Vaccine against Trypanosoma cruzi infection using the parasite antigen TcTASV displayed at baculovirus capsid

MASIP, YAMIL E.; CAEIRO, LUCAS D.; COSENZA, MAXIMILIANO; POSTAN, MIRIAM; MOLINA, GUIDO; PASCUA, TADEO; TABOGA, OSCAR; MOLINARI, MARÍA PAULA; TEKIEL, VALERIA

Congreso; LXXI Reunión Anual de la Sociedad Argentina de Inmunología; 2023

Chagas' is a neglected disease caused by the eukaryotic parasite Trypanosoma cruzi, which has a complex life cycle with intracellular (amastigotes) and bloodstream circulating (trypomastigotes) stages in the vertebrate host. TcTASV is a T. cruzi multigene family with approximately 40 members classified in four subfamilies, being TcTASV-A and TcTASV-C the most abundant and characterized. TcTASV-A is expressed both in trypomastigotes and amastigotes, with an intracellular location. TcTASV-C is expressed in trypomastigotes, located at T. cruzi surface, and secreted freely and into extracellular vesicles. In this study, we demonstrated the effectiveness of a novel immunization strategy that employs TcTASV antigens delivered in a combined formulation as recombinant proteins and displayed at the capsid of recombinant baculovirus. Vaccinated mice exhibited a potent antibody response with a predominant Th1 profile (the most appropriate for controlling T. cruzi) and complement-mediated trypomastigote lytic ability. Vaccination also stimulated TcTASV-specific IFNγ-secreting CD4+ and CD8+ T cell populations. Besides, the vaccination scheme affected both early (acute, i.e., parasitemia) and long (chronic, i.e., tissue parasite burden) infection and significantly improved survival. Moreover, vaccination allowed animals to control the reactivation of parasitemia after immunosuppression. We believe that the present results are promising for the development of a protective vaccine against Chagas disease.