Suppressor and protector factors derived from Trypanosoma lewisi

Ndarathi, C.M.

doi:10.1016/0020-7519(91)90143-u

Cited by 3 publications

(1 citation statement)

References 28 publications

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“…Además, la observación de que la diferencia en cuanto al número de quistes en el cerebro entre el grupo control y en los pocos animales que sobrevivieron fue bastante marcada, independientemente del inóculo del tripanosoma, nos indica que el factor que induce el efecto está en el parásito o es liberado por éste, y que presenta una actividad tal, que solo necesita la reproducción del mismo durante cuatro días para ejercer su acción inhibidora. Productos derivados de protozoarios con esta capacidad inmunosupresora han sido encontrados en tripanosomas africanos (Darji et al 1992(Darji et al , 1996, así como para T. lewisi (Ndarathi 1991).…”

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Efecto inmunosupresor de la infección por <i>Trypanosoma musculi</i> (Mastigophora: Trypanosomatidae) en la toxoplasmosis experimental

Piccolo-Johanning

Kellerman-Guterman

Valerio-Campos

et al. 2013

RBT

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Immunosuppressor effect of Trypanosoma musculi (Mastigophora: Trypanosomatidae) on experimental toxoplasmosis. The immunosuppression caused by species of the gender Trypanosoma has been widely documented. The influence over experimental infections with Toxoplasma gondii is evident when using Trypanosoma lewisi, a natural parasite of white rats. We decided to test the effect of Trypanosoma musculi from mice, an organism with very similar biological characteristics to T. lewisi, to see if this trypanosomatid could induce a similar effect. Four groups of Swiss mice were inoculated with T. musculi previously to infection with T. gondii, and we determined the survival of the animals, as well as the number of cysts developed in the brain of survivors. We isolated and tested different strains of T. gondii from different sources. In a first experiment, the animals were previously inoculated with T. musculi at different times prior to the infection with Toxoplasma; this allowed us to determine that the immunosuppression process resulted more evident when T. musculi inoculation was made four days before. In a second experiment, we used different inoculi dose and found that it did not influenced the process. Furthermore, the results were negative when evaluating if the amount of the inoculated trypomastigote influenced the process. In order to demonstrate if there were differences in the immnosuppressive effect, related to Toxoplasma strains, groups of mice were inoculated with brain cysts of TFC, TLP, TLW and TBT strains. Excluding the TLP strain, that resulted to be very pathogenic regardless the previous inoculation with T. lewisi, the other strains kept the same pattern of immunosuppression in mice, whose survival time was shorter as the presence of cysts in the brain was higher. These observations were in agreement with an experimental immunosuppression model, associated with immunosuppressive diseases, specially cancer and AIDS. Rev. Biol. Trop. 61 (2): 981-990. Epub 2013 June 01.

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Section: Resultsunclassified

Efecto inmunosupresor de la infección por <i>Trypanosoma musculi</i> (Mastigophora: Trypanosomatidae) en la toxoplasmosis experimental

Piccolo-Johanning

Kellerman-Guterman

Valerio-Campos

et al. 2013

RBT

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Trypanocidal drugs and their effect on parasitaemia, specific IgG production and protective immunity in rats infected withTrypanosoma lewisi

Ndarathi

1992

Parasitol Res

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In rats infected with Trypanosoma lewisi, parasitaemia normally resolves by day 32; thereafter, the rodents become solidly immune to re-infection. Rats treated on day 5 of infection with a single i.m. dose of 35 mg/kg of the trypanocidal drug ethidium bromide (EB) had recovered from parasitaemia by day 12, whereas berenil (BE) given at 100 mg/kg, more than twice the recommended dose, had no effect on parasitaemia. However, rats treated for 4 consecutive days beginning on day 5 of infection with Lampit (LA) and Radanil (RA) at 350 mg/kg showed no parasitaemia on days 16 and 20, respectively. EB was the most effective drug in lowering the total IgG antibody as compared with the control animals, whose specific IgG titres remained elevated for over 200 days after the parasitaemia had been cleared. LA also significantly reduced the antibody levels through day 240, whereas RA only transitorily depressed the antibody levels on days 20 and 30. BE, which had no effect on parasitaemia, correspondingly failed to depress the total IgG levels. Re-challenge infection of the drug-treated, recovered animals on day 240 (208 days after the normal resolution of the infection) revealed that except for the EB group, which displayed transitory parasitaemia for 4 days, other treated and control rats completely resisted the challenge; pre-challenge antibody titres were lower than 1:160 in EB-treated animals in contrast to the levels of 1:320 or higher measured in the other drug-treated and control animals, which resisted the infection.(ABSTRACT TRUNCATED AT 250 WORDS)

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Cellular responses to culture-derived soluble exoantigens ofTrypanosoma lewisi

Ndarathi

1992

Parasitol Res

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Soluble exoantigens of Trypanosoma lewisi were obtained from short-culture systems of dividing epimastigotes and non-dividing trypomastigotes incubated in phosphate-buffered saline glucose solution (PBSG) for 3 h at 37 degrees C. Suppression of normal rat-spleen cell responses to mitogen concanavalin A (Con A) occurred at high exoantigens concentrations. The epimastigote-derived exoantigens were more suppressive than the trypomastigote-derived exoantigens. The suppression of Con A stimulation was ablated by the addition of exogenous interleukin-2 (IL-2) or washing of spleen cells that had been incubated with suppressing concentrations of the epimastigote exoantigens for 24 h prior to Con A stimulation. These results strongly suggest that exoantigens of T. lewisi play an important immunoregulatory role during the course of infection and that they achieve this by inhibiting the production of IL-2 by T-helper cells.

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Suppressor and protector factors derived from Trypanosoma lewisi

Cited by 3 publications

References 28 publications

Efecto inmunosupresor de la infección por <i>Trypanosoma musculi</i> (Mastigophora: Trypanosomatidae) en la toxoplasmosis experimental

Efecto inmunosupresor de la infección por <i>Trypanosoma musculi</i> (Mastigophora: Trypanosomatidae) en la toxoplasmosis experimental

Trypanocidal drugs and their effect on parasitaemia, specific IgG production and protective immunity in rats infected withTrypanosoma lewisi

Cellular responses to culture-derived soluble exoantigens ofTrypanosoma lewisi

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