Trypanosoma cruzi: Maintenance in Culture Modify Gene and Antigenic Expression of Metacyclic Trypomastigotes

Serological diagnosis of Chagas disease: evaluation and characterisation of a low cost antigen with high sensitivity and specificity

“…The change in the pattern of labelling is associated with improvements in sensitivity and specificity of the antigens obtained from epimastigotes subjected to nutrient stress and autoclaving. As reported by other investigators, modifications in culture conditions, like those evaluated here, induce biochemical and molecular changes in the antigens produced (Contreras et al 1994(Contreras et al , 1998. The expression of these changes is evident in the immunofluorescence of epimastigotes subjected to different culture conditions.…”

Plasminogen interaction with Trypanosoma cruzi

“…The lower enhancement of plasminogen activation by metacyclic trypomastigotes compared to epimastigotes could reflect the molecular changes associated to culture conditions. Axenic metacyclic forms derived from epimastigotes maintained more than 78 days in culture are less virulent and have different protein profile than the insect-born metacyclic trypomastigotes (Contreras et al 1998). By contrast, the protein profile of epimastigotes do not change by several passage in axenic medium (Contreras et al 1998).…”

Production of amastigotes from metacyclic trypomastigotes of Trypanosoma cruzi

“…Antisera production and Western blot analysisMetacyclic trypomastigote stage-specific antiserum (anti-META) was prepared as previously described (Contreras et al 1998). Antiserum directed against intracellular metacyclic-derived amastigotes (anti-IMA) was prepared in New Zealand rabbits as follows.…”

“…For Western blot analyses, total proteins of META, IMA and EMA were electrophoretically transferred from a linear gradient of 7-15% SDS-PAGE gels to nitrocellulose membranes according to the method of Towbin et al (1979) as previously described (Contreras et al 1998). Four µg of protein of each stage were applied to the lanes.…”