Desenvolvimento de uma vacina sintética contra a Leishmaniose Visceral Canina utilizando tecnologia peptídica (Phage Display e Spot Síntese)

Abstract

Leishmania chagasi is one of the most important etiological agents which can cause visceral leishmaniasis and gives wide geographical distribution in Brazil. Visceral leishmaniasis is a public health problem and is untreated can lead to death. In this work, the protective efficacy against L. chagasi infection has been evaluated in BALB/c mice by immunization with synthetic peptides selected by Phage Display technique. The protective levels through parasitary charge and cellular immune response were also evaluated. Peptides were screened with specific to soluble L. chagasi antigenic extract IgGs antibodies from dogs suffering visceral leishmaniasis. Three clones were found to interact with anti- L. chagasi IgG and the corresponding synthetic peptides were synthesized by the Spot method on cellulose membrane. The 11H (KCPSIPGAVLCV) and 12A (ICARQDPAGNCS) epitopes recognized in Spot-ELISA by anti-L. chagasi IgG, the soluble extract of L. chagasi and a non related peptide, were encapsulated by lipossomes and used as immunogens. The humoral response were observed only in groups immunized with 12A peptide and L. chagasi soluble extract. Our results about cellular immune response were not concluded. The protection against L. chagasi by immunization with synthetic peptides were found thirty days after infection. The results detected that the groups immunized with 12A and 11H peptides showed lower levels of parasites than control groups. The initial results showed that those peptides can be considered to compose a vaccine against canine visceral leishmaniasis.