Trypanosoma cruzi: Experimental immunization of mice

Enhanced Mononuclear Phagocytic Activity during <i>Trypanosoma cruzi </i>Infection in Mice

“…The activation of the mononuclear phagocytic system in T. cruzi-in fected mice could participate in localization and possibly in destruction of the organisms, as has been shown by others [23]. Although our experi ments showed activation of the mononuclear phagocytic system after T. cruzi infection, its contribution to resistance against homologous organ isms remains to be seen.…”

Mitomycin C-treated Trypanosoma cruzi in vaccination of mice: induction of immunosuppression but not protection

“…Under conditions used in the present study, however, it was not possible to induce protective immunity in susceptible C3H(He) mice with mitomycin C-treated culture forms of T. cruzi. Although it has been previously shown that C3H(He) mice are not easily immunized against T. cruzi, it is known that a degree of protective immunity is developed during the course of infection, and on infrequent occasions we have had a few C3H(He) mice survive acute infections after immunization protocols similar to those used by Yanovsky et al (23). Spleen cells from these rare C3H(He) survivors when transferred to normal syngeneic mice protected recipients against subsequent challenge with virulent trypomastigotes (R. E. Kuhn, unpublished data).…”

“…A number of procedures have been used in attempts to induce immunity in experimental animals against the protozoan parasite 7rypanosoma cruzi. These methods have included the use of various antigenic preparations of killed or disrupted culture forms of the parasite (12,20,23) as well as avirulent (8,11) or irradiated (9) preparations of living trypanosomes. Treatment of mice with these vaccines followed by infection with virulent trypomastigotes has resulted in varying degrees of resistance and has generally not been effective in providing a predictable level of protection against the parasite, particularly in highly susceptible hosts.…”

“…Treatment of mice with these vaccines followed by infection with virulent trypomastigotes has resulted in varying degrees of resistance and has generally not been effective in providing a predictable level of protection against the parasite, particularly in highly susceptible hosts. Although it seems that vaccination with attenuated preparations of living trypomastigote forms (8,9,11,12) may provide the best protection against challenge with T. cruzi, there is evidence that disrupted culture forms are also effective (15,23), suggesting that the antigens responsible for conferring resistance in immunized animals are present in such preparations or that sensitization to antigenic determinants in these preparations can sufficiently prime these hosts against subsequent challenge with infective forms.…”