Trypanosoma cruzi is a protozoan parasite and the causative agent of Chagas disease. The T. cruzi protein trans-sialidase (TS) is currently under investigation as a vaccine candidate. There are defects in CD4+ T cell responses after T. cruzi infection as compared to TS vaccination. We sought to compare T cell receptor transgenic (Tg) TS-specific CD4+ T cell responses induced by infection versus vaccination through RNA microarrays. Tg TSaa57-74-specific CD4+ T cells were purified from naïve transgenic mice and activated in vitro by peptide-pulsed DCs or T. cruzi-infected and peptide-pulsed DCs, as well as in vivo by TS-DNA vaccination or T. cruzi infection. At various time points post activation, RNA was extracted from purified Tg CD4+ T cells and analyzed by microarray. In vitro, infection of DCs resulted in an increase in the expression of the signaling molecule Map3k10, the cytokine Il21, and factors involved in cell death/survival in CD4+ T cells. Following in vivo activation, proliferation was similar among Tg T cells stimulated with TS vaccination and T. cruzi infection. The microarray will reveal genes differentially expressed in response to T. cruzi infection with further analysis ongoing. These in vitro and in vivo studies using our transgenic T. cruzi-specific CD4+ T cells suggest that T. cruzi infection and TS vaccination differentially activate CD4+ T cells which may explain the defects in CD4+ T cells observed following T. cruzi infection.
- Copyright © 2013 by The American Association of Immunologists, Inc.