Abstract
Virulent strains of the coccidian parasiteToxoplasma gondii become attenuated so as to survive and complete their life cycle; however, it is not known whether the attenuation process is attributable to an innate cystogenic capacity of the parasite or to host-induced mechanisms. This report presents direct evidence of RH cystogenesis in non-immunised Fischer rats and subsequent attenuation of RH pathogenicity in non-immunised mice following a single passage through rats. Taken together, these preliminary observations tend to suggest that at least one mechanism ofT. gondii involves intermediate host attenuation.
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References
Ambroise-Thomas P (1976) Immunofluorescence in the diagnosis therapeutic follow-up and sero-epidemiological studies of some parasitic diseases. Trans R Soc Trop Med Hyg 70:107–113
Blewett DA, Miller JK, Harding J (1983) A simple technique for direct isolation ofToxoplasma tissue cysts from foetal brain Vet Rec 112:98–100
Brown CR, McLeod R (1990) Class I MHC genes and CD8+ T cells determine cyst number inToxoplasma gondii infection. J Immunol 145:3438–3441
Chinchilla M, Guerrero OM, Solaono E (1982) Lack of multiplication ofToxoplasma in macrophages of rats. J Parasitol 68:952–955
Conley FS, Jenkins KA, Remington JS (1981)Toxoplasma gondii infection of the central nervous system. Hum Pathol 12:690–698
Feldman HA (1968) Toxoplasmosis. N Engl J Med 279:1370–1375
Ferguson DJP, Hutchison WM, Petterson E (1989) Tissue cyst rupture in mice chronically infected withToxoplasma gondii. Parasitol Res 75:599–603
Gazzinelli RT, Harim FT, Hieny S, Shearer GM, Sher A (1991) Synergistic role of CD4+ and CD8+ T lymphocytes in IFNγ production and protective immunity by an attenuatedToxoplasma gondii vaccine. J Immunol 146:286–292
Krahenbuhl JL, Blazkovec AA (1975)Toxoplasma gondii: immunopathology of cutaneous hypersensitivity reaction in guinea pigs injected with living parasites. Exp Parasitol 37:83–91
Lainson R (1955) Toxoplasmosis in England: II. Variation factors in the pathogenesis ofToxoplasma infections. Ann Trop Med Parasitol 49:397–416
Liu J, Greeley H, Shadduck JA (1989) mechanisms of resistance/ susceptibility to murine encephalitozoonosis. Parasite Immunol 11:241–256
McCabe RE, Remington JS (1986) Mechanisms of killing ofToxoplasma gondii by rat peritoneal macrophages. Infect Immun 52:151–155
Niederkorn JY, Shadduck JA, Schmidt EC (1981) Susceptibility of selected inbred strains of mice toEncephalitozoon cuniculi. J Infect Dis 144:228–232
Remington JS, Jacobs L, Kaufman HE (1958) Studies on chronic toxoplasmosis. Am J Ophthalmol 46:261–268
Ridel PR, Auriault C, Darcy F, Pierce RJ, Leite P, Santoro F, Neyrinck JL, Kusnierz JP, Capron A (1988) Protective role of IgE in immunocompromised rat toxoplasmosis. J Immunol 141:978–983
Sabin AB (1941) Toxoplasmic encephalitis in children. JAMA 116:801–807
Santoro F, Auriault C, Leite P, Darcy F, Capron A (1987) Infection du rat athymique parToxoplasma gondii. C R Acad Sci [III] 304:297–299
Yano K, Nakabayashi T (1986) Attenuation of the virulent RH strain ofToxoplasma gondii by passages in mice immunized withToxoplasma lysate. Biken J 29:31–37
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Lecomte, V., Chumpitazi, B.F.F., Pasquier, B. et al. Brain-tissue cysts in rats infected with the RH strain ofToxoplasma gondii . Parasitol Res 78, 267–269 (1992). https://doi.org/10.1007/BF00931740
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DOI: https://doi.org/10.1007/BF00931740