Avaliação do papel do agonista de TLR1\2 (PAM3CSK4) na potencialização do efeito protetor da vacina LaAg administrada por via intranasal contra a leishmaniose visceral murina

• Autor(a) principal: Dias, Emmanoel Loss
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7099
• topic: Leishmaniasis; Vaccine; Leishmaniose; LaAg; Pam3CSK4; Vacina; Biotecnologia; 61

PAM3CSK4 (PAM) is a synthetic TLR1/2 agonist compound by triacylated lipopeptide that mimics bacterial lipoprotein and presenting a potent ability to induce proinflammatory activity mediated by NF-κB activation. In the present study, we investigated the ability of intranasal immunization with whole L. amazonensis promastigote antigens (LaAg) associated with PAM adjuvant to improve the immunogenic immune response in mice. So, BALB/c mice were immunized by intranasal route (nasal instillation) with 2 doses of 20 µg of LaAg associated with 20 µg of PAM adjuvant intercalated for 7 days. PBS, LaAg or PAM alone were used as controls. The measurement of transaminases and creatinine in animals serum demonstrated the biocompatibility and safety of the combination LaAg/PAM. LaAg/PAM vaccinated mice showed the highest level of cutaneous hypersensitivity reaction (DTH) 24 and 48 hours respectively, after hind footpad LaAg injection (20 µg) when compared to control groups. In addition, compared to control groups, splenocytes from LaAg/PAM vaccinated mice produced significant IFN-γ, TNF-α and IL-4 amount after in vitro recall with LaAg antigen (50 µg/mL). Analyzed cells ex vivo, demonstrated that the combination Lag/PAM did not alter the frequency of CD4 + cells and CD8 + memory and total populations in the spleen. The vaccination with LaAg/PAM was able to induce reduction in parasitism of the liver, compared to the untreated group. The animals vaccinated with Lag/PAM showed a significant increase in IFN-γ production and decreased in IL-4 production on the spleen supernatant. In addition, a significant increase of NO was observed in liver macerated supernatants vaccinated with LaAg/PAM. Together, our data showed for the first time the feasibility of intranasal immunization with whole leishmanial antigens (LaAg) associated with PAM as an effective mechanism to induce a Leishmania immunogenicity.