Incubation in mice provides a signal for the differentiation of Trypanosoma cruzi epimastigotes to trypomastigotes.
The differentiation of Trypanosoma cruzi epimastigotes into trypomastigotes was studied in diffusion chambers subcutaneously implanted in mice. Using epimastigotes of the Tulahuén strain, transformation was first evident at 16 h after implantation and reached its maximum (92% trypomastigotes) by 24 h. Shortly before their differentiation into trypomastigotes, epimastigotes were found to develop resistance to lysis by the alternative pathway of complement. Furthermore, implantation of stationary-phase (as opposed to log-phase) parasites resulted in the accumulation of large numbers of complement-resistant epimastigotes in the chambers. These observations suggest that epimastigotes pass through a complement-resistant transitional stage before differentiating into trypomastigotes and that transformation may require cell division. In a further series of experiments, epimastigotes recovered 7 h after implantation in mice were found to differentiate into trypomastigotes when cultured in vitro for an additional 17 h at 37 degrees C. This observation indicates that the events which trigger the morphologic transformation of epimastigotes into trypomastigotes can be dissociated operationally from the differentiation process itself.
D000818:Animals; D002455:Cell Division; D003170:Complement Pathway, Alternative; D003165:Complement System Proteins / Q000502:physiology; D051379:Mice; D014349:Trypanosoma cruzi / Q000166:cytology* / Q000276:immunology / Q000502:physiology
D003165:Complement System Proteins