Figure 5.

Prevention of tissue damage by vaccine treatment during the acute phase of the parasite infection. (A) Enzymatic activity of CK and CK-MB enzymes represented as international units (IU/L). (B–E) Representative image of hematoxylin–eosin-stained skeletal muscle samples taken at day 100 after the last immunization; magnification: 40× and the inbox 100×. Animals showed (B) multiple confluent foci and necrosis with diffuse distribution (SControl); (C) nonconfluent mononuclear inflammatory infiltrate (SChg); (D) isolated foci of mononuclear inflammatory infiltrate (SCz); (E) few and isolated infiltrates (SChg+SCz). (F) Semi-quantified inflammation expressed as inflammation index: (1) isolated foci; (2) multiple nonconfluent foci; (3) inflammatory confluent foci; and (4) multiple diffuse foci (40). (G) Parasitism in skeletal and cardiac tissues by qPCR at day 100 after the last immunization. Parasite burden in each tissue was expressed as T. cruzi equivalents per 50 ng of total DNA referred to a calibration curve previously constructed containing known concentrations of T. cruzi epimastigotes. These results are representative of at least three independent experiments, each one being carried out with five animals per group. *p < 0.05, **p < 0.01, ***p < 0.001; ^###p < 0.01.