Do self-heart-reactive T cells expand in Trypanosoma cruzi-immune hosts?
C R Gattass, M T Lima, A F Nóbrega, M A Barcinski and G A Dos Reis Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Brazil. ABSTRACT Anti-heart T-cell activity was evaluated by a lymph node cell proliferative assay in isogenic strains of mice immunized with several Trypanosoma cruzi epimastigote and trypomastigote antigenic preparations. In addition, chronically infected animals were boosted with trypomastigote antigens and their lymph node cells were tested by in vitro proliferative responses. Our results indicated that (i) use of allogeneic sources of heart antigens may induce alloreactive responses in T. cruzi-immune T cells, (ii) specific autoimmune T-cell reactivity against self-heart constituents could not be demonstrated after immunization of the host with T. cruzi, and (iii) a proportion of chronically infected mice showed a small but detectable level of auto-anti-heart T-cell reactivity. These results argue against the notion that T. cruzi epi