Mucosal vaccine based in a fragment of recombinant trans-silidase protects against experimental oral chagas disease

MARIA FLORENCIA PACINI, ; BRENDA DINATALE, ; CAMILA BULFONI BALBI, ; FLORENCIA BELÉN GONZÁLEZ; CECILIA FARRÉ, SILVINA VILLAR, GUSTAVO CHAPO, OSCAR BOTTASSO, ESTEFANIA PROCHETTO, IVAN MARCIPAR, ANA ROSA PÉREZ

Congreso; Reunión anual de Sociedades de Biociencias SAIC.SAI.AAFE.NANOMED.AR; 2021

Oral Chagas disease is a frequent form of infection in some countriesof 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 efficacyagainst oral infection generated by a N-terminal recombinant fragmentof Trans-sialidase (TSNt), containing different B and T epitopesconfirmed by bioinformatics. For mucosal immunization, 10μg ofTSNt was combined with different adjuvants: c-di-AMP(A) or ISPA(I).Thus, female BALB/c mice (n=6/group) were immunized intranasally(3 doses, one every 2 weeks). As control groups we used mice notimmunized (NI) or only treated with TSNt. To evaluate the immunogenicity,15 days after the last immunization, we performed an invivo cell-mediated test (delayed hypersensitivity test, DHT), splenicmultifunctional T cell (IFNγ+/RORγt+) detection by flow cytometryafter in vitro stimulation with TSNt, and specific humoral responseby ELISA. Next, we evaluated prophylactic efficacy during acutephase. Thus, animals were orally challenged with 3000 Tulahuenstrain/mice (sub-lethal challenge). Parasitemia, clinical affectation(score), muscle and liver damage (plasma CK, GOT, GPT) was alsoassessed. In terms of immunogenicity, TSNt+A and TSNt+I vaccinesdeveloped an enhanced DHT until 72 h, compared to control groups(in all cases, p