Autor(es): Grenfell, Rafaella Fortini Queiroz ; Silva, Eduardo de Almeida Marques da ; Testasicca, Miriam Conceição de Souza ; Coelho, Eduardo Antônio Ferraz ; Fernandes, Ana Paula ; Afonso, Luís Carlos Crocco ; Rezende, Simone Aparecida
Data: 2014
Origem: Oasisbr
Assunto(s): Vaccine; Leishmania chagasi; Leishmania braziliensis; Leishmania amazonensis
This study evaluated two vaccine candidates for their effectiveness in protecting BALB/c mice against Leishma¬nia chagasi infection. These immunogenic preparations were composed of Leishmania amazonensis or Leishmania braziliensis antigenic extracts in association with saponin adjuvant. Mice were given three subcutaneous doses of one of these vaccine candidates weekly for three weeks and four weeks later challenged with promastigotes of L. chagasi by intravenous injection. We observed that both vaccine candidates induced a significant reduction in the parasite load of the liver, while the L. amazonensis antigenic extract also stimulated a reduction in spleen parasite load. This protection was associated with a suppression of both interleukin (IL)-10 and IL-4 cytokines by spleen cells in response to L. chagasi antigen. No change was detected in the production of IFN-γ. Our data show that these im-munogenic preparations reduce the type 2 immune response leading to the control of parasite replication.
