Corpus Christi strain-induced protection to Trypanosoma cruzi infection in C3H(He) mice: transfer of resistance to Brazil strain challenge with lymphocytes.

Treatment of susceptible C3H(He) mice with 10(7) live Corpus Christi strain culture-derived Trypanosoma cruzi provided protection against a subsequent Brazil strain challenge. This protection was indicated by a greater than 10-fold decrease in parasitemia and an increase in longevity (including survival) in many groups. The Corpus Christi organisms were unable to establish an apparent infection, but viability is an important element in the treatment in that freeze-thawed, non-viable preparations of the Corpus Christi strain were unable to provide protection. Adoptive transfer of resistance was achieved with spleen cells from Corpus Christi-treated, Brazil-infected mice which had recovered from the acute phase of infection. The T cell-depleted population of these spleen cells was able to transfer resistance whereas the T cell-enriched population was not protective. Passive transfer of serum from Corpus Christi-treated and Brazil-infected mice provided a temporary decrease in parasitemia in infected mice. The results presented herein suggest that Corpus Christi-induced protection to virulent T. cruzi challenge is mediated by antibody mechanisms.