyzo¬ite development. J Eukaryot Microbiol. 1996; 43:120S.
Soête M, Camus D, Dubremetz JF. Experi¬mental induction of bradyzoite-specific anti¬gen expression and cyst formation by the RH strain of Toxo¬plasma gondii in vitro. Exp Parasi¬tol. 1994; 78:361- 370.
Ferguson JP, Hutchinson WM. The host-parasite relationship of Toxoplasma gondii in the brains of chronically infected mice. Virchows Archiv. 1987; 411: 39-43.
Guimaraes EV, De Carvalho L, Bar-bosa HS. An alternative technique to reveal poly-saccharides in Toxoplasma gondii tissue cysts. Mem Inst Oswaldo Cruz. 2003;98(7):915-917.
Dubey JP, Frenkel JK. Feline toxo-plasmosis from acutely infected mice and the develop¬ment of Toxoplasma cysts. J Protozool. 1976; 23: 537-546.
Burg JL, Perelman D, Kasper LH, Ware PL. Molecular analysis of the gene encoding the major surface antigen of T. gondii. J Immunol. 1988; 144: 3584- 3591.
Windeck T, Gross U. Toxoplasma gondii strain- specific transcript levels of SAG1 and their as¬sociation with viru-lence. Parasitol Res. 1996; 82: 715- 719.
Tomavo S, Fortier B, Soete M, Ansel C, Ca¬mus D, Dubremetz JF. Characterization of bradyzoite- specific antigens of Toxoplasma gondii. Infect Immun. 1991; 59: 3750- 3753.
Files | ||
Issue | Vol 11 No 1 (2016) | |
Section | Original Article(s) | |
Keywords | ||
Toxoplasma gondii RH strain cell culture cyst |
Rights and permissions | |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |