A novel multi-epitope recombinant protein elicits an antigen-specific CD8+ T cells response in Trypanosoma cruzi-infected mice.

• The recombinant multi-epitope Tc24-C4.10E reduces parasitemia peak in acute T. cruzi infected mice. • The recombinant multi-epitope Tc24-C4.10E elicit an antigen-specific CD8 + T cell response producing IFNγ and IL-4 cytokines. • This is the first approach using as scaffold a recombinant protein to fuse 10 CD8 + T. cruzi epitopes. About 6.5 million people worldwide are afflicted by Chagas disease, which is caused by the protozoan parasite Trypanosoma cruzi. The development of a therapeutic vaccine to prevent the progression of Chagasic cardiomyopathy has been proposed as an alternative for antiparasitic chemotherapy. Bioinformatics tools can predict MHC class I CD8 + epitopes for inclusion in a single recombinant protein with the goal to develop a multivalent vaccine. We expressed a novel recombinant protein Tc24-C4.10E harboring ten nonameric CD8 + epitopes and using Tc24-C4 protein as scaffold to evaluate the therapeutic effect in acute T. cruzi infection. T. cruzi -infected mice were immunized with Tc24-C4.10E or Tc24-C4 in a 50-day model of acute infection. Tc24-C4.10E-treated mice showed a decreased parasitemia compared to the Tc24-C4 (non-adjuvant) immunized mice or control group. Moreover, Tc24-C4.10E induced a higher stimulation index of CD8 + T cells producing IFNγ and IL-4 cytokines. These results suggest that the addition of the MHC Class I epitopes to Tc24-C4 can synergize the antigen-specific cellular immune responses, providing proof-of-concept that this approach could lead to the development of a promising vaccine candidate for Chagas disease. [ABSTRACT FROM AUTHOR]