• Vaccine Name: T. cruzi DNA vaccine encoding TcTASV-C
• Target Pathogen: Trypanosoma cruzi
• Target Disease: Chagas disease
• Type: DNA vaccine
• Status: Research
• Host Species for Licensed Use: Mouse
• Antigen: TcTASV-C (Caeiro et al., 2020) - highly conserved antigen in different strains of T. cruzi and is mainly found in extracellular vesicles and has a great expression increment in bloodstream trypomastigotes in vivo. These features indicate that TcTASV-C may play a role during the early acute phase of infection. (Caeiro et al., 2018)
• Immunization Route: Intramuscular injection (i.m.)
• Description: T. cruzi DNA vaccine encoding the TcTASV-C protein adminstrated with U-Omp19

Mouse Response

• Host Strain: C3H/He
• Vaccination Protocol: C3H/He mice (n = 5 per group) were vaccinated with recombinant proteins. Briefly, three doses of subcutaneous injections of mixed TcTASV-CGST and TcTASV-CHIS (25 µg each one) with a colloidal suspension of aluminum hydroxide (Sigma), 25 µg of saponin (Sigma) and/or purified 150 µg of U-Omp19-His [60], [22]. Control groups were immunized with the same procedure but with 50 μg of GST or with TcTASV-C with PBS as adjuvant. (Caeiro et al., 2020)
• Immune Response: Mice immunized with TcTASV-C and formulations with aluminum hydroxide induced a specific IgG immune response with titers higher than 6400. The TcTASV-C + U-Omp19 vaccinated group showed an IgG response similar to the group immunized with the protein alone (titer: 3200). Mixed IgG1 and IgG2a responses were observed with all the different adjuvants formulations tested. However, in the TcTASV-C + PBS group the specific response was mostly IgG1. The TcTASV-C + U-Omp19 immunization scheme induced IFN-γ and IL-17 production in a dose-dependent manner regarding the TcTASV-C concentration used for cell stimulation. This did not occur with TcTASV-C + PBS immunization or with TcTASV-C and all adjuvants together. (Caeiro et al., 2020)
• Challenge Protocol: Fifteen days after the last dose, mice were challenged with 100 bloodstream trypomastigotes of the RA strain by the intraperitoneal route. (Caeiro et al., 2020)
• Efficacy: After T. cruzi challenge, the IgG2a response was predominant, with antibodies of IgG1 isotype in surviving mice at 90 d.p.i. resulting undetectable.