Vaccination with a Trypanosoma cruzi Protein Extract Plus BCG∆BCG1419c Promotes a Balanced Th1/Th2 Immune Profile That Improves Control of Acute Chagas Disease in BALB/c Mice

Adjuvants in vaccine candidates against Chagas disease (ChD) have been tested with the aim of improving efficacy against this disease. <i>Trypanosoma cruzi</i> total protein extract (TcTPE) combined with <i>Mycobacterium bovis</i> BCG Pasteur strain ATCC 35734 or its isogenic derivative mutant BCGΔBCG1419c-in which the <i>BCG1419c</i> gene was deleted-were used as a vaccine formulation in BALB/c mice. After immunization and <i>T. cruzi</i> challenge, parasitological and clinical parameters of acute stage were recorded. Antibody titers, cytokine concentrations, macroscopic abnormalities, and histological analysis of experimental ChD were determined. The vaccine formulation with the combination of TcTPE and BCGΔBCG1419c, used as the adjuvant, reduced parasitemia by 50%, promoted a survival rate of 80%, improved the clinical status, favored greater body weight gain, induced high titers of specific anti-<i>T. cruzi</i> IgG antibodies and some cytokines, leading to a balanced Th1/Th2 immunological profile as well as a lower degree of inflammation and tissue damage (50% reduction). A good protective effect in the acute stage of experimental ChD was observed by favorably modulating the immune response and reducing heart and muscle damage, therefore, highlighting that the combination tested here for the control of ChD provides a promising basis that warrants further investigation to validate a future potential translation to humans.