Therapeutic effects of vaccine derived from amastigote surface protein‐2 (ASP‐2) against Chagas disease in mouse liver
&NA; This study investigated the efficacy of the vaccine in liver of mice infected with the Trypanosoma cruzi (T. cruzi) and immunized with AdASP‐2. For this purpose, histopathological analysis and gene expression of COX‐2, TNF‐alpha, TNFR, iNOS, cytochrome C, caspase‐3, TLR4, IL‐6 and IL10 were evaluated. The following groups were used in this study: Group 1 ‐ Control Group (CTRL) animals received Ad&bgr;Gal vehicle; Group 2 ‐ Infected Group (TC) animals were infected with T. cruzi; Group 3 ‐ Immunized Group (AdASP‐2): animals were immunized by AdASP‐2 vaccine; Group 4 ‐ Immunized and Infected Group (AdASP‐2+TC) animals were infected with T. cruzi and immunized by AdSP‐2 vaccine. A significant decrease of amastigote nests was noticed in the group of animals that were immunized with AdASP‐2 and infected on the same day. COX‐2 and TNF‐alpha gene expressions increased in TC group, whereas TNF‐alpha decreased in the TC+AdASP‐2 group. TNFR expression was high in AdASP‐2+TC group. iNOS expression was high for all experimental groups whereas cytochrome C decreased for all experimental groups. Caspase 3 increased in TC and TC+AdASP‐2 groups. The gene expression of TLR4 and IL‐10 showed an increase in AdASP‐2+TC group. Finally, hepatic fibrosis was noticed to TC and AdASP‐2 + TC groups. Taken together, our results demonstrated that vaccination with AdASP‐2 was effective against the acute phase of experimental Chagas disease as a result of a more powerful and rapid immune response closely related to expression of some inflammatory genes, such as iNOS, TNF‐alpha, TLR 4, and IL‐10.