Abstract
Soluble exoantigens ofTrypanosoma 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°C. Suppression of normal ratspleen cell responses to mitogen concanavalin A (Con A) occurred at high exoantigens concentrations, whereas the responses were enhanced at low 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 ofT. 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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This study was supported by an operating from the Natural Sciences and Engineering Council of Canada. Research at the Institute of Parasitology is supported by the Natural Sciences and Engineering Research Council of Canada and by the Fonds FCAR pour et le sortier a la recherche. Support for the author was provided by the General Training Fund and by the Canadian International Development Agency
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Ndarathi, C.M. Cellular responses to culture-derived soluble exoantigens ofTrypanosoma lewisi . Parasitol Res 78, 324–328 (1992). https://doi.org/10.1007/BF00937091
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DOI: https://doi.org/10.1007/BF00937091