Development of a novel bivalent antigen effective to control Trypanosoma cruzi infection.

VAZQUEZ, MARÍA ELISA; ZABALA, BRENDA A; MESÍAS, ANDREA C; PÉREZ BRANDÁN, CECILIA; ACUÑA, LEONARDO

Mendoza

Congreso; XI Congreso SAP; 2022

Sociedad Argentina de Protozoología

Development of a novel bivalent antigen effective to control Trypanosoma cruzi infection. Vázquez ME, Zabala B, Mesías AC, Parodi C, Pérez Brandán C, Acuña L Instituto de Patología Experimental, Salta, Argentina Resumen Chagas disease (CD) is a neglected and silent disease caused by a flagellar protozoan, named Trypanosoma cruzi, that affect over 8 million people around the world. CD is the principal cause of an infectious heart disease in the world. Nowadays, there is not an available vaccine for the CD prevention, but the research around vaccines development is improving. One of these new perspectives is the multi-component vaccine strategy. In this sense, we constructed a fusion protein based on two T. cruzi antigens with different goals. On one hand, the N-terminus Tc52 (N-Tc52) develops a humoral response, and in the other hand, an epitope of TS protein called TSKB20 possess immunodominance in cellular response against the parasite. N-Tc52 was amplified by PCR from T. cruzi CL Brener strain and subsequently reamplified to incorporate, with specific primers, two TSKB20 sequences in tandem. Next, this genetic construct was cloned into a bacterial plasmid, pRSET-A and finally, we expressed and purified the chimeric protein resulting (N-Tc52/TSKB20). No genomic mutations and its primary structure were confirmed. To prove the biological activity of this bivalent antigen, an immunization scheme in mice was diagrammed. Animals were inoculated with chimera protein plus a saponin-type adjuvant 3 times separated between 21 days. Blood was collected before each dose and 21 days after last dose when the half of animals were sacrificed, and spleens were taken to evaluate the immune response. The other half of mice were challenged with a lethal dose of T. cruzi trypomastigotes. Parasitemias were recorded twice a week for 25 days for assessed vaccine effectiveness. Lastly animals were sacrificed, and hearts, colon and muscle were taken to measure parasitic load. In brief, mice inoculated with chimeric protein were able to control parasitemias and reduce parasitic burden in target organs exhibiting an immune response against T. cruzi in comparation with controls.