Ostolin, Thais Lopes Valentim Di PaschoaleGusmão, Miriã RodriguesMathias, Fernando Augusto SiqueiraCardoso, Jamille Mirelle de OliveiraRoatt, Bruno MendesSoares, Rodrigo Dian de Oliveira AguiarRuiz, Jeronimo ConceiçãoResende, Daniela de MeloBrito, Rory Cristiane Fortes deReis, Alexandre Barbosa2021-09-032021-09-032021OSTOLIN, T. L. V. D. P. et al. A chimeric vaccine combined with adjuvant system induces immunogenicity and protection against visceral leishmaniasis in BALB/c mice. Vaccine, v. 39, p. 2755-2763, 2021. Disponível em: <https://www.sciencedirect.com/science/article/pii/S0264410X21004291?via%3Dihub>. Acesso em: 10 jun. 2021.0264-410Xhttp://www.repositorio.ufop.br/jspui/handle/123456789/13648In Brazil, canine visceral leishmaniasis is an important public health problem due to its alarming growth. The high prevalence of infected dogs reinforces the need for a vaccine for use in prophylactic vaccination campaigns. In the present study, we evaluate the immunogenicity and protection of the best dose of Chimera A selected through the screening of cytokines production important in disease. BALB/c mice were vaccinated subcutaneously with three doses and challenged intravenously with 1 107 L. infantum promastigotes. Spleen samples were collected to assess the intracellular cytokine profile production, T cell proliferation and parasite load. At first, three different doses of Chimera A (5 lg, 10 lg and 20 lg) were evaluated through the production of IFN-c and IL-10 cytokines. Since the dose of 20 lg showed the best results, it was chosen to continue the study. Secondarily, Chimera A at dose of 20 lg was formulated with Saponin plus Monophosphoryl lipid A. Vaccination with Chimera A alone and formulated with SM adjuvant system was able to increase the percentage of the proliferation of specific T lymphocytes and stimulated a Th1 response with increased levels of IFN-c, TNF-a and IL-2, and decreased of IL-4 and IL-10. The vaccine efficacy through real-time PCR demonstrated a reduction in the splenic parasite load in animals that received Chimera A formulated with the SM adjuvant system (92%). Additionally, we observed increased levels of nitric oxide in stimulated-culture supernatants. The Chimera A formulated with the SM adjuvant system was potentially immunogenic, being able to induce immunoprotective mechanisms and reduce parasite load. Therefore, the use of T-cell multi-epitope vaccine is promising against visceral leishmaniasis.en-USrestritoLeishmania infantumMulti-epitope vaccineImmune responseArtigo publicado em periodicohttps://www.sciencedirect.com/science/article/pii/S0264410X21004291?via%3Dihubhttps://doi.org/10.1016/j.vaccine.2021.04.004