?Recombinant TS-based nasal vaccine protects against oral infection with T. cruzi.?

PACINI M. FLORENCIA, ; GONZÁLEZ FLORENCIA, ; BULFONI BALBI CAMILA, DINATALE BRENDA, FARRÉ CECILIA, VILLAR SILVINA, CHAPO GUSTAVO, BOTTASSO O, PROCHETTO ESTEFANIA, MARCIPAR I, PEREZ ANA R

Congreso; Reunión Sociedades de Biociencias; 2020

Sociedad Argentina de Inmunología

Chagas disease, caused by the Trypanosoma cruzi (Tc) parasite, is an important public health problem in Latin America. Although there are drugs for its treatment, currently there are no prophylactic vaccines to combat the disease. Here, we evaluated the immunogenicity and prophylactic efficacy generated by a recombinant Trans-sialidase (TSr) expressed in E. coli. This fragment was selected by bioinformatics and contains different B and T epitopes. Thus, female BALB/c mice (n=5/6/group) were immunized intranasally (three doses, one every two weeks) with different formulations that combine the TSr with different adjuvants (c-di-AMP or ISPA). As control groups we used mice not immunized (NI) or only treated with TSr. Fifteen days after the last immunization, in vivo cell-mediated (delayed hypersensitivity test -DHT-), in vitro specific splenocyte proliferation (Ki67 by flow cytometry) and specific humoral (ELISA) response were assayed. Then, animals were orally challenged with 2500 Tc/mice (Tulahuen strain). During acute phase, parasitemia, clinical affectation (score), muscle damage (plasma CK) was evaluated. In terms of immunogenicity,TSr+c-di-AMP and TSr+ISPA groups developed an enhanced DHT after 24-48 h, compared to control groups (in all cases, p